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Sample records for quantifying tillage effects

  1. A simplified modelling approach for quantifying tillage effects on soil carbon stocks

    DEFF Research Database (Denmark)

    Chatskikh, Dmitri; Hansen, Søren; Olesen, Jørgen E.

    2009-01-01

    Soil tillage has been shown to affect long-term changes in soil organic carbon (SOC) content in a number of field experiments. This paper presents a simplified approach for including effects of tillage in models of soil C turnover in the tilled-soil layer. We used an existing soil organic matter...... (SOM) model (CN-SIM) with standard SOC data for a homogeneous tilled layer from four long-term field experiments with conventionally tilled (CT) and no-till (NT) treatments. The SOM model was tested on data from long-term (>10 years) field trials differing in climatic conditions, soil properties......, residue management and crop rotations in Australia, Brazil, the USA and Switzerland. The C input for the treatments was estimated using data on crop rotation and residue management. The SOM model was applied for both CT and NT trials without recalibration, but incorporated a 'tillage factor' (TF) to scale...

  2. Tillage Effects on Soil Properties & Respiration

    Science.gov (United States)

    Rusu, Teodor; Bogdan, Ileana; Moraru, Paula; Pop, Adrian; Duda, Bogdan; Cacovean, Horea; Coste, Camelia

    2015-04-01

    Soil tillage systems can be able to influence soil compaction, water dynamics, soil temperature and soil structural condition. These processes can be expressed as changes of soil microbiological activity, soil respiration and sustainability of agriculture. Objectives of this study were: 1) to assess the effects of tillage systems (Conventional System-CS, Minimum Tillage-MT, No-Tillage-NT) on soil compaction, soil temperature, soil moisture and soil respiration and 2) to establish the relationship that exists in changing soil properties. Three treatments were installed: CS-plough + disc; MT-paraplow + rotary grape; NT-direct sowing. The study was conducted on an Argic-Stagnic Faeoziom. The MT and NT applications reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first year of application. The degree of compaction is directly related to soil type and its state of degradation. The state of soil compaction diminished over time, tending toward a specific type of soil density. Soil moisture was higher in NT and MT at the time of sowing and in the early stages of vegetation and differences diminished over time. Moisture determinations showed statistically significant differences. The MT and NT applications reduced the thermal amplitude in the first 15 cm of soil depth and increased the soil temperature by 0.5-2.20C. The determinations confirm the effect of soil tillage system on soil respiration; the daily average was lower at NT (315-1914 mmoli m-2s-1) and followed by MT (318-2395 mmoli m-2s-1) and is higher in the CS (321-2480 mmol m-2s-1). Comparing with CS, all the two conservation tillage measures decreased soil respiration, with the best effects of no-tillage. An exceeding amount of CO2 produced in the soil and released into the atmosphere, resulting from aerobic processes of mineralization of organic matter (excessive loosening) is considered to be not only a way of increasing the CO2 in the atmosphere, but also a loss of

  3. Tillage and manure effect on soil microbial biomass and respiration ...

    African Journals Online (AJOL)

    The objective of this study was to determine the influence of both tillage and liquid pig manure application on soil microbial biomass, enzyme activities and microbial respiration in a meadow soil. The results obtained did not show any significant effect of tillage and manure on microbial biomass carbon (C) and nitrogen (N) ...

  4. The Effect of Conservation Tillage and Cover Crop Residue on Beneficial Arthropods and Weed Seed Predation in Acorn Squash.

    Science.gov (United States)

    Quinn, N F; Brainard, D C; Szendrei, Z

    2016-12-01

    Conservation tillage combined with cover crops or mulching may enhance natural enemy activity in agroecosystems by reducing soil disturbance and increasing habitat structural complexity. In particular, weed seed predation can increase with vegetation cover and reduced tillage, indicating that mulches may improve the quality of the habitat for weed seed foraging. The purpose of this study was to quantify the effects of tillage and mulching for conservation biological control in cucurbit fields. The effects of mulch and reduced tillage on arthropods and rates of weed seed loss from arenas were examined in field trials on sandy soils in 2014 and 2015. Experimental factors included tillage and cover crop, each with two levels: strip-tillage or full-tillage, and cover crop mulch (rye residue) or no cover crop mulch (unmulched). Arthropod abundance on the crop foliage was not affected by tillage or cover crops. Contrary to expectations, epigeal natural enemies of insects and rates of weed seed removal either did not respond to treatments or were greater in full-tilled plots and plots without mulch. Our study demonstrates the potential importance of weed seed predators in reducing weed seedbanks in vegetable agroecosystems, and suggests that early-season tillage may not be detrimental to epigeal predator assemblages. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. Effects of Tillage Practices on Soil Organic Carbon and Soil Respiration

    Science.gov (United States)

    Rusu, Teodor; Ioana Moraru, Paula; Bogdan, Ileana; Ioan Pop, Adrian

    2016-04-01

    Soil tillage system and its intensity modify by direct and indirect action soil temperature, moisture, bulk density, porosity, penetration resistance and soil structural condition. Minimum tillage and no-tillage application reduce or completely eliminate the soil mobilization, due to this, soil is compacted in the first years of application. The degree of compaction is directly related to soil type and its state of degradation. All this physicochemical changes affect soil biology and soil respiration. Soil respiration leads to CO2 emissions from soil to the atmosphere, in significant amounts for the global carbon cycle. Soil respiration is one measure of biological activity and decomposition. Soil capacity to produce CO2 varies depending on soil, season, intensity and quality of agrotechnical tillage, soil water, cultivated plant and fertilizer. Our research follows the effects of the three tillage systems: conventional system, minimum tillage and no-tillage on soil respiration and finally on soil organic carbon on rotation soybean - wheat - maize, obtained on an Argic Faeoziom from the Somes Plateau, Romania. To quantify the change in soil respiration under different tillage practices, determinations were made for each crop in four vegetative stages (spring, 5-6 leaves, bean forming, harvest). Soil monitoring system of CO2 and O2 included gradient method, made by using a new generation of sensors capable of measuring CO2 concentration in-situ and quasi-instantaneous in gaseous phase. At surface soil respiration is made by using ACE Automated Soil CO2 Exchange System. These areas were was our research presents a medium multi annual temperature of 8.20C medium of multi annual rain drowns: 613 mm. The experimental variants chosen were: i). Conventional system: reversible plough (22-25 cm) + rotary grape (8-10 cm); ii). Minimum tillage system: paraplow (18-22 cm) + rotary grape (8-10 cm); iii). No-tillage. The experimental design was a split-plot design with three

  6. Modeling Edge Effects of Tillage Erosion

    Science.gov (United States)

    Tillage erosion has been recognized as an important factor in redistribution of soil over time and in the development of morphological changes within agricultural fields. Field borders, fences, and vegetated strips that interrupt soil fluxes lead to the creation topographic discontinuities or lynche...

  7. Tillage and Farmyard Manure Effects on Crusting and Compacting ...

    African Journals Online (AJOL)

    Seasonal rainwater losses through increased runoff volumes reduce soil moisture and hence result in agricultural drought. The objective of this study was to examine the hydrological effects of two tillage practices with and without farmyard manure on surface runoff and soil loss of crusting and compacting soils under field ...

  8. Effect of tillage and fumigation on Pasteuria penetrans

    Science.gov (United States)

    The endospore-forming bacterium Pasteuria penetrans (Pp) is a parasite of Meloidogyne spp. In this study, the effect of tillage and the fumigant 1,3-dichloropropene (1,3-D) on numbers of Pp and suppression of M. incognita (Mi) was evaluated from 2011-2013. A split-plot experiment was established i...

  9. Effect of Tillage Technology on Species Composition of Weeds in Monoculture of Maize

    OpenAIRE

    S. Chovancova; F. Illek; J. Winkler

    2014-01-01

    The effect of tillage technology of maize on intensity of weed infestation and weed species composition was observed at experimental field. Maize is grown consecutively since 2001. The experimental site is situated at an altitude of 230 m above sea level in the Czech Republic. Variants of tillage technology are CT: plowing – conventional tillage 0.22 m, MT: loosening – disc tillage on the depth of 0.1 – 0.12 m, NT: direct sowing – without tillage. The evaluation of weed infestation was carrie...

  10. Soil tillage practices and crops rotations effects on yields and ...

    African Journals Online (AJOL)

    Methodology and Results: Three soil tillage practices in main plot (T1 = no tillage with direct sowing, T2 = minimum tillage by soil scarifying with IR12 tool and T3 = conventional tillage with animals drawn plough) were compared and combined to four crops rotation systems, in a split-plot experimental design. Soil chemical ...

  11. EFFECTS OF DIFFERENT SOIL TILLAGE SYSTEMS ON NODULATION AND YIELD OF SOYBEAN

    Directory of Open Access Journals (Sweden)

    D. Jug

    2005-12-01

    Full Text Available The primary soil tillage for different crops in Croatia is generally based on mouldboard ploughing which is the most expensive for crops production. Negative effects due to frequent passes by equipment and machines (deterioration of soil structure, soil compaction, lower biogenity and soil tilth, together with negative economical and energetical costs, can be lowered and avoided by introduction of reduced soil tillage or direct drilling (No-tillage. Accordingly, the main goal of this research was to determine effects of conventional and reduced soil tillage systems on yield components and nodulation ability of nitrogen fixing bacteria in soybean crop. The research was established at chernozem soil type of northern Baranja as monofactorial completely randomized block design in four repetitions. The soil tillage variants were as follows: CT Conventional Tillage (primary soil tillage by moldboard ploughing at 25-30 cm depth, DH Multiple Diskharrowing at 10-15 cm as primary tillage, and NT No-tillage system. Results show significantly lower plant density, mass of 1000 grains and grain yield at variants with reduced soil tillage in both investigation years. However, reduced tillage systems had positive trend on nitrogen-fixing bacteria nodulation, since the highest values of number and mass of nodules per plant were recorded. This research was run during the years 2002 and 2003, the last one extremely droughty, thus it requires continuation.

  12. Tillage System and Cover Crop Effects on Soil Quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    2014-01-01

    ), and moldboard plowing (MP) with and without a cover crop were evaluated in a long-term experiment on a sandy loam soil in Denmark. Chemical, physical, and biological soil properties were measured in the spring of 2012. The field measurements included mean weight diameter (MWD) after the drop-shatter test......, penetration resistance, and visual evaluation of soil structure (VESS). In the laboratory, aggregate strength, water-stable aggregates (WSA), and clay dispersibility were measured. The analyzed chemical and biological properties included soil organic C (SOC), total N, microbial biomass C, labile P and K......Optimal use of management systems including tillage and winter cover crops is recommended to improve soil quality and sustain agricultural production. The effects on soil properties of three tillage systems (as main plot) including direct drilling (D), harrowing to a depth of 8 to 10 cm (H...

  13. [Effects of Tillage on Soil Respiration and Root Respiration Under Rain-Fed Summer Corn Field].

    Science.gov (United States)

    Lu, Xing-li; Liao, Yun-cheng

    2015-06-01

    To explore the effects of different tillage systems on soil respiration and root respiration under rain-fed condition. Based on a short-term experiment, this paper investigated soil respiration in summer corn growth season under four tillage treatments including subsoiling tillage (ST), no tillage (NT), rotary tillage (RT) and moldboard plow tillage (CT). The contribution of root respiration using root exclusion method was also discussed. The results showed that soil respiration rate presented a single peak trend under four tillage methods during the summer corn growing season, and the maximum value was recorded at the heading stage. The trends of soil respiration were as follows: heading stage > flowering stage > grain filling stage > maturity stage > jointing stage > seedling stage. The trends of soil respiration under different tillage systems were as follows: CT > ST > RT > NT. There was a significant correlation between soil respiration rate and soil temperatures (P soil respiration using exponential function equation. However, there was no significant correlation between soil respiration rate and soil moisture. Root respiration accounted for 45.13%-56.86% of the proportion of soil respiratio n with the mean value 51.72% during the summer corn growing season under different tillage systems. Therefore, root exclusion method could be used to study the contribution of crop growth to carbon emission, to compare effects of different tillage systems on the contribution of root respiration provides the bases for selecting the measures to slow down the decomposition of soil carbon.

  14. The effect of tillage systems and mulching on soil microclimate ...

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-17

    Dec 17, 2008 ... Most of these traditional farmers employ zero tillage system and mulching .... Based on tillage systems, some researchers have ... The planting activity took ... tree as practised by most traditional farmers, owing to the high cost.

  15. Effects of no tillage on the abundance and diversity of soil and olive tree canopy arthropods.

    OpenAIRE

    Lousão, C.; Bento, Albino; Campos, M.; Ruano, F.; Pereira, J.A.

    2007-01-01

    Soil tillage is a traditional practice in the olive groves of Trás-os-Montes region (Northeast of Portugal) where the soil is maintained without any vegetal cover. However, this agronomic practice may have dangerous environmental effects of several orders. In this way, with the present work we aimed to contribute for the knowledge about the effect of two soil management practices in the olive grove (traditional tillage in comparison to no tillage) on the arthropods abundance an...

  16. EFFECTS OF DIFFERENT SOIL TILLAGE SYSTEMS ON NODULATION AND YIELD OF SOYBEAN

    OpenAIRE

    D. Jug; Mihaela Blažinkov; S. Redžepović; Irena Jug; B. Stipešević

    2005-01-01

    The primary soil tillage for different crops in Croatia is generally based on mouldboard ploughing which is the most expensive for crops production. Negative effects due to frequent passes by equipment and machines (deterioration of soil structure, soil compaction, lower biogenity and soil tilth), together with negative economical and energetical costs, can be lowered and avoided by introduction of reduced soil tillage or direct drilling (No-tillage). Accordingly, the main goal of this resear...

  17. Effect of Interplanting with Zero Tillage and Straw Manure on Rice Growth and Rice Quality

    Directory of Open Access Journals (Sweden)

    Shi-ping LIU

    2007-09-01

    Full Text Available The interplanting with zero-tillage of rice, i.e. direct sowing rice 10–20 days before wheat harvesting, and remaining about 30-cm high stubble after cutting wheat or rice with no tillage, is a new cultivation technology in wheat-rice rotation system. To study the effects of interplanting with zero tillage and straw manure on rice growth and quality, an experiment was conducted in a wheat-rotation rotation system. Four treatments, i.e. ZIS (Zero-tillage, straw manure and rice interplanting, ZI (Zero-tillage, no straw manure and rice interplanting, PTS (Plowing tillage, straw manure and rice transplanting, and PT (Plowing tillage, no straw manure and rice transplanting, were used. ZIS reduced plant height, leaf area per plant and the biomass of rice plants, but the biomass accumulation of rice at the late stage was quicker than that under conventional transplanting cultivation. In the first year (2002, there was no significant difference in rice yield among the four treatments. However, rice yield decreased in interplanting with zero-tillage in the second year (2003. Compared with the transplanting treatments, the number of filled grains per panicle decreased but 1000-grain weight increased in interplanting with zero-tillage, which were the main factors resulting in higher yield. Interplanting with zero-tillage improved the milling and appearance qualities of rice. The rates of milled and head rice increased while chalky rice rate and chalkiness decreased in interplanting with zero-tillage. Zero-tillage and interplanting also affected rice nutritional and cooking qualities. In 2002, ZIS showed raised protein content, decreased amylose content, softer gel consistency, resulting in improved rice quality. In 2003, zero-tillage and interplanting decreased protein content and showed similar amylose content as compared with transplanting treatments. Moreover, protein content in PTS was obviously increased in comparison with the other three treatments

  18. EFFECT OF SOIL TILLAGE AND PLANT RESIDUE ON SURFACE ROUGHNESS OF AN OXISOL UNDER SIMULATED RAIN

    Directory of Open Access Journals (Sweden)

    Elói Panachuki

    2015-02-01

    Full Text Available Surface roughness of the soil is formed by mechanical tillage and is also influenced by the kind and amount of plant residue, among other factors. Its persistence over time mainly depends on the fundamental characteristics of rain and soil type. However, few studies have been developed to evaluate these factors in Latossolos (Oxisols. In this study, we evaluated the effect of soil tillage and of amounts of plant residue on surface roughness of an Oxisol under simulated rain. Treatments consisted of the combination of the tillage systems of no-tillage (NT, conventional tillage (CT, and minimum tillage (MT with rates of plant residue of 0, 1, and 2 Mg ha-1 of oats (Avena strigosa Schreb and 0, 3, and 6 Mg ha-1 of maize (Zea mays L.. Seven simulated rains were applied on each experimental plot, with intensity of 60±2 mm h-1 and duration of 1 h at weekly intervals. The values of the random roughness index ranged from 2.94 to 17.71 mm in oats, and from 5.91 to 20.37 mm in maize, showing that CT and MT are effective in increasing soil surface roughness. It was seen that soil tillage operations carried out with the chisel plow and the leveling disk harrow are more effective in increasing soil roughness than those carried out with the heavy disk harrow and leveling disk harrow. The roughness index of the soil surface decreases exponentially with the increase in the rainfall volume applied under conditions of no tillage without soil cover, conventional tillage, and minimum tillage. The oat and maize crop residue present on the soil surface is effective in maintaining the roughness of the soil surface under no-tillage.

  19. Tillage System and Cover Crop Effects on Soil Quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    2014-01-01

    Information about the quantitative effect of conservation tillage combined with a cover crop on soil structure is still limited. This study examined the effect of these management practices on soil pore characteristics of a sandy loam soil in a long-term field trial. The tillage treatments (main...... plots) included direct drilling (D), harrowing to a depth of 8 to 10 cm (H), and moldboard plowing (MP). The cover crop treatments were subplot with cover crop (+CC) and without cover crop (−CC). Minimally disturbed soil cores were taken from the 4- to 8-, 12- to 16-, and 18- to 27-cm depth intervals...... in the spring of 2012 before cultivation. Soil water retention and air permeability were measured for matric potentials ranging from −1 to −30 kPa. Gas diffusivity was measured at −10 kPa. Computed tomography (CT) scanning was also used to characterize soil pore characteristics. At the 4- to 8- and 18- to 27-cm...

  20. Effect of tillage on earthworms over short- and medium-term in conventional and organic farming

    NARCIS (Netherlands)

    Crittenden, S.; Eswaramurthy, T.; Goede, de R.G.M.; Brussaard, L.; Pulleman, M.M.

    2014-01-01

    Earthworms play an important role in many soil functions and are affected by soil tillage in agricultural soils. However, effects of tillage on earthworms are often studied without considering species and their interactions with soil properties. Furthermore, many field studies are based on one-time

  1. Sustainable semiarid dryland production in relation to tillage effects on Hydrology: 1983-2013

    Science.gov (United States)

    Semiarid dryland crop yields with no-till, NT, residue management are often greater than stubble-mulch tillage, SM, as a result of improved soil conditions or water conservation, but knowledge of long-term tillage effects on the comprehensive field hydrology and sustained crop production is needed. ...

  2. Effects of over-winter green cover on soil solution nitrate concentrations beneath tillage land.

    Science.gov (United States)

    Premrov, Alina; Coxon, Catherine E; Hackett, Richard; Kirwan, Laura; Richards, Karl G

    2014-02-01

    There is a growing need to reduce nitrogen losses from agricultural systems to increase food production while reducing negative environmental impacts. The efficacy of vegetation cover for reducing nitrate leaching in tillage systems during fallow periods has been widely investigated. Nitrate leaching reductions by natural regeneration (i.e. growth of weeds and crop volunteers) have been investigated to a lesser extent than reductions by planted cover crops. This study compares the efficacy of natural regeneration and a sown cover crop (mustard) relative to no vegetative cover under both a reduced tillage system and conventional plough-based system as potential mitigation measures for reducing over-winter soil solution nitrate concentrations. The study was conducted over three winter fallow seasons on well drained soil, highly susceptible to leaching, under temperate maritime climatic conditions. Mustard cover crop under both reduced tillage and conventional ploughing was observed to be an effective measure for significantly reducing nitrate concentrations. Natural regeneration under reduced tillage was found to significantly reduce the soil solution nitrate concentrations. This was not the case for the natural regeneration under conventional ploughing. The improved efficacy of natural regeneration under reduced tillage could be a consequence of potential stimulation of seedling germination by the autumn reduced tillage practices and improved over-winter plant growth. There was no significant effect of tillage practices on nitrate concentrations. This study shows that over winter covers of mustard and natural regeneration, under reduced tillage, are effective measures for reducing nitrate concentrations in free draining temperate soils. © 2013.

  3. The effect of conservation tillage on crop yield in China

    Directory of Open Access Journals (Sweden)

    Hongwen LI,Jin HE,Huanwen GAO,Ying CHEN,Zhiqiang ZHANG

    2015-06-01

    Full Text Available Traditional agricultural practices have resulted in decreased soil fertility, shortage of water resources and deterioration of agricultural ecological environment, which are seriously affecting grain production. Conservation tillage (CT research has been developed and applied in China since the 1960s and 1970s, and a series of development policies have been issued by the Chinese government. Recent research and application have shown that CT has positive effects on crop yields in China. According to the data from the Conservation Tillage Research Center (CTRC, Chinese Ministry of Agriculture (MOA, the mean crop yield increase can be at least 4% in double cropping systems in the North China Plain and 6% in single cropping systems in the dryland areas of North-east and North-west China. Crop yield increase was particularly significant in dryland areas and drought years. The mechanism for the yield increase in CT system can be attributed to enhanced soil water content and improved soil properties. Development strategies have been implemented to accelerate the adoption of CT in China.

  4. The effect of conservation tillage forward speed and depth on farm fuel consumption

    Directory of Open Access Journals (Sweden)

    A Jalali

    2015-09-01

    Full Text Available Introduction: In recent years, production techniques and equipment have been developed for conservation tillage systems that have been adopted by many farmers. With proper management, overall yield averages for conventional and reduced tillage systems are nearly identical. Sometimes, field operations can be combined by connecting two or more implements. Much research has focused on either reducing or eliminating tillage operations to develop sustainable crop production methods. The greatest costs in farm operations are associated with tillage due to greater specific energy requirement in tillage and the high fuel costs. Combined operations reduce both fuel consumption and time and labor requirements by eliminating at least one individual trip over the field. Light tillage, spraying, or fertilizing operations can be combined with eitherprimary or secondary tillage or planting operations. The amount of fuel saved depends on the combined operations. Generally, light tillage, spraying, and fertilizing operations consume between 0.25 and 0.50 gallons of diesel fuel per acre. Fuel savings of 0.12 to 0.33 gallons per acre can usually be expected from combining operations. Eliminating one primary tillage operation and combining one light tillage, spraying, or fertilizing operation with another tillage or planting operation can usually save at least a gallon of diesel fuel per acre. Combining operations has the added benefit of reducing wheel traffic and compaction. To improve the tillage energy efficiency, implementing effective and agronomic strategies should be improved. Different tillage systems should be tested to determine the most energy efficient ones. Tillage helps seed growth and germination through providing appropriate conditions for soil to absorb sufficient temperature and humidity. Tillage is a time consuming and expensive procedure. With the application of agricultural operations, we can save considerable amounts of fuel, time and

  5. Effects of Tillage Model on Healthy Plough Layer Structure and Its Development Trends

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    HU Jun-ming

    2018-02-01

    Full Text Available Soil cultivation is closely related to land productivity. Nutrient in plough layer is the key factor affecting the absorption and utilization of crop nutrients. Good plough layer structure is beneficial to the coordination of water, fertilizer, gas and heat. The depth of arable layer is related to tillage methods. Constructing good plough layer structure is conducive to crop growth and distribution. This paper reviewed both domestic and foreign researches regarding tillage models, which included conventional tillage, protective cultivation, rotary tillage, deep tillage, and so on. Based on the above research results, the effects of tillage models on the healthy soil layer construction were discussed from the soil bulk density, soil porosity, soil aggregates, infiltration of soil, soil heavy metals, soil respiration and the characters of root system. The deficiencies of current research were pointed out from several aspects such as tillage system, system positioning, tillage efficiency, suitable crop. In order to maximize the comprehensive production capacity of cultivated land resources and solve the contradiction between human being and land, this paper forecasted the development trend of ideal plough layer structure from four aspects:Cultivate patterns according to local conditions, the establishment of complex farming models, accelerating the research and application of new agricultural machinery, conducting systematic research of farmland microclimate environment. This will provide the theoretical basis and technical support for the optimal farming mode in agricultural production.

  6. Tillage and NPK Effect on growth and yield of spring maize in islamabad, pakistan

    International Nuclear Information System (INIS)

    Memon, S.Q.; Mughal, A.Q.; Amjad, N.; Javed, H.I.

    2013-01-01

    Tillage is a very important crop production practice which affect crop performance. An experiment was conducted during the spring crop season 2009 to compare the effect of three different tillage regimes i.e. deep, conventional and zero and four fertilizer levels viz., control 100-50-50, 150-75-75 and 200-100-100 NPK kg ha. The randomized complete block design was used with three replications. There was significant differences in maize emergence percentage, plant height, grains cob, 1000-grain weight and grain yield due to tillage practices and various fertilizer levels, between tillage practices. However, the NPK at the rate 200-100-100 kg ha and deep tillage produced the highest emergence percentage, plant height, grains per cob, 1000-grain weight and grain yield followed by other fertilizer levels and conventional tillage. The zero tillage plots produced the low emergence percentage, plant height, grains cob, 1000-grain weight and grain yield. Therefore, considering the environ-mental conditions, the deep tillage with recommended dose of NPK performed best and provided more vegetative growth and grain yield in maize. However, poor-resource farmers can use the medium level of NPK at the rate 150-75-75 kg ha for getting an economical and successful maize crop. (author)

  7. The effect of tillage intensity on soil structure and winter wheat root/shoot growth

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Hansen, Elly Møller; Olesen, Jørgen E

    2008-01-01

    was followed during the growing seasons using spectral reflectance and mini-rhizotron measurements, respectively. A range of soil physical properties were measured. We found decreased early season shoot and root growth with decreasing tillage intensity. Differences diminished later in the growing season...... of this study was to investigate the effect of tillage intensity on crop growth dynamics and soil structure. A tillage experiment was established in autumn 2002 on two Danish sandy loams (Foulum and Flakkebjerg) in a cereal-based crop rotation. The tillage systems included in this study were direct drilling (D...... with decreasing tillage intensity for the first year winter wheat at Foulum. In general ploughing resulted in the highest grain yields. This study highlights the important interaction between soil structure and crop growth dynamics....

  8. Effects of ridge tillage on photosynthesis and root characters of rice

    Directory of Open Access Journals (Sweden)

    Yao Yuan-zhi

    2015-03-01

    Full Text Available Rice (Oryza sativa L. is an important crop and breeding has not been able to improve yield. Root characteristics of hybrid rice 'Zhuliangyou 02' under conventional tillage and ridge tillage were studied in a Calcisols in Huaihua, China, from 2011 to 2013 to find better tillage methods to resolve massive water consumption, improve yield, and enhance productivity of agricultural labor for rice cultivation. Results showed ridge tillage increased photosynthetic parameters such as photosynthetic rate (P N, stomatal conductance (g s, and water use efficiency (WUE. It also significantly enhanced rice root number, root activity, and antioxidant enzyme activities; it also increased effective panicle number and actual yield by 22.12% and 15.18%, respectively, and enhanced aerenchymae during the early growth stage. Overall, ridge tillage could promote hybrid rice yields by enhancing root absorption, gas exchange, and reducing water consumption. It could be widely used in rice cultivation.

  9. Tillage and residue effects on rainfed wheat and corn production in the Semi-Arid Regions of Northern China

    NARCIS (Netherlands)

    Wang, X.B.; Hoogmoed, W.B.; Perdok, U.D.; Cai, D.X.

    2003-01-01

    Field studies on tillage and residue management for spring corn were conducted at two sites, in Tunliu (1987-1990), and Shouyang (1992-1995) counties of Shanxi province in the semihumid arid regions of northern China. This paper discusses the effects of different fall tillage (winter fallow tillage)

  10. Tillage effects on soil. Physical properties and sunflower ...

    African Journals Online (AJOL)

    Soil physical properties and sunflower (Helianthus annuus) yield under convectional tillage (CT) and zero-tillage (Z,TJ. was monitored for 3 consecutive years in Ilorin, Southern Guinea Savannah zone of Nigeria (SGSZN). While bulk density of CT increased slightly over the years, significant decrease of 12 and 8% were ...

  11. Extrapolating effects of conservation tillage on yield, soil moisture and dry spell mitigation using simulation modelling

    Science.gov (United States)

    Mkoga, Z. J.; Tumbo, S. D.; Kihupi, N.; Semoka, J.

    There is big effort to disseminate conservation tillage practices in Tanzania. Despite wide spread field demonstrations there has been some field experiments meant to assess and verify suitability of the tillage options in local areas. Much of the experiments are short lived and thus long term effects of the tillage options are unknown. Experiments to study long term effects of the tillage options are lacking because they are expensive and cannot be easily managed. Crop simulation models have the ability to use long term weather data and the local soil parameters to assess long term effects of the tillage practices. The Agricultural Production Systems Simulator (APSIM) crop simulation model; was used to simulate long term production series of soil moisture and grain yield based on the soil and weather conditions in Mkoji sub-catchment of the great Ruaha river basin in Tanzania. A 24 year simulated maize yield series based on conventional tillage with ox-plough, without surface crop residues (CT) treatment was compared with similar yield series based on conservation tillage (ox-ripping, with surface crop residues (RR)). Results showed that predicted yield averages were significantly higher in conservation tillage than in conventional tillage ( P APSIM simulation model, showed that average soil moisture in the conservation tillage was significantly higher ( P < 0.05) (about 0.29 mm/mm) than in conventional tillage (0.22 mm/mm) treatment during the seasons which received rainfall between 468 and 770 mm. Similarly the conservation tillage treatment recorded significantly higher yields (4.4 t/ha) ( P < 0.01) than the conventional tillage (3.6 t/ha) treatment in the same range of seasonal rainfall. On the other hand there was no significant difference in soil moisture for the seasons which received rainfall above 770 mm. In these seasons grain yield in conservation tillage treatment was significantly lower (3.1 kg/ha) than in the conventional tillage treatment (4.8 kg

  12. Thermosensory reversal effect quantified

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kappers, A.M.L.

    2008-01-01

    At room temperature, some materials feel colder than others due to differences in thermal conductivity, heat capacity and geometry. When the ambient temperature is well above skin temperature, the roles of 'cold' and 'warm' materials are reversed. In this paper, this effect is quantified by

  13. Thermosensory reversal effect quantified

    NARCIS (Netherlands)

    Bergmann Tiest, W.M.; Kappers, A.M.L.

    2008-01-01

    At room temperature, some materials feel colder than others due to differences in thermal conductivity, heat capacity and geometry. When the ambient temperature is well above skin temperature, the roles of ‘cold’ and ‘warm’ materials are reversed. In this paper, this effect is quantified by

  14. Effect of simulated tillage on microbial autotrophic CO2 fixation in paddy and upland soils

    Science.gov (United States)

    Ge, Tida; Wu, Xiaohong; Liu, Qiong; Zhu, Zhenke; Yuan, Hongzhao; Wang, Wei; Whiteley, A. S.; Wu, Jinshui

    2016-01-01

    Tillage is a common agricultural practice affecting soil structure and biogeochemistry. To evaluate how tillage affects soil microbial CO2 fixation, we incubated and continuously labelled samples from two paddy soils and two upland soils subjected to simulated conventional tillage (CT) and no-tillage (NT) treatments. Results showed that CO2 fixation (14C-SOC) in CT soils was significantly higher than in NT soils. We also observed a significant, soil type- and depth-dependent effect of tillage on the incorporation rates of labelled C to the labile carbon pool. Concentrations of labelled C in the carbon pool significantly decreased with soil depth, irrespective of tillage. Additionally, quantitative PCR assays revealed that for most soils, total bacteria and cbbL-carrying bacteria were less abundant in CT versus NT treatments, and tended to decrease in abundance with increasing depth. However, specific CO2 fixation activity was significantly higher in CT than in NT soils, suggesting that the abundance of cbbL-containing bacteria may not always reflect their functional activity. This study highlights the positive effect of tillage on soil microbial CO2 fixation, and the results can be readily applied to the development of sustainable agricultural management. PMID:26795428

  15. Effect of Tillage Systems with Corn Residue on Grain Yield of Rapeseed in Moghan Region

    Directory of Open Access Journals (Sweden)

    J Taghinazhad

    2014-09-01

    Full Text Available This study carried out to evaluate the effect of different tillage systems on rapeseed yield (hayola 401 planted in corn residues. This experiment was done in Moghan region with clay soils during 2009-2012. Different seedbed preparation methods include MT: moldboard + disk tillage (conventional tillage was included, SCT: Stem Crusher + chisel + disk tandem harrow, STT: Stem Crusher + double-disc, CT: chisel + disk tillage and DD: two heavy disks. The experiment was conducted in a randomized complete block design with four replications. The results showed that soil bulk density in the 0-10 cm layer was not significant in different tillage treatments, but it was significantly higher than the conventional tillage in 10-20 cm depth. However, penetration resistance in 10-30 cm under DD was significantly higher than other treatments, but it was not significant in 0-10 cm layer among all tillage treatments. Thus, Comparison of the soil bulk density, penetration resistance, and plant establishment showed that the reduced tillage in canola seedbed preparation was effective. Besides, the surveys indicated that there was a significant different between MWD after primary and secondary tillage. The mean diameter weighted under SCT and DD, were 1.19 and 1.24 cm, respectively had the best status. The highest value and the worst status of this parameter observed for MT which was 1.92 cm. The highest rate of grain yield obtained by application of treatment SCT, and it was 2563.8 kg ha-1, The SCT treatment can be recommended as an effective canola bed preparation due to its significant saving in time and cost after corn harvesting.

  16. Effect of tillage systems and permanent groundcover intercropped with orange trees on soil enzyme activities

    Directory of Open Access Journals (Sweden)

    Elcio Liborio Balota

    2011-04-01

    Full Text Available The objective of this study was to evaluate the effect of different soil tillage systems and groundcover crops intercropped with orange trees on soil enzyme activities. The experiment was performed in an Ultisol soil in northwestern Paraná State. Two soil tillage systems were evaluated [conventional tillage (CT across the entire area and strip tillage (ST with a 2-m strip width] in combination with various groundcover vegetation management systems. Soil samples were collected after five years of experimental management at a depth of 0-15 cm under the tree canopy and in the inter-row space in the following treatments: (1 CT-Calopogonium mucunoides; (2 CT-Arachis pintoi; (3 CT-Bahiagrass; (4 CT-Brachiaria humidicola; and (5 ST-B. humidicola. The soil tillage systems and groundcover crops influenced the soil enzyme activities both under the tree canopy and in the inter-row space. The cultivation of B. humidicola provided higher amylase, arylsulfatase, acid phosphatase and alkaline phosphatase than other groundcover species. Strip tillage increased enzyme activities compared to the conventional tillage system.

  17. 105-116 Effect of Winged Subsoiler and Traditional Tillage ...

    African Journals Online (AJOL)

    3) compared to traditional tillage (Qs = 34 mm-season-. 1, T = 49 ... Maresha plow that cuts soil deeper than achieved with the traditional .... Data Processing and Analysis. Statistical ... soil compaction and shallow depth could be addressed.

  18. Defining the effect of sweep tillage tool cutting edge geometry on tillage forces using 3D discrete element modelling

    Directory of Open Access Journals (Sweden)

    Mustafa Ucgul

    2015-09-01

    Full Text Available The energy required for tillage processes accounts for a significant proportion of total energy used in crop production. In many tillage processes decreasing the draft and upward vertical forces is often desired for reduced fuel use and improved penetration, respectively. Recent studies have proved that the discrete element modelling (DEM can effectively be used to model the soil–tool interaction. In his study, Fielke (1994 [1] examined the effect of the various tool cutting edge geometries, namely; cutting edge height, length of underside rub, angle of underside clearance, on draft and vertical forces. In this paper the experimental parameters of Fielke (1994 [1] were simulated using 3D discrete element modelling techniques. In the simulations a hysteretic spring contact model integrated with a linear cohesion model that considers the plastic deformation behaviour of the soil hence provides better vertical force prediction was employed. DEM parameters were determined by comparing the experimental and simulation results of angle of repose and penetration tests. The results of the study showed that the simulation results of the soil-various tool cutting edge geometries agreed well with the experimental results of Fielke (1994 [1]. The modelling was then used to simulate a further range of cutting edge geometries to better define the effect of sweep tool cutting edge geometry parameters on tillage forces. The extra simulations were able to show that by using a sharper cutting edge with zero vertical cutting edge height the draft and upward vertical force were further reduced indicating there is benefit from having a really sharp cutting edge. The extra simulations also confirmed that the interpolated trends for angle of underside clearance as suggested by Fielke (1994 [1] where correct with a linear reduction in draft and upward vertical force for angle of underside clearance between the ranges of −25 and −5°, and between −5 and 0°. The

  19. The effects of forward speed and depth of conservation tillage on soil bulk density

    Directory of Open Access Journals (Sweden)

    A Mahmoudi

    2015-09-01

    , besides the importance of tillage depth and speed in different tiller performance. Materials and methods: This investigation was carried out based on random blocks in the form of split plot experimental design. The main factor, tillage depth, (was 10 and 20cm at both levels and the second factor, tillage speed, (was 6, 8, 10, 12 km h-1 in four levels for Bostan-Abad and 8,10,12,14 km h-1 for Hashtrood with four repetitions. It was carried out using complex tillage made in Sazeh Keshte Bukan Company, which is mostly used in Eastern Azerbaijanand using Massey Ferguson 285 and 399 tractors in Bostab-Abad and Hashtrood, respectively. In this investigation, the characteristics of soil bulk density were studied in two sampling depths of 7 and 17 centimeters. Bulk density is an indicator of soil compaction. It is calculated as the dry weight of soil divided by its volume. This volume includes the volume of soil particles and the volume of pores among soil particles. Bulk density is typically expressed in g cm-3. Results and Discussion: In this study, the effect of both factors on the feature of the soil bulk density at the sampling depth of 5-10 and 15-20 cm was examined. In Bostan-Abad, regarding tillage speed effect for studies characteristics at 1% probability level on soil bulk density was effective. The effect of tillage depth on the soil bulk density was significant at 5% probability level . The interaction effect of tillage speed and depth on soil bulk density was significant at probability level of 1%. Regarding sampling depth effect, the soil bulk density was significant at 5% probability level, respectively. In Hashtrood, the effect of tillage speed on soil bulk density at probability level of 1%, and also tillage depth effect on soil bulk density was significant at 5% level of probability. The interaction effect of tillage speed and depth on soil bulk density was significant at 5% level of probability. Regarding the depth of sampling it was significant on soil bulk

  20. Effects of tillage and nitrogen fertilizers on CH4 and CO2 emissions and soil organic carbon in paddy fields of central China.

    Directory of Open Access Journals (Sweden)

    Li Cheng-Fang

    Full Text Available Quantifying carbon (C sequestration in paddy soils is necessary to help better understand the effect of agricultural practices on the C cycle. The objective of the present study was to assess the effects of tillage practices [conventional tillage (CT and no-tillage (NT] and the application of nitrogen (N fertilizer (0 and 210 kg N ha(-1 on fluxes of CH(4 and CO(2, and soil organic C (SOC sequestration during the 2009 and 2010 rice growing seasons in central China. Application of N fertilizer significantly increased CH(4 emissions by 13%-66% and SOC by 21%-94% irrespective of soil sampling depths, but had no effect on CO(2 emissions in either year. Tillage significantly affected CH(4 and CO(2 emissions, where NT significantly decreased CH(4 emissions by 10%-36% but increased CO(2 emissions by 22%-40% in both years. The effects of tillage on the SOC varied with the depth of soil sampling. NT significantly increased the SOC by 7%-48% in the 0-5 cm layer compared with CT. However, there was no significant difference in the SOC between NT and CT across the entire 0-20 cm layer. Hence, our results suggest that the potential of SOC sequestration in NT paddy fields may be overestimated in central China if only surface soil samples are considered.

  1. Effects of tillage and nitrogen fertilizers on CH4 and CO2 emissions and soil organic carbon in paddy fields of central China.

    Science.gov (United States)

    Cheng-Fang, Li; Dan-Na, Zhou; Zhi-Kui, Kou; Zhi-Sheng, Zhang; Jin-Ping, Wang; Ming-Li, Cai; Cou-Gui, Cao

    2012-01-01

    Quantifying carbon (C) sequestration in paddy soils is necessary to help better understand the effect of agricultural practices on the C cycle. The objective of the present study was to assess the effects of tillage practices [conventional tillage (CT) and no-tillage (NT)] and the application of nitrogen (N) fertilizer (0 and 210 kg N ha(-1)) on fluxes of CH(4) and CO(2), and soil organic C (SOC) sequestration during the 2009 and 2010 rice growing seasons in central China. Application of N fertilizer significantly increased CH(4) emissions by 13%-66% and SOC by 21%-94% irrespective of soil sampling depths, but had no effect on CO(2) emissions in either year. Tillage significantly affected CH(4) and CO(2) emissions, where NT significantly decreased CH(4) emissions by 10%-36% but increased CO(2) emissions by 22%-40% in both years. The effects of tillage on the SOC varied with the depth of soil sampling. NT significantly increased the SOC by 7%-48% in the 0-5 cm layer compared with CT. However, there was no significant difference in the SOC between NT and CT across the entire 0-20 cm layer. Hence, our results suggest that the potential of SOC sequestration in NT paddy fields may be overestimated in central China if only surface soil samples are considered.

  2. Effect of Soil Tillage Practices on Dynamic of Bacterial Communities in Soil

    OpenAIRE

    Mirna Mrkonjić Fuka; Mihaela Blažinkov; Viviane Radl; Danijel Jug; Nataša Hulak; Sulejman Redžepović; Michael Schloter

    2016-01-01

    Several studies have indicated that intensive tillage has notable effect on properties of the soil microbiota that may influence numerous important soils functions, e.g. mobilization of nutrients or change of the overall emission rates of greenhouse gases. Therefore, the aim of our study was to investigate dynamic of microbial communities in soil planted with soybean under different tillage systems. Moreover, abundance of populations harboring the nitrous- oxide reductase gene (nosZ) a...

  3. Identifying the Tillage Effects on Phosphorus Export from Phaeozems-Dominated Agricultural Watershed: a Plot-Scale Rainfall-Runoff Study in Northeast China

    Science.gov (United States)

    Zhou, Yuyan; Xu, Y. Jun; Xiao, Weihua; Wang, Jianhua; Hao, Cailian; Zhou, Pu; Shi, Min

    2017-12-01

    Evaluating tillage effects on soil phosphorus (P) loss at the plot-scale has significant implication for developing best management practices (BMPs) to protect water quality and soil productivity management in agricultural watersheds. This paper aims to quantify P loss from tilled soils under different rainfall patterns in a Phaeozems-dominated agricultural watershed. Eleven rainfall events were monitored at three experimental sites growing corns with conventional till, conservational till, and no-till during a growing season from July to August in 2013. Mean event mean concentration of dissolved phosphorus was 0.130, 0.213 and 0.614 mg L-1 and mean particulate phosphorus transfer rate was 103.502, 33.359 and 27.127 g ha-1 hr-1, respectively for three tillage practices. Results showed that less tillage practices could significantly reduce sediment runoff and PP loss, accompanied with a moderate reduction of runoff yield. While the proportion of PP has been cut down, the proportion of DP could account for the majority. Hydrological factors, including antecedent soil moisture and rainfall variables, could exert various effects on DP, PP and sediment losses under different tillage conditions. Further, the results of this study imply that the soil P loss management and water quality protection in black soil region of Northeast China should take consideration of diverse effects of tillage on phosphorus loss and the dynamics of P between different forms.

  4. Effects of tillage on the Fe oxides activation in soil

    Science.gov (United States)

    Chi, Guangyu; Chen, Xin; Shi, Yi; Wang, Jun; Zheng, Taihui

    2009-07-01

    Since mid-1950s, the wetland ecosystems in Sanjiang Plain of Northeast China have been experiencing greater changes in land use, which had negative effects on the soil environments. This study assessed the effects of soil tillage on the activation of soil Fe in the region. The test ecosystems included natural wetland, paddy field and upland field converted from wetland. Soil samples at the depths of 0-10 cm, 10-20 cm, 20-30 cm, 30-40 cm, 40-60 cm, 60-90 cm and 90-120 cm were collected from each of the ecosystems for the analysis of vertical distribution of soil pH, organic carbon, chelate Fe oxides and Fe(II). The results showed that the conversion of wetland into paddy field and upland field induced a decrease of organic carbon content in 0-10 cm soil layer by 61.8% (P carbon showed that chelate Fe oxides and Fe(II) was correlated positively with soil organic carbon and chelate ratio had a more positive relationship with organic carbon than chelate Fe oxides and Fe(II). The results of chelate Fe oxides, Fe(II) and chelate ratio of Fe suggested that reclamation could prevent the Fe activation and organic matter is credited for having an important influence on the process of Fe activation.

  5. Tillage effects on N2O emissions as influenced by a winter cover crop

    DEFF Research Database (Denmark)

    Petersen, Søren O; Mutegi, James; Hansen, Elly Møller

    2011-01-01

    emissions may be more important than the effect on soil C. This study monitored emissions of N2O between September 2008 and May 2009 in three tillage treatments, i.e., conventional tillage (CT), reduced tillage (RT) and direct drilling (DD), all with (+CC) or without (−CC) fodder radish as a winter cover...... application by direct injection N2O emissions were stimulated in all tillage treatments, reaching 250–400 μg N m−2 h−1 except in the CT + CC treatment, where emissions peaked at 900 μg N m−2 h−1. Accumulated emissions ranged from 1.6 to 3.9 kg N2O ha−1. A strong positive interaction between cover crop......Conservation tillage practices are widely used to protect against soil erosion and soil C losses, whereas winter cover crops are used mainly to protect against N losses during autumn and winter. For the greenhouse gas balance of a cropping system the effect of reduced tillage and cover crops on N2O...

  6. Effect of subsoil tillage depth on nutrient accumulation, root distribution, and grain yield in spring maize

    Directory of Open Access Journals (Sweden)

    Hongguang Cai

    2014-10-01

    Full Text Available A four-year field experiment was conducted to investigate the effect of subsoiling depth on root morphology, nitrogen (N, phosphorus (P, and potassium (K uptake, and grain yield of spring maize. The results indicated that subsoil tillage promoted root development, increased nutrient accumulation, and increased yield. Compared with conventional soil management (CK, root length, root surface area, and root dry weight at 0–80 cm soil depth under subsoil tillage to 30 cm (T1 and subsoil tillage to 50 cm (T2 were significantly increased, especially the proportions of roots in deeper soil. Root length, surface area, and dry weight differed significantly among three treatments in the order of T2 > T1 > CK at the 12-leaf and early filling stages. The range of variation of root diameter in different soil layers in T2 treatment was the smallest, suggesting that roots were more likely to grow downwards with deeper subsoil tillage in soil. The accumulation of N, P, and K in subsoil tillage treatment was significantly increased, but the proportions of kernel and straw were different. In a comparison of T1 with T2, the grain accumulated more N and P, while K accumulation in kernel and straw varied in different years. Grain yield and biomass were increased by 12.8% and 14.6% on average in subsoil tillage treatments compared to conventional soil treatment. Although no significant differences between different subsoil tillage depths were observed for nutrient accumulation and grain yield, lodging resistance of plants was significantly improved in subsoil tillage to 50 cm, a characteristic that favors a high and stable yield under extreme environments.

  7. The tillage effect on the soil acid and alkaline phosphatase activity

    Directory of Open Access Journals (Sweden)

    Lacramioara Oprica

    2011-12-01

    Full Text Available Phosphatases (acid and alkaline are important in soils because these extracellular enzymes catalyze the hydrolysis of organic phosphate esters to orthophosphate; thus they form an important link between biologically unavailable and mineral phosphorous. Phosphatase activity is sensitive to environmental perturbations such as organic amendments, tillage, waterlogging, compaction, fertilizer additions and thus it is often used as an environmental indicator of soil quality in riparian ecosystems. The aim of the study was to assess the effect of tillage systems on phosphatases activity in a field experiment carried out in Ezăreni farm. The phosphatase activitiy were determined at two depths (7-10 cm and 15-25cm layers of a chernozem soil submitted to conventional tillage (CT in a fertilised and unfertilised experiment. Monitoring soil alkaline phosphatase activity showed, generally, the same in fertilized soil profiles collected from both depths; the values being extremely close. In unfertilized soils, alkaline phosphatase activity is different only in soils that were exposed to unconventional work using disc harrows and 30cm tillage. Both works type (no tillage and conventional tillage cause an intense alkaline phosphatase activity in 7-10 cm soil profile. Acid phosphatase activity is highly fluctuating in both fertilized as well unfertilized soil, this enzyme being influenced by the performed works.

  8. [Effects of different tillage patterns on soil properties, maize yield and water use efficiency in Weibei Highland, China.

    Science.gov (United States)

    Liu, Dan; Zhang, Xia; Li, Jun; Wang, Xu-Dong

    2018-02-01

    An eight-year field experiment of straw returning was conducted on dark loessial soil in Weibei Highland to investigate the effects of tillage patterns on soil aggregate, soil organic carbon (SOC), corn yield and soil water use efficiency (WUE). There were six tillage patterns, including conventional tillage (CT/CT), no-tillage (NT/NT), subsoiling tillage (ST/ST), no-tillage/subsoiling tillage (NT/ST), conventional tillage/no-tillage (CT/NT) and conventional tillage/subsoiling tillage (CT/ST). The results showed that compared with CT/CT, the patterns of NT/NT, ST/ST and the rotational tillage patterns (NT/ST, CT/NT and CT/ST) decreased the mean mass diameter of soil mechanical stable aggregate. The patterns of NT/NT, ST/ST and NT/ST increased the content of soil water-stable aggregate with the particle size >0.25 mm (WR 0.25 ) and their mean mass diameter, especially in the depth of 20-50 cm. These patterns reduced the proportion of aggregate destruction (PAD). Compared with CT/CT, the patterns of NT/ST, CT/NT, NT/NT and ST/ST increased the content of SOC in 0-10 cm soil layer. The content of SOC decreased as the increases of soil depth for all tillage patterns, but the decrease in SOC of three single tillage patterns (ST/ST, NT/NT and CT/CT) was larger than that of three rotational tillage patterns. Compared with CT/CT, the other five tillage patterns increased soil water storage in 0-200 cm soil profile, crop yield and WUE in maize. The yield and WUE in NT/ST pattern were significantly increased by 15.1% and 27.5%, respectively. Both corn yield and WUE were significantly and positively correlated with soil water storage in 0-200 cm soil profile in field during the cropping and fallow periods. Moreover, soil water storage during the cropping period was positively correlated with WR 0.25 , but negatively correlated with PAD in 0-50 cm soil layer. Particularly, maize yield, WUE and soil water storage during the cropping period were closely related to WR 0.25 in 20

  9. Effects of Different Soil Tillage Intensity on Yields of Spring Barley

    Directory of Open Access Journals (Sweden)

    Alena Pernicová

    2014-01-01

    Full Text Available Within the period 1990–2012, effects of different soil tillage intensity on yields of spring barley were studied in a field experiment in the sugar-beet producing region (Ivanovice na Hané, Czech Republic. The forecrop of the spring barley was always sugar beet; following in three different crop rotations, after maize for silage, winter wheat and spring barley. Four variants of tillage were evaluated: Variant 1 – ploughing to the depth of 0.22 m; Variant 2 – shallow ploughing to the depth of 0.15 m; Variant 3 – no tillage; Variant 4 – shallow loosening soil to the depth of 0.10 m.Effect of different tillage on yields of spring barley was statistically insignificant. In all three crop rotations, the highest and the lowest average yields were obtained in Variant 2 (ploughing to the depth of 0.15 m and Variant 1 (ploughing to the depth of 0.22 m, respectively. Average yields in variants of soil tillage were these: variant 1 – 6.42 t.ha−1; variant 2 – 6.57 t.ha−1, variant 3 – 6.53 t.ha−1, variant 4 – 6.50 t.ha−1. The obtained results indicate that in these pedo-climatic conditions reduction of intensity soil tillage represented a very suitable alternative in case of growing spring barley after sugar beet as compared with the conventional method of tillage by ploughing to the depth of 0.22 m.

  10. Effects of tillage on contents of organic carbon, nitrogen, water-stable aggregates and light fraction for four different long-term trials

    Science.gov (United States)

    Andruschkewitsch, R.; Geisseler, D.; Koch, H.-J.; Ludwig, B.

    2012-04-01

    Despite increasing interest in tillage techniques as a factor affecting organic carbon (Corg) dynamics and stabilization mechanisms little is known about the underlying processes. Our objectives were (i) to quantify the impact of different tillage treatments on the amount and distribution of of labile Corg pools, on the water-stable macro-aggregate (>250 µm) contents and on organic carbon (Corg) storage and (ii) to quantify the ability of soils under different tillage treatments, light fraction (LF) inputs and clay contents in macro-aggregate formation. Therefore four long-term tillage trials on loess soil in Germany with regular conventional tillage (CT, to 30 cm), mulch tillage (MT, to 10 cm), and no-tillage (NT) treatments. Samples were taken in 0-5 cm, 5-25 cm and 25-40 cm depth after 18-25 years of different tillage treatments and investigated on free and occluded LF (fLF and oLF, respectively) and on macro-aggregate contents. Furthermore an incubation experiment for the quantifcation of macro-aggregate formation was conducted. Macro-aggregates in soils from CT and NT treatments (0-5 and 5-25 cm soil depth) were destroyed and different amounts of light fraction (LF) and clay were applied. The four long-term tillage trials, differing in texture and climatic conditions, revealed consistent results in Corg storage among each other. Based on the equivalent soil mass approach (CT: 0-40, MT: 0-38, NT: 0-36 cm) the Corg stocks in the sampled profile were significantly higher for the MT treatment than for the CT and NT treatments. Significantly lower Corg, fLF, oLF, and macro-aggregate contents for the soils under CT treatment in comparison with the soils under NT and MT treatments were restricted on the top 5 cm. The correlation of the macro-aggregate content against the fLF and oLF contents suggested that the macro-aggregate content is influenced to a lesser extent directly by the physical impact of the different tillage treatments but by the contents of available

  11. Effect of tillage system on yield and weed populations of soybean ( Glycin Max L.).

    Science.gov (United States)

    Hosseini, Seyed Z; Firouzi, Saeed; Aminpanah, Hashem; Sadeghnejhad, Hamid R

    2016-03-01

    Field experiment was conducted at Agricultural and Natural Resources Research Center of Golestan Province, Iran, to determine the effects of tillage system and weed management regime on yield and weed populations in soybean ( Glycin max L.). The experimental design was a split plot where the whole plot portion was a randomized complete block with three replicates. Main plots were tillage system: 1- No-till row crop seeding, 2- No-till seed drilling, 3- Tillage with disc harrow and drill planting, 4- Tillage with chisel packer and drill planting. The subplots were weed management regimes: 1-Weed control with herbicide application, 2- Hand weeding, 3- Herbicide application plus hand weeding, and 4- Non-weeding. Results indicated that the main effects of tillage system and weed management regime were significant for seed yield, pod number per plant, seed number per pod, weed density and biomass, while their interaction were significant only for weed density, weed biomass, and seed number per pod. The highest grain yields (3838 kg ha-1) were recorded for No-till row crop seeding. The highest seed yield (3877 kg ha-1) also was recorded for weed control with herbicide and hand weeding treatment, followed by hand weeding (3379 kg ha-1).

  12. The effect of different tillage and cover crops on soil quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    This paper examines the effect of different tillage treatments and cover crop on soil physical, chemical and biological properties of a sandy loam soil in a long-term field trial set up in 2007 at Foulum, Denmark. The experimental design is a split plot design with different tillage practices (di...... that P improved soil quality compared to H and D, especially when combined with cover crop. We also conclude that D may benefit from cover crop to yield better soil friability and hence soil quality.......This paper examines the effect of different tillage treatments and cover crop on soil physical, chemical and biological properties of a sandy loam soil in a long-term field trial set up in 2007 at Foulum, Denmark. The experimental design is a split plot design with different tillage practices...... (direct drilling (D), harrowing (H) to a depth of 8 cm and ploughing to a depth of 20 cm (P)) as main plot. The soil was cropped with cover crop (+CC) or left without cover crop (-CC) as split plot treatments in the main plots with different tillage treatments. We assessed topsoil structural quality...

  13. Potential and economic efficiency of using reduced tillage to mitigate climate effects in Danish agriculture

    DEFF Research Database (Denmark)

    Zandersen, Marianne; Jørgensen, Sisse Liv; Nainggolan, Doan

    2016-01-01

    , research also suggests that soil carbon stocks are declining. The scope of Payment for Ecosystem Service (PES) approaches to effectively and efficiently address climate regulation will depend on the spatial distribution of the carbon assimilation capacity, current land use, the value of avoided emissions...... and compare these to the marginal abatement costs curve used in Danish climate policy. The cost effectiveness of reduced tillage as a climate mitigation PES scheme critically depends on the current debate on the net effects of carbon sequestration in reduced tillage practices. Based on existing IPCC...

  14. Quantifying requirements volatility effects

    NARCIS (Netherlands)

    Kulk, G.P.; Verhoef, C.

    2008-01-01

    In an organization operating in the bancassurance sector we identified a low-risk IT subportfolio of 84 IT projects comprising together 16,500 function points, each project varying in size and duration, for which we were able to quantify its requirements volatility. This representative portfolio

  15. Soil Tillage Conservation and its Effect on Soil Properties Bioremediation and Sustained Production of Crops

    Science.gov (United States)

    Rusu, Teodor; Ioana Moraru, Paula; Muresan, Liliana; Andriuca, Valentina; Cojocaru, Olesea

    2017-04-01

    Soil Tillage Conservation (STC) is considered major components of agricultural technology for soil conservation strategies and part of Sustainable Agriculture (SA). Human action upon soil by tillage determines important morphological, physical-chemical and biological changes, with different intensities and evaluative directions. Nowadays, internationally is unanimous accepted the fact that global climatic changes are the results of human intervention in the bio-geo-chemical water and material cycle, and the sequestration of carbon in soil is considered an important intervention to limit these changes. STC involves reducing the number of tillage's (minimum tillage) to direct sowing (no-tillage) and plant debris remains at the soil surface in the ratio of at least 30%. Plant debris left on the soil surface or superficial incorporated contributes to increased biological activity and is an important source of carbon sequestration. STC restore soil structure and improve overall soil drainage, allowing more rapid infiltration of water into soil. The result is a soil bioremediation, more productive, better protected against wind and water erosion and requires less fuel for preparing the germinative bed. Carbon sequestration in soil is net advantageous, improving the productivity and sustainability. We present the influence of conventional plough tillage system on soil, water and organic matter conservation in comparison with an alternative minimum tillage (paraplow, chisel plow and rotary harrow) and no-tillage system. The application of STC increased the organic matter content 0.8 to 22.1% and water stabile aggregate content from 1.3 to 13.6%, in the 0-30 cm depth, as compared to the conventional system. For the organic matter content and the wet aggregate stability, the statistical analysis of the data showed, increasing positive significance of STC. While the soil fertility and the wet aggregate stability were initially low, the effect of conservation practices on the

  16. The Energy Effectiveness Of Crops In Crop Rotation Under Different Soil Tillage Systems

    Directory of Open Access Journals (Sweden)

    Strašil Zdeněk

    2015-09-01

    Full Text Available The paper identifies and compares the energy balance of winter wheat, spring barley and white mustard – all grown in crop rotation under different tillage conditions. The field trial included the conventional tillage (CT method, minimum tillage (MT and a system with no tillage (NT. The energy inputs included both the direct and indirect energy component. Energy outputs are evaluated as gross calorific value (gross heating value of phytomass dry matter of the primary product and the total harvested production. The energy effectiveness (energy output: energy input was selected for evaluation. The greatest energy effectiveness for the primary product was established as 6.35 for barley, 6.04 for wheat and 3.68 for mustard; in the case of total production, it was 9.82 for barley, 10.08 for wheat and 9.72 for mustard. When comparing the different tillage conditions, the greatest energy effectiveness was calculated for the evaluated crops under the MT operation and represented the primary product of wheat at 6.49, barley at 6.69 and mustard at 3.92. The smallest energy effectiveness for the primary product was found in wheat 5.77 and barley 6.10 under the CT option; it was 3.55 for mustard under the option of NT. Throughout the entire cropping pattern, the greatest energy effectiveness was established under the minimum tillage option – 5.70 for the primary product and 10.47 for the total production. On the other hand, the smallest values were calculated under CT – 5.22 for the primary product and 9.71 for total production.

  17. The effect of different tillage methods and organic fertilizers on soil physical state and crop yield

    OpenAIRE

    Ožeraitienė, Danutė; Čiuberkis, Steponas

    2006-01-01

    The present paper summarises the data of field and laboratory trials conducted in Lithuania (Vežaiciai Branch of the Lithuanian Institute of Agriculture) during the period 2003-2006. The effects of primary soil tillage: 1) deep (22-25 cm) ploughing; 2) shallow (10-12 cm) ploughing; 3) shallow (8-10 cm) tillage with a disc harrow as well as the effects of different organic fertilizers (farmyard manure, green manure and straw) on the main physical indicators of moraine loam soil (structure, bul...

  18. Effects of different tillage and transplanting methods on rice rooting ability

    International Nuclear Information System (INIS)

    Ren Wanjun; Yang Wenyu; Fan Gaoqiong; Wu Jinxiu; Wang Lihong

    2007-01-01

    Effects of different tillage and transplanting methods on rice rooting ability were studied with the methods of water culture and 3 H labeling. The results showed that the dynamic curve of rooting ability had single peak during growth period, and the peak of root length per plant, root number and root dry weight appeared at booting. With conventional tillage and transplanting method, the rice plant had the strongest rooting ability, under non-tillage treatment (BCSNT), the rooting ability was the lowest during elongating to heading. After 10d of heading, the dry weight and 3 H specific activity of BCSNT was higher than other treatments, at the same time, the percentage of 3 H assimilate at new root was the highest. Dry weight was positively correlated with percentage of 3 H assimilate of new root, while negatively with percentage of 3 H assimilate of panicle. (authors)

  19. Effect of different tillage intensity on yields and yield-forming factors in winter wheat

    Directory of Open Access Journals (Sweden)

    Martin Houšť

    2012-01-01

    Full Text Available The paper presents results of a study on application of minimum tillage technologies when growing winter wheat. Experiments were performed in the sugar-beet-growing region with loamy chernozem within the period of 2005–2009. Aanalysed and evaluated were effects of different methods of soil processing on yield-forming factors in stands of winter wheat grown after three different preceding crops (i.e. alfalfa, maize for silage and pea. Evaluated were the following four variants of tillage: (1 conventional ploughing to the depth of 0.22 m (Variant 1; (2 ploughing to the depth of 0.15 m (Variant 2; (3 direct sowing into the untilled soil (Variant 3, and (4 shallow tillage to the depth of 0.10 m (Variant 4.The effect of different tillage intensity on winter wheat yields was statistically non-significant after all forecrops. After alfalfa, the highest and the lowest average yields were recorded in Variant 2 (i.e. with ploughing to the depth of 0.15 m and Variant 3 (direct sowing into the untilled soil, respectively. After maize grown for silage, higher yields were obtained in Variant 2 and Variant 1 (conventional ploughing while in Variants 4 and 3 the obtained yields were lower. When growing winter wheat after pea as a preceding crop, the highest and the lowest average yields were recorded after direct sowing (Variant 3 and in Variant 1 (i.e. ploughing to the depth of 0.22 m, respectively. Results of studies on effect of different tillage technologies on yields of winter wheat crops indicate that under the given pedological and climatic conditions it is possible to apply methods of reduced tillage intensity. However, the choice of the corresponding technology must be performed with regard to the type of preceding crop.

  20. Long-term conventional and no-tillage effects on field hydrology and yields of a dryland crop rotation

    Science.gov (United States)

    Semiarid dryland crop yields with no-till, NT, residue management are often greater than stubble-mulch, SM, tillage as a result of improved soil conditions and water conservation, but information on long-term tillage effects on field hydrology and sustained crop production are needed. Our objective ...

  1. Assessing Tillage Effects on Soil Hydraulic Properties via Inverse Parameter Estimation using Tension Infiltrometry

    Science.gov (United States)

    Schwen, Andreas; Bodner, Gernot; Loiskandl, Willibald

    2010-05-01

    Hydraulic properties are key factors controlling water and solute movement in soils. While several recent studies have focused on the assessment of the spatial variability of hydraulic properties, the temporal dynamics are commonly not taken into account, primarily because its measurement is costly and time-consuming. However, there is extensive empirical evidence that these properties are subject to temporal changes, particularly in the near-saturated range where soil structure strongly influences water flow. One main source of temporal variability is soil tillage. It can improve macroporosity by loosening the soil and thereby changing the pore-size distribution. Since these modifications are quite unstable over time, the pore space partially collapses after tillage. This effect should be largest for conventional tillage (CT), where the soil is ploughed after harvest every year. Assessing the effect of different tillage treatments on the temporal variability of hydraulic properties requires adequate measurement techniques. Tension infiltrometry has become a popular and convenient method providing not only the hydraulic conductivity function but also the soil rentention properties. The inverse estimation of parameters from infiltration measurements remains challenging, despite some progress since the first approach of Šimůnek et al. (1998). Measured data like the cumulative infiltration, the initial and final volumetric water content, as well as independently measured retention data from soil core analysis with laboratory methods, have to be considered to find an optimum solution describing the soil's pore space. In the present study we analysed tension infiltration measurements obtained several times between August 2008 and December 2009 on an arable field in the Moravian Basin, Lower Austria. The tillage treatments were conventional tillage including ploughing (CT), reduced tillage with chisel only (RT), and no-tillage treatment using a direct seeding

  2. Effect of Tillage Practices on Soil Properties and Crop Productivity in Wheat-Mungbean-Rice Cropping System under Subtropical Climatic Conditions

    Science.gov (United States)

    Islam, Md. Monirul; Hasanuzzaman, Mirza

    2014-01-01

    This study was conducted to know cropping cycles required to improve OM status in soil and to investigate the effects of medium-term tillage practices on soil properties and crop yields in Grey Terrace soil of Bangladesh under wheat-mungbean-T. aman cropping system. Four different tillage practices, namely, zero tillage (ZT), minimum tillage (MT), conventional tillage (CT), and deep tillage (DT), were studied in a randomized complete block (RCB) design with four replications. Tillage practices showed positive effects on soil properties and crop yields. After four cropping cycles, the highest OM accumulation, the maximum root mass density (0–15 cm soil depth), and the improved physical and chemical properties were recorded in the conservational tillage practices. Bulk and particle densities were decreased due to tillage practices, having the highest reduction of these properties and the highest increase of porosity and field capacity in zero tillage. The highest total N, P, K, and S in their available forms were recorded in zero tillage. All tillage practices showed similar yield after four years of cropping cycles. Therefore, we conclude that zero tillage with 20% residue retention was found to be suitable for soil health and achieving optimum yield under the cropping system in Grey Terrace soil (Aeric Albaquept). PMID:25197702

  3. [Effects of conservation tillage on soil CO2 and N2O emission during the following winter-wheat season].

    Science.gov (United States)

    Pan, Ying; Hu, Zheng-Hu; Wu, Yang-Zhou; Sun, Yin-Yin; Sheng, Lu; Chen, Shu-Tao; Xiao, Qi-Tao

    2014-07-01

    In order to study the effect of conservation tillage on soil CO2 and N2O emissions in the following crop-growing season, field experiments were conducted in the winter wheat-growing season. Four treatments were conventional tillage (T), no-tillage with no straw cover (NT), no-tillage with straw cover (NTS), and conventional tillage with straw incorporation (TS), respectively. The CO2 and N2O fluxes were measured using a static chamber-gas chromatograph technique. The results showed that in the following winter wheat-growing season, conservation tillage did not change the seasonal pattern of CO2 and N2O emission fluxes from soil, and had no significant effect on crop biomass. Conservation tillage significantly reduced the accumulative amount of CO2 and N2O. Compared with the T treatment, the accumulative amount of CO2 under TS, NT, and NTS treatments were reduced by 5.95% (P = 0.132), 12.94% (P = 0.007), and 13.91% (P = 0.004), respectively, and the accumulative amount of N2O were significantly reduced by 31.23% (P = 0.000), 61.29% (P = 0.000), and 33.08% (P = 0.000), respectively. Our findings suggest that conservation tillage significantly reduced CO2 and N2O emission from soil in the following winter wheat-growing season.

  4. Effect of no-tillage crop rotation systems on nutrient status of a rhodic ...

    African Journals Online (AJOL)

    In this study the effects of no-tillage and eight crop rotations (established in 1985) on chemical properties of a Rhodic Ferralsol (Typic Haplorthox, Soil Taxonomy) and on nutrient uptake by maize (Zea mays L.) and soybean (Glycine max L. Merrill) leaves were assessed in the state of São Paulo, Brazil, using a randomized ...

  5. Effects of phosphorus and four tillage mulch systems on the physico ...

    African Journals Online (AJOL)

    Effects of phosphorus and four tillage mulch systems on the physico-chemical properties of an ultisol in Eastern Nigeria. ... Micro-porosity, macro-porosity, total porosity, mean weight diameter of water stable aggregates and saturated hydraulic conductivity, however, did not show significance. The infiltration rates of the TM, ...

  6. Effects of different tillage and straw return on soil organic carbon in a rice-wheat rotation system.

    Directory of Open Access Journals (Sweden)

    Liqun Zhu

    Full Text Available Soil management practices, such as tillage method or straw return, could alter soil organic carbon (C contents. However, the effects of tillage method or straw return on soil organic C (SOC have showed inconsistent results in different soil/climate/cropping systems. The Yangtze River Delta of China is the main production region of rice and wheat, and rice-wheat rotation is the most important cropping system in this region. However, few studies in this region have been conducted to assess the effects of different tillage methods combined with straw return on soil labile C fractions in the rice-wheat rotation system. In this study, a field experiment was used to evaluate the effects of different tillage methods, straw return and their interaction on soil total organic C (TOC and labile organic C fractions at three soil depths (0-7, 7-14 and 14-21 cm for a rice-wheat rotation in Yangzhong of the Yangtze River Delta of China. Soil TOC, easily oxidizable C (EOC, dissolved organic C (DOC and microbial biomass C (MBC contents were measured in this study. Soil TOC and labile organic C fractions contents were significantly affected by straw returns, and were higher under straw return treatments than non-straw return at three depths. At 0-7 cm depth, soil MBC was significantly higher under plowing tillage than rotary tillage, but EOC was just opposite. Rotary tillage had significantly higher soil TOC than plowing tillage at 7-14 cm depth. However, at 14-21 cm depth, TOC, DOC and MBC were significantly higher under plowing tillage than rotary tillage except for EOC. Consequently, under short-term condition, rice and wheat straw both return in rice-wheat rotation system could increase SOC content and improve soil quality in the Yangtze River Delta.

  7. Effect of conservation tillage and peat application on weed infestation on a clay soil

    Directory of Open Access Journals (Sweden)

    P. VANHALA

    2008-12-01

    Full Text Available Amendment of soil with peat is an attempt to avoid crop yield variation in the transition to conservation tillage, as it improves seedbed conditions and crop growth in drought-sensitive clay soils. Weed infestations were compared in 1999-2000 between the original and peat-amended clay (Typic Cryaquept, very fine, illitic or mixed under different autumn tillage systems in an oats-barley rotation. In a field experiment, sphagnum peat (H = 4 had been spread (0.02 m 3 m -2 on the soil surface in August 1995. Tillage treatments included mouldboard ploughing (to 20 cm and stubble cultivations of different working depths (8 or 15 cm and intensity (once or twice. Weed biomass and density were assessed by an area of 1 m 2 per field plot in August 1999-2000 and June 2000. The 1999 season was dry, but soil moisture conditions were more favourable in 2000. Peat application tended to increase the number of volunteer oats and Chenopodium album in 1999, while decreasing Galium spurium biomass. Ploughing significantly increased the abundance of Chenopodium album and Lamium purpureum in barley (Hordeum vulgare in 1999. Weed infestation was much lower in 2000, and tillage effect on Chenopodium album was minor in oats (Avena sativa. Growth of Lamium purpureum and Fumaria officinalis was stimulated in ploughed soils both years. Intensity and working depth of stubble cultivation had no significant effect on weeds.;

  8. Long-term effects of conventional and reduced tillage systems on soil condition and yield of maize

    Science.gov (United States)

    Rátonyi, Tamás; Széles, Adrienn; Harsányi, Endre

    2015-04-01

    As a consequence of operations which neglect soil condition and consist of frequent soil disturbance, conventional tillage (primary tillage with autumn ploughing) results in the degradation and compaction of soil structure, as well as the reduction of organic matter. These unfavourable processes pose an increasing economic and environmental protection problem today. The unfavourable physical condition of soils on which conventional tillage was performed indicate the need for preserving methods and tools. The examinations were performed in the multifactorial long-term tillage experiment established at the Látókép experiment site of DE MÉK. The experiment site is located in the Hajdúság loess ridge (Hungary) and its soil is loess-based calcareous chernozem with deep humus layer. The physical soil type is mid-heavy adobe. The long-term experiment has a split-split plot design. The main plots are different tillage methods (autumn ploughing, spring shallow tillage) without replication. In this paper, the effect of conventional and reduced (shallow) tillage methods on soil conditions and maize yield was examined. A manual penetrometer was used to determine the physical condition and compactedness of the soil. The soil moisture content was determined with deep probe measurement (based on capacitive method). In addition to soil analyses, the yield per hectare of different plots was also observed. In reduced tillage, one compacted layer is shown in the soil resistance profile determined with a penetrometer, while there are two compacted layers in autumn ploughing. The highest resistance was measured in the case of primary tillage performed at the same depth for several years in the compacted (pan disk) layer developed under the developed layer in both treatments. The unfavourable impact of spring shallow primary tillage on physical soil conditions is shown by the fact that the compaction of the pan disk exceed the critical limit value of 3 MPa. Over the years, further

  9. Gross mineralization of nitrogen in fertile soils. Effects of the tillage system and soil depths

    International Nuclear Information System (INIS)

    Videla, C.; Echeverria, H.; Studdert, G.

    2002-01-01

    A greenhouse experiment was carried out with the aim of determining the effect of different tillage systems and soil depths on gross mineralization rates (TMB). The studied soil was a Typic Argiudoll Petrocalcic Paleudoll complex, under: conventional tillage for 23 yr. (PC treatment); no tillage for 6 yr. (PD treatment), and pasture for 4 yr. (P treatment) and 0-10 and 10-20 sampling depths. TMB were estimated through 15 N dilution technique, by addition of labelled (NH 4 ) 2 SO 4 (10% 15 N at. exc.) at days 0, 7, 21 and 35. Twenty-four and 72 h after each addition, N inorganic content and 15 N enrichment of inorganic were determined on 2M KCl extracts in order to estimate the TMB. At 0-10 cm depth, TMB increase until day 21 and decreased afterwards. There were no significant differences between tillage treatments. At 10-20 cm soil depth PC and PD TMB were constant during the whole analysed period. P treatment had a quadratic adjust, with negative linear component. P TMB was lower than PC and PD until day 21 but afterwards it was significantly higher. These results suggest the presence in the pasture of an organic matter fraction, which mineralizes lately but with a high rate. (author)

  10. Effects of tillage on the activity density and biological diversity of carabid beetles in spring and winter crops.

    Science.gov (United States)

    Hatten, Timothy D; Bosque-Pérez, Nilsa A; Labonte, James R; Guy, Stephen O; Eigenbrode, Sanford D

    2007-04-01

    The effects of tillage regimen (conventional [CT] and no-tillage [NT]) on the activity density and diversity of carabid beetles (Coleoptera: Carabidae) was studied by pitfall trapping within a rain-fed cropping system in northwestern Idaho, 2000-2002. The cropping rotation consisted of a spring cereal (barley, Hordeum vulgare L., in 2000 and 2001; and wheat, Triticum aestivum L., in 2002), spring dry pea (Pisum sativum L.) 2000-2002, and wheat (T. aestivum), spring in 2000 and 2001, and winter in 2002. A total of 14,480 beetles comprised of 30 species was captured, with five numerically dominant species [Poecilus scitulus L., Poecilus lucublandus Say, Microlestes linearis L., Pterostichus melanarius Ill., and Calosoma cancellatum (Eschscholtz)], accounting for 98% of all captures. All species including the dominants responded idiosyncratically to tillage regimen. Adjusting for trapping biases did not significantly change seasonal activity density of Poecilus spp. or Pt. melanarius to tillage. More beetles were captured in CT than in NT crops because of the dominance of P. scitulus in CT, whereas species richness and biological diversity were generally higher in NT crops. Observed patterns suggest that direct effects of tillage affected some species, whereas indirect effects related to habitat characteristics affected others. CT may provide habitat preferable to xerophilic spring breeders. A relationship was found between beetle species size and tillage regimen in pea and to a lesser extent across all spring crops, with large species (>14 mm) conserved more commonly in NT, small species (tillage systems.

  11. Effect of tillage and planting date on seasonal abundance and diversity of predacious ground beetles in cotton.

    Science.gov (United States)

    Shrestha, R B; Parajulee, M N

    2010-01-01

    A 2-year field study was conducted in the southern High Plains region of Texas to evaluate the effect of tillage system and cotton planting date window on seasonal abundance and activity patterns of predacious ground beetles. The experiment was deployed in a split-plot randomized block design with tillage as the main-plot factor and planting date as the subplot factor. There were two levels for each factor. The two tillage systems were conservation tillage (30% or more of the soil surface is covered with crop residue) and conventional tillage. The two cotton planting date window treatments were early May (normal planting) and early June (late planting). Five prevailing predacious ground beetles, Cicindela sexguttata F., Calosoma scrutator Drees, Pasimachus spp., Pterostichus spp., and Megacephala Carolina L. (Coleoptera: Carabidae), were monitored using pitfall traps at 2-week intervals from June 2002 to October 2003. The highest total number of ground beetles (6/trap) was observed on 9 July 2003. Cicindela sexguttata was the dominant ground dwelling predacious beetle among the five species. A significant difference between the two tillage systems was observed in the abundances of Pterostichus spp. and C. sexguttata. In 2002. significantly more Pterostichus spp. were recorded from conventional plots (0.27/trap) than were recorded from conservation tillage plots (0.05/trap). Significantly more C. sexguttata were recorded in 2003 from conservation plots (3.77/trap) than were recorded from conventional tillage plots (1.04/trap). There was a significant interaction between year and tillage treatments. However, there was no significant difference in the abundances of M. Carolina and Pasimachus spp. between the two tillage practices in either of the two years. M. Carolina numbers were significantly higher in late-planted cotton compared with those observed in normal-planted cotton. However, planting date window had no significant influence on the activity patterns of the

  12. [Diversity of soil fauna in corn fields in Huang-Huai-Hai Plain of China under effects of conservation tillage].

    Science.gov (United States)

    Zhu, Qiang-Gen; Zhu, An-Ning; Zhang, Jia-Bao; Zhang, Huan-Chao; Huang, Ping; Zhang, Cong-Zhi

    2009-10-01

    An investigation was made on the abundance and diversity of soil fauna in the corn fields under conventional and conservation tillage in Huang-Huai-Hai Plain of China. The abundance and diversity of soil fauna were higher at corn maturing (September) than at its jointing stage (July), and higher at jointing stage under conservation tillage than under conventional tillage. Soil fauna mainly distributed in surface soil layer (0-10 cm), but still had a larger number in 10-20 cm layer under conservation tillage. The individuals of acari, diptera, diplura, and microdrile oligochaetes, especially those of acari, were higher under conservation tillage than under conventional tillage. At maturing stage, an obvious effect of straw-returning under conservation tillage was observed, i. e., the more the straw returned, the higher the abundance of soil fauna, among which, the individuals of collembola, acari, coleopteran, and psocoptera, especially those of collembolan, increased significantly. The abundance of collembola at both jointing and maturing stages was significantly positively correlated with the quantity of straw returned, suggesting that collembola played an important role in straw decomposition and nutrient cycling.

  13. Effects of No-tillage Combined with Reused Plastic Film Mulching on Maize Yield and Irrigation Water Productivity

    OpenAIRE

    SU Yong-zhong; ZHANG Ke; LIU Ting-na; WANG Ting

    2016-01-01

    A field experiment was conducted to determine the effects of reused plastic film mulching and no-tillage on maize yield and irriga-tion water productivity(IWP) in the marginal oasis in the middle of Hexi Corridor region of northwestern China. The aim is to provide an alternative tillage and cultivation pattern for reducing plastic film pollution, saving cost and increasing income, and improving resource use efficiency. The field experiment was carried out in three soils with different texture...

  14. Predicting soil workability and fragmentation in tillage: a review

    DEFF Research Database (Denmark)

    Obour, Peter Bilson; Lamandé, Mathieu; Edwards, Gareth T. C.

    2017-01-01

    of SWRC and the drop-shatter tests or tensile strength; (i) to quantify the effects of soil texture, organic matter and compaction on soil workability; and (ii) to compare soil water content for workability in the field with theoretical soil workability, thereby improving the prediction of soil......Soil workability and friability are required parameters to consider when creating suitable seedbeds for crop establishment and growth. Knowledge of soil workability is important for scheduling tillage operations and for reducing the risk of tillage-induced structural degradation of soils....... A reliable evaluation of soil workability implies a distinctive definition of the critical water content (wet and dry limits) for tillage. In this review, we provide a comprehensive assessment of the methods for determining soil workability, and the effects of soil properties and tillage systems on soil...

  15. Effect of Different Tillage Methods and Cover Crop Types on Yield and Yield Components of Wheat

    Directory of Open Access Journals (Sweden)

    Z Sharefee

    2018-05-01

    Full Text Available Introduction Conservation agriculture is an appropriate strategy for maintaining and improving agricultural resources which increases crop production and stability and also provides environmental protection. This attitude contributes to the conservation of natural resources (soil, water, and air and is one of the most effective ways to overcome the drought crisis, water management and compensation of soil organic matter in arid and semi-arid regions. The practice of zero-tillage decreases the mineralization of organic matter and contributes to the sequestration of organic carbon in the soil. Higher amounts of organic matter in the soil improve soil structure and root growth, water infiltration and retention, and cation exchange capacity. In addition, zero-tillage reduces soil compaction and crop production costs. Cover crops are cultivated to protect the soil from erosion and elements loss by leaching or runoff and also improve the soil moisture and temperature. Given that South Khorasan farmers still use traditional methods of cultivation of wheat, and cover crops have no place in their farming systems, the aim of this study was to investigate the effect of cover crops types and tillage systems on yield and yield components of wheat in Birjand region. Materials and Methods A split plot field experiment was conducted based on randomized complete block design with three replications at the Research Farm of the University of Birjand over the growing season of 2014-2015. The main factor was the type of tillage (no-till, reduced tillage and conventional tillage and cover crop type (chickling pea (Lathyrus sativus, rocket salad (Eruca sativa, triticale (X Triticosecale witmack, barley (Hordeum vulgaris and control (no cover crop was considered as sub plots. Cover crops were planted on July 2014. Before planting wheat, cover crops were dried through spraying paraquat herbicide using a backpack sprayer at a rate of 3 L ha-1. Then the three tillage

  16. Tillage effects on N2O emission from soils under corn and soybeans in eastern Canada

    International Nuclear Information System (INIS)

    Gregorich, E.G.; St-Georges, P.; McKim, U.F.; Chan, C.; Rochette, P.

    2008-01-01

    New research has suggested that no-till agricultural practices will result in higher levels of nitrous oxide (N 2 O) emissions due to increased levels of denitrification. This study was evaluated and compared N 2 O emissions from tilled and no-till soils. Data used in the study were comprised of more than 1500 flux measurements of N 2 O taken between April and October over a period of 3 years at a site in Ottawa, Ontario. Soybean and corn crop rotations were used. Treatment effects of tillage, crop, and time of season on N 2 O fluxes were assessed using analysis of variance (ANOVA) methods. The study evaluated the responses of tillage during periods when soil temperatures were above 0 degrees C. Results of the studies demonstrated that fertilization management practices contributed to the higher N 2 O emissions observed in soils planted with corn when compared with soils planted with soybeans. Biological nitrogen (N) fixation in soybeans did not contribute to annual N 2 O emissions, and the effects of tillage on N 2 O emissions varied from year to year. The tilled soils typically had better aeration, higher temperatures, and lower water content than no-till soils. N 2 O emissions from no-till soils were lower than rates observed in tilled soils in 2 of the 3 years studied. Higher emissions observed in no-till soils were attributed to timing and the method of fertilizer placement. It was concluded that further studies are needed to develop methods of improving N use efficiency within tillage systems. 30 refs., 5 tabs., 2 figs

  17. TILLAGE EFFECTS ON SUNFLOWER (HELIANTHUS ANNUUS, L. EMERGENCE, YIELD, QUALITY, AND FUEL CONSUMPTION IN DOUBLE CROPPING SYSTEM

    Directory of Open Access Journals (Sweden)

    ABDULLAH SESSIZ

    2009-06-01

    Full Text Available The relation between crop growing and soil tillage treatment are play important role in agricultural production. Soils under conventional tillage (CT generally have lower bulk density and associated higher total porosity within the plough layer than under no tillage (NT. No-till farming can reduce soil erosion, conserve soil moisture and minimize labor and fuel consumption. The aim of this study were to investigate the effects of conventional, reduced and notillage methods on soil physical properties, sunfl ower yield and yield components, protein and oil content and fuel consumption in Southeastern of Turkey. Six tillage methods for the second crop sunfl ower were tested and compared each other within after lentil harvesting at 2003 and 2004 years in a clay loam soil. According to results, the fi rst year, the bulk density had decreased from 1.29 to 1.09 g cm-3, the second year the δb had decreased from 1.41 to 1.23 g cm-3. Differences between years and tillage methods in terms of yield were found signifi cant (p<0.05. However, no differences were found between the NT and CT. There were also no signifi cance differences in content of protein, oil and ash among six tillage methods. The highest fuel consumption was measured in conventional method (CT whereas the lowest value was found in direct seeding method as 33.48 L ha-1 and 6.6 L ha-1, respectively.

  18. Effects of Tillage Systems on Changes of Soil Nutrients, Yield and Land Equivalent Ratio in Roselle – Green Gram Intercropping

    Directory of Open Access Journals (Sweden)

    A Hodiani mehr

    2017-10-01

    Full Text Available Introduction Intercropping is one of the components of sustainable agriculture and as part of crop rotation in the design of sustainable system. One of the benefits of intercropping is greater use of available resources. The aims of this study were to evaluate different tillage systems and cropping patterns of Roselle and Green Gram on some soil nutrients and the use efficiency of environmental resources. Usually, intercropping used at Low fertility soil with low input conditions in the tropics region. Bahrani et al. (2007 reported that no tillage systems compared with conventional tillage with crop residue, were increased soil organic carbon content in maize production. Ramroudi et al. (2011 expressed conventional tillage reduced amount of nitrogen compared to no tillage system. Material and Methods The research was conducted at Zabol city. Split plot experiment performed based on a randomized complete block design with three replications. Main plot was three levels of tillage system (zero (without plowing, reduced (disk and conventional tillage (disc plow and sub plot was planting ratio with five levels (pure culture of Roselle, pure culture of Green gram, 50% roselle+50% green gram, 25% roselle+75% green gram, 75% roselle+25% green gram were considered. Preparing the ground in mid-June 2012, according to the type of plowing was performed. For comparison of means were used by Duncan's test at 5% probability. Results and Discussion The effects of tillage systems, planting ratios and interaction of tillage systems × planting ratio on soil organic carbon and nitrogen were very significant. The highest and lowest levels of organic carbon were obtained in zero tillage (1.14% and conventional tillage systems (0.63 %, respectively. The highest and lowest nitrogen of soil after harvest, of pure culture of Green gram (0.11 % and 75 % of Roselle + 25% Green gram intercropping (0.06 % were obtained respectively, Tillage system could not affected the

  19. Soil tillage

    OpenAIRE

    Dierauer, Hansueli

    2013-01-01

    The web platform offers a compilation of various formats and materials dealing with reduced tillage and its challenges regarding weeds. A selection of short movies about mechanical weeding, green manure and tailor-made machinery is listed. Leaflets and publications on reduced tillage can be downloaded. In there, different treatments and machinery are tested and compared to advice farmers on how to conserve soil while keeping weed under control. For Swiss farmers information on the leg...

  20. Soil-blade orientation effect on tillage forces determined by 3D finite element models

    Directory of Open Access Journals (Sweden)

    Ayadi Ibrahmi

    2014-10-01

    Full Text Available This paper investigated the effect of the cutting parameters of a blade on the tillage force components using finite element modeling. A three-dimensional model was carried out with Abaqus Explicit in order to study the interaction between the tool and soil. The soil was modeled with linear forms of the Drucker-Pager model, while the tool was considered as a rigid body with a reference point taken at its tip. The effect of tillage depth and the width of a vertical blade were studied. It was found that the amounts of the draught and vertical forces increase linearly with a slope of 0.037 and 0.0143 respectively when the width increases. The narrow tool (width< 60mm has a greater effect on the specific draught force than a larger tool. Draught and specific draught force increase with polynomial and linear curve respectively versus the depth. However, this effect was reduced for the vertical force. These results were in a good agreement with previously published works. The second part of this paper is focused on the oblique position of the blade to evaluate the effect of the attack angles on both the tillage forces (draught, lateral and vertical and the cutting process of the soil during and after its failure. For all considered angles, the draught force presents the highest values compared to the vertical and lateral forces. Results showed that working with small cutting and an average rake angles (30° to 60° and 45° respectively can produce a good soil inversion.

  1. Chemical, green and organic manure effects on chemical properties on a savannah oxisol and on corn under conventional tillage and no-tillage

    Science.gov (United States)

    Mannigel, Anny R.; Alves, Marlene C.; Valério Filho, Walter V.

    2015-04-01

    Modern agriculture, in general, has always been based on the concept that natural resources are endless; however, this concept is changing. Concern for the environment is increasingly becoming part of farming practices, either by the awareness of society, or because the high cost of fertilizers or even the exhaustion of soils. The objective of this research was to evaluate the effects of the green manure and mineral fertilizer and/or organic manure and, on the chemical properties of an Oxisol, on "Savannah" (cerrado) area in Mato Grosso do Sul-Brazil, cultivated with corn (Zea mays L.) on the following management conditions: no-tillage and conventional tillage, on area previously under pasture (Brachiaria decumbens). The experimental design was a randomized blocks and the tested treatments were: control (without organic manure or chemical fertilizer); chemical fertilizer, as recommended for the culture and based on the chemical soil analysis; organic manure (cow manure); organic manure + half of the mineral fertilizer recommended rate; and the green manure Crotalaria juncea and Pennisetum americanum. The chemical analyses were the soil chemical analysis to the intent of soil fertility. Corn yield was evaluated. The collect of soil samples were realized in depths of 0.00-0.05 m and 0.05-0.10 m and 0.10-0.20 m. The organic manure and the organic manure + half of the mineral recommended rate increased P, Ca, Mg, K and Organic Matter in the first depth (0.00 - 0.05 m). These treatments also increased K and Mg at the second depth analyzed (0.05 - 0.10 m) and K in the depth from 0.10 - 0.20 m. Under conventional tillage management presents better crop results with an average grain yield of 3649 kg ha-1 versus 2374 kg ha-1 obtained under no-tillage. The use of chemical fertilizer, organic manure + half of the mineral recommended rate, Crotalaria juncea, organic manure and Pennisetum americanum increased corn yield by 84, 79, 58, 44 and 41 %, respectively.

  2. Characterization of tillage effects on soil permeability using different measures of macroporosity derived from tension infiltrometry

    Science.gov (United States)

    Bodner, G.; Schwen, A.; Scholl, P.; Kammerer, G.; Buchan, G.; Kaul, H.-P.; Loiskandl, W.

    2010-05-01

    approaches (direct vs. inverse evaluation, capillary vs. flow weighted pore radius). We will show the influence of the distinct evaluation procedures on the resulting effective macroporosity, as well as on the relationships between macropore radius and hydraulic conductivity (Moret and Arrúe, 2007) and pore fraction respectively (Carey et al., 2007). The infiltration measurements used in this study were obtained in a long-term tillage trial located in the semi-arid region of Eastern Austria. Measurements were taken five times over the vegetation period, starting immediately after tillage until harvest of the winter wheat crop. Three tillage systems were evaluated, being conventional tillage with plough, minimum tillage with chisel and no-tillage. Additional to infiltration measurements, also soil water content was monitored continuously by a capacitance probe in all three replicates of each tillage treatment in 10, 20 and 40 cm soil depth. Water content time series are used to derive flow velocity in the wet range by cross-correlation analysis (Wu et al., 1997). This effective parameter of water transmission will then be compared to the flow behaviour expected from the characterization of soil macroporosity. We will show that mainly in no-tillage systems large macropores contribute essentially to flow and therefore the decision on pore measure and evaluation procedure to be used leads to substantial differences. For a detailed comparison of tillage effects on soil hydraulic properties it is therefore essential to analyse the contribution of different tension infiltrometry based evaluation methods to explain effective water transmission through the complex porous network of the soil. References Carey, S.K., Quinton, W.L., Goeller, N.T. 2007. Field and laboratory estimates of pore size properties and hydraulic characteristics for subarctic organic soils. Hydrol. Process. 21, 2560-2571. Moret, D., Arrúe, J.L. 2007. Characterizing soil water conducting macro- and mesoporosity

  3. Temporary effect of chiseling on the compaction of a Rhodic Hapludox under no-tillage

    Directory of Open Access Journals (Sweden)

    Sâmala Glícia Carneiro Silva

    2012-04-01

    Full Text Available Mechanical chiseling has been used to alleviate the effects of compaction in soils under no-tillage (NT. However, its effect on the soil physical properties does not seem to have a defined duration period. The purpose of this study was to evaluate the behavior of the bulk density (BD and degree of compaction (DC at different soil depths, after chiseling in no-tillage, for one year. The experiment was performed in Ponta Grossa, Paraná State, Brazil, using an Oxisol (Rhodic Hapludox. Bulk density and DC were previously measured in an area under NT for 16 years, then immediately after chiseling (CHI in May 2009, six months after chiseling (CHI6M in October 2009 and one year after chiseling (CHI12M in May 2010. In the layers 0.0-0.10, 0.10-0.20 and 0.20-0.30 m, there was a significant BD reduction CHI and a marked increase CHI6M. The BD values measured CHI12M were similar to those before tillage. Chiseling reduced the DC in the layers 0.0-0.10 m and 0.10-0.20 m, but returned to the initial values one year later. During the evaluation periods CHI, CHI6M and CHI12M, the BD increased in the layer 0.30-0.40 m, compared with NT. The highest DC values were observed six months after chiseling; nevertheless the structural recovery of the soil was considerable, possibly due to the high degree of soil resilience and the influence of the wetting and drying cycles detected in the study period. The chiseling effects, evaluated by BD and DC, lasted less than one year, i.e., the beneficial short-term effects of chiseling on the reduction of the surface BD increased the risk of compaction in deeper soil layers.

  4. [Effect of tillage patterns on the structure of weed communities in oat fields in the cold and arid region of North China].

    Science.gov (United States)

    Zhang, Li; Zhang, Li; Wu, Dong-Xia; Zhang, Jun-Jun

    2014-06-01

    In order to clarify the effects of tillage patterns on farmland weed community structure and crop production characteristics, based on 10 years location experiment with no-tillage, subsoiling and conventional tillage in the cold and arid region of North China, and supplementary experiment of plowing after 10 years no-tillage and subsoiling, oat was planted in 2 soils under different tillage patterns, and field weed total density, dominant weed types, weed diversity index, field weed biomass and oats yield were measured. The results showed that the regional weed community was dominated by foxtail weed (Setaira viridis); the weed density under long-term no-tillage was 2.20-5.14 times of tillage at different growing stages of oat, but there were no significant differences between conditional tillage and plowing after long-term no-tillage and subsoiling. Field weed Shannon diversity indices were 0.429 and 0.531, respectively, for sandy chestnut soil and loamy meadow soil under no-tillage conditions, and field weed biomass values were 1.35 and 2.26 times of plowing treatment, while the oat biomass values were only 2807.4 kg x hm(-2) and 4053.9 kg x hm(-2), decreased by 22.3% and 46.2%, respectively. The results showed that the weed community characteristics were affected by both tillage patterns and soil types. Long-term no-tillage farmland in the cold and arid region of North China could promote the natural evolution of plant communities by keeping more perennial weeds, and the plowing pattern lowered the annual weed density, eliminated perennial weeds with shallow roots, and stimulated perennial weeds with deep roots.

  5. Effect of tillage and rainfall on transport of manure-applied Cryptosporidium parvum oocysts through soil.

    Science.gov (United States)

    Ramirez, Norma E; Wang, Ping; Lejeune, Jeff; Shipitalo, Martin J; Ward, Lucy A; Sreevatsan, Srinand; Dick, Warren A

    2009-01-01

    Most waterborne outbreaks of cryptosporidiosis have been attributed to agricultural sources due to the high prevalence of Cryptosporidium oocysts in animal wastes and manure spreading on farmlands. No-till, an effective conservation practice, often results in soil having higher water infiltration and percolation rates than conventional tillage. We treated six undisturbed no-till and six tilled soil blocks (30 by 30 by 30 cm) with 1 L liquid dairy manure containing 10(5) C. parvum oocysts per milliliter to test the effect of tillage and rainfall on oocyst transport. The blocks were subjected to rainfall treatments consisting of 5 mm or 30 mm in 30 min. Leachate was collected from the base of the blocks in 35-mL increments using a 64-cell grid lysimeter. Even before any rain was applied, approximately 300 mL of water from the liquid manure (30% of that applied) was transported through the no-till soil, but none through the tilled blocks. After rain was applied, a greater number and percentage of first leachate samples from the no-till soil blocks compared to the tilled blocks tested positive for Cryptosporidium oocysts. In contrast to leachate, greater numbers of oocysts were recovered from the tilled soil, itself, than from the no-till soil. Although tillage was the most important factor affecting oocyst transport, rainfall timing and intensity were also important. To minimize transport of Cryptosporidium in no-till fields, manure should be applied at least 48 h before heavy rainfall is anticipated or methods of disrupting the direct linkage of surface soil to drains, via macropores, need to be used.

  6. Wind tunnel experiments on the effects of tillage ridge features on wind erosion horizontal fluxes

    Directory of Open Access Journals (Sweden)

    M. Kardous

    2005-11-01

    Full Text Available In addition to the well-known soil factors which control wind erosion on flat, unridged surfaces, two specific processes affect the susceptibility of tillage ridged surfaces to wind erosion: ridge-induced roughness and ridge- trapping efficiency. In order to parameterize horizontal soil fluxes produced by wind over tillage ridges, eight-ridge configurations composed of sandy soil and exhibiting ridge heights to ridge spacing (RH/RS ratios ranging from 0.18 to 0.38 were experimented in a wind tunnel. These experiments are used to develop a parameterization of the horizontal fluxes over tillage ridged surfaces based only on the geometric characteristics of the ridges. Indeed, the key parameters controlling the horizontal flux, namely the friction velocity, threshold friction velocity and the adjustment coefficient, are derived through specific expressions, from ridge heights (RH and ridge spacing (RS. This parameterization was evaluated by comparing the results of the simulations to an additional experimental data set and to the data set obtained by Hagen and Armbrust (1992. In both cases, predicted and measured values are found to be in a satisfying agreement. This parameterization was used to evaluate the efficiency of ridges in reducing wind erosion. The results show that ridged surfaces, when compared to a loose, unridged soil surface, lead to an important reduction in the horizontal fluxes (exceeding 60%. Moreover, the effect of ridges in trapping particles contributes for more than 90% in the flux reduction while the ridge roughness effect is weak and decreases when the wind velocity increases.

  7. Wind tunnel experiments on the effects of tillage ridge features on wind erosion horizontal fluxes

    Directory of Open Access Journals (Sweden)

    M. Kardous

    2005-11-01

    Full Text Available In addition to the well-known soil factors which control wind erosion on flat, unridged surfaces, two specific processes affect the susceptibility of tillage ridged surfaces to wind erosion: ridge-induced roughness and ridge- trapping efficiency.

    In order to parameterize horizontal soil fluxes produced by wind over tillage ridges, eight-ridge configurations composed of sandy soil and exhibiting ridge heights to ridge spacing (RH/RS ratios ranging from 0.18 to 0.38 were experimented in a wind tunnel. These experiments are used to develop a parameterization of the horizontal fluxes over tillage ridged surfaces based only on the geometric characteristics of the ridges. Indeed, the key parameters controlling the horizontal flux, namely the friction velocity, threshold friction velocity and the adjustment coefficient, are derived through specific expressions, from ridge heights (RH and ridge spacing (RS. This parameterization was evaluated by comparing the results of the simulations to an additional experimental data set and to the data set obtained by Hagen and Armbrust (1992. In both cases, predicted and measured values are found to be in a satisfying agreement.

    This parameterization was used to evaluate the efficiency of ridges in reducing wind erosion. The results show that ridged surfaces, when compared to a loose, unridged soil surface, lead to an important reduction in the horizontal fluxes (exceeding 60%. Moreover, the effect of ridges in trapping particles contributes for more than 90% in the flux reduction while the ridge roughness effect is weak and decreases when the wind velocity increases.

  8. Tillage and residue management effect on soil properties, crop performance and energy relations in greengram (Vigna radiata L. under maize-based cropping systems

    Directory of Open Access Journals (Sweden)

    J.R. Meena

    2015-12-01

    Full Text Available Effect of tillage and crop residue management on soil properties, crop performance, energy relations and economics in greengram (Vigna radiata L. was evaluated under four maize-based cropping systems in an Inceptisol of Delhi, India. Soil bulk density, hydraulic conductivity and aggregation at 0–15 cm layer were significantly affected both by tillage and cropping systems, while zero tillage significantly increased the soil organic carbon content. Yields of greengram were significantly higher in maize–chickpea and maize–mustard systems, more so with residue addition. When no residue was added, conventional tillage required 20% higher energy inputs than the zero tillage, while the residue addition increased the energy output in both tillage practices. Maize–wheat–greengram cropping system involved the maximum energy requirement and the cost of production. However, the largest net return was obtained from the maize–chickpea–greengram system under the conventional tillage with residue incorporation. Although zero tillage resulted in better aggregation, C content and N availability in soil, and reduced the energy inputs, cultivation of summer greengram appeared to be profitable under conventional tillage system with residue incorporation.

  9. Comparison of effects of machine performance parameters and energy indices of soybean production in conservation and conventional tillage systems

    Directory of Open Access Journals (Sweden)

    A Sharifi

    2016-09-01

    Full Text Available Introduction Nowadays, agricultural systems are seeking economic, ecological and bioenvironmental goals for production of agricultural crops with protection and sustainability of the environment. Therefore, there is need to extend sustainable agricultural systems such as conservation agriculture. One of the principles of conservation agriculture is conservation tillage. Conservation tillage is a kind of tillage that retains crop residues on the soil surface or mixes it with soil using related machines. It could also affect on machine performance parameters. Energy consumption for producing one kilogram crop could be studied for conservation tillage. Several researchers have conducted studies on this issue for production of different crops including wheat, sunflower and forage crops. This study conducted to assess machine performance parameters and energy indices of conservation tillage systems for soybean cultivation in Golestan province. Materials and Methods This study was conducted to investigate the effects of conservation tillage systems on machine performance and energy indices in soybean production at the Gorgan research station of Golestan Agricultural and Natural Resource Research Center in 2012. The precipitation was 450 mm. Soil texture was silty clay loam. Treatments were four tillage methods, including no-till using row crop direct planter, no-till using grain direct drill, conventional tillage usin a disk harrow with working depth of 10-15 cm and minimum tillage using chisel packer with a working depth of 20 cm. Machine performance parameters and energy indices studied in a farm covered by wheat residues in a randomized complete block design (RCBD with four treatments and four replications. Machine performance parameters consisted of field efficiency, field capacity, total field capacity and planting uniformity index were measured. Energy indices such as energy ratio, energy productivity, energy intensity and net energy gain were

  10. Effect of tillage fertilizer treatments on maize fodder yield under rainfed conditions of Pakistan

    International Nuclear Information System (INIS)

    Khaliq, P.; Cheema, N.M.; Malik, M.A.

    2012-01-01

    The effect of deep and shallow tillage and fertilizer treatments i.e., recommended dose of fertilizer (RF), farm yard manure (FYM) and recommended dose of fertilizer plus farmyard manure (RF+FYM) on maize fodder yield was studied under rainfed conditions of Pakistan. It was observed that the emergence count m-2, maize fodder biomass, plant height, number of leaves per plant and maize fodder yield enhanced, with the application of RF+FYM. However, the effect of FYM+RF and recommended dose of fertilizer was statistically non-significant and on average basis RF+FYM treatment produced higher green fodder (19971.5 kg ha/sup -1/) than fodder yield of 18349.1 kg ha/sup -1/ produced by applying recommended dose of fertilizer. However, green fodder yield produced with these two fertilizer treatments were significantly higher than that of the FYM and control treatments. The FYM treatment gave lowest fodder yield (16997 kg ha/sup -1/) and was significantly lower than the fodder yield (17278.7 kg ha/sup -1/) obtained in control treatment. The nutrient availability in RF+FYM treatment significantly increased the biomass production, however, application of FYM promoted the weed infestation that reduced the green fodder yield of maize, but it improved the overall forage yield as recorded in RF+FYM treatment. The effect of deep tillage on maize fodder yield was non-significant. (author)

  11. Effect of tillage and crop residue management on nematode densities on corn.

    Science.gov (United States)

    McSorley, R; Gallaher, R N

    1994-12-01

    Effects of winter cover crop management on nematode densities associated with a subsequent corn (Zea mays) crop were examined in five sites in north Florida. Two sites had received winter cover crops of lupine (Lupinus angustifolius), and one site each had rye (Secale cereale), hairy vetch (Vicia villosa), and crimson clover (Trifolium incarnatum). In each site, five different management regimes were compared: 1) conventional tillage after the cover crop was removed for forage; 2) conventional tillage with the cover crop retained as green manure; 3) no-till with the cover crop mowed and used as a mulch; 4) no-till with the cover crop removed as forage; and 5) fallow. Sites were sampled at corn planting and harvest for estimates of initial (Pi) and final (Pf) nematode population densities, respectively. Whether the cover crop was removed as forage or retained as green manure or mulch had no effect (P > 0.10) on population densities of any plant-parasitic nematode before or after corn at any site. Differences between conventional-till and no-till treatments were significant (P cover crop residues had little consistent effect on nematodes, and these practices should be considered based on agronomic benefits rather than for nematode management.

  12. Effect of tillage and crop residue on soil temperature following planting for a Black soil in Northeast China.

    Science.gov (United States)

    Shen, Yan; McLaughlin, Neil; Zhang, Xiaoping; Xu, Minggang; Liang, Aizhen

    2018-03-14

    Crop residue return is imperative to maintain soil health and productivity but some farmers resist adopting conservation tillage systems with residue return fearing reduced soil temperature following planting and crop yield. Soil temperatures were measured at 10 cm depth for one month following planting from 2004 to 2007 in a field experiment in Northeast China. Tillage treatments included mouldboard plough (MP), no till (NT), and ridge till (RT) with maize (Zea mays L.) and soybean (Glycine max Merr.) crops. Tillage had significant effects on soil temperature in 10 of 15 weekly periods. Weekly average NT soil temperature was 0-1.5 °C lower than MP, but the difference was significant (P Northeast China representative of a cool to temperate zone.

  13. Effects of Conventional and Conservation Tillage on Soil Hydraulic Properties of a Silty-loamy Soil

    DEFF Research Database (Denmark)

    Wahl, Niels Arne; Bens, O.; Buczko, U.

    2004-01-01

    Infiltration into soils is strongly correlated with macroporosity. Under agricultural land use, the properties of the macropore network are governed by the applied management and tillage system. On an experimental site with a silt loam soil partly under conventional and conservation tillage, the ......, conservation tillage could possibly offer a means to reduce surface runoff and flood generation in agricultural landscapes dominated by silty-loamy soils. d 2...

  14. Effects of tillage methods, corn residue mulch and n fertilizer levels on the wheat crop productivity under the rain fed condition of loess plateau china

    International Nuclear Information System (INIS)

    Tanveer, S.K.; Zhang, J.L.; Lu, X.L.; Wen, X.; Tanveer, S.K.

    2015-01-01

    A 2 years study was conducted to assess the effects of different tillage methods (Chisel plough tillage, Zero-tillage, Rotary tillage and Mould board plough tillage), two mulch levels (M0 i.e. No corn residue mulch and M1 i.e. Corn residue mulch) and 5 N fertilizer levels (0, 80, 160, 240 and 320 kg N/ha) on the wheat crop productivity under the rain fed condition of Loess Plateau, China. Factorial experiment with three replications, having strip, split-split arrangement, with tillage methods in the main plots, mulch levels in sub- plots and N-fertilizer levels in the sub-sub plots was used for this study. Due to variations in rainfalls, during the year, 2010-11, maximum grain yields i.e. 6.58 t/ha and 6.72 t/ha were recorded in case of Zero tillage planting method and similarly in case of 80 kg N/ha, while during the cropping year 2011-12 equal grain yields were recorded in case of all tillage methods, however maximum grain yield (7.46 t /ha) was recorded in case of 320 kg N/ha, N fertilizer level. On two years average basis, maximum grain yields i.e. 6.75 t/ha and 6.80 t/ha were recorded in case of Zero tillage planting method and similarly in case of 80 kg N/ha as compared with the other tillage methods or N fertilizer levels. Use of mulch reduced > 40% weeds infestation. Economic analysis shows that Zero tillage and minimum use of N fertilizer according to the projected rainfalls along with the use of mulch are both economic and environmental friendly. (author)

  15. The effect of soil tillage system and weeding time on the growth of weed and yield of soybean (Glycine max (L. Merril

    Directory of Open Access Journals (Sweden)

    Husni Thamrin Sebayang

    2018-04-01

    Full Text Available The growth and yield of soybeans can decrease due to competition from weeds. Various efforts have been made to control the growth of weeds such as land preparation and weeding periods. An experiment to study the effect of soil tillage systems and weeding time on the growth of weeds and soybean crop yield (Glycine max (L. Merril has been done in Wringinsongo Village, Tumpang Sub-District, Malang Regency from February to May 2017. The split-plot design with three replicates was used with the soil tillage system as the main plot consisting of three levels, T0: no tillage, T1: minimum tillage, and T2: conventional tillage, and weeding time as the sub plot consisting of 4 levels, P0: no weeding, P1: weeding 1 time, P2: weeding two times and P3: weeding three times. The results showed that the dominant weed species before treatment were Amaranthus spinosus (Spiny amaranth, Cynodon dactylon (Bermuda grass, Cyperus rotundus (Purple nutsedge, Ageratum conyzoides (Billygoat weed, and Portulaca oleracea (Common purslane. After treatment, the dominant weed species were Cyperus rotundus (Purple nutsedge, Amaranthus spinosus (Spiny amaranth, Ageratum conyzoides (Billygoat weed, Physalis peruviana (Cape gooseberry, and Eclipta alba (False daisy. There was no significant difference of the dry weight of weeds in conventional tillage followed by weeding 3 times at 15, 30 and 45 days after planting, and minimum tillage and no tillage. For the yield of soybeans, conventional tillage followed by weeding 3 times at 15, 30 and 45 days after planting were not significant with that of minimum tillage. The yield of soybeans was lower than that of with no tillage and no weeding.

  16. [Effects of Short-time Conservation Tillage Managements on Greenhouse Gases Emissions from Soybean-Winter Wheat Rotation System].

    Science.gov (United States)

    Xie, Yan; Chen, Xi; Hu, Zheng-hua; Chen, Shu-tao; Zhang, Han; Ling, Hui; Shen, Shuang-he

    2016-04-15

    Field experiments including one soybean growing season and one winter-wheat growing season were adopted. The experimental field was divided into four equal-area sub-blocks which differed from each other only in tillage managements, which were conventional tillage (T) , no-tillage with no straw cover ( NT) , conventional tillage with straw cover (TS) , and no-tillage with straw cover (NTS). CO₂ and N₂O emission fluxes from soil-crop system were measured by static chamber-gas chromatograph technique. The results showed that: compared with T, in the soybean growing season, NTS significantly increased the cumulative amount of CO₂ (CAC) from soil-soybean system by 27.9% (P = 0.045) during the flowering-podding stage, while NT significantly declined CAC by 28.9% (P = 0.043) during the grain filling-maturity stage. Compared with T, NT significantly declined the cumulative amount of N₂O (CAN) by 28.3% (P = 0.042) during the grain filling-maturity stage. In the winter-wheat growing season, compared with T, TS and NT significantly declined CAC by 24.3% (P = 0.032) and 36.0% (P = 0.041) during the elongation-booting stage, and also declined CAC by 26.8% (P = 0.027) and 33.1% (P = 0.038) during the maturity stage. During the turning-green stage, compared with T treatment, NT, NTS, and TS treatments had no significant effect on CAN, while NTS significant declined CAN by 42.0% (P = 0.035) compared with NT. Our findings suggested that conservation tillage managements had a more significant impact on CO₂ emission than 20 emission from soil-crop system.

  17. Effects of No-tillage Combined with Reused Plastic Film Mulching on Maize Yield and Irrigation Water Productivity

    Directory of Open Access Journals (Sweden)

    SU Yong-zhong

    2016-09-01

    Full Text Available A field experiment was conducted to determine the effects of reused plastic film mulching and no-tillage on maize yield and irriga-tion water productivity(IWP in the marginal oasis in the middle of Hexi Corridor region of northwestern China. The aim is to provide an alternative tillage and cultivation pattern for reducing plastic film pollution, saving cost and increasing income, and improving resource use efficiency. The field experiment was carried out in three soils with different textures and fertility levels. Three treatments for each soil were set up:(1 conventional tillage,winter irrigation, and new plastic mulching cultivation(NM;(2 no tillage, less winter irrigation and reused plastic mulching cultivation (RM;(3 no tillage, less winter irrigation and reused plastic mulching combined with straw mulching (RMS. The results showed that the average daily soil temperature in the two reused plastic mulching treatment(RM and RMS during maize sowing and elongation stage was lower 0.6~1.0℃(5 cm depth and 0.5~0.8℃(15 cm depth than that in the NM. This result suggested that no tillage and reused plastic mulching cultivation still had the effect of increasing soil temperature. Maize grain yield in the RM was reduced by 4.4%~10.6% compared with the conventional cultivation(NM, while the net income increased due to saving in plastic film and tillage ex-penses. There was no significant difference in maize grain yield between the RMS and NM treatment, but the net income in the RMS was in-creased by 12.5%~17.1% than that in the NM. Compared with the NM, the two reused plastic film mulching treatments (RM and RMS decreased the volume of winter irrigation, but maize IWP increased. Soil texture and fertility level affected significantly maize nitrogen uptake and IWP. In the arid oases with the shortage of water resources, cultivation practices of conservation tillage with recycle of plastic film is an ideal option for saving cost and increasing income

  18. Vegetation barrier and tillage effects on runoff and sediment in an alley crop system on a Luvisol in Burkina Faso

    NARCIS (Netherlands)

    Spaan, W.P.; Sikking, A.F.S.; Hoogmoed, W.B.

    2005-01-01

    The effects of vegetation barriers and tillage on runoff and soil loss were evaluated in an alley crop system at a research station in central Burkina Faso. On a 2% slope of a sandy loam various local species (grasses, woody species and a succulent) were planted as conservation barriers in order to

  19. Effect of tillage on water advance and distribution under surge and continuous furrow irrigation methods for cotton in Egypt

    NARCIS (Netherlands)

    Ismail, S.M.

    2006-01-01

    A field experiment was carried out to assess the effect of tillage on water advance and water distribution in the root zone area (0.5 m) under continuous and surge flow irrigation in a cotton field. The experiment was conducted at the Agriculture Experimental Station, Assiut University, Assiut,

  20. Fertilizer placement and tillage effects on phosphorus leaching in fine-textured soils

    Science.gov (United States)

    Adoption of no-tillage in agricultural watersheds has resulted in substantial reductions in sediment and particulate phosphorus (P) delivery to surface waters. No-tillage, however, may result in increased losses of dissolved P in tile-drained landscapes due to the accumulation of P in surface soil l...

  1. Tillage and Water Deficit Stress Effects on Corn (Zea mays, L.) Root Distribution

    Science.gov (United States)

    One goal of soil management is to provide optimum conditions for root growth. Corn root distributions were measured in 2004 from a crop rotation – tillage experiment that was started in 2000. Corn was grown either following corn or following sunflower with either no till or deep chisel tillage. Wate...

  2. Pesticide Interactions with N source and Tillage: Effects on soil biota and ecosystem services

    DEFF Research Database (Denmark)

    Jensen, John; Petersen, Søren O; Elsgaard, Lars

    . This study was planned to evaluate interactions between pesticide use and other soil management factors. The study was carried out within a long-term tillage experiment using two tillage practices (no-till (NT) and mouldboard ploughing (MP), two contrasting N sources (manure and mineral fertiliser), and two...

  3. Emissions of nitrous oxide from Irish arable soils: effects of tillage and reduced N input

    DEFF Research Database (Denmark)

    Abdalla, M.; Jones, M.B.; Ambus, Per

    2010-01-01

    and reduced N fertilizer on seasonal fluxes and emission factors of N2O and to study the relationship between crop yield and N-induced fluxes of N2O. The soil is classified as a sandy loam with a pH of 7.4 and a mean organic carbon and nitrogen content at 15 cm of 19 and 1.9 g kg(-1) dry soil, respectively....... Reduced tillage had no significant effect on N2O fluxes from soils or crop grain yield. Multiple regression analysis revealed that soil moisture and an interaction between soil moisture and soil nitrate are the main significant factors affecting N2O flux. The derived emission factor was 0...... nitrogen fertilizer by 50% compared to the normal field rate, N2O emissions could be reduced by 57% with no significant decrease on grain yield or quality. This was consistent over the 2 years of measurements....

  4. Effect of Tillage Systems and Fertilizer on Quality and Quantity of Marigold (Calendula officinalis L.

    Directory of Open Access Journals (Sweden)

    Reza Tabatabaee

    2017-09-01

    Full Text Available Introduction The marigold is a medicinal plant from Asteraceae family and widely used as a medicinal plant. The marigold extract is widely used in the traditional medicine and herbal therapy. According to previous studies on the medicinal plant in the natural and agricultural ecosystem, using the sustainable agricultural systems provides the best conditions for plant qualitative and quantitative production. So, the global approach in production of products especially medicinal plants is toward using the ecologic management methods in the format of sustainable agricultural systems. The objectives of this experiment were to study on the effect of using the nitrogen chemical fertilizers and the variety of composts in the format of different tillage systems on the leaf area, dry weight, flower yield and the extract yield of marigold plant. Material and methods A field experiment was conducted in order to assessing the effect of conventional farming, ecological management and semi ecological management systems on the dry weight and the height of plant, yield of flower, the percentage of extract and the essence of marigold, in two years of 2013 and 2014 in Fars province, Shiraz in the format of randomized complete block design with 4 replications and 12 treatments. All the data were submitted to an analysis of variance (ANOVA and Least Significant Different test (LSD was used to verify the significant differences among treatment means at the 5% probability level. Results and discussion The results of analysis of variance showed that the effect of different farming systems treatment on vegetative and reproductive growth of marigold were significant (p≤0.01 (Table 3. For example, the highest dry weight and leaf area of marigold were obtained from the conventional tillage system treatment and 165 kg ha-1 urea fertilizer. Furthermore, the highest flower dry weight, the number of flower and flowers harvest index and extract yield of marigold were

  5. Descompactación de suelos franco limosos en siembra directa: efectos sobre las propiedades edáficas y los cultivos Decompaction of no-tillage soils: effects on soil properties and crops

    Directory of Open Access Journals (Sweden)

    Carina R Álvarez

    2009-12-01

    Full Text Available La descompactación mecánica puede mejorar las condiciones físicas de suelos franco limosos que sufren compactación en siembra directa. Los objetivos del presente trabajo fueron: 1-evaluar la influencia de la descompactación mecánica (e.g. paratill o cultivie sobre algunas propiedades físicas y químicas de suelos manejados bajo siembra directa; 2- cuantificar el impacto de la descompactación sobre el rendimiento de maíz; 3-evaluar la perdurabilidad de la descompactación sobre variables físicas edáficas, desarrollo de raíces y rendimiento de los cultivos implantados luego del maíz. Durante la campaña 2006/07 se condujeron seis ensayos de campo en lotes de producción de maíz ubicados en la Pampa Ondulada. Se compararon parcelas apareadas en siembra directa continua (TEST vs. parcelas con pasaje de equipo descompactador a 30 cm (DESC. La resistencia a la penetración disminuyó 37 y 24% (p Mechanical decompaction may improve the physical properties of no-tillage silty loam soils. The aims of this study were to: 1- evaluate the influence of mechanical tilling (e.g. paratill or cultivie on soil physical (gravimetric water content, bulk density, penetration resistance and infiltration rate and chemical (nitrate content properties in no-tillage soils; 2- quantify the impact of soil decompaction on maize yield; and 3- evaluate the persistence of soil compaction alleviation on soil penetration resistance, root abundance and crop yields after maize. Six field experiments were conducted in no-tillage maize plots in the Rolling Pampa region. Paired plots were compared: continuous no tillage (TEST vs. soil compaction alleviation by deep tillage (DESC. Soil penetration resistance decreased by 37and 24 % (p < 0.05 at the 0-25 cm and 0-40 cm soil layers, respectively, and the soil infiltration rate increased (p= 0.07 from TEST to DESC at the V5-V6 maize growing stage. No deep tillage effect was observed on soil bulk density and nitrate content

  6. Effect of pre-sowing soil tillage for wheat on the crop structure and the yield components in Dobrudzha region

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    P. Yankov

    2017-06-01

    Full Text Available Abstract. The investigation was carried out in the trial field of Dobrudzha Agricultural Institute on slightly leached chernozem soil. In order to clarify the effect of some types of pre-sowing soil tillage for wheat on the crop structure and certain yield components, the following variants of a stationary field experiment were analyzed: double disking at depth 10-12 cm (check variant; ploughing at 14-16 cm + disking; no-tillage (direct sowing – pre-sowing treatment of the area with total herbicides. Wheat was sown after previous crop grain maize and was fertilized with N P K . Wheat cultivar Enola was planted at norm 550 germinating 140 120 80 2 seeds/m . The number of emerging wheat plants was read using square sampling frames sized 50 cm x 50 cm. Using the same sampling frames, the tillering in autumn prior to the wintering of the crops was followed, and in spring – prior to booting stage. The number of productive tillers was also read using these sampling frames. To determine the length of spike, the number of grains in it, and their weight, 30 spikes from 8 replications of each variant were analyzed. The emerging of the wheat plants, under the conditions of slightly leached chernozem soil in Dobrudzha region, was more uniform after sowing following disking, and after direct sowing. The minimal pre-sowing tillage and no-tillage for wheat ensured better autumn development of the crop and the plants. In these variants, higher number of overwintering plants and productive tillers per unit area were registered. Spike length was the highest after ploughing as pre-sowing tillage. Significant variations in the number of grains per spike of the investigated variants were not found. Grain weight per spike was the lowest under direct sowing.

  7. Effect of different fertilizer resources on yield and yield components of grain maize (Zea mays L. affected by tillage managements

    Directory of Open Access Journals (Sweden)

    Ahmad Ghasemi

    2016-03-01

    Full Text Available Introduction Due to the development of sustainable agriculture and the reduction of utilizing chemical fertilizers, it is essential to use organic fertilizer. Organic matter is vital to soil fertility and its productivity. To maintain the level of fertility and the strength of soil, organic matter levels should be maintained at an appropriate level. Unfortunately, the level of organic matter in soil is generally less than 1%. One solution to increase the soil’s organic matter content is to use organic fertilizers such as animal manure, green manure, and vermicompost (Nuralvandy, 2011. As a correction factor, green manure can increase water supply and nutrient soil conservation (Tajbakhsh et al., 2005. Materials and methods In order to assess the effects of fertilizer sources (green manure, cow manure, and chemical fertilizer on maize yield and yield components (KSC 704 under tillage management, a field experiment was carried out at Zahak Agricultural and Natural Resource Research Station in two years (from 2013 to 2014. Before corn planting, barley was planted as green manure in the fall of each year. The experiment was conducted as a split plot arranged in a completely randomized block design with three replications. The main plots were tillage and no tillage, whereas the sub plots were: 1-barley green manure (without application of fertilizer, 2-barley green manure with applying 100% chemical fertilizer (NPK to the barley during cultivation, tillering and stemming stages, 3- green manure with 2/3 of chemical fertilizer to the barley and 1/3 to the maize, 4- green manure with 1/3 of chemical fertilizer to the barley and 2/3 to the maize, 5- barley green manure with 50% animal and chemical manures, 6- barley green manure with 40 t ha-1 of animal manure, 7-control (non-fertilizer application. Corn was planted on 15 March each year. Phosphorus, potassium fertilizer, and animal manure were added to the soil as the base fertilizers. At full

  8. Tillage and crop residue management methods had minor effects on the stock and stabilization of topsoil carbon in a 30-year field experiment.

    Science.gov (United States)

    Singh, Pooja; Heikkinen, Jaakko; Ketoja, Elise; Nuutinen, Visa; Palojärvi, Ansa; Sheehy, Jatta; Esala, Martti; Mitra, Sudip; Alakukku, Laura; Regina, Kristiina

    2015-06-15

    We studied the effects of tillage and straw management on soil aggregation and soil carbon sequestration in a 30-year split-plot experiment on clay soil in southern Finland. The experimental plots were under conventional or reduced tillage with straw retained, removed or burnt. Wet sieving was done to study organic carbon and soil composition divided in four fractions: 1) large macroaggregates, 2) small macroaggregates, 3) microaggregates and 4) silt and clay. To further estimate the stability of carbon in the soil, coarse particulate organic matter, microaggregates and silt and clay were isolated from the macroaggregates. Total carbon stock in the topsoil (equivalent to 200 kg m(-2)) was slightly lower under reduced tillage (5.0 kg m(-2)) than under conventional tillage (5.2 kg m(-2)). Reduced tillage changed the soil composition by increasing the percentage of macroaggregates and decreasing the percentage of microaggregates. There was no evidence of differences in the composition of the macroaggregates or carbon content in the macroaggregate-occluded fractions. However, due to the higher total amount of macroaggregates in the soil, more carbon was bound to the macroaggregate-occluded microaggregates in reduced tillage. Compared with plowed soil, the density of deep burrowing earthworms (Lumbricus terrestris) was considerably higher under reduced tillage and positively associated with the percentage of large macroaggregates. The total amount of microbial biomass carbon did not differ between the treatments. Straw management did not have discernible effects either on soil aggregation or soil carbon stock. We conclude that although reduced tillage can improve clay soil structure, generally the chances to increase topsoil carbon sequestration by reduced tillage or straw management practices appear limited in cereal monoculture systems of the boreal region. This may be related to the already high C content of soils, the precipitation level favoring decomposition and

  9. Effects of soil tillage on the energy budget of soybean (Glycine max (L.) Merr.)

    International Nuclear Information System (INIS)

    Casa, R.; Cascio, B. lo

    1997-01-01

    The different terms of the energy budget were measured by the Bowen ratio method on soybean (Glycine max (L.) Merr.) grown on a conventional tillage and a direct drilling system. The differences found in the energy budgets varied according to the degree of fractional ground cover and of soil water availability. Soil heat flux was greater for the direct drilling treatment, although soil heating was slower as compared to the conventional tillage. Comparisons for well watered and dry conditions revealed that the conventional tillage system used as latent heat a fraction of net radiation greater than the direct drilling treatment only in well watered conditions. In dry conditions the differences in latent heat fluxes and canopy resistances between the two tillage systems were smaller [it

  10. Effects of tillage during the nonwaterlogged period on nitrous oxide and nitric oxide emissions in typical Chinese rice-wheat rotation ecosystems

    Science.gov (United States)

    Yao, Zhisheng; Zhou, Zaixing; Zheng, Xunhua; Xie, Baohua; Liu, Chunyan; Butterbach-Bahl, Klaus; Zhu, Jianguo

    2010-03-01

    Tillage practices result in major changes to soil environmental conditions and to the distribution of crop residues and nutrients in the soil profile, which may consequently affect the biogenic production and emission of N trace gases. To investigate the effects of tillage during the nonwaterlogged period on nitric oxide (NO) and nitrous oxide (N2O) emissions in rice-wheat rotation systems, we performed field experiments at three sites (Suzhou, Wuxi, and Jiangdu) in the Yangtze River Delta using static chamber techniques. The results showed that the effect of tillage on the emissions of both gases differed among the three field sites due to differences in agricultural management and soil texture. At the site with a light soil texture (Jiangdu: sandy loam), no tillage resulted in reduced NO emissions (0.5 kg N ha-1) as compared to conventionally tilled fields (0.9 kg N ha-1; p tillage plots showed significantly higher emissions (p tillage resulted in lower NO and higher N2O emissions from either N fertilized or unfertilized fields even though these results were not statistically significant. In the silty clay loam soils (Suzhou), which showed the highest soil organic carbon contents and the highest rates of N trace gas emissions in all three of the investigated sites, reduced tillage resulted in much higher NO emissions, whereas N2O emissions were not obviously influenced by tillage practices (reduced tillage versus tillage: NO, 9.5 versus 5.4 kg N ha-1; N2O, 10.6 versus 9.0 kg N ha-1). Similar effects of tillage were observed for the direct emission factors of the applied N during the wheat season. The observed emission factors for the different sites ranged from 0.3% to 2.4% for N2O (mean: 1.0%) and from 0.1% to 4.0% (mean: 0.9%) for NO, respectively. The observed site-to-site differences in emission factors are most likely the results of variations in soil properties (such as texture and pH) and agricultural practices (such as tillage and crop residue management

  11. Effects of Tillage Methods on Some Soil Physical Properties, Growth and Yield of Water Melon in a Semi-Arid Region of Nigeria

    Directory of Open Access Journals (Sweden)

    A. Dauda

    2017-02-01

    Full Text Available An appropriate tillage method is necessary to create an optimum seed bed condition for optimum crop growth and yield. Two-year field experiment was conducted in 2013 and 2014 to investigate the effects of different tillage methods on the physical properties of sandy loam soil, growth and yield of water melon (Citrullus vulgaris in a semi-arid environment. The Tillage treatments were disc ploughing plus disc harrowing (DP+DH, double disc ploughing (DDP, double disc harrowing (DDH, disc ploughing (DP and disc harrowing (DH as minimum tillage (MT and zero tillage (ZT and direct drilling method (control. The watermelon seeds were Planted manually placing three (3 seeds per hole at an interval of 1.5m along the rows and 50cm between the rows at an average depth of 5cm. The treatments were laid in a randomized complete block design (RCBD with four replications. Results showed that disc ploughing + disc harrowing (DP+DH was found to be more appropriate and profitable tillage method in improving soil physical properties and growth and yield of water melon in a sandy loam soil. Watermelon yield, fruit weight (FW, fruit length (FL, fruit diameter (FD and leaf area index (LAI were significantly influenced (P=0.05, but influence of tillage treatments were not significant on the number of fruit per plant (NFPP. A numerical value of 31.0t/ha, 26.0, 5.4kg, 29.0cm, and 33.8cm were recorded for maximum crop yield, NFPP, FW, FD and FL respectively in DP+DH-treated plots. For zero tillage (ZT treatment, maximum of crop yield and NFPP were 26.5t/ha and 20.0 respectively. Thus for enhanced growth and yield of watermelon, DP/DH would be more preferable. The orthodox method of zero tillage is out rightly discouraged

  12. Effect of various tillage practices on soil properties and maize growth

    International Nuclear Information System (INIS)

    Leghari, N.

    2016-01-01

    Appropriate tillage practices are vital for good tilth that is pre-requisite for aggregate formation, soil aeration, better root development and plant growth. A field experiment of maize was carried out at the experimental site of Sindh Agriculture University Tandojam during two consecutive growing seasons 2009 and 2010. A randomized complete block design with three treatment conventional tillage (CT), reduced tillage (RT) and no tillage (NT) was used in the study. Significant differences between tillage treatments were observed in the soil properties, growth and root development of plants. The NT treatment retained higher soil water contents (15.8 and 16.0%) measured at 0-20 cm depth during 2009 and 2010, respectively. Likewise, the soil bulk density (1.4 and 1.4 cm-3) was higher at this depth consequently; it resulted in greater soil strength (81 N m-2 and 79 N m-2) during 2009 and 2010, respectively. The negative and significant correlations were recorded between root dry weight and soil strengths. On the other hand, positive and significant relationship of root dry weight with mean total dry matter production and LAI was observed. Moreover, the root development related observations were significantly enhanced under CT as compared to RT and NT treatments. The results indicate that conventional tillage improve maize growth and root development by improving soil properties. (author)

  13. Evaluation of Tillage, Residue Management and Nitrogen Fertilizer Effects on CO2 Emission in Maize (Zea Mays L. Cultivation

    Directory of Open Access Journals (Sweden)

    Rooholla Moradi

    2016-02-01

    Full Text Available Introduction: The latest report of the Intergovernmental Panel on Climate Change (IPCC states that future emissions of greenhouse gases (GHGs will continue to increase and cause climatic change (16. These conditions are also true for Iran. The three greenhouse gases associated with agriculture are carbon dioxide (CO2, methane (CH4, and nitrous oxide (N2O. The three GHGs associated with agriculture CO2, CH4, and N2O differ in their effectiveness in trapping heat and in their turnover rates in the atmosphere. This environmental change will have serious impacts on different growth and development processes of crops. Increasing temperature could affect physiological processes such as photosynthesis, respiration and partitioning of photoassimilates. Farmers are not able to change or manage the climatic conditions, but some factors such as soil, water, seed and agricultural practices can be managed to reduce the adverse impacts of climate change (32. Mitigation and adaptation are two known ways for reducing the negative impacts of climate change. Mitigation strategies are associated with decreasing greenhouse gas (GHG emissions through management practices such as reducing chemical fertilizer application, mechanization, increasing carbon storage in agroecosystems, planting biofuel crops and moving towards organic farming (42, etc. Material and Methods: This study was carried out at the experimental field of the Ferdowsi University of Mashhad in 2011 and was repeated in 2012. The Research Station (36°16´N, 59°36´E is located at about 985 m a.s.l. Average temperature and precipitation rate of the research station in two years are shown in Figure. 1. The three-factor experiment was set up in a strip-split-plot arranged in a randomized complete block design with three replications. The experimental treatments were tillage systems (conventional and reduced tillage and residual management (remaining and leaving of maize residual assigned to main plots

  14. Effects of Long-term Conservation Tillage on Soil Nutrients in Sloping Fields in Regions Characterized by Water and Wind Erosion

    Science.gov (United States)

    Tan, Chunjian; Cao, Xue; Yuan, Shuai; Wang, Weiyu; Feng, Yongzhong; Qiao, Bo

    2015-12-01

    Conservation tillage is commonly used in regions affected by water and wind erosion. To understand the effects of conservation tillage on soil nutrients and yield, a long-term experiment was set up in a region affected by water and wind erosion on the Loess Plateau. The treatments used were traditional tillage (CK), no tillage (NT), straw mulching (SM), plastic-film mulching (PM), ridging and plastic-film mulching (RPM) and intercropping (In). Our results demonstrate that the available nutrients in soils subjected to non-traditional tillage treatments decreased during the first several years and then remained stable over the last several years of the experiment. The soil organic matter and total nitrogen content increased gradually over 6 years in all treatments except CK. The nutrient content of soils subjected to conservative tillage methods, such as NT and SM, were significantly higher than those in soils under the CK treatment. Straw mulching and film mulching effectively reduced an observed decrease in soybean yield. Over the final 6 years of the experiment, soybean yields followed the trend RPM > PM > SM > NT > CK > In. This trend has implications for controlling soil erosion and preventing non-point source pollution in sloping fields by sacrificing some food production.

  15. Long-term rotation and tillage effects on soil structure and crop yield

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Heck, R; Deen, B

    2013-01-01

    long-term rotation and tillage treatment experiment on a Canadian silt loam soil. Topsoil measurements were carried out for three different rotations: R1, (C–C–C–C) continuous corn (Zea mays L.), R6, (C–C–O(RC), B(RC)) corn, corn, oats (Avena fatua L.) and spring barley (Hordeum vulgare L.) and R8, (C......–C–S–S) corn, corn, soybean (Glycine max L.), soybean. A red clover (Trifolium pretense L.) cover crop was under seeded in oats and spring barley in R6. In 2010, first year corn was grown in R6 and R8. The tillage treatments included no tillage, NT and mouldboard ploughing, MP. Topsoil structural quality...

  16. Effects of 24 Years of Conservation Tillage Systems on Soil Organic Carbon and Soil Productivity

    Directory of Open Access Journals (Sweden)

    Kenneth R. Olson

    2013-01-01

    Full Text Available The 24-year study was conducted in southern Illinois (USA on land similar to that being removed from Conservation Reserve Program (CRP to evaluate the effects of conservation tillage systems on: (1 amount and rates of soil organic carbon (SOC storage and retention, (2 the long-term corn and soybean yields, and (3 maintenance and restoration of soil productivity of previously eroded soils. The no-till (NT plots did store and retain 7.8 Mg C ha−1 more and chisel plow (CP −1.6 Mg C ha−1 less SOC in the soil than moldboard plow (MP during the 24 years. However, no SOC sequestration occurred in the sloping and eroding NT, CP, and MP plots since the SOC level of the plot area was greater at the start of the experiment than at the end. The NT plots actually lost a total of −1.2 Mg C ha−1, the CP lost −9.9 Mg C ha−1, and the MP lost −8.2 Mg C ha−1 during the 24-year study. The long-term productivity of NT compared favorably with that of MP and CP systems.

  17. Effect of Tillage in Day or Night and Application of Reduced Dosage of Imazethapyr and Trifluralin on Weed Control, Yield and Yield Components of Chickpea

    Directory of Open Access Journals (Sweden)

    A Abbasian

    2015-07-01

    Full Text Available This Experiment was arranged as a strip-plot on the base of a completely randomized block design with three replications to study the effect of tillage (whether in day or night or in day by light-proof cover and application of reduced dosage of imazethapyr and trifluralin on weed control, yield and yield components of chickpea. Main plots consisted of tillage methods and subplots consisted of trifluralin (at doses of 480, 960 and 1440 g ai /ha and imazethapyr (at doses of 50, 100 and 150 g ai /ha, plus weed free and weedy checks. Results showed weed biomass in day tillage, night tillage and in light-proof cover tillage were respectively 86, 127 and 148 g m-2. Therefore tillage at night or by light-proof cover in day time showed not enough efficiency in weed control. Weed biomass increased when application dose of herbicides decreased. Chickpea grain yield showed significant differences when different doses of herbicides applied. The minimum and the maximum seed yield were obtained respectively in weed free (by 208 g m-2 and weedy checks (by 123 g m-2. Reduced dosage of imazethapyr and trifluralin could control weeds good enough by no significant decrease in chickpea yield. Efficacy of imazethapyr to control weeds grown in chickpea was significantly better than that of trifluralin

  18. Sediment yield control in vineyards covered with cereal. Effect of tillage

    International Nuclear Information System (INIS)

    Ruiz-Colmenero, M.; Bienes, R.; Marques, M. J.

    2009-01-01

    A study has been carried out about the use of plant cover treatment to avoid land degradation in a hillside rainfed vineyard in Madrid under Mediterranean semiarid climate. Three treatments were tested: traditional tillage (lab) soil covered by Brachypodium distrachyon (bra) with self-sowing, soil covered by Scale cereale (sec) mown in Spring. Three erosion plots per treatment were placed in the middle of the strips and 2 simulated rainfalls were carried out at each plot in autumn, before and after the tillage. (Author) 7 refs.

  19. Effects of tropical ecosystem engineers on soil quality and crop performance under different tillage and residue management

    Science.gov (United States)

    Pulleman, Mirjam; Paul, Birthe; Fredrick, Ayuke; Hoogmoed, Marianne; Hurisso, Tunsisa; Ndabamenye, Telesphore; Saidou, Koala; Terano, Yusuke; Six, Johan; Vanlauwe, Bernard

    2014-05-01

    Feeding a future global population of 9 billion will require a 70-100% increase in food production, resulting in unprecedented challenges for agriculture and natural resources, especially in Sub-saharan Africa (SSA). Agricultural practices that contribute to sustainable intensification build on beneficial biological interactions and ecosystem services. Termites are the dominant soil ecosystem engineers in arid to sub-humid tropical agro-ecosystems. Various studies have demonstrated the potential benefits of termites for rehabilitation of degraded and crusted soils and plant growth in semi-arid and arid natural ecosystems. However, the contribution of termites to agricultural productivity has hardly been experimentally investigated, and their role in Conservation Agriculture (CA) systems remains especially unclear. Therefore, this study aimed to quantify the effects of termites and ants on soil physical quality and crop productivity under different tillage and residue management systems in the medium term. A randomized block trial was set up in sub-humid Western Kenya in 2003. Treatments included a factorial combination of residue retention and removal (+R/-R) and conventional and reduced tillage (+T/-T) under a maize (Zea mays L.) and soybean (Glyxine max. L.) rotation. A macrofauna exclusion experiment was superimposed in 2005 as a split-plot factor (exclusion +ins; inclusion -ins) by regular applications of pesticides (Dursban and Endosulfan) in half of the plots. Macrofauna abundance and diversity, soil aggregate fractions, soil carbon contents and crop yields were measured between 2005 and 2012 at 0-15 cm and 15-30 cm soil depths. Termites were the most important macrofauna species, constituting between 48-63% of all soil biota, while ants were 13-34%, whereas earthworms were present in very low numbers. Insecticide application was effective in reducing termites (85-56% exclusion efficacy) and earthworms (87%), and less so ants (49-81%) at 0-15 cm soil depth

  20. Effect of N fertilization and tillage on nitrous oxide (N2O) loss from soil under wheat production

    Science.gov (United States)

    Bansal, Sheel; Aberle, Ezra; Teboh, Jasper; Yuja, Szilvia; Liebig, Mark; Meier, Jacob; Boyd, Alec

    2017-01-01

    Nitrous oxide (N2O-N) is one of the most important gases in the atmosphere because it is 300 times more powerful than carbon dioxide in its ability to trap heat, and is a key chemical agent of ozone depletion. The amount of N2O-N emitted from agricultural fields can be quite high, depending on the complex interplay between N fertility and residue management, plant N uptake, microbial processes, environmental conditions, and wet-up and dry-down events. High N fertilizer rates generally increase yields, but may disproportionately increase N2O-N losses due to prolonged residence time in soil when not used by the crop, and incomplete decomposition of excess N-compounds by microbes. Tillage could also affect N2O-N losses through changes in soil moisture content. Though nitrogen monoxide (NO) is one form of N lost from the soil, especially under conventional tillage, this study objective was to quantify N2O loss in wheat fields from applied urea on soil under no-till (NT) versus incorporated urea under conventional till (CT).

  1. The Effect of Tillage on Organic Carbon Stabilization in Microaggregates in Different Climatic Zones of European Russia

    Directory of Open Access Journals (Sweden)

    Zinaida S. Artemyeva

    2016-12-01

    Full Text Available Tillage may affect the microstructural organization of soil, including the distribution of microaggregates with different mechanical strengths. We quantified the impact of tillage treatment on the amount and distribution of free organic matter, microaggregates (unstable and stable under low intensity sonification and their components, in the upper horizons of zonal soils of the Center of the Russian Plain. Under plowing, the carbon content decreases, both in unstable and stable microaggregates. The loss of carbon in unstable microaggregates was ~24%, whereas in stable microaggregates, it was ~37%, relative to native soils. The carbon content of organic (LFoc and organo-clay (Clayrd fractions in unstable microaggregates (CLFoc/CClayrd was almost identical in the upper horizons of native soils: the ratio of these components is for Albeluvisols (1.1, Phaeozem (0.8 and Chernozems (1.0. Under plowing, these decrease to: Albeluvisols and Chernozems (0.6 and Phaeozem (0.5. The shares of carbon accumulated within the unstable and stable microaggregates (Cunstable/Cstable are constant under equilibrium conditions and show a tendency to decrease from north to south on the order of: Albeluvisols and Phaeozem (2.2 > Chernozems (1.0. Under plowing, they increase to: Albeluvisols (3.0 and Phaeozem (3.2 > Chernozems (1.5.

  2. Effects of tillage operations and plant density on leaf spot disease ...

    African Journals Online (AJOL)

    Two seasons experiments conducted in 2002 and 2003 revealed that Tillage operations significantly influenced leafspot disease severity; Percentage lodging 3.14; 2.08 and Grain yield 3.02; 3.84 in 2002 and 2003 respectively. Plant density also had significant difference on leafspot disease severity; Percentage lodging ...

  3. Tillage effects on soil quality after three years of irrigation in Northern Spain

    Science.gov (United States)

    Irrigation is being initiated on large areas of traditionally rainfed land to meet increasing global demand for food, feed, fiber, and fuel. However, the consequences of this transition on soil quality (SQ) have scarcely been studied. Therefore, after previously identifying the most tillage-sensitiv...

  4. Effect of inoculum density and soil tillage on the development and severity of rhizoctonia root rot.

    Science.gov (United States)

    Schroeder, K L; Paulitz, T C

    2008-03-01

    Rhizoctonia spp. cause substantial yield losses in direct-seeded cereal crops compared with conventional tillage. To investigate the mechanisms behind this increased disease, soils from tilled or direct-seeded fields were inoculated with Rhizoctonia spp. at population densities from 0.8 to 250 propagules per gram and planted with barley (Hordeum vulgare). The incidence and severity of disease did not differ between soils with different tillage histories. Both R. solani AG-8 and R. oryzae stunted plants at high inoculum densities, with the latter causing pre-emergence damping-off. High inoculum densities of both species stimulated early production of crown roots in barley seedlings. Intact soil cores from these same tilled and direct-seeded fields were used to evaluate the growth of Rhizoctonia spp. from colonized oat seeds. Growth of R. oryzae was not affected by previous tillage history. However, R. solani AG-8 grew more rapidly through soil from a long-term direct-seeded field compared to tilled soils. The differential response between these two experiments (mixed, homogenized soil versus intact soil) suggests that soil structure plays a major role in the proliferation of R. solani AG-8 through soils with different tillage histories.

  5. Effects of the Tillage Technology and the Forecrop on Weeds in Stands of Winter Wheat

    Directory of Open Access Journals (Sweden)

    Jan Winkler

    2015-01-01

    Full Text Available The semipilot-scale field experiment was established in the cadastre of the village Letkovice in the South Moravian Region (Czech Republic. The study area was situated in a warm climatic region T2. Winter wheat was cultivated in two variants of tillage, viz. conventional tillage (CT and minimum tillage (MT and after three different forecrops (fodder beet, late potatoes, and broad (faba bean. Weed infestation of wheat stands was evaluated in spring seasons of 2007 and 2008, always before the application of herbicides. Numbers of weed specimens and their species were defined by means of a calculation method. Recorded data were processed by means of multidimensional analyses of ecological data, viz. Data Correspondence Analysis (DCA and Redundancy Analysis (RDA. Within the study period, altogether 22 weed species were identified in all variants with different tillage technologies and different forecrops. In the MT variant, the degree of winter wheat stand infestation with weeds was lower. As far as the forecrops were concerned, the most and the least intensive degrees of infestation were recorded on plots with faba bean and late potatoes, respectively.

  6. 35-40 The Effect of Tillage Frequency and Weed Control on Yield of ...

    African Journals Online (AJOL)

    The objective of the experiment was to determine the optimum tillage frequency, time and weeding frequency for tef production in the Yielmana ... post-harvest management cost, low risk crop and the straw provides better animal feed than ..... Kalyani publishers, New Delhi- 110 002, India. Rezene, F. and Zerihun, T. 2001.

  7. Effect of tillage on the efficacy of CGA362622 on weed control in maize

    African Journals Online (AJOL)

    STORAGESEVER

    2008-12-03

    Dec 3, 2008 ... time and resources managing weeds. Tillage alone or in combination with good cropping methods is ... help in managing herbicide resistance weeds and may also increase weed density as well as reduce crop yield .... This change in weed compo- sition agrees with Richley et al. (1977) indicating shift.

  8. The effects of mulching, tillage, and herbicides on weed control and watermelon yield

    Science.gov (United States)

    Currently few producers in the Southeast US have adopted conservation tillage practices in specialty crop production. The lack of conservation adoption is likely due to the added challenges in producing vegetables in cover crop residues, especially high biomass cover crop systems. The objective of t...

  9. Impact of agronomy practices on the effects of reduced tillage systems on CH4 and N2O emissions from agricultural fields: A global meta-analysis.

    Science.gov (United States)

    Feng, Jinfei; Li, Fengbo; Zhou, Xiyue; Xu, Chunchun; Ji, Long; Chen, Zhongdu; Fang, Fuping

    2018-01-01

    The effect of no- and reduced tillage (NT/RT) on greenhouse gas (GHG) emission was highly variable and may depend on other agronomy practices. However, how the other practices affect the effect of NT/RT on GHG emission remains elusive. Therefore, we conducted a global meta-analysis (including 49 papers with 196 comparisons) to assess the effect of five options (i.e. cropping system, crop residue management, split application of N fertilizer, irrigation, and tillage duration) on the effect of NT/RT on CH4 and N2O emissions from agricultural fields. The results showed that NT/RT significantly mitigated the overall global warming potential (GWP) of CH4 and N2O emissions by 6.6% as compared with conventional tillage (CT). Rotation cropping systems and crop straw remove facilitated no-tillage (NT) to reduce the CH4, N2O, or overall GWP both in upland and paddy field. NT significantly mitigated the overall GWP when the percentage of basal N fertilizer (PBN) >50%, when tillage duration > 10 years or rainfed in upland, while when PBN agronomy practices and land use type.

  10. Effect of cover crops on emergence and growth of carrot (Daucus carota L. in no-plow and traditional tillage

    Directory of Open Access Journals (Sweden)

    Marzena Błażewicz-Woźniak

    2015-03-01

    Full Text Available The aim of the experiment was to determine the influence of cover crop biomass incorporated into the soil at different times and using different treatments on carrot emergence and growth. 7 species of cover crops were included in the study: Secale cereale, Avena sativa, Vicia sativa, Sinapis alba, Phacelia tanacetifolia, Fagopyrum esculentum, and Helianthus annuus.  Number of emerged carrot plants significantly depended on the cover crop used and on the method of pre-winter and spring pre-sowing tillage. Carrot emerged best after a rye or oats cover crop. Regardless of the cover crop species used, the largest number of carrots emerged in cultivation on ridges. In other variants of no-plow tillage, number of seedlings was significantly lower and did not differ from that under traditional plow tillage. The highest leaf rosettes were formed by carrot growing after a rye or oats cover crop. The highest rosettes were produced by carrots in the treatments where tillage was limited to the use of a tillage implement in spring and the lowest ones after pre-winter plowing. The effect of tillage on the emergence and height of carrot leaves largely depended on weather conditions in the successive years of the study. The largest number of leaves was found in carrots grown after a buckwheat cover crop and in cultivation without cover crop, while the smallest one after phacelia and white mustard. Carrots produced the largest number of leaves after a sunflower cover crop and the use of a tillage implement in spring, while the number of leaves was lowest when the mustard biomass was incorporated into the soil in spring. The use of cover crops significantly increased the mass of leaves produced by carrot as compared to the cultivation without cover crop. The largest mass of leaves was produced by carrots grown after the phacelia and mustard cover crops. Conventional plow tillage and pre-winter tillage using a stubble cultivator promoted an increase in the mass

  11. The Effects of Different Tillage Systems on Soil Hydrology and Erosion in Southeastern Brazil

    Science.gov (United States)

    Bertolino, A. V. F. A.; Fernandes, N. F.; Souza, A. P.; Miranda, J. P.; Rocha, M. L.

    2009-04-01

    Conventional tillage usually imposes a variety of modifications on soil properties that can lead to important changes in the type and magnitude of the hydrological processes that take place at the upper portion of the soil profile. Plough pan formation, for example, is considered to be an important consequence of conventional tillage practices in southeastern Brazil, decreasing infiltration rates and contributing to soil erosion, especially in steep slopes. In order to characterize the changes in soil properties and soil hydrology due to the plough pan formation we carried out detailed investigations in two experimental plots in Paty do Alferes region, located in the hilly landscape of Serra do Mar in southeastern Brazil, close to Rio de Janeiro city. Farming activities are very important in this area, in particular the ones related to the tomato production. The local hilly topography with short and steep hillslopes, as well as an average annual rainfall of almost 2000 mm, favor surface runoff and the evolution of rill and gully erosion. The two runoff plots are 22m long by 4m wide and were installed side by side along a representative hillslope, both in terms of soil (Oxisol) and steepness. At the lower portion of each plot there is a collecting trough connected by a PVC pipe to a 500 and 1000 liters sediment storage boxes. Soil tillage treatments used in the two plots were: Conventional Tillage (CT), with one plowing using disc-type plow (about 18 cm depth) and one downhill tractor leveling, in addition to burning residues from previous planting; and Minimum Tillage (MT), which did not allow burning residues from previous planting and preserved a vegetative cover between plantation lines. Runoff and soil erosion measurements were carried out in both plots immediately after each rainfall event. In order to characterize soil water movements under the two tillage systems (CT and MT), 06 nests of tensiometers and 04 nests of Watermark sensors were installed in each

  12. Effects of tillage practice and atmospheric CO2 level on soil CO2 efflux

    Science.gov (United States)

    Elevated atmospheric carbon dioxide (CO2) affects both the quantity and quality of plant tissues, which impacts the cycling and storage of carbon (C) within plant/soil systems and thus the rate of CO2 release back to the atmosphere. Research to accurately quantify the effects of elevated CO2 and as...

  13. Temperature and water pressure head effects on the degradation of the diketonitrile metabolite of isoxaflutole in a loamy soil under two tillage systems

    Energy Technology Data Exchange (ETDEWEB)

    Alletto, Lionel [Universite de Toulouse - Ecole d' ingenieurs de Purpan, Agronomy Department, 75, voie du TOEC BP 57 611, 31 076 Toulouse Cedex 3 (France); UMR 1091 INRA/AgroParisTech Environment and Arable Crops, Institut National de la Recherche Agronomique/Institut National des Sciences et Industries du Vivant et de l' Environnement, BP 01, 78 850 Thiverval-Grignon (France)], E-mail: lionel.alletto@purpan.fr; Benoit, Pierre [UMR 1091 INRA/AgroParisTech Environment and Arable Crops, Institut National de la Recherche Agronomique/Institut National des Sciences et Industries du Vivant et de l' Environnement, BP 01, 78 850 Thiverval-Grignon (France)], E-mail: benoit@grignon.inra.fr; Bergheaud, Valerie [UMR 1091 INRA/AgroParisTech Environment and Arable Crops, Institut National de la Recherche Agronomique/Institut National des Sciences et Industries du Vivant et de l' Environnement, BP 01, 78 850 Thiverval-Grignon (France)], E-mail: bergheau@grignon.inra.fr; Coquet, Yves [UMR 1091 INRA/AgroParisTech Environment and Arable Crops, Institut National de la Recherche Agronomique/Institut National des Sciences et Industries du Vivant et de l' Environnement, BP 01, 78 850 Thiverval-Grignon (France)], E-mail: Yves.Coquet@agroparistech.fr

    2008-12-15

    Laboratory studies were conducted to evaluate the effects of temperature and water pressure head on the degradation of the diketonitrile metabolite (DKN) of isoxaflutole during 84 d in samples collected in a loamy soil under conventional (CT) and conservation (MT) tillage systems. Soil temperature was the major factor controlling DKN degradation in the two tillage systems. The shortest half-lives (T{sub 1/2}) were measured in the seedbed samples under MT at 25 deg. C and -33 cm water pressure head. We found that mouldboard ploughing under CT was responsible for the spatial variability of herbicide degradation properties, whereas under MT herbicide degradation was associated to the vertical distribution of organic matter. - Tillage practices influence the spatial variability of diketonitrile degradation in soil and its sensitivity to pedoclimatic conditions.

  14. Temperature and water pressure head effects on the degradation of the diketonitrile metabolite of isoxaflutole in a loamy soil under two tillage systems

    International Nuclear Information System (INIS)

    Alletto, Lionel; Benoit, Pierre; Bergheaud, Valerie; Coquet, Yves

    2008-01-01

    Laboratory studies were conducted to evaluate the effects of temperature and water pressure head on the degradation of the diketonitrile metabolite (DKN) of isoxaflutole during 84 d in samples collected in a loamy soil under conventional (CT) and conservation (MT) tillage systems. Soil temperature was the major factor controlling DKN degradation in the two tillage systems. The shortest half-lives (T 1/2 ) were measured in the seedbed samples under MT at 25 deg. C and -33 cm water pressure head. We found that mouldboard ploughing under CT was responsible for the spatial variability of herbicide degradation properties, whereas under MT herbicide degradation was associated to the vertical distribution of organic matter. - Tillage practices influence the spatial variability of diketonitrile degradation in soil and its sensitivity to pedoclimatic conditions

  15. Effects of N Fertilizer Sources and Tillage Practices on NH3 Volatilization, Grain Yield, and N Use Efficiency of Rice Fields in Central China.

    Science.gov (United States)

    Liu, Tianqi; Huang, Jinfeng; Chai, Kaibin; Cao, Cougui; Li, Chengfang

    2018-01-01

    Tillage practices and nitrogen (N) sources are important factors affecting rice production. Few studies, however, have examined the interactions between tillage practices and N fertilizer sources on NH 3 volatilization, nitrogen use efficiency (NUE), and rice grain yield. This study aimed to investigate the effects of N fertilizer sources (no N fertilizer, inorganic N fertilizer, organic N fertilizer alone, organic N fertilizer plus inorganic N fertilizer, and slow-release N fertilizer plus inorganic N fertilizer) and tillage practices (no-tillage [NT] and conventional intensive tillage [CT]) on NH 3 flux, grain yield, and NUE in the rice field of central China. N sources significantly affected NH 3 volatilization, as the cumulative volatilization from the treatments of inorganic N fertilizer, organic N fertilizer, organic N fertilizer plus inorganic N fertilizer, slow-release N fertilizer plus inorganic N fertilizer was 4.19, 2.13, 3.42, and 2.23 folds in 2013, and 2.49, 1.68, 2.08, and 1.85 folds in 2014 compared with that under no N fertilizer treatment, respectively. The organic N fertilizer treatment had the lowest grain yield and NUE among all N fertilizer treatments, while slow-release N fertilizer plus inorganic N fertilizer treatment led to relatively higher grain yield and the greatest N use efficiency. Moreover, NT only markedly increased NH 3 volatilization from basal fertilizer by 10-14% in average compared with CT, but had no obvious effects on total volatilization during the whole seasons. Tillage practices had no significant effects on grain yield and NUE. Our study suggested that the combination of slow-release N fertilizer plus inorganic N fertilizer and NT might be a sustainable method for mitigating greenhouse gas and NH 3 emissions and improving grain yield and NUE in paddy fields of central China.

  16. Effects of N Fertilizer Sources and Tillage Practices on NH3 Volatilization, Grain Yield, and N Use Efficiency of Rice Fields in Central China

    Directory of Open Access Journals (Sweden)

    Tianqi Liu

    2018-03-01

    Full Text Available Tillage practices and nitrogen (N sources are important factors affecting rice production. Few studies, however, have examined the interactions between tillage practices and N fertilizer sources on NH3 volatilization, nitrogen use efficiency (NUE, and rice grain yield. This study aimed to investigate the effects of N fertilizer sources (no N fertilizer, inorganic N fertilizer, organic N fertilizer alone, organic N fertilizer plus inorganic N fertilizer, and slow-release N fertilizer plus inorganic N fertilizer and tillage practices (no-tillage [NT] and conventional intensive tillage [CT] on NH3 flux, grain yield, and NUE in the rice field of central China. N sources significantly affected NH3 volatilization, as the cumulative volatilization from the treatments of inorganic N fertilizer, organic N fertilizer, organic N fertilizer plus inorganic N fertilizer, slow-release N fertilizer plus inorganic N fertilizer was 4.19, 2.13, 3.42, and 2.23 folds in 2013, and 2.49, 1.68, 2.08, and 1.85 folds in 2014 compared with that under no N fertilizer treatment, respectively. The organic N fertilizer treatment had the lowest grain yield and NUE among all N fertilizer treatments, while slow-release N fertilizer plus inorganic N fertilizer treatment led to relatively higher grain yield and the greatest N use efficiency. Moreover, NT only markedly increased NH3 volatilization from basal fertilizer by 10–14% in average compared with CT, but had no obvious effects on total volatilization during the whole seasons. Tillage practices had no significant effects on grain yield and NUE. Our study suggested that the combination of slow-release N fertilizer plus inorganic N fertilizer and NT might be a sustainable method for mitigating greenhouse gas and NH3 emissions and improving grain yield and NUE in paddy fields of central China.

  17. Long term effects of different tillage systems influencing yield and energy efficiency in maize (Zea mays L.)

    OpenAIRE

    Momirović, Nebojša; Dolijanović, Željko; Oljača, Mićo V.; Videnović, Živorad

    2011-01-01

    Adoption and improvement of different tillage systems toward agricultural sustainability has a great social, economical and environmental impact. The base of sustainability is a system productivity as ratio of output to input in a given system, measured in the same units, commonly as energy requirements. The objective of this study was to evaluate the aspect of energy requirements in the different soil tillage systems regarding total energy consumption under conventional tillage. The appropri...

  18. Effects of Conservation Tillage on Topsoil Microbial Metabolic Characteristics and Organic Carbon within Aggregates under a Rice (Oryza sativa L.) –Wheat (Triticum aestivum L.) Cropping System in Central China

    Science.gov (United States)

    Liu, Tian-Qi; Cao, Cou-Gui; Li, Cheng-Fang

    2016-01-01

    Investigating microbial metabolic characteristics and soil organic carbon (SOC) within aggregates and their relationships under conservation tillage may be useful in revealing the mechanism of SOC sequestration in conservation tillage systems. However, limited studies have been conducted to investigate the relationship between SOC and microbial metabolic characteristics within aggregate fractions under conservation tillage. We hypothesized that close relationships can exist between SOC and microbial metabolic characteristics within aggregates under conservation tillage. In this study, a field experiment was conducted from June 2011 to June 2013 following a split-plot design of a randomized complete block with tillage practices [conventional intensive tillage (CT) and no tillage (NT)] as main plots and straw returning methods [preceding crop residue returning (S, 2100−2500 kg C ha−1) and removal (NS, 0 kg C ha-1)] as subplots with three replications. The objective of this study was to reveal the effects of tillage practices and residue-returning methods on topsoil microbial metabolic characteristics and organic carbon (SOC) fractions within aggregates and their relationships under a rice–wheat cropping system in central China. Microbial metabolic characteristics investigated using the Biolog system was examined within two aggregate fractions (>0.25 and 0.25 aggregate, and 0.25 mm aggregate (11.3%), and 0.25 mm aggregate, and 0.25 mm aggregate, and tillage (NT and S) increased microbial metabolic activities and Shannon index in >0.25 and directly improved SOC by promoting DOC in >0.25 mm aggregate in the upper (0−5 cm) soil layer under conservation tillage systems, as well as directly and indirectly by promoting DOC and MBC in tillage increased SOC in aggregates in the topsoil by improving microbial metabolic activities. PMID:26731654

  19. The Effects of Different Tillage Methods on Available Soil Potassium Measured by Various Extractors in a Soil with High Specific Surface Area

    Directory of Open Access Journals (Sweden)

    M. Hosseini

    2016-02-01

    Full Text Available Introduction: The effects of any tillage method on soil properties, depends on location (soil, water and air and the number of (years their implementation. Soil compaction reduces yield through increased soil mechanical resistance against root growth and lower water and nutrient use efficiency (Gamda et al. 18 & Ishagh et al 23. Soil surface and sub surface compaction both reduce yield due to limited root growth and plant potassium uptake (Doulan et al. 14. Sabt et al. (50 reported that in the study area, which the lands are mostly illite clay (high specific surface area with sufficient nitrogen, soil potassium is the most important limiting factor for the growth of wheat.Considering the point that loess soils in Golestan Province have a high specific surface area,they can provide potassium for plants to produce crop, but for a higher production, potassium fertilizers should be used. Previous studies indicated that production of wheat is limited due to potassium deficiency (4, 49, 54 and 57. In these soils with a high specific surface area, the speed of movement of potassium from the soil solution is low, and doing solimits wheat yield.In loess soils containing high illite and high specific surface area (eg, soilsin the series of Rahmat Abad of Gorgan, ammonium acetate measured potassium on exchange and solution surfaces, which is highly correlated with grain yield (54 . There is a high correlation between grain yield with overload of potassium and Na TPB extraction (57. The aim of this study was to absorb potassium (limiting factor for plant growth with different tillage systemsat different depths. International recommendations towards reducing the depth and intensity of tillage (from minimum tillage to no-tillage in order to reduce erosion and oxidation of organic substances plays an important role in determining the amount of greenhouse gases. If potassium absorption does not reduceafter reducing tillage intensity,low or no-tillage methods

  20. Soil tillage conservation and its effect on erosion control, water management and carbon sequestration

    Science.gov (United States)

    Rusu, Dr.; Gus, Dr.; Bogdan, Dr.; Moraru, Dr.; Pop, Dr.; Clapa, Dr.; Pop, Drd.

    2009-04-01

    The energetic function of the soil expressed through the potential energy accumulated through humus, the biogeochemical function (the circuit of the nutrient elements) are significantly influenced by its hydrophysical function and especially by the state of the bedding- consolidation, soil capacity of retaining an optimal quantity of water, and then its gradual disponibility for plant consumption. The understanding of soil functions and management including nutrient production, stocking, filtering and transforming minerals, water , organic matter , gas circuit and furnishing breeding material, all make the basis of human activity, Earth's past, present and especially future. The minimum tillage soil systems - paraplow, chisel or rotary grape - are polyvalent alternatives for basic preparation, germination bed preparation and sowing, for fields and crops with moderate loose requirements being optimized technologies for: soil natural fertility activation and rationalization, reduction of erosion, increasing the accumulation capacity for water and realization of sowing in the optimal period. By continuously applying for 10 years the minimum tillage system in a crop rotation: corn - soy-bean - wheat - potato / rape, an improvement in physical, hydro-physical and biological properties of soil was observed, together with the rebuilt of structure and increase of water permeability of soil. The minimum tillage systems ensure an adequate aerial-hydrical regime for the biological activity intensity and for the nutrients solubility equilibrium. The vegetal material remaining at the soil surface or superficially incorporated has its contribution to intensifying the biological activity, being an important resource of organic matter. The minimum tillage systems rebuild the soil structure, improving the global drainage of soil which allows a rapid infiltration of water in soil. The result is a more productive soil, better protected against wind and water erosion and needing less

  1. The effect of soil extracts from a monoculture of spring wheat (Triticum aestivum L. grown under different tillage systems on the germination of its seeds

    Directory of Open Access Journals (Sweden)

    Piotr Kraska

    2012-12-01

    Full Text Available The present experiment was carried out in the period 2006-2008. The aim of this study was to determine the effect of aqueous soil extracts from the soil of a spring wheat monoculture on seed germination energy and capacity, the length of the first leaf and of the longest radicle as well as the number of radicles. Moreover, the content of 0-dihydroxyphenols in the soil was compared in the last year of the study. The soil used to prepare the solutions came from a field experiment established on medium heavy mixed rendzina soil. Spring wheat, cv. Zebra, was grown using plough tillage and two conservation tillage methods in the presence of undersown crops (red clover, Westerwolds ryegrass and stubble crops (lacy phacelia, white mustard. Germination energy of the seeds watered with the soil extracts from the ploughed plots was significantly higher than this trait in the seeds watered with the extracts from the conservation tillage treatments with spring disking of the catch crops. Germination energy and capacity of spring wheat in the control treatment watered with distilled water were significantly higher compared to the other treatments under evaluation. Spring wheat watered with the aqueous extract prepared from the soil obtained from the plough tillage treatment produced a significantly longer first leaf compared to the treatments in which both conservation tillage methods had been used. The shortest leaf and the lowest number of radicles were produced by the seedlings watered with the soil extract from the treatment with the white clover stubble crop. Radicle length was not significantly differentiated by the soil extracts under consideration. The content of 0-dihydroxyphenols in the rendzina soil determined during the spring period was higher than that determined in the autumn. The content of 0-dihydroxyphenols in the soil was lower in the conservation tillage treatments with autumn incorporation of the catch crops than in the plots in which

  2. Effects of tillage, organic resources and nitrogen fertiliser on soil carbon dynamics and crop nitrogen uptake in semi-arid West Africa

    NARCIS (Netherlands)

    Ouédraogo, E.; Mando, A.; Stroosnijder, L.

    2006-01-01

    Tillage, organic resources and fertiliser effects on soil carbon (C) dynamics were investigated in 2000 and 2001 in Burkina Faso (West Africa). A split plot design with four replications was laid-out on a loamy-sand Ferric Lixisol with till and no-till as main treatments and fertiliser types as

  3. Impact of different cropping conditions and tillage practices on the soil fungal abundance of a Phaeozem luvico

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, R.P.; Aulicino, M.B.; Mónaco, C.I.; Kripelz, N.; Cordo, C.A.

    2015-07-01

    Fungal diversity seems to be a good indicator of ecosystem disturbance and functioning. The purpose of this work was to quantify the fungal population as a sensitive indicator of the changes caused by stubble placement in two tillage systems: reduced tillage (RT) and conventional tillage (CT) with and without cropping. To this end, we determined the effect of soil disturbances such as N fertilization, tillage practice, and cropped area on the soil fungal communities of a Phaeozem luvico of the El Salado river basin (Argentina). Soil samples (at 0-10 cm depth) were collected from a field cultivated with wheat at post-harvest, before sowing and at tillering. The relative abundance of individuals of the fungal population was studied on Nash Snyder and Oxgall agar media after different treatments and assessed as colony forming units (CFU/gof soil). The diversity of the fungal population was studied by Shannon´s index (H). The tillage system showed a marked effect only at post-harvest and the number of propagules was highest under RT for both culture media. The largest values of H were found only at post-harvest when Oxgall agar was used. A significant decrease in the values of H was observed when CT and high fertilization was applied in the wheat cropped area. The relative abundance of individuals of the fungal population was different in soils under the different tillage practices. (Author)

  4. Effects of Tillage on Yield and Economic Returns of Maize and Cowpea in Semi-Arid Eastern Kenya

    International Nuclear Information System (INIS)

    Miriti, M.J; Kironchi, G; Gachene, K.K.C; Esilaba, O.A.; Mwangi, M.D; Nyamwaro, S.O; Heng, K.L

    2014-01-01

    Crop yields and financial returns are important criteria for adoption of conservation tillage by farmers. A study was conducted between 2007-2010 to compare the financial returns of subsoiling-ripping and tied-ridge tillage with the conventional ox-plough tillage in the production of maize (Zea mays L.) and cowpea (Vigna unguiculata L.) under semi-arid subsistence farming conditions in lower eastern Kenya. Four cropping systems namely maize sole crop, cowpea sole crop, maize/cowpea intercrop and maize sole crop with manure were evaluated in a split-plot treatments arrangement with tillage practices as the main plots and cropping systems as the sub-plots. The grain yields of maize and cowpea, prevailing market prices for cowpea and maize grains, labour, inputs applied and other relevant socio-economic data were collected every season, to enable estimation of economic returns and acceptability of the technologies. The results showed that average grain yield for maize sole crop, cowpea sole crop, maize/cowpea intercrop and maize sole crop with manure cropping systems under tied-ridge were 5, 9, 97 and 27% greater than the yields under oxplough tillage, respectively. Crop yields produced under subsoiling-ripping and ox-plough tillage were generally similar. However, land preparation and weeding labour expenses (KES 4240 / ha) for ox-plough tillage were 34% greater than those for subsoiling-ripping tillage but 40% lower than those for tied-ridge tillage. When averaged across seasons and tillage systems, the highest gross margins (KES 8567 / ha) were obtained in sole cowpea cropping system, followed by sole maize with manure (KES 4070 / ha), intercrop (KES 864 / ha) and least (loss of KES 1330 / ha) in sole maize without manure cropping system. (author)

  5. Effects of long-term reduced tillage on weed infestation of pea (Pisum sativum L.

    Directory of Open Access Journals (Sweden)

    Andrzej Woźniak

    2014-09-01

    Full Text Available The study evaluated weed infestation of pea (Pisum sativum L. cultivated under conditions of conventional (CT, reduced (RT and herbicide tillage (HT. It demonstrated the highest weed density per m2 in plots with the herbicide (HT and reduced (RT systems and significantly lower weed infestation in plots cultivated in the conventional system (CT. In addition, more weeds occurred at the third leaf stage (13/14 in BBCH scale than at the pod development stage (73/74 BBCH of pea. The highest biomass was produced by weeds in the herbicide system (HT, a lower one – in the reduced system (RT, and the lowest one – in the conventional system (CT. The air-dry weight of weeds depended also on pea development stage. At the pod development stage (73/74 BBCH, the air-dry weight of weeds was significantly higher than at the third leaf stage (13/14 BBCH. The tillage system was also observed to influence the species composition of weeds. This trait was also affected by the period of weed infestation assessment. At the third leaf stage of pea (13/14 BBCH, there occurred 26 weed species, including 24 annual ones. The most abundant species included: Chenopodium album L., Stellaria media (L. Vill., Capsella bursa-pastoris (L. Med., Matricaria inodora L., Thlaspi arvense L., and Fallopia convolvulus (L. A. Löve. At the pod development stage (73/74 BBCH, the pea crop was colonized by 24 weed species, including 3 perennial ones. At this stage the predominant species included: Avena fatua L., Amaranthus retroflexus L., Papaver rhoeas L., Echinochloa crus-galli (L. P.B., Matricaria inodora L., and Galeopsis tetrahit L.

  6. Effect of tillage and crop residues management on mungbean (vigna radiata (L.) wilczek) crop yield, nitrogen fixation and water use efficiency in rainfed areas

    International Nuclear Information System (INIS)

    Mohammad, W.; Shehzadi, S.; Shah, S.M.; Shah, Z.

    2010-01-01

    A field experiment was conducted to study the effect of crop residues and tillage practices on BNF, WUE and yield of mungbean (Vigna radiata (L.) Wilczek) under semi arid rainfed conditions at the Livestock Research Station, Surezai, Peshawar in North West Frontier Province (NWFP) of Pakistan. The experiment comprised of two tillage i) conventional tillage (T1) and ii) no-tillage (T0) and two residues i) wheat crop residues retained (+) and ii) wheat crop residues removed (-) treatments. Basal doses of N at the rate of 20: P at the rate of 60 kg ha-1 were applied to mungbean at sowing time in the form of urea and single super phosphate respectively. Labelled urea having 5% 15N atom excess was applied at the rate of 20 kg N ha-1 as aqueous solution in micro plots (1m2) in each treatment plot to assess BNF by mungbean. Similarly, maize and sorghum were grown as reference crops and were fertilized with 15N labelled urea as aqueous solution having 1% 15N atom excess at the rate of 90 kg N ha/sup -1/. The results obtained showed that mungbean yield (grain/straw) and WUE were improved in notillage treatment as compared to tillage treatment. Maximum mungbean grain yield (1224 kg ha/sup -1/) and WUE (6.61kg ha/sup -1 mm/sup -1/) were obtained in no-tillage (+ residues) treatment. The N concentration in mungbean straw and grain was not significantly influenced by tillage or crop residue treatments. The amount of fertilizer-N taken up by straw and grain of mungbean was higher under no-tillage with residues-retained treatment but the differences were not significant. The major proportion of N (60.03 to 76.51%) was derived by mungbean crop from atmospheric N2 fixation, the remaining (19.6 to 35.91%) was taken up from the soil and a small proportion (3.89 to 5.89%) was derived from the applied fertilizer in different treatments. The maximum amount of N fixed by mungbean (82.59 kg ha/sup -1/) was derived in no-tillage with wheat residue-retained treatment. By using sorghum as

  7. Burrower bugs (Heteroptera: Cydnidae) in peanut: seasonal species abundance, tillage effects, grade reduction effects, insecticide efficacy, and management.

    Science.gov (United States)

    Chapin, Jay W; Thomas, James S

    2003-08-01

    Pitfall traps placed in South Carolina peanut, Arachis hypogaea (L.), fields collected three species of burrower bugs (Cydnidae): Cyrtomenus ciliatus (Palisot de Beauvois), Sehirus cinctus cinctus (Palisot de Beauvois), and Pangaeus bilineatus (Say). Cyrtomenus ciliatus was rarely collected. Sehirus cinctus produced a nymphal cohort in peanut during May and June, probably because of abundant henbit seeds, Lamium amplexicaule L., in strip-till production systems. No S. cinctus were present during peanut pod formation. Pangaeus bilineatus was the most abundant species collected and the only species associated with peanut kernel feeding injury. Overwintering P. bilineatus adults were present in a conservation tillage peanut field before planting and two to three subsequent generations were observed. Few nymphs were collected until the R6 (full seed) growth stage. Tillage and choice of cover crop affected P. bilineatus populations. Peanuts strip-tilled into corn or wheat residue had greater P. bilineatus populations and kernel-feeding than conventional tillage or strip-tillage into rye residue. Fall tillage before planting a wheat cover crop also reduced burrower bug feeding on peanut. At-pegging (early July) granular chlorpyrifos treatments were most consistent in suppressing kernel feeding. Kernels fed on by P. bilineatus were on average 10% lighter than unfed on kernels. Pangaeus bilineatus feeding reduced peanut grade by reducing individual kernel weight, and increasing the percentage damaged kernels. Each 10% increase in kernels fed on by P. bilineatus was associated with a 1.7% decrease in total sound mature kernels, and kernel feeding levels above 30% increase the risk of damaged kernel grade penalties.

  8. Shallow tillage effects on soil properties for temperate-region hard-setting soils

    DEFF Research Database (Denmark)

    Schjønning, Per; Thomsen, Ingrid Kaag

    2013-01-01

    Shallow tillage (ST; typically soil physical properties and hence modifies significantly the conditions for root growth and soil biotic activity as compared to mouldboard ploughing (MP; typically ∼25 cm). At field capacity in the spring, we measured cone...... quoted 1.5 MPa critical limit for root growth. Across the 11 field experiments, the untilled ST soil at 14–18 cm generally had lower ɛa and ka than the mechanically loosened soil at the same depth for MP. Also the specific air permeability (pore organization = ka/ɛa) was lower for ST than for MP. SOC...... penetration resistance (PR) of the top 40 cm soil and sampled intact soil cores (at 0–4 and 14–18 cm depths) in 11 field experiments (4–23% clay) after continued ST and MP management for mostly 4–8 years (two experiments >30 years). Bulk soil was sampled from 0 to ∼20 cm of the MP soil and from the two layers...

  9. Effects of tillage on runoff from a bare clayey soil on a semi-arid ...

    African Journals Online (AJOL)

    arid areas. However, by adopting appropriate soil management practices, the runoff can be harnessed for improving crop yields. The main objective of this study was to quantify rainfall-runoff relationships under in-field rainwater harvesting ...

  10. Effect of 15n-labeled hairy vetch and nitrogen fertilization on maize nutrition and yield under no-tillage

    International Nuclear Information System (INIS)

    Almeida Acosta, Jose Alan de; Amado, Telmo Jorge Carneiro; Silva, Leandro Souza da; Silveira Nicoloso, Rodrigo da

    2011-01-01

    This study evaluated the effect of hairy vetch (Vicia villosa Roth) as cover crop on maize nutrition and yield under no tillage using isotope techniques. For this purpose, three experiments were carried out: quantification of biological nitrogen fixation (BNF) in hairy vetch; estimation of the N release rate from hairy vetch residues on the soil surface; quantification of 15 N recovery by maize from labeled hairy vetch under three rates of mineral N fertilization. This two year field experiment was conducted on a sandy Acrisol (FAO soil classification) or Argissolo Vermelho distrofico arenico (Brazilian Soil Classification), at a mean annual temperature of 18 deg C and mean annual rainfall of 1686 mm. The experiment was arranged in a double split-plot factorial design with three replications. Two levels of hairy vetch residue (50 and 100 % of the aboveground biomass production) were distributed on the surface of the main plots (5 x 12 m). Maize in the sub-plots (5 x 4 m) was fertilized with three N rates (0, 60, and 120 kg ha -1 N), with urea as N source. The hairy vetch-derived N recovered by maize was evaluated in microplots (1.8 x 2.2 m). The BFN of hairy vetch was on average 72.4 %, which represents an annual input of 130 kg ha -1 of atmospheric N. The N release from hairy vetch residues was fast, with a release of about 90 % of total N within the first four weeks after cover crop management and soil residue application. The recovery of hairy vetch 15 N by maize was low, with an average of 12.3 % at harvest. Although hairy vetch was not directly the main source of maize N nutrition, the crop yield reached 8.2 Mg ha -1 , without mineral fertilization. There was an apparent synergism between hairy vetch residue application and the mineral N fertilization rate of 60 kg ha -1 , confirming the benefits of the combination of organic and inorganic N sources for maize under no tillage. (author)

  11. Effects of tillage technologies and application of biopreparations on micromycetes in the rhizosphere and rhizoplane of spring wheat

    Science.gov (United States)

    Shirokikh, I. G.; Kozlova, L. M.; Shirokikh, A. A.; Popov, F. A.; Tovstik, E. V.

    2017-07-01

    The population density and structure of complexes of soil microscopic fungi in the rhizosphere and rhizoplane of spring wheat ( Triticum aestivum L.), plant damage by root rot and leaf diseases, and crop yield were determined in a stationary field experiment on a silty loamy soddy-podzolic soil (Albic Retisol (Loamic, Aric)) in dependence on the soil tillage technique: (a) moldboard plowing to 20-22 cm and (b) non-inversive tillage to 14-16 cm. The results were treated with the two-way ANOVA method. It was shown that the number of fungal propagules in the rhizosphere and rhizoplane of plants in the variant with non-inversive tillage was significantly smaller than that in the variant with plowing. Minimization of the impact on the soil during five years led to insignificant changes in the structure of micromycete complexes in the rhizosphere of wheat. The damage of the plants with root rot and leaf diseases upon non-inversive tillage did not increase in comparison with that upon plowing. Wheat yield in the variant with non-inversive tillage was insignificantly lower than that in the variant with moldboard plowing. The application of biopreparations based on the Streptomyces hygroscopicus A4 and Pseudomonas aureofaciens BS 1393 resulted in a significant decrease of plant damage with leaf rust.

  12. Cover plants and mineral nitrogen: effects on organic matter fractions in an oxisol under no-tillage in the cerrado

    Directory of Open Access Journals (Sweden)

    Isis Lima dos Santos

    2014-12-01

    Full Text Available Cover plants are essential for the sustainability of no-tillage systems in tropical regions. However, information on the effects of these plants and N fertilization on soil organic matter fractions is still scarce. This study evaluated the effect of cover crops with different chemical composition and of N topdressing on the labile and humified organic matter fractions of an Oxisol of the Cerrado (savanna-like vegetation. The study in a randomized complete block design was arranged in split-plots with three replications. Four cover species were tested in the plots and the presence or absence of N topdressing in the subplot. The following cover species were planted in succession to corn for eight years: Urochloa ruziziensis; Canavalia brasiliensis M. ex Benth; Cajanus cajan (L. Millsp; and Sorghum bicolor (L. Moench. In general, the cultivation of U. ruziziensis increased soil C levels, particularly of C in the humic acid and particulate organic C fractions, which are quality indicators of soil organic matter. The C in humic substances and mineral organic C accounted for the highest proportions of total organic C, demonstrating the strong interaction between organic matter, Fe and Al oxides and kaolinite, which are predominant in these weathered soils of the Cerrado.

  13. Soil workability as a basis for advice on tillage activities

    OpenAIRE

    Cadena Zapata, M.

    1999-01-01

    In the tropical area of Mexico, when and how to carry out tillage is a qualitative decision. There is no quantified information about the interaction between a chosen process of cultivation, soil type and weather, which dictate the tool and power requirements. Waste of energy and soil degradation by erosion and compaction, and lack of timeliness are recognized problems caused by inadequate tillage management in the tropical area of Mexico.

    In this thesis, the workab...

  14. Long-Term Effects of Rotational Tillage On Visual Evaluation of Soil Structure, Soil Quality and Crop Yield

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Heck, Richard; Deen, Bill

    year old long-term rotation and tillage treatment experiment on a Canadian silt loam soil. Measurements were carried out in the topsoil for three different rotations: R1 (C-C-C-C) continuous corn (Zea mays L.), R6. (C-C-O(RC), B(RC)) corn, corn, oats (Avena fatua L.) and spring barley (Hordeum vulgare...... L.) and R8, (C-C-S-S) corn, corn, soybean (Glycine max L.), soybean. A red clover (Trifolium pretense L.) cover crop was under seeded in oats and spring barley in R6. In 2010, first year corn was grown in R6 and R8. The tillage treatments included no tillage, NT and mouldboard plowing, MP. Topsoil...

  15. Effect of different pre-sowing tillage on quantity and quality of parsnip (Pastinaca sativa L. root yield in ridge cultivation

    Directory of Open Access Journals (Sweden)

    Mirosław Konopiński

    2012-12-01

    Full Text Available Parsnip is a very valuable vegetable due to its nutritional value and dietetic quality. It is moreover herbal raw material abundant in active substances. The yield quality of vegetables greatly depends on thorough pre-sowing soil tillage. The present study aimed at evaluating the influence of different presowing soil tillage (medium-deep ploughing, cultivating and plant growing methods, flat or ridge cultivation, on the yield of parsnip and some biometric traits of its roots. The field experiment was carried out in 1999, 2000 and 2002 on lessive soil with the granulometric composition corresponding to medium silty loam. The parsnip cultivar 'Półdługi Biały' was the experimental plant species. The cultivation of parsnip on ridges had a significant influence on increased total yield of roots and decreased yield of small roots, as compared to flat cultivation. A significant increase in unit weight of the root and its diameter in the top part was also recorded in the latter type of cultivation. Spring pre-sowing tillage had no significant effect on parsnip yields. An increasing trend was observed only for total and marketable root yield in the ploughed plots. When parsnip is grown on lessive soil (which has an unstable structure, plants cultivated on ridges after spring pre-sowing plough are the most beneficial treatment combination.

  16. Quantification of tillage, plant cover, and cumulative rainfall effects on soil surface microrelief by statistical, geostatistical and fractal indices

    Science.gov (United States)

    Paz-Ferreiro, J.; Bertol, I.; Vidal Vázquez, E.

    2008-07-01

    Changes in soil surface microrelief with cumulative rainfall under different tillage systems and crop cover conditions were investigated in southern Brazil. Surface cover was none (fallow) or the crop succession maize followed by oats. Tillage treatments were: 1) conventional tillage on bare soil (BS), 2) conventional tillage (CT), 3) minimum tillage (MT) and 4) no tillage (NT) under maize and oats. Measurements were taken with a manual relief meter on small rectangular grids of 0.234 and 0.156 m2, throughout growing season of maize and oats, respectively. Each data set consisted of 200 point height readings, the size of the smallest cells being 3×5 cm during maize and 2×5 cm during oats growth periods. Random Roughness (RR), Limiting Difference (LD), Limiting Slope (LS) and two fractal parameters, fractal dimension (D) and crossover length (l) were estimated from the measured microtopographic data sets. Indices describing the vertical component of soil roughness such as RR, LD and l generally decreased with cumulative rain in the BS treatment, left fallow, and in the CT and MT treatments under maize and oats canopy. However, these indices were not substantially affected by cumulative rain in the NT treatment, whose surface was protected with previous crop residues. Roughness decay from initial values was larger in the BS treatment than in CT and MT treatments. Moreover, roughness decay generally tended to be faster under maize than under oats. The RR and LD indices decreased quadratically, while the l index decreased exponentially in the tilled, BS, CT and MT treatments. Crossover length was sensitive to differences in soil roughness conditions allowing a description of microrelief decay due to rainfall in the tilled treatments, although better correlations between cumulative rainfall and the most commonly used indices RR and LD were obtained. At the studied scale, parameters l and D have been found to be useful in interpreting the configuration properties of

  17. Entomofauna associated to soybean [Glycine max (L. Merr.] in direct seeding and conventional tillage

    Directory of Open Access Journals (Sweden)

    Arahis Cruz Limonte

    2016-01-01

    Full Text Available The main purpose of this research work was to investigate the effect of the direct seeding and conventional tillage of soybean on the incidence of plagues and natural enemies. The study was carried out on the farm “Día y Noche” of the Basic Unit of Cooperative Production “28 de Octubre” (UBPC, for its Spanish acronym, and in the Laboratories of the Agricultural Research Center of Central University of Las Villas. Field experiments were conducted on an Inceptisol, since November 2013 to May 2014. The soybean cultivar Incasoy – 27 was used. The insects in relation to the development stages of the plant were identified and quantified. In both systems 10 species of phytophagous insects and one of entomophagous insects were quantified; Hedylepta indicata L. stands out with more presence in the direct seeding, while Diabrotica balteata LeConte and the species belong to the family Pentatomidae caused most damage to the plants in conventional tillage.

  18. Effects of tillage practice on soil structure, N2O emissions and economics in cereal production under current socio-economic conditions in central Bosnia and Herzegovina.

    Science.gov (United States)

    Žurovec, Ognjen; Sitaula, Bishal Kumar; Čustović, Hamid; Žurovec, Jasminka; Dörsch, Peter

    2017-01-01

    Conservation tillage is expected to have a positive effect on soil physical properties, soil Carbon (C) storage, while reducing fuel, labour and machinery costs. However, reduced tillage could increase soil nitrous oxide (N2O) emissions and offset the expected gains from increased C sequestration. To date, conservation tillage is barely practiced or studied in Bosnia and Herzegovina (BH). Here, we report a field study on the short-term effects of reduced (RT) and no tillage (NT) on N2O emission dynamics, yield-scaled N2O emissions, soil structure and the economics of cereal production, as compared with conventional tillage (CT). The field experiment was conducted in the Sarajevo region on a clayey loam under typical climatic conditions for humid, continental BH. N2O emissions were monitored in a Maize-Barley rotation over two cropping seasons. Soil structure was studied at the end of the second season. In the much wetter 2014, N2O emission were in the order of CT > RT > NT, while in the drier 2015, the order was RT > CT > NT. The emission factors were within or slightly above the uncertainty range of the IPCC Tier 1 factor, if taking account for the N input from the cover crop (alfalfa) preceding the first experimental year. Saturated soils in spring, formation of soil crusts and occasional droughts adversely affected yields, particularly in the second year (barley). In 2014, yield-scaled N2O emissions ranged from 83.2 to 161.7 g N Mg-1 grain (corn) but were much greater in the second year due to crop failure (barley). RT had the smallest yield-scaled N2O emission in both years. NT resulted in economically inacceptable returns, due to the increased costs of weed control and low yields in both years. The reduced number of operations in RT reduced production costs and generated positive net returns. Therefore, RT could potentially provide agronomic and environmental benefits in crop production in BH.

  19. Tillage effects on topsoil structural quality assessed using X-ray CT, soil cores and visual soil evaluation

    DEFF Research Database (Denmark)

    Garbout, Amin; Munkholm, Lars Juhl; Hansen, Søren Baarsgaard

    2013-01-01

    stratification of the 0–20 cm topsoil layer for both tillage treatments. The stratification of the direct drilled soil was in accordance with our expectations whereas it was surprising for the ploughed soil. The dense lower topsoil layer for the ploughed soil was probably caused by compaction during secondary...

  20. Tillage system affects microbiological properties of soil

    Science.gov (United States)

    Delgado, A.; de Santiago, A.; Avilés, M.; Perea, F.

    2012-04-01

    Soil tillage significantly affects organic carbon accumulation, microbial biomass, and subsequently enzymatic activity in surface soil. Microbial activity in soil is a crucial parameter contributing to soil functioning, and thus a basic quality factor for soil. Since enzymes remain soil after excretion by living or disintegrating cells, shifts in their activities reflect long-term fluctuations in microbial biomass. In order to study the effects of no-till on biochemical and microbiological properties in comparison to conventional tillage in a representative soil from South Spain, an experiment was conducted since 1982 on the experimental farm of the Institute of Agriculture and Fisheries Research of Andalusia (IFAPA) in Carmona, SW Spain (37o24'07''N, 5o35'10''W). The soil at the experimental site was a very fine, montomorillonitic, thermic Chromic Haploxerert (Soil Survey Staff, 2010). A randomized complete block design involving three replications and the following two tillage treatments was performed: (i) Conventional tillage, which involved mouldboard plowing to a depth of 50 cm in the summer (once every three years), followed by field cultivation to a depth of 15 cm before sowing; crop residues being burnt, (ii) No tillage, which involved controlling weeds before sowing by spraying glyphosate and sowing directly into the crop residue from the previous year by using a planter with double-disk openers. For all tillage treatments, the crop rotation (annual crops) consisted of winter wheat, sunflower, and legumes (pea, chickpea, or faba bean, depending on the year), which were grown under rainfed conditions. Enzymatic activities (ß-glucosidase, dehydrogenase, aryl-sulphatase, acid phosphatase, and urease), soil microbial biomass by total viable cells number by acridine orange direct count, the density of cultivable groups of bacteria and fungi by dilution plating on semi-selective media, the physiological profiles of the microbial communities by BiologR, and the

  1. Impact of tillage intensity on clay loam soil structure

    DEFF Research Database (Denmark)

    Daraghmeh, Omar; Petersen, Carsten; Munkholm, Lars Juhl

    Soil structure and structural stability are key parameters in sustainable soil management and optimum cropping practices. Locally and temporally adapted precision tillage may improve crop performance while at the same time reduce environmental impacts. The main objective of this study...... was to improve the knowledge of precision tillage practices through characterizing the effect of varied tillage intensities on structural properties of a clay loam soil. A field experiment was conducted using a randomized complete block design with two main factors, i.e. operational speed (OS, 2 levels......) and rotovating speed (RS, 3 levels). The tillage was conducted using a PTO-driven rotovator equipped to measure angular velocity. The effect of traffic compaction, made directly after tillage, was measured on soil taken from wheel track (WT) compared with soil outside wheel track (NWT). Soil samples from 0-3 cm...

  2. Quantifying Temperature Effects on Fall Chinook Salmon

    Energy Technology Data Exchange (ETDEWEB)

    Jager, Yetta [ORNL

    2011-11-01

    The motivation for this study was to recommend relationships for use in a model of San Joaquin fall Chinook salmon. This report reviews literature pertaining to relationships between water temperature and fall Chinook salmon. The report is organized into three sections that deal with temperature effects on development and timing of freshwater life stages, temperature effects on incubation survival for eggs and alevin, and temperature effects on juvenile survival. Recommendations are made for modeling temperature influences for all three life stages.

  3. Effects of Zero Tillage (No-Till) Conservation Agriculture on soil physical and biological properties and their contributions to sustainability

    Science.gov (United States)

    Landers, John N.; Rass, Gerard; de Freitas, Pedro L.; Basch, Gottlieb; González Sanchez, Emilio J.; Tabaglio, Vincenzo; Kassan, Amir; Derpsch, Rolf; Friedrich, Theodor; Giupponi, Luca

    2013-04-01

    Not cultivating soil, rotating crops over the years, and leaving crop residues on the surface in the practice of zero tillage/conservation agriculture (ZT/CA) reverses the historically accelerating degradation of soil organic matter (SOM) and soil structure, while increasing soil biological activity by a factor of 2 to 4. The results of this are many: (a) not cultivating reduces soil compaction, leaving old root holes to facilitate internal drainage, averts the pulverization of soil aggregates and formation of pans, reduces draft power for planting and gives shelter, winter food and nesting sites for fauna, (b) crop residues on the surface practically eliminate wind and water erosion, reduce soil moisture loss through the mulch effect, slow spring warm-up (possibly offset by a lower specific heat demand with less water retention in surface soil) and act as a reserve of organically-compounded nutrients (as they decompose to humus), (c) more SOM means higher available water and nutrient retention, higher biological activity year round (enhancing biological controls), higher levels of water-stable aggregates and a positive carbon sink in incremental SOM. The positive impacts for society are: (i) more and cheaper food, (ii) reduced flood and drought-induced famine risks, (iii) a positive carbon sink in SOM and possible reductions in NO2 emissions, (iv) cleaner water and greater aquifer recharge due to reduced runoff, (v) cleaner air through effective elimination of dust as a product of cultivation (vi) less water pollution and greater aquifer recharge from reduced rainfall runoff, (vii) farm diesel consumption halved, (viii) reduced demand for (tropical) de-forestation, by permitting crop expansion on steeper lands, (ix) increased wildlife populations (skylarks, plovers, partridge and peccaries) and (x) an improved conservation mindset in farmers. It is notable that, in spite of successful practitioners in all European countries, mainstream adoption is still to come

  4. Tillage Effect on Soil Moisture Storage and Wheat Yield on the ...

    African Journals Online (AJOL)

    Vertisols are one of the agriculturally important soils in Delanta Dawunt, north central highlands of Ethiopia, for peasant farmers as almost all the cereal, soil and forage crops are grown on them. However, waterlogging during the growing season impedes the performances of cereal crops. It is crucial to seek for cost effective ...

  5. Nitrogen fertilization (15NH4NO3 of palisadegrass and residual effect on subsequent no-tillage corn

    Directory of Open Access Journals (Sweden)

    Emerson Borghi

    2014-10-01

    Full Text Available Nitrogen is required in large amounts by plants and their dinamics in corn and perennial forages intercropped is little known. This study analyzed the efficiency of nitrogen fertilization (15NH4NO3 applied after corn grain harvest to palisadegrass (Brachiaria brizantha cv. Marandu in intercrops sown at two times, as well as the N residual effect on the subsequent corn crop. The field experiment was performed in Botucatu, São Paulo State, in southeastern Brazil, on a structured Alfisol under no-tillage. The experiment was arranged in a randomized block design in a split plot scheme with four replications. The main plots consisted of two intercropping systems (corn and palisadegrass sown together and palisadegrass sown later, at corn top-dressing fertilization. The subplots consisted of four N rates (0, 30, 60, and 120 kg ha-1 N. The subplots contained microplots, in which enriched ammonium nitrate (15NH4NO3 was applied at the same rates. The time of intercrop sowing affected forage dry matter production, the amount of fertilizer-derived N in and the N use efficiency by the forage plants. Nitrogen applied in autumn to palisadegrass intercropped with corn, planted either at corn sowing or at N top-dressing fertilization, increased the forage yield up to a rate of 60 kg ha-1. The amount of fertilizer-derived N by the forage plants and the fertilizer use efficiency by palisadegrass were highest 160 days after fertilization for both intercrop sowing times, regardless of N rates. Residual N did not affect the N nutrition of corn plants grown in succession to palisadegrass, but increased grain yield at rates of 60 and 120 kg ha-1 N, when corn was grown on palisadegrass straw from the intercrop installed at corn fertilization (top-dressing. Our results indicated that the earlier intercropping allowed higher forage dry matter production. On the other hand, the later intercrop allowed a higher corn grain yield in succession to N-fertilized palisadegrass.

  6. Quantified Effects of Late Pregnancy and Lactation on the Osmotic ...

    African Journals Online (AJOL)

    Quantified Effects of Late Pregnancy and Lactation on the Osmotic Stability of ... in the composition of erythrocyte membranes associated with the physiologic states. Keywords: Erythrocyteosmotic stability, osmotic fragility, late pregnancy, ...

  7. Effect of simplified tillage and mineral fertilization on weed infestation of potato growing on loess soil

    Directory of Open Access Journals (Sweden)

    Karol Bujak

    2012-12-01

    Full Text Available In the paper effect of limitation of postharvest measure to single cultivating or disking of soil and mineral fertilization level on number, air-dry matter and botanical composition of weeds in the potato-field is presented. Simplifield postharvest measure was increasing insignificantly and more intensive fertilization was limiting the weed infestation of potato-field. Decteasing of weeds number increasing fertilization was ststistically significant. Dominating species of weeds in the potato-field were Capsella bursa-pastoris, Poa annua, Viola arvensis, Chenopodium album, Elymus repens i Equisetum arvense.

  8. Soil tillage and windbreak effects on millet and cowpea: I. Wind speed, evaporation, and wind erosion

    International Nuclear Information System (INIS)

    Banzhaf, J.; Leihner, D.E.; Buerkert, A.; Serafini, P.G.

    1992-01-01

    Deforestation, overgrazing, and declining soil regeneration periods have resulted in increased wind erosion problems in dry areas of the West African Sahel, but little is known about the bio-physical factors involved. This research was conducted to determine the effects of ridging and four different windbreak spacings on wind erosion, potential evaporation, and soil water reserves. A field trial was conducted from 1985 to 1987 on 12 ha of a Psammentic Paleustalf in Southern Niger. Millet, Pennisetum glaucum (L.), and cowpea, Vigna unguiculata (L.) Walp., were seeded in strips on flat and ridged soil. Windbreaks of savannah vegetation were spaced at 6, 20, 40, and 90 m. The effects of ridging on wind speed, evaporation, and wind erosion were small and mostly non-significant. However, average wind speed at 0.3 m above ground in the center of cowpea and millet strips was significantly reduced from 2.8 to 2.1 m s -1 as windbreak distances narrowed from 90 to 6 m. As a consequence, potential evaporation declined by 15% and the amount of windblown soil particles by 50% in ridged and by 70% in flat treatments. Despite reduced potential evaporation, average subsoil water reserves were 14 mm smaller in the 6- than in the 20-m windbreak spacing indicating excessive water extraction by the windbreak vegetation. Thus, establishing windbreaks with natural savannah vegetation may require a careful consideration of the agronomic benefits and costs to competing crops. 21 refs., 5 figs

  9. Overall assessment of soil quality on humid sandy loams: Effects of location, rotation and tillage

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Hansen, Elly Møller; Rickson, J.M.

    2015-01-01

    .e. visual evaluation of soil structure (VESS), overall visual structure (OVS) and overall soil structure (OSS)) were employed to differentiate the effects of these alternative management practices on soil structural quality and relative crop yield (RY). A Pearson correlation was also employed to find...... the correlation between the soil quality indices and relative crop yield. Relevant soil properties for calculating the soil quality indices were measured or obtained from previous publications. Crop rotation affected the soil structure and RY. The winter-dominated crop rotation (R2) resulted in the poorest soil...... correlations were found in most cases between soil quality indices (including M-SQR) and RY. This highlights the influence of soil quality (as measured by the selected indicators) – and soil structure in particular – on crop yield potential....

  10. Efeitos da calagem em semedura direta de milho Effect of lime application on no-tillage corn

    Directory of Open Access Journals (Sweden)

    Josinei Antonio Tissi

    2004-12-01

    Full Text Available As conseqüências das alterações químicas do solo, decorrentes da calagem na superfície, sobre o crescimento radicular e a nutrição do milho cultivado em semeadura direta são pouco conhecidas. Com o objetivo de avaliar os efeitos da aplicação superficial de calcário nos atributos químicos do solo, no crescimento de raízes e na nutrição da planta de milho, e seus reflexos sobre o rendimento de grãos, foi realizado um experimento em Latossolo Vermelho distrófico textura muito argilosa, manejado há seis anos em semeadura direta, em Tibagi (PR. Os tratamentos, aplicados em parcelas de 44,8 m², foram dispostos em blocos completos ao acaso com quatro repetições e constaram da aplicação de quatro doses de calcário dolomítico na superfície: 0, 1, 2 e 3 t.ha-1 (PRNT = 100%. As doses de calcário (27% de CaO, 20% de MgO e 85% de PRNT foram baseadas no requerimento de 1/3, 2/3 e na quantidade total calculada para elevar a saturação por bases do solo, na camada de 0-20 cm, a 70%. A calagem, após 22 meses, aumentou o pH em CaCl2 0,01 mol.L-1, os teores de Ca e Mg trocáveis e a saturação por bases, e reduziu os teores de H + Al e de Al trocável, na camada superficial do solo (0-10 cm, e ocasionou aumento de Ca trocável e redução de Al trocável no subsolo (20-40 cm. A aplicação superficial de doses de calcário não alterou o comprimento e a distribuição relativa de raízes de milho até a profundidade de 40 cm, reduziu o raio médio de raízes e aumentou a absorção de P, Ca, Mg e S pelas plantas, sem causar reflexos sobre o rendimento de grãos. Os teores de Cu, Fe, Mn e Zn no solo e no tecido foliar do milho, bem como sua absorção pelas plantas, não foram alterados com a aplicação de calcário na superfície.The effects of superficial lime application on chemical soil attributes under no-tillage systems and its influence on root growth and mineral nutrition in maize crops have not been thoroughly investigated

  11. Effect of water management, tillage options and phosphorus status on arsenic uptake in rice.

    Science.gov (United States)

    Talukder, A S M H M; Meisner, C A; Sarkar, M A R; Islam, M S

    2011-05-01

    High arsenic (As) concentrations in soil may lead to elevated concentrations of arsenic in agricultural products. Field experiments were conducted to examine the effects of water management (WM) and Phosphorus (P) rates on As uptake, rice growth, yield and yield attributes of winter (boro) and monsoon (aman) rice in an As contaminated soil-water at Gobindagonj, Gaibandha, Bangladesh in 2004 and 2005. Significantly, the highest average grain yields (6.88±0.07 t ha(-1) in boro 6.38±0.06 t ha(-1) in aman) were recorded in permanent raised bed (PRB; aerobic WM: Eh=+360 mV) plus 100% P amendment. There was a 12% yield increase over conventional till on flat (CTF; anaerobic WM: Eh=-56 mV) at the same P level. In boro, the As content in grain and As content in straw were about 3 and 6 times higher in CTF compared to PRB, respectively. The highest total As content (0.646±0.01 ppm in grain and 10.93±0.19 ppm in straw) was recorded under CTF, and the lowest total As content (0.247±0.01 and 1.554±0.09 ppm in grain and straw, respectively) was recorded under PRB (aerobic WM). The results suggest that grain and straw As are closely associated in boro rice. The furrow irrigation approach of the PRB treatments consistently reduced irrigation input by 29-31% for boro and 27-30% for aman rice relative to CTF treatments in 2004 and 2005, respectively, thus reducing the amount of As added to the soil from the As-contaminated irrigation water. Yearly, 30% less As was deposited to the soil compared to CTF system through irrigation water during boro season. High As concentrations in grain and straw in rice grown using CTF in the farmers' field, and the fact that using PRB reduced grain As concentrations to value less than half of the proposed food hygiene standard. Copyright © 2010 Elsevier Inc. All rights reserved.

  12. Effects of land clearing techniques and tillage systems on runoff and soil erosion in a tropical rain forest in Nigeria.

    Science.gov (United States)

    Ehigiator, O A; Anyata, B U

    2011-11-01

    This work reports runoff and soil loss from each of 14 sub-watersheds in a secondary rain forest in south-western Nigeria. The impact of methods of land clearing and post-clearing management on runoff and soil erosion under the secondary forest is evaluated. These data were acquired eighteen years after the deforestation of primary vegetation during the ' West bank' project of the International Institute for Tropical Agriculture (IITA). These data are presented separately for each season; however, statistical analyses for replicates were not conducted due to differences in their past management. Soil erosion was affected by land clearing and tillage methods. The maximum soil erosion was observed on sub-watersheds that were mechanically cleared with tree-pusher/root-rake attachments and tilled conventionally. A high rate of erosion was observed even when graded-channel terraces were constructed to minimize soil erosion. In general there was much less soil erosion on manually cleared than on mechanically cleared sub-watersheds (2.5 t ha(-1) yr(-1) versus 13.8 t ha(-1) yr(-1)) and from the application of no-tillage methods than from conventionally plowed areas (6.5 t ha(-1) yr(-1) versus 12.1 t ha(-1) yr(-1)). The data indicate that tillage methods and appropriate management of soils and crops play an important role in soil and water conservation and in decreasing the rate of decline of soil quality. Copyright © 2011 Elsevier Ltd. All rights reserved.

  13. Uncertainties in assessing tillage erosion - How appropriate are our measuring techniques?

    Science.gov (United States)

    Fiener, P.; Wilken, F.; Aldana-Jague, E.; Deumlich, D.; Gómez, J. A.; Guzmán, G.; Hardy, R. A.; Quinton, J. N.; Sommer, M.; Van Oost, K.; Wexler, R.

    2018-03-01

    Tillage erosion on arable land is a very important process leading to a net downslope movement of soil and soil constitutes. Tillage erosion rates are commonly in the same order of magnitude as water erosion rates and can be even higher, especially under highly mechanized agricultural soil management. Despite its prevalence and magnitude, tillage erosion is still understudied compared to water erosion. The goal of this study was to bring together experts using different techniques to determine tillage erosion and use the different results to discuss and quantify uncertainties associated with tillage erosion measurements. The study was performed in northeastern Germany on a 10 m by 50 m plot with a mean slope of 8%. Tillage erosion was determined after two sequences of seven tillage operations. Two different micro-tracers (magnetic iron oxide mixed with soil and fluorescent sand) and one macro-tracer (passive radio-frequency identification transponders (RFIDs), size: 4 × 22 mm) were used to directly determine soil fluxes. Moreover, tillage induced changes in topography were measured for the entire plot with two different terrestrial laser scanners and an unmanned aerial system for structure from motion topography analysis. Based on these elevation differences, corresponding soil fluxes were calculated. The mean translocation distance of all techniques was 0.57 m per tillage pass, with a relatively wide range of mean soil translocation distances ranging from 0.39 to 0.72 m per pass. A benchmark technique could not be identified as all used techniques have individual error sources, which could not be quantified. However, the translocation distances of the macro-tracers used were consistently smaller than the translocation distances of the micro-tracers (mean difference = - 26 ± 12%), which questions the widely used assumption of non-selective soil transport via tillage operations. This study points out that tillage erosion measurements, carried out under almost

  14. Soil workability as a basis for advice on tillage activities

    NARCIS (Netherlands)

    Cadena Zapata, M.

    1999-01-01

    In the tropical area of Mexico, when and how to carry out tillage is a qualitative decision. There is no quantified information about the interaction between a chosen process of cultivation, soil type and weather, which dictate the tool and power requirements. Waste of energy and soil

  15. Identifying conservation hotspots using tillage erosion modeling

    Science.gov (United States)

    Tillage operations redistribute soil within agricultural landscapes due to deviations in the quantity of soil moved during tillage. Tillage erosion is the net loss or accumulation of soil at any spot within an agricultural landscape due to soil being directly moved by tillage; it is a dominant erosi...

  16. Monitoring of Conservation Tillage and Tillage Intensity by Ground and Satellite Imagery

    Directory of Open Access Journals (Sweden)

    M.A Rostami

    2014-09-01

    Full Text Available Local information about tillage intensity and ground residue coverage is useful for policies in agricultural extension, tillage implement design and upgrading management methods. The current methods for assessing crop residue coverage and tillage intensity such as residue weighing methods, line-transect and photo comparison methods are tedious and time-consuming. The present study was devoted to investigate accurate methods for monitoring residue management and tillage practices. The satellite imagery technique was used as a rapid and spatially explicit method for delineating crop residue coverage and as an estimator of conservation tillage adoption and intensity. The potential of multispectral high-spatial resolution WorldView-2 local data was evaluated using the total of eleven satellite spectral indices and Linear Spectral Unmixing Analysis (LSUA. The total of ninety locations was selected for this study and for each location the residue coverage was measured by the image processing method and recorded as ground control. The output of indices and LSUA method were individually correlated to the control and the relevant R2 was calculated. Results indicated that crop residue cover was related to IPVI, RVI1, RVI2 and GNDVI spectral indices and satisfactory correlations were established (0.74 - 0.81. The crop residue coverage estimated from the LSUA approach was found to be correlated with the ground residue data (0.75. Two effective indices named as Infrared Percentage Vegetation Index (IPVI and Ratio Vegetation Index (RVI with maximum R2 were considered for classification of tillage intensity. Results indicated that the classification accuracy with IPVI and RVI indices in different conditions varied from 78-100 percent and therefore in good agreement with ground measurement, observations and field records.

  17. Influence of Tillage and Mulch on Soil Physical Properties and ...

    African Journals Online (AJOL)

    User

    tillage along with plastic mulch have positive impact on soil physical properties, root growth, water use efficiency ... positive effects on crop yield (Gla & Kulig,. 2008). ... potash fertilizers were applied at 120, 100 and 60 .... 0-10. 1.57B. 1.57B. 1.57B. 1.8B. 1.7B. 1.8B. Tillage × Soil depth. CTInitial. 0-5 ...... (Brassica napus). Eur.

  18. Water erosion and soil water infiltration in different stages of corn development and tillage systems

    Directory of Open Access Journals (Sweden)

    Daniel F. de Carvalho

    2015-11-01

    Full Text Available ABSTRACTThis study evaluated soil and water losses, soil water infiltration and infiltration rate models in soil tillage systems and corn (Zea mays, L. development stages under simulated rainfall. The treatments were: cultivation along contour lines, cultivation down the slope and exposed soil. Soil losses and infiltration in each treatment were quantified for rains applied using a portable simulator, at 0, 30, 60 and 75 days after planting. Infiltration rates were estimated using the models of Kostiakov-Lewis, Horton and Philip. Based on the obtained results, the combination of effects between soil tillage system and corn development stages reduces soil and water losses. The contour tillage system promoted improvements in soil physical properties, favoring the reduction of erosion in 59.7% (water loss and 86.6% (soil loss at 75 days after planting, and the increase in the stable infiltration rate in 223.3%, compared with the exposed soil. Associated to soil cover, contour cultivation reduces soil and water losses, and the former is more influenced by management. Horton model is the most adequate to represent soil water infiltration rate under the evaluated conditions.

  19. Two years monitoring of soil N_{2}O emissions on durum wheat in a Mediterranean area: the effect of tillage intensity and N-fertilizer rate.

    Science.gov (United States)

    Volpi, Iride; Bosco, Simona; Triana, Federico; Di Nasso, Nicoletta Nassi o.; Laville, Patricia; Virgili, Giorgio; Bonari, Enrico

    2016-04-01

    Evaluating the magnitude and the key factors affecting N2O emissions from agriculture has a scientific and practical relevance, in fact emissions from agricultural and natural soils account for 56-70% of all global N2O sources (Syakila and Kroeze, 2011). Moreover, the necessity to increase the food production rate minimizing greenhouse gas emissions require a deeper understanding of the effect of the agricultural practices on direct soil emissions. Therefore, the aim of this work is to assess the effect of tillage intensity and nitrogen rate on soil N2O emissions on durum wheat. A two years monitoring campaign was carried out using a high-sensibility transportable instrument developed within the LIFE+ "Improved flux Prototypes for N2O emission from Agriculture" IPNOA project (Bosco et al., 2015; Laville et al., 2015). The project aims at improving the measurement technique of N2O flux directly in field using the flow-through non-steady state chamber technique. The monitoring campaign on durum wheat lasted for two growing seasons and two fallow periods (2013-14 and 2014-15). Treatment on the main plot was tillage intensity with two levels, ploughing and minimum tillage, and three different nitrogen rates were distributed to the subplots (N0: 0 kg ha-1, N1: 110 kg ha-1, N2: 170 kg ha-1). Ancillary measurements concerned meteorological data, soil temperature and moisture, NO3-, NH4+ soil concentration. Main results of the two years highlighted N rate as the main driver for both N2O daily flux and cumulative emissions during the growing season, while in the fallow period treatments did not affect the emission magnitude. Tillage intensity was not a key factor for N2O emissions. N2O emissions were significantly different in the two years. In particular, cumulative emissions of 2013-14 were about five times higher than in 2014-15, respectively on average 2885±260 g N-N2O ha-1 and 534±53 g N-N2O ha-1 for a similar monitoring period of about 300 days. Differences could be

  20. Efectos de tratamientos de labranza sobre la resistencia a la penetración de un Andisol Effects of tillage treatments on penetration resistance on an andisol

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    Jiménez Javier

    1992-06-01

    Full Text Available Se evaluó el efecto sobre la resistencia a la penetración de cuatro implementos de labranza (arado de cinceles, arado de discos, rastrillo californiano y arado rotatorio en un Andisol (Andic-Eutropept serie Tibaitatá. Para las medidas, se utilizó un penetrómetro registrador digital. Los resultados mostraron que los tratamientos que involucraron arado rotatorio y arado de discos y rastrillo fueron los que causaron el mayor grado de aflojamiento del suelo. Sin embargo, dichos tratamientos fueron los más susceptibles a la compactación por pase de llantas. No se pudo concluir lo planteado por la literatura de que el fondo de surco de arado es una zona de alto
    riesgo de compactación del subsuelo. La resistencia a la penetración resultó un buen indicador para evaluar efectos físicos sobre el suelo causarlos por implementos de labranza y él tránsito de maquinaria.The effects on Cone Penetration Resistance caused by four tillage implements (chisel plow, disk plough, disk harrow and rotatiller were assesed on an Andisol, using a digital penetrometer. The results showed the treatments using rota-tiller and those using disk plough and disk harrow caused
    the maximun soilloosening. However those treatments were the most sensitive to compaction due to the traffic of tractor
    wheels. This work did not present conclusive evidence that bottom of furrow made by disk plough is a place of high risk for subsoil cornpactlon. Cone penetration resistance looks like a good index to assess changes in physical properties of the soil caused by tillage operations and machinery traffic.

  1. A multifractal approach to characterize cumulative rainfall and tillage effects on soil surface micro-topography and to predict depression storage

    Directory of Open Access Journals (Sweden)

    E. Vidal Vázquez

    2010-10-01

    discriminate data sets with similar values for the vertical component of roughness. Conversely, both, rough and smooth soil surfaces, with high and low roughness values, respectively, can display similar levels of spectral complexity. Although in most of the studied cases trend removal produces increasing homogeneity in the spatial configuration of height readings, spectral complexity of individual data sets may increase or decrease, when slope or slope plus tillage tool marks are filtered. Increased cumulative rainfall had significant effects on various parameters from the generalized dimension, Dq, and singularity spectrum, f(α. Overall, micro-topography decay by rainfall was reflected on a shift of the singularity spectra, f(α from the left side (q>>0 to the right side (q<<0 and also on a shift of the generalized dimension spectra from the right side (q>>0 to the left side (q<<0. The use of an exponential model of vertical roughness indices, RR, and multifractal parameters accounting for the spatial configuration such as D1 or D5 improved estimation of water stored in surface depressions.

  2. Effects of tillage and application rate on atrazine transport to subsurface drainage: Evaluation of RZWQM using a six-year field study

    Science.gov (United States)

    Malone, Robert W.; Nolan, Bernard T.; Ma, Liwang; Kanwar, Rameshwar S.; Pederson, Carl H.; Heilman, Philip

    2014-01-01

    Well tested agricultural system models can improve our understanding of the water quality effects of management practices under different conditions. The Root Zone Water Quality Model (RZWQM) has been tested under a variety of conditions. However, the current model's ability to simulate pesticide transport to subsurface drain flow over a long term period under different tillage systems and application rates is not clear. Therefore, we calibrated and tested RZWQM using six years of data from Nashua, Iowa. In this experiment, atrazine was spring applied at 2.8 (1990–1992) and 0.6 kg/ha/yr (1993–1995) to two 0.4 ha plots with different tillage (till and no-till). The observed and simulated average annual flow weighted atrazine concentrations (FWAC) in subsurface drain flow from the no-till plot were 3.7 and 3.2 μg/L, respectively for the period with high atrazine application rates, and 0.8 and 0.9 μg/L, respectively for the period with low application rates. The 1990–1992 observed average annual FWAC difference between the no-till and tilled plot was 2.4 μg/L while the simulated difference was 2.1 μg/L. These observed and simulated differences for 1993–1995 were 0.1 and 0.1 μg/L, respectively. The Nash–Sutcliffe model performance statistic (EF) for cumulative atrazine flux to subsurface drain flow was 0.93 for the no-till plot testing years (1993–1995), which is comparable to other recent model tests. The value of EF is 1.0 when simulated data perfectly match observed data. The order of selected parameter sensitivity for RZWQM simulated FWAC was atrazine partition coefficient > number of macropores > atrazine half life in soil > soil hydraulic conductivity. Simulations from 1990 to 1995 with four different atrazine application rates applied at a constant rate throughout the simulation period showed concentrations in drain flow for the no-till plot to be twice those of the tilled plot. The differences were more pronounced in the early

  3. Long-term influence of tillage and fertilization on net carbon dioxide exchange rate on two soils with different textures.

    Science.gov (United States)

    Feiziene, Dalia; Feiza, Virginijus; Slepetiene, Alvyra; Liaudanskiene, Inga; Kadziene, Grazina; Deveikyte, Irena; Vaideliene, Asta

    2011-01-01

    The importance of agricultural practices to greenhouse gas mitigation is examined worldwide. However, there is no consensus on soil organic carbon (SOC) content and CO emissions as affected by soil management practices and their relationships with soil texture. No-till (NT) agriculture often results in soil C gain, though, not always. Soil net CO exchange rate (NCER) and environmental factors (SOC, soil temperature [T], and water content [W]), as affected by soil type (loam and sandy loam), tillage (conventional, reduced, and NT), and fertilization, were quantified in long-term field experiments in Lithuania. Soil tillage and fertilization affected total CO flux (heterotrophic and autotrophic) through effect on soil SOC sequestration, water, and temperature regime. After 11 yr of different tillage and fertilization management, SOC content was 23% more in loam than in sandy loam. Long-term NT contributed to 7 to 27% more SOC sequestration on loam and to 29 to 33% more on sandy loam compared with reduced tillage (RT) or conventional tillage (CT). Soil water content in loam was 7% more than in sandy loam. Soil gravimetric water content, averaged across measurement dates and fertilization treatments, was significantly less in NT than CT and RT in both soils. Soil organic carbon content and water storage capacity of the loam and sandy loam soils exerted different influences on NCER. The NCER from the sandy loam soil was 13% greater than that from the loam. In addition, NCER was 4 to 9% less with NT than with CT and RT systems on both loam and sandy loam soils. Application of mineral NPK fertilizers promoted significantly greater NCER from loam but suppressed NCER by 15% from sandy loam. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  4. Quantifying Effectiveness of Streambank Stabilization Practices on Cedar River, Nebraska

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    Naisargi Dave

    2017-11-01

    Full Text Available Excessive sediment is a major pollutant to surface waters worldwide. In some watersheds, streambanks are a significant source of this sediment, leading to the expenditure of billions of dollars in stabilization projects. Although costly streambank stabilization projects have been implemented worldwide, long-term monitoring to quantify their success is lacking. There is a critical need to document the long-term success of streambank restoration projects. The objectives of this research were to (1 quantify streambank retreat before and after the stabilization of 18 streambanks on the Cedar River in North Central Nebraska, USA; (2 assess the impact of a large flood event; and (3 determine the most cost-efficient stabilization practice. The stabilized streambanks included jetties (10, rock-toe protection (1, slope reduction/gravel bank (1, a retaining wall (1, rock vanes (2, and tree revetments (3. Streambank retreat and accumulation were quantified using aerial images from 1993 to 2016. Though streambank retreat has been significant throughout the study period, a breached dam in 2010 caused major flooding and streambank erosion on the Cedar River. This large-scale flood enabled us to quantify the effect of one extreme event and evaluate the effectiveness of the stabilized streambanks. With a 70% success rate, jetties were the most cost-efficient practice and yielded the most deposition. If minimal risk is unacceptable, a more costly yet immobile practice such as a gravel bank or retaining wall is recommended.

  5. Economic and energy assessment of minimalized soil tillage methods in maize cultivation

    OpenAIRE

    Piotr Szulc; Andrzej Dubas

    2014-01-01

    Grain yield of maize cultivated in the years 1997-2009 in monoculture and with annual tillage simplifications was assessed in energy and economy terms. Effects of no-tillage system and direct sowing (D) with cultivation with autumn deep (A) and shallow (B) ploughing and cultivation with spring pre-sowing ploughing (C) were compared. It was demonstrated that the 13-year maize grain yield in no-tillage system and direct sowing was lower by 10.4% than the yield obtained in conventional tillage s...

  6. Turbulent characteristics of a semiarid atmospheric surface layer from cup anemometers – effects of soil tillage treatment (Northern Spain

    Directory of Open Access Journals (Sweden)

    S. Yahaya

    2003-10-01

    Full Text Available This paper deals with the characteristics of turbulent flow over two agricultural plots with various tillage treatments in a fallow, semiarid area (Central Aragon, Spain. The main dynamic characteristics of the Atmospheric Surface Layer (ASL measured over the experimental site (friction velocity, roughness length, etc., and energy budget, have been presented previously (Frangi and Richard, 2000. The current study is based on experimental measurements performed with cup anemometers located in the vicinity of the ground at 5 different levels (from 0.25 to 4 m and sampled at 1 Hz. It reveals that the horizontal wind variance, the Eulerian integral scales, the frequency range of turbulence and the turbulent kinetic energy dissipation rate are affected by the surface roughness. In the vicinity of the ground surface, the horizontal wind variance logarithmically increases with height, directly in relation to the friction velocity and the roughness length scale. It was found that the time integral scale (and subsequently the length integral scale increased with the surface roughness and decreased with the anemometer height. These variations imply some shifts in the meteorological spectral gap and some variations of the spectral peak length scale. The turbulent energy dissipation rate, affected by the soil roughness, shows a z-less stratification behaviour under stable conditions. In addition to the characterization of the studied ASL, this paper intends to show which turbulence characteristics, and under what conditions, are accessible through the cup anemometer.Key words. Meteorology and atmospheric dynamics (climatology, turbulence, instruments and techniques

  7. Turbulent characteristics of a semiarid atmospheric surface layer from cup anemometers – effects of soil tillage treatment (Northern Spain

    Directory of Open Access Journals (Sweden)

    S. Yahaya

    Full Text Available This paper deals with the characteristics of turbulent flow over two agricultural plots with various tillage treatments in a fallow, semiarid area (Central Aragon, Spain. The main dynamic characteristics of the Atmospheric Surface Layer (ASL measured over the experimental site (friction velocity, roughness length, etc., and energy budget, have been presented previously (Frangi and Richard, 2000. The current study is based on experimental measurements performed with cup anemometers located in the vicinity of the ground at 5 different levels (from 0.25 to 4 m and sampled at 1 Hz. It reveals that the horizontal wind variance, the Eulerian integral scales, the frequency range of turbulence and the turbulent kinetic energy dissipation rate are affected by the surface roughness. In the vicinity of the ground surface, the horizontal wind variance logarithmically increases with height, directly in relation to the friction velocity and the roughness length scale. It was found that the time integral scale (and subsequently the length integral scale increased with the surface roughness and decreased with the anemometer height. These variations imply some shifts in the meteorological spectral gap and some variations of the spectral peak length scale. The turbulent energy dissipation rate, affected by the soil roughness, shows a z-less stratification behaviour under stable conditions. In addition to the characterization of the studied ASL, this paper intends to show which turbulence characteristics, and under what conditions, are accessible through the cup anemometer.

    Key words. Meteorology and atmospheric dynamics (climatology, turbulence, instruments and techniques

  8. Tillage and Fertilizer Management Effects on Soil-Atmospheric Exchanges of Methane and Nitrous Oxide in a Corn Production System

    Directory of Open Access Journals (Sweden)

    Ermson Z. Nyakatawa

    2011-01-01

    Full Text Available Land application of poultry litter (PL presents an opportunity to improve soil productivity and disposal of poultry waste. We investigated methane (CH4 and nitrous oxide (N2O emissions from agricultural soil receiving PL and ammonium nitrate (AN fertilizers using surface (SA, soil incorporation (SI, and subsurface band (BA application methods in conventional (CT and no-tillage (NT systems on a Decatur silt loam soil in North Alabama. Plots under CT and NT were sinks of CH4 in spring, summer, and fall. In winter, the plots had net emissions of 3.32 and 4.24 g CH4 ha-1 day-1 in CT and NT systems, respectively. Plots which received AN were net emitters of CH4 and N2O, whereas plots which received PL were net sinks of CH4. Plots which received PL using SA or SI methods were net emitters of N2O, whereas under PL using BA application, the plots were net sinks of N2O. Our study indicates that using subsurface band application of PL was the most promising environmentally sustainable poultry waste application method for reducing CH4 and N2O emissions from agricultural soil in NT and CT corn production systems on the Decatur soil in north Alabama.

  9. Evaluating energy efficiency of site-specific tillage in maize in NE Italy.

    Science.gov (United States)

    Bertocco, M; Basso, B; Sartori, L; Martin, E C

    2008-10-01

    This paper examine the efficiency of energy use of three conservation tillage practices (SST - sub-soil tillage; MT - minimum tillage; and NT - no tillage) performed within two management zones, previously identified in a field according to the stability of yield variability. Experiments were carried out in 2003 in NE Italy, on a farm near Rovigo, on a 8-ha field with clay soil, in maize (Zea mays, L.). The purpose of the paper is (i) to investigate the energy variability due to these tillage practices performed spatially within two management zones and (ii) to analyze the long-term energetic efficiency for each tillage practice. The energy balance was highest for SST with respect to MT and NT, due to labor and fuel consumption rates. The energy balance was influenced by the spatial pattern of yield, with appreciable differences between practices in terms of both the conversion index of energy for tillage (9.0, 12.6 and 22.8GJha(-1) for SST, MT and NT, respectively) and the energy use efficiency for tillage (8.0, 11.6, 21.8GJha(-1) for SST, MT and NT, respectively). Based on the simulated data and the calibration results, SALUS model proved to be a good tool for analyzing long-term effects of tillage practices on yield. The NT treatment showed the best efficiency over years, due to the low inputs in comparison with the output level.

  10. Tillage methods and mulch on water saving and yield of spring maize in Chitwan

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    Ishwari Prasad Upadhyay

    2016-12-01

    Full Text Available Tillage methods and mulch influences the productivity and water requirement of spring maize hence a field experiment was conducted at the National Maize Research Program, Rampur in spring seasons of 2011 and 2012 with the objectives to evaluate different tillage methods with and without mulch on water requirement and grain yield of spring maize. The experiment was laid out in two factors factorial randomized complete design with three replications. The treatments consisted of tillage methods (Permanent bed, Zero tillage and Conventional tillage and mulch (with and without. Irrigation timing was fixed as knee high stage, tasseling stage and milking/dough stage. Data on number of plants, number of ears, thousand grain weight and grain yield were recorded and analysed using GenStat. Two years combined result showed that the effect of tillage methods and mulch significant influenced grain yield and water requirement of spring maize. The maize grain yield was the highest in permanent beds with mulch (4626 kg ha-1 followed by zero tillage with mulch (3838 kg ha-1. Whereas total water applied calculated during the crop period were the highest in conventional tillage without mulch followed by conventional tillage with mulch. The permanent bed with mulch increased the yield and reduced the water requirement of spring maize in Chitwan.

  11. Soil respiration in a long-term tillage treatment experiment

    Science.gov (United States)

    Gelybó, Györgyi; Birkás, Márta; Dencsö, Márton; Horel, Ágota; Kása, Ilona; Tóth, Eszter

    2016-04-01

    Regular soil CO2 efflux measurements have been carried out at Józsefmajor longterm tillage experimental site in 2014 and 2015 with static chamber technique in no-till and ploughing plots in seven spatial replicates. The trial was established in 2002 on a loamy chernozem soil at the experimental site of the Szent István University nearby the city Hatvan, northern Hungary. At the site sunflower (Helianthus A.) and wheat (Triticum A.) was grown in 2014 and 2015, respectively. Ancillary measurements carried out at the site included weather parameters, soil water content, soil temperature. The aim of the investigation was to detect the effect of soil disturbance and soil tillage treatments on soil CO2 emission in agricultural ecosystems. Soil respiration measurements were carried out every week during the vegetation period and campaign measurements were performed scheduled to tillage application. In this latter case, measurements were carried out 1, 2, 3, 4, 6, 12, 18, 24, 48, 72, 96, 120 hours and 7 days after tillage operation. Results showed that during the vegetation season in the majority of measurement occasions emission was higher in the no-till plots. These differences; however were not found to be statistically significant. Due to the short term effect of tillage treatment, emissions increased following tillage treatment in the ploughed plots. Soil water content was also examined as main driver of soil CO2 fluxes. Soil water content sharply decreases in the surface layer (5-10 cm depth) after tillage treatment indicating a fast drying due to soil disturbance. This effect slowly attenuated and eventually extincted in approx. two weeks. CO2 emission measurements were associated with high uncertainties as a result of the measurement technique. Our further aim is to reduce this uncertainty using independent measurement techniques on the field.

  12. Monoculture Maize (Zea mays L. Cropped Under Conventional Tillage, No-tillage and N Fertilization: (II Fumonisin Incidence on Kernels

    Directory of Open Access Journals (Sweden)

    Adriano Marocco

    2009-09-01

    Full Text Available Planting maize under no-tillage is an increasing farming practice for sustainable agriculture and sound environmental management. Although several studies on yield of no-till maize have been done, there is few information about the effect of tillage on fumonisin contamination. The present study was done to determine the effect of notillage and conventional tillage with two rates of nitrogen on fumonisin content in kernels of continuous maize. Average grain contamination with fumonisins B1 and B2 over the years 2004-06 was not significantly different, with mean values of 1682, 1984 and 2504 μg kg-1, respectively. Fumonisin B1 was the most abundant toxin found in the samples. No-tillage significantly affected the incidence of fumonisins during the first year of the trial, in which fumonisin content was significantly higher with no-till (2008 μg kg-1 compared with conventional tillage (1355 μg kg-1. However, no-tillage did not significantly affect the incidence of fumonisins in the second and third years of the study. Fumonisin content at the rate of 300 kg N ha-1 was not statistically different compared to that obtained without N fertilization. The interaction between the soil management system and the rate of applied nitrogen was only evident in the second year. Our results indicate that fumonisin contamination was affected by no-tillage only in the first year. Nitrogen fertilization had no significant effect on fumonisin content in any year. The weather conditions during susceptible stages of maize development have probably overridden the effect of nitrogen fertilization.

  13. Energy indices in irrigated wheat production under conservation and conventional tillage and planting methods

    Directory of Open Access Journals (Sweden)

    S. M Hosseini

    2016-04-01

    Full Text Available Introduction: Conservation tillage system was recommended for soil erosion control in North America for the first time 60 years ago (Wang et al., 2006. Using this tillage system including minimum and zero tillage has been rapidly developed in recent years. Thearea covered by zero tillage in 2006 was 95 million ha all over the world (Dumanski et al., 2006. In addition to saving soil and water resources, conservation tillage system reduces energy consumption and improves energy indices by combining different tillage and planting operations. Results of research conducted in Fars province shows that conservation tillage saves fuel consumption for 77% compared to the conventional system (Afzalinia et al., 2009. Conservation tillage also reduces energy consumption from 23.6 to 42.8% in comparison to the conventional tillage (Rusu, 2005. Since energy indices would be affected by reduced input energies in conservation tillage, this research was conducted to evaluate the effect of different tillage and planting methods on energy inputs and energy indices in irrigated wheat production in Eghlid region. Materials and Methods: This research was performed to evaluate and compare the energy indices in irrigated wheat production under different tillage and planting methods. The study was conducted in the form of a randomized complete block experimental design with five treatments and three replications in Eghlid region. The treatments were included, conventional tillage and seed broadcasting (A, conventional tillage and planting with Machine Barzegar grain drill (B, reduced tillage and seeding with Roto-seeder (C, direct seeding with Jairan Sanaat grain drill (D, and direct seeding with Sfoggia direct drill (E. Experimental plots with 10 by 50 m dimensions were used in this study. Loss crop residues were taken out of the experimental plots and standing crop residues were retained in the plots. In the conventional tillage method, primary tillage was performed

  14. Monitoring Two Small Catchments to Evaluate Effects of No-Tillage Agricultural Management in São Paulo State, Brazil

    Science.gov (United States)

    Figueiredo, R. D. O.; Gonçalves, A. O.; Melo, A. D. S.; de Bona, F. D.; Hernani, L. C.

    2015-12-01

    In recent years, declines in water and soil quality have been observed in areas of Brazil where no-till agriculture had been previously implemented. Poor soil management associated with the absence of public policies has caused soil erosion, because many farmers are moving back from no-till to traditional cultivation for faster economic gains. A research project - SoloVivo Project - leaded by Embrapa (Brazilian Agricultural Research Corporation) in partnership with Itaipu Binacional aims to develop and validate, in a participatory way, tools to evaluate the technical performance of soil and water management at the rural properties that practice no-till agriculture. In this context we have selected two paired small (figure bellow it can be seen a scene of one of the two studied catchments. For monitoring rainfall, soil solution and stream water, each catchment will be equipped with a programmable datalogger (with cell phone communication for data collection) linked to: a high intensity tipping bucket rain gage; a reflectometer to monitor soil volumetric water content, bulk electric conductivity and temperature; a radar water level sensor; a turbidity sensor; and an electric conductivity-temperature probe. We expect that stream flow and sediment generation, besides water quality (measured by conductivity) may serve as indicators of the benefits of no-tillage agriculture done more or less well. The results of this study will be used to stimulate discussions at workshops with the farmers who participate in a rural producers association in the region. In addition this and other results can be used to help the Brazilian National Water Agency (ANA) decide about applying no-till agricultural management systems in its programs of payment for environmental services.

  15. influence of tillage practices on physical properties of a sandy loam

    African Journals Online (AJOL)

    DR. AMINU

    many regions of the world if the mechanics of tillage effects on soil physical properties is to be well understood. Thus, the ... tillage systems on water storage of a sandy loam soil after 22 years of ..... Soil infiltration ... and processes. Academy ...

  16. Soil water retention as affected by tillage and residue management in semiarid Spain

    NARCIS (Netherlands)

    Bescansa, P.; Imaz, M.J.; Virto, I.; Enrique, A.; Hoogmoed, W.B.

    2006-01-01

    Conservation tillage preserves soil water and this has been the main reason for its rapid dissemination in rainfed agriculture in semiarid climates. We determined the effects of conservation versus conventional tillage on available soil water capacity (AWC) and related properties at the end of 5

  17. Effect of {sup 15}n-labeled hairy vetch and nitrogen fertilization on maize nutrition and yield under no-tillage

    Energy Technology Data Exchange (ETDEWEB)

    Almeida Acosta, Jose Alan de [Drakkar Solos, Santa Maria, RS (Brazil); Amado, Telmo Jorge Carneiro; Silva, Leandro Souza da, E-mail: tamado@smail.ufsm.b, E-mail: leandro@smail.ufsm.b [Universidade Federal de Santa Maria (UFSM), RS (Brazil). Soil Dept.; Neergaard, Andreas de; Vinther, Mads, E-mail: adn@life.ku.d [University of Copenhagen (Denmark); Silveira Nicoloso, Rodrigo da, E-mail: rodrigo.nicoloso@cnpsa.embrapa.b [Embrapa Swine and Poultry, Concordia, SC (Brazil)

    2011-07-15

    This study evaluated the effect of hairy vetch (Vicia villosa Roth) as cover crop on maize nutrition and yield under no tillage using isotope techniques. For this purpose, three experiments were carried out: quantification of biological nitrogen fixation (BNF) in hairy vetch; estimation of the N release rate from hairy vetch residues on the soil surface; quantification of {sup 15}N recovery by maize from labeled hairy vetch under three rates of mineral N fertilization. This two year field experiment was conducted on a sandy Acrisol (FAO soil classification) or Argissolo Vermelho distrofico arenico (Brazilian Soil Classification), at a mean annual temperature of 18 deg C and mean annual rainfall of 1686 mm. The experiment was arranged in a double split-plot factorial design with three replications. Two levels of hairy vetch residue (50 and 100 % of the aboveground biomass production) were distributed on the surface of the main plots (5 x 12 m). Maize in the sub-plots (5 x 4 m) was fertilized with three N rates (0, 60, and 120 kg ha{sup -1} N), with urea as N source. The hairy vetch-derived N recovered by maize was evaluated in microplots (1.8 x 2.2 m). The BFN of hairy vetch was on average 72.4 %, which represents an annual input of 130 kg ha{sup -1} of atmospheric N. The N release from hairy vetch residues was fast, with a release of about 90 % of total N within the first four weeks after cover crop management and soil residue application. The recovery of hairy vetch {sup 15}N by maize was low, with an average of 12.3 % at harvest. Although hairy vetch was not directly the main source of maize N nutrition, the crop yield reached 8.2 Mg ha{sup -1}, without mineral fertilization. There was an apparent synergism between hairy vetch residue application and the mineral N fertilization rate of 60 kg ha{sup -1}, confirming the benefits of the combination of organic and inorganic N sources for maize under no tillage. (author)

  18. Simulation of Tillage Systems Impact on Soil Biophysical Properties Using the SALUS Model

    Directory of Open Access Journals (Sweden)

    Luigi Sartori

    2011-02-01

    Full Text Available A sustainable land management has been defined as the management system that allows for production, while minimizing risk, maintaining quality of soil and water. Tillage systems can significantly decrease soil carbon storage and influence the soil environment of a crop. Crop growth models can be useful tools in evaluating the impact of different tillage systems on soil biophysical properties and on the growth and final yield of the crops. The objectives of this paper were i to illustrate the SALUS model and its tillage component; ii to evaluate the effects of different tillage systems on water infiltration and time to ponding, iii to simulate the effect of tillage systems on some soil biophysical properties. The SALUS (System Approach to Land Use Sustainability model is designed to simulate continuous crop, soil, water and nutrient conditions under different tillage and crop residues management strategies for multiple years. Predictions of changes in surface residue, bulk density, runoff, drainage and evaporation were consistent with expected behaviours of these parameters as described in the literature. The experiment to estimate the time to ponding curve under different tillage system confirmed the theory and showed the beneficial effects of the residue on soil surface with respect to water infiltration. It also showed that the no-tillage system is a more appropriate system to adopt in areas characterized by high intensity rainfall.

  19. Simulation of Tillage Systems Impact on Soil Biophysical Properties Using the SALUS Model

    Directory of Open Access Journals (Sweden)

    Bruno Basso

    2006-12-01

    Full Text Available A sustainable land management has been defined as the management system that allows for production, while minimizing risk, maintaining quality of soil and water. Tillage systems can significantly decrease soil carbon storage and influence the soil environment of a crop. Crop growth models can be useful tools in evaluating the impact of different tillage systems on soil biophysical properties and on the growth and final yield of the crops. The objectives of this paper were i to illustrate the SALUS model and its tillage component; ii to evaluate the effects of different tillage systems on water infiltration and time to ponding, iii to simulate the effect of tillage systems on some soil biophysical properties. The SALUS (System Approach to Land Use Sustainability model is designed to simulate continuous crop, soil, water and nutrient conditions under different tillage and crop residues management strategies for multiple years. Predictions of changes in surface residue, bulk density, runoff, drainage and evaporation were consistent with expected behaviours of these parameters as described in the literature. The experiment to estimate the time to ponding curve under different tillage system confirmed the theory and showed the beneficial effects of the residue on soil surface with respect to water infiltration. It also showed that the no-tillage system is a more appropriate system to adopt in areas characterized by high intensity rainfall.

  20. Quantifying induced effects of subsurface renewable energy storage

    Science.gov (United States)

    Bauer, Sebastian; Beyer, Christof; Pfeiffer, Tilmann; Boockmeyer, Anke; Popp, Steffi; Delfs, Jens-Olaf; Wang, Bo; Li, Dedong; Dethlefsen, Frank; Dahmke, Andreas

    2015-04-01

    New methods and technologies for energy storage are required for the transition to renewable energy sources. Subsurface energy storage systems such as salt caverns or porous formations offer the possibility of hosting large amounts of energy or substance. When employing these systems, an adequate system and process understanding is required in order to assess the feasibility of the individual storage option at the respective site and to predict the complex and interacting effects induced. This understanding is the basis for assessing the potential as well as the risks connected with a sustainable usage of these storage options, especially when considering possible mutual influences. For achieving this aim, in this work synthetic scenarios for the use of the geological underground as an energy storage system are developed and parameterized. The scenarios are designed to represent typical conditions in North Germany. The types of subsurface use investigated here include gas storage and heat storage in porous formations. The scenarios are numerically simulated and interpreted with regard to risk analysis and effect forecasting. For this, the numerical simulators Eclipse and OpenGeoSys are used. The latter is enhanced to include the required coupled hydraulic, thermal, geomechanical and geochemical processes. Using the simulated and interpreted scenarios, the induced effects are quantified individually and monitoring concepts for observing these effects are derived. This presentation will detail the general investigation concept used and analyze the parameter availability for this type of model applications. Then the process implementation and numerical methods required and applied for simulating the induced effects of subsurface storage are detailed and explained. Application examples show the developed methods and quantify induced effects and storage sizes for the typical settings parameterized. This work is part of the ANGUS+ project, funded by the German Ministry

  1. Tillage, fertilization systems and chemical attributes of a Paleudult

    Directory of Open Access Journals (Sweden)

    Evelyn Penedo Dorneles

    2015-02-01

    Full Text Available Tillage and fertilization methods may affect soil fertility. With the aim of assessing changes in soil chemical properties over a period of ten years, soil samples of a Paleudult were collected over nine seasons at three layer depths (0-5, 5-10, 10-20 cm and were chemically analyzed. Grain yield and nutrient export in two summer crops, soybean (Glycine max and corn (Zea mays, in a field experiment set in Eldorado do Sul, in the state of Rio Grande do Sul, Brazil, were determined. Three soil tillage systems were evaluated, conventional (CT, reduced (RT and no-tillage (NT, combined with mineral (lime and fertilizers and organic (poultry litter fertilization. The no-tillage system stood out as compared to the others, especially in the surface layer, in terms of values of organic matter, soil pH, available phosphorus, cation exchange capacity and base saturation. Phosphorus content was higher under organic than mineral fertilization due to the criteria used for the establishment of fertilizer doses. Under organic fertilization, soil pH values were similar to those obtained in limed soil samples because of the cumulative effect of the organic fertilizer. Soybean yield was lower under NT in comparison to the RT and CT systems. Consequently, soybean grain exported a lower content of nutrients than maize grain. Maize yield was not affected by either tillage or fertilization systems.

  2. Soil biological activity as affected by tillage intensity

    Science.gov (United States)

    Gajda, A. M.; Przewłoka, B.

    2012-02-01

    The effect of tillage intensity on changes of microbiological activity and content of particulate organic matter in soil under winter wheat duirng 3 years was studied. Microbial response related to the tillage-induced changes in soil determined on the content of biomass C and N, the rate of CO2 evolution, B/F ratio, the activity of dehydrogenases, acid and alkaline phosphatases, soil C/N ratio and microbial biomass C/N ratio confirmed the high sensitivity of soil microbial populations to the tillage system applied. After three year studies, the direct sowing system enhanced the increase of labile fraction of organic matter content in soil. There were no significant changes in the labile fraction quantity observed in soil under conventional tillage. Similar response related to the tillage intensity was observed in particulate organic matter quantities expressed as a percentage of total organic matter in soil. A high correlation coefficients calculated between contents of soil microbial biomass C and N, particulate organic matter and potentially mineralizable N, and the obtained yields of winter wheat grown on experimental fields indicated on a high importance of biological quality of status of soil for agricultural crop production.

  3. Repeated soil application of organic waste amendments reduces draught force and fuel consumption for soil tillage

    DEFF Research Database (Denmark)

    Peltrea, Clément; Nyord, Tavs; Bruun, Sander

    2015-01-01

    Abstract Soil application of organic waste products (OWP) can maintain or increase soil organic carbon (SOC) content, which in turn could lead to increased porosity and potentially to reduced energy use for soil tillage. Only a few studies have addressed the effect of SOC content on draught force...... for soil tillage, and this still needs to be addressed for fields that receive diverse types of organic waste of urban, agricultural and agro-industrial origin. The objective of this study was to determine the effect of changes in SOC induced by repeated soil application of OWP on draught force for soil...... tillage and tractor fuel consumption. Draught force was measured for tillage with conventional spring tillage tines, as well as bulk density, soil texture and SOC content in the CRUCIAL field experiment, Denmark in which diverse types of OWP had been applied annually for 11 years. The OWP included...

  4. Sediment yield control in vineyards covered with cereal. Effect of tillage; Control de la perdida de suelo en vinedos con cubiertas de gramineas. Efecto del laboreo

    Energy Technology Data Exchange (ETDEWEB)

    Ruiz-Colmenero, M.; Bienes, R.; Marques, M. J.

    2009-07-01

    A study has been carried out about the use of plant cover treatment to avoid land degradation in a hillside rainfed vineyard in Madrid under Mediterranean semiarid climate. Three treatments were tested: traditional tillage (lab) soil covered by Brachypodium distachyon (bra) with self-sowing, soil covered by Scale cereale (sec) mown in Spring. Three erosion plots per treatment were placed in the middle of the strips and 2 simulated rainfalls were carried out at each plot in autumn, before and after the tillage. (Author) 7 refs.

  5. Avaliação dos atributos físicos de um Nitossolo Vermelho distroférrico sob sistema plantio direto, preparo convencional e mata nativa Evaluation of physical attributes of a dystrophic Red Nitosol under no-tillage, conventional tillage and native forest systems

    Directory of Open Access Journals (Sweden)

    Renato Lara de Assis

    2005-07-01

    Full Text Available Com o aumento do tempo de uso do sistema plantio direto (SPD, atributos físicos do solo são modificados; entretanto, os efeitos ainda não estão bem quantificados. O presente estudo teve como objetivo avaliar o efeito do tempo de adoção do sistema plantio direto, comparativamente com área de mata nativa e preparo convencional, usando atributos físicos do solo em um Nitossolo Vermelho distroférrico. Os sistemas de manejo estudados foram: mata nativa (MN, preparo convencional (PC, plantio direto com um ano (PD1, plantio direto com quatro anos (PD4, plantio direto com cinco anos (PD5 e plantio direto com 12 anos (PD12. Os valores de densidade do solo foram menores na profundidade de 0-5 cm em relação a 10-15 cm para todos os sistemas. Os sistemas de manejo MN e PD12, na profundidade de 0-5 cm, apresentaram densidade do solo inferior à dos demais sistemas. O diâmetro médio geométrico (DMG dos agregados do solo foi crescente com o tempo de adoção do sistema plantio direto, na profundidade de 0-5 cm, e a mata nativa (MN apresentou maior DMG em ambas as profundidades. O tempo de adoção do SPD não promoveu diferenciação na porosidade total. O PD12 apresentou aumento da macroporosidade e diminuição da microporosidade na profundidade de 0-5 cm em relação aos demais sistemas. A resistência do solo à penetração não apresentou tendência predominante de variação com o tempo de adoção no SPD, tampouco em relação ao tipo de preparo. Os sistemas PD12 e MN apresentaram maiores velocidades de infiltração tridimensional de água no solo e condutividade hidráulica do solo saturado.As the time of adoption of no-tillage systems lengthens thee occur modification in soil physical attributes; however, these effects are not well quantified yet. The present study had the objective to evaluate the effect of time of adoption of a no-tillage system, compared to native forest and a conventional tillage system using physical attributes of

  6. Quantifying the dilution effect for models in ecological epidemiology.

    Science.gov (United States)

    Roberts, M G; Heesterbeek, J A P

    2018-03-01

    The dilution effect , where an increase in biodiversity results in a reduction in the prevalence of an infectious disease, has been the subject of speculation and controversy. Conversely, an amplification effect occurs when increased biodiversity is related to an increase in prevalence. We explore the conditions under which these effects arise, using multi species compartmental models that integrate ecological and epidemiological interactions. We introduce three potential metrics for quantifying dilution and amplification, one based on infection prevalence in a focal host species, one based on the size of the infected subpopulation of that species and one based on the basic reproduction number. We introduce our approach in the simplest epidemiological setting with two species, and show that the existence and strength of a dilution effect is influenced strongly by the choices made to describe the system and the metric used to gauge the effect. We show that our method can be generalized to any number of species and to more complicated ecological and epidemiological dynamics. Our method allows a rigorous analysis of ecological systems where dilution effects have been postulated, and contributes to future progress in understanding the phenomenon of dilution in the context of infectious disease dynamics and infection risk. © 2018 The Author(s).

  7. Quantifying the emissions reduction effectiveness and costs of oxygenated gasoline

    International Nuclear Information System (INIS)

    Lyons, C.E.

    1993-01-01

    During the fall, winter, and spring of 1991-1992, a measurement program was conducted in Denver, Colorado to quantify the technical and economic effectiveness of oxygenated gasoline in reducing automobile carbon monoxide (CO) emissions. Emissions from 80,000 vehicles under a variety of operating conditions were measured before, during, and after the seasonal introduction of oxygenated gasoline into the region. Gasoline samples were taken from several hundred vehicles to confirm the actual oxygen content of the fuel in use. Vehicle operating conditions, such as cold starts and warm operations, and ambient conditions were characterized. The variations in emissions attributable to fuel type and to operating conditions were then quantified. This paper describes the measurement program and its results. The 1991-1992 Colorado oxygenated gasoline program contributed to a reduction in carbon monoxide (CO) emissions from gasoline-powered vehicles. The measurement program demonstrated that most of the reduction is concentrated in a small percentage of the vehicles that use oxygenated gasoline. The remainder experience little or not reduction in emissions. The oxygenated gasoline program outlays are approximately $25 to $30 million per year in Colorado. These are directly measurable costs, incurred through increased government expenditures, higher costs to private industry, and losses in fuel economy. The measurement program determined the total costs of oxygenated gasoline as an air pollution control strategy for the region. Costs measured included government administration and enforcement, industry production and distribution, and consumer and other user costs. This paper describes the ability of the oxygenated gasoline program to reduce pollution; the overall cost of the program to government, industry, and consumers; and the effectiveness of the program in reducing pollution compared to its costs

  8. Improvement of native grassland by legumes introduction and tillage techniques

    Directory of Open Access Journals (Sweden)

    Syamsu Bahar

    1999-10-01

    Full Text Available A factorial design using three species of legumes (Siratro, Centro and Stylo and three different of tillage techniques (no-tillage, minimum tillage and total tillage was applied in this experiment. The results showed that there was no interaction between species and tillage techniques. There was significant reductions on bulk density from 1.23±0.03 g/cm3 (no-tillage to 1.07±0.02 g/cm3 (minimum tillage and 1.05±0.03 g/cm3 (total tillage. Also reductions on penetration resistance from 17.47±3.84 kg/cm2 (no-tillage to 3.31±0.43 kg/cm2 (minimum tillage and 3.19±0.45 kg/cm2 (total tillage. Otherwise significant increasing on aeration porosity from 12.80±0.80% vol. (no-tillage to 21.70±0.95% vol. (minimum tillage and 20.70±0.35% vol. (total tillage. Total tillage gives increased dry matter yield. Also both total tillage and minimum tillage give yields with a higher percentage of legumes compared with no-tillage. It was concluded that total tillage and minimum tillage could be used for improving native grassland.

  9. Fungal Communities in Rhizosphere Soil under Conservation Tillage Shift in Response to Plant Growth

    Directory of Open Access Journals (Sweden)

    Ziting Wang

    2017-07-01

    Full Text Available Conservation tillage is an extensively used agricultural practice in northern China that alters soil texture and nutrient conditions, causing changes in the soil microbial community. However, how conservation tillage affects rhizosphere and bulk soil fungal communities during plant growth remains unclear. The present study investigated the effect of long-term (6 years conservation (chisel plow, zero and conventional (plow tillage during wheat growth on the rhizosphere fungal community, using high-throughput sequencing of the internal transcribed spacer (ITS gene and quantitative PCR. During tillering, fungal alpha diversity in both rhizosphere and bulk soil were significantly higher under zero tillage compared to other methods. Although tillage had no significant effect during the flowering stage, fungal alpha diversity at this stage was significantly different between rhizosphere and bulk soils, with bulk soil presenting the highest diversity. This was also reflected in the phylogenetic structure of the communities, as rhizosphere soil communities underwent a greater shift from tillering to flowering compared to bulk soil communities. In general, less variation in community structure was observed under zero tillage compared to plow and chisel plow treatments. Changes in the relative abundance of the fungal orders Capnodiales, Pleosporales, and Xylariales contributed the highest to the dissimilarities observed. Structural equation models revealed that the soil fungal communities under the three tillage regimes were likely influenced by the changes in soil properties associated with plant growth. This study suggested that: (1 differences in nutrient resources between rhizosphere and bulk soils can select for different types of fungi thereby increasing community variation during plant growth; (2 tillage can alter fungal communities' variability, with zero tillage promoting more stable communities. This work suggests that long-term changes in

  10. Effects of tillage and cropping systems on yield and nitrogen fixation of cowpea intercropped with maize in northen Guinea savanna zone of Ghana

    International Nuclear Information System (INIS)

    Kombiok, J.M.; Safo, E.Y; Quansah, C.

    2006-01-01

    Published information is scanty on the response of crops in mixed cropping systems to the various tillage systems practised by farmers in the northern savanna zone of Ghana. A field experiment assessed the yield and nitrogen (N) fixation of cowpea (Vigna unguiculata (L.) Walp) intercropped with maize (Zea mays L.) on four different tillage systems at Nyankpala in the Northern Region of Ghana. The experiment was laid in a split-plot design with four replications. The main factor was tillage systems comprising conventional (Con), bullock plough (BP), hand hoe (HH) and zero tillage (ZT). The sub-factor was cropping systems (CRPSYT) which consisted of sole maize, sole cowpea, maize/cowpea inter-row cropping system, and bare fallow in 2000. The last named was replaced by maize/cowpea intra-row cropping system in 2001. The results showed that Con and BP, which produced over 10 cm plough depth, significantly reduced soil bulk density that favoured significant (P I). The LERs ranged from 1.43 to 1.79 in 2000, and from 1.23 to 1.24 in 2001 for Con and ZT, respectively. These indicate 33 and 52 percent mean increases in productivity of cowpea and maize, respectively, over their pure stands across the 2 years. However, grain yields of both crops from the inter- and intra-row cropping systems were not different. (au)

  11. Particulate emissions calculations from fall tillage operations using point and remote sensors.

    Science.gov (United States)

    Moore, Kori D; Wojcik, Michael D; Martin, Randal S; Marchant, Christian C; Bingham, Gail E; Pfeiffer, Richard L; Prueger, John H; Hatfield, Jerry L

    2013-07-01

    Soil preparation for agricultural crops produces aerosols that may significantly contribute to seasonal atmospheric particulate matter (PM). Efforts to reduce PM emissions from tillage through a variety of conservation management practices (CMPs) have been made, but the reductions from many of these practices have not been measured in the field. A study was conducted in California's San Joaquin Valley to quantify emissions reductions from fall tillage CMP. Emissions were measured from conventional tillage methods and from a "combined operations" CMP, which combines several implements to reduce tractor passes. Measurements were made of soil moisture, bulk density, meteorological profiles, filter-based total suspended PM (TSP), concentrations of PM with an equivalent aerodynamic diameter ≤10 μm (PM) and PM with an equivalent aerodynamic diameter ≤2.5 μm (PM), and aerosol size distribution. A mass-calibrated, scanning, three-wavelength light detection and ranging (LIDAR) procedure estimated PM through a series of algorithms. Emissions were calculated via inverse modeling with mass concentration measurements and applying a mass balance to LIDAR data. Inverse modeling emission estimates were higher, often with statistically significant differences. Derived PM emissions for conventional operations generally agree with literature values. Sampling irregularities with a few filter-based samples prevented calculation of a complete set of emissions through inverse modeling; however, the LIDAR-based emissions dataset was complete. The CMP control effectiveness was calculated based on LIDAR-derived emissions to be 29 ± 2%, 60 ± 1%, and 25 ± 1% for PM, PM, and TSP size fractions, respectively. Implementation of this CMP provides an effective method for the reduction of PM emissions. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

  12. Temporal Dynamics of Soil Microbial Communities below the Seedbed under Two Contrasting Tillage Regimes

    Directory of Open Access Journals (Sweden)

    Florine Degrune

    2017-06-01

    Full Text Available Agricultural productivity relies on a wide range of ecosystem services provided by the soil biota. Plowing is a fundamental component of conventional farming, but long-term detrimental effects such as soil erosion and loss of soil organic matter have been recognized. Moving towards more sustainable management practices such as reduced tillage or crop residue retention can reduce these detrimental effects, but will also influence structure and function of the soil microbiota with direct consequences for the associated ecosystem services. Although there is increasing evidence that different tillage regimes alter the soil microbiome, we have a limited understanding of the temporal dynamics of these effects. Here, we used high-throughput sequencing of bacterial and fungal ribosomal markers to explore changes in soil microbial community structure under two contrasting tillage regimes (conventional and reduced tillage either with or without crop residue retention. Soil samples were collected over the growing season of two crops (Vicia faba and Triticum aestivum below the seedbed (15–20 cm. Tillage, crop and growing stage were significant determinants of microbial community structure, but the impact of tillage showed only moderate temporal dependency. Whereas the tillage effect on soil bacteria showed some temporal dependency and became less strong at later growing stages, the tillage effect on soil fungi was more consistent over time. Crop residue retention had only a minor influence on the community. Six years after the conversion from conventional to reduced tillage, soil moisture contents and nutrient levels were significantly lower under reduced than under conventional tillage. These changes in edaphic properties were related to specific shifts in microbial community structure. Notably, bacterial groups featuring copiotrophic lifestyles or potentially carrying the ability to degrade more recalcitrant compounds were favored under conventional

  13. Temporal Dynamics of Soil Microbial Communities below the Seedbed under Two Contrasting Tillage Regimes.

    Science.gov (United States)

    Degrune, Florine; Theodorakopoulos, Nicolas; Colinet, Gilles; Hiel, Marie-Pierre; Bodson, Bernard; Taminiau, Bernard; Daube, Georges; Vandenbol, Micheline; Hartmann, Martin

    2017-01-01

    Agricultural productivity relies on a wide range of ecosystem services provided by the soil biota. Plowing is a fundamental component of conventional farming, but long-term detrimental effects such as soil erosion and loss of soil organic matter have been recognized. Moving towards more sustainable management practices such as reduced tillage or crop residue retention can reduce these detrimental effects, but will also influence structure and function of the soil microbiota with direct consequences for the associated ecosystem services. Although there is increasing evidence that different tillage regimes alter the soil microbiome, we have a limited understanding of the temporal dynamics of these effects. Here, we used high-throughput sequencing of bacterial and fungal ribosomal markers to explore changes in soil microbial community structure under two contrasting tillage regimes (conventional and reduced tillage) either with or without crop residue retention. Soil samples were collected over the growing season of two crops ( Vicia faba and Triticum aestivum ) below the seedbed (15-20 cm). Tillage, crop and growing stage were significant determinants of microbial community structure, but the impact of tillage showed only moderate temporal dependency. Whereas the tillage effect on soil bacteria showed some temporal dependency and became less strong at later growing stages, the tillage effect on soil fungi was more consistent over time. Crop residue retention had only a minor influence on the community. Six years after the conversion from conventional to reduced tillage, soil moisture contents and nutrient levels were significantly lower under reduced than under conventional tillage. These changes in edaphic properties were related to specific shifts in microbial community structure. Notably, bacterial groups featuring copiotrophic lifestyles or potentially carrying the ability to degrade more recalcitrant compounds were favored under conventional tillage, whereas

  14. Spatially quantifying the leadership effectiveness in collective behavior

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Haitao [State Key Laboratory of Digital Manufacturing Equipment and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Wang Ning [Department of Control Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Chen, Michael Z Q [Department of Mechanical Engineering, University of Hong Kong, Pok Fu Lam Road, Hong Kong (Hong Kong); Su Riqi; Zhou Tao [Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China); Zhou Changsong, E-mail: zht@mail.hust.edu.cn, E-mail: cszhou@hkbu.edu.hk, E-mail: zhutou@ustc.edu [Department of Physics, Centre for Nonlinear Studies, and Beijing-Hong Kong-Singapore Joint Centre for Nonlinear and Complex Systems (Hong Kong), Hong Kong Baptist University, Kowloon Tong (Hong Kong)

    2010-12-15

    Among natural biological flocks/swarms or mass social activities, when the collective behavior of the followers has been dominated by the direction or opinion of one leader group, it seems difficult for later-coming leaders to reverse the orientation of the mass followers, especially when they are in quantitative minority. This paper, however, reports a counter-intuitive phenomenon, i.e. Following the Later-coming Minority, provided that the later-comers obey a favorable distribution pattern that enables them to spread their influence to as many followers as possible within a given time and to be dense enough to govern these local followers they can influence directly from the beginning. We introduce a discriminant index to quantify the whole group's orientation under competing leaderships, with which the eventual orientation of the mass followers can be predicted before launching the real dynamical procedure. From the application point of view, this leadership effectiveness index also helps us to design an economical way for the minority later-coming leaders to defeat the dominating majority leaders solely by optimizing their spatial distribution pattern provided that the premeditated goal is available. Our investigation provides insights into effective leadership in biological systems with meaningful implications for social and industrial applications.

  15. Spatially quantifying the leadership effectiveness in collective behavior

    International Nuclear Information System (INIS)

    Zhang Haitao; Wang Ning; Chen, Michael Z Q; Su Riqi; Zhou Tao; Zhou Changsong

    2010-01-01

    Among natural biological flocks/swarms or mass social activities, when the collective behavior of the followers has been dominated by the direction or opinion of one leader group, it seems difficult for later-coming leaders to reverse the orientation of the mass followers, especially when they are in quantitative minority. This paper, however, reports a counter-intuitive phenomenon, i.e. Following the Later-coming Minority, provided that the later-comers obey a favorable distribution pattern that enables them to spread their influence to as many followers as possible within a given time and to be dense enough to govern these local followers they can influence directly from the beginning. We introduce a discriminant index to quantify the whole group's orientation under competing leaderships, with which the eventual orientation of the mass followers can be predicted before launching the real dynamical procedure. From the application point of view, this leadership effectiveness index also helps us to design an economical way for the minority later-coming leaders to defeat the dominating majority leaders solely by optimizing their spatial distribution pattern provided that the premeditated goal is available. Our investigation provides insights into effective leadership in biological systems with meaningful implications for social and industrial applications.

  16. Conservation tillage, optimal water and organic nutrient supply enhance soil microbial activities during wheat (Triticum Aestivum L.) cultivation

    Science.gov (United States)

    Sharma, Pankaj; Singh, Geeta; Singh, Rana P.

    2011-01-01

    The field experiments were conducted on sandy loam soil at New Delhi, during 2007 and 2008 to investigate the effect of conservation tillage, irrigation regimes (sub-optimal, optimal and supra-optimal water regimes), and integrated nutrient management (INM) practices on soil biological parameters in wheat cultivation. The conservation tillage soils has shown significant (pbiofertilizer+25% Green Manure) has been used in combination with the conservation tillage and the optimum water supply. Study demonstrated that microbial activity could be regulated by tillage, water and nitrogen management in the soil in a sustainable manner. PMID:24031665

  17. Weed Population Dynamics, Water Productivity and Grain Yield of Durum Wheat (Triticum durum L. in No-Tillage and Conventional Tillage Systems

    Directory of Open Access Journals (Sweden)

    Mehdi Mojab

    2016-09-01

    Full Text Available Introduction: Elimination or reduction of tillage in conservation agricultural systems has led to wide variations in germination, emergence, and growth of weeds and has caused variations in the density and diversity of weeds under such systems. Maintaining crop residues on the soil surface has many potential benefits in agricultural production systems; such as reducing water and wind erosions, increasing the soil organic matter content, improving the soil structure and sowing conditions, as well as a better weed management through allelopathy or physical interference provided by the crop residues. Crop residue and tillage system cause potential changes in the soil temperature and water content, which influence soil density, structure, moisture, as well as soil temperature and nutrients. Crop residues act as mulches and can effect on weed seed germination and seedling emergence. Therefore, the objectives of current study were to evaluate the effects of no-tillage systems on: (i narrow- and broadleaved weed densities, (ii crop yield and (iii water productivity (WP. Materials and Methods: A two-year field study based on a split plot experiment in a randomized complete block design with four replications was carried out in Zahedshahr, Fars province, Iran (latitude 28˚44΄N, longitude 53˚48΄E, 1180 m altitude during 2009-10 and 2010-11 growing seasons. The planting practices including moldboard plow, disk and leveler were practiced in conventional tillage plots and crop planting was performed using a drill seeder (made by Kohorasan Co., Iran. The no-tillage plots were directly planted without any soil disturbance and removing wheat residues of the last year using a direct planter machine (model Berteni, Argentina. Furrow irrigation was used at both systems and a water counter (model WD, size DN100 was applied to measure the amount of used water based on m3 ha-1. 1 x 1 m quadrates that were installed at the center of each plot. Crop density, narrow

  18. to Phosphorus Fertilization, Crop Sequence and Tillage Management

    Directory of Open Access Journals (Sweden)

    Xiaopeng Gao

    2012-01-01

    Full Text Available Field experiments were conducted at two locations in Manitoba, Canada, to determine the effect of crop rotation, phosphorus (P fertilization and tillage on grain yield and grain concentrations of Cd and Zn in durum wheat (Triticum durum L.. Compared to conventional tillage (CT, reduced tillage (RT management decreased grain Cd and increased grain yield and grain Zn in half of the site-years. The type of preceding crops of spring wheat-flax or canola-flax had little influence. Rate and timing of P application had little effect on grain Cd, but increasing P rate tended to decrease grain Zn. No interactive effect was detected among tested factors. Grain Zn was not related to grain Cd, but positively to other nutrients such as Fe, Mn, P, Ca, K, and Mg. Both grain Zn and Fe correlated positively with grain protein content, suggesting protein may represent a sink for micronutrients. The study suggested that the tillage management may have beneficial effects on both grain yield and quality. Phosphorus fertilizer can remain available for subsequent crops and high annual inputs in the crop sequence may decrease crop grain Zn. Understanding the environment is important in determining the impact of agricultural management on agronomic and nutrient traits.

  19. Yield and water use efficiencies of maize and cowpea as affected by tillage and cropping systems in semi-arid Eastern Kenya

    International Nuclear Information System (INIS)

    Miriti, M.J; Kironchi, G; Gachene, K.K.C; Esilaba, O.A.; Mwangi, M.D; Heng, K.L

    2012-01-01

    Soil water conservation through tillage is widely accepted as one of the ways of improving crop yields in rainfed agriculture. Field experiments were conducted between 2007 and 2009 to evaluate the effects of conservation tillage on the yields and crop water use efficiency of maize (Zea mays L.) and cowpea (Vigna unguiculata L.) in eastern Kenya. Experimental treatments were a combination of three tillage practices and four cropping systems. Tillage practices were tied-ridges, subsoiling-ripping and ox-ploughing. The cropping systems were single crop maize, single crop cowpea, intercropped maize.cowpea and single crop maize with manure. The treatments were arranged in split plots with tillage practices as the main plots and cropping systems as the sub-plots in a Randomized Complete Block Design (RCBD). The results showed that tied-ridge tillage had the greatest plant available water content while subsoiling-ripping tillage had the least in all seasons. Averaged across seasons and cropping season, tillage did not have a significant effects on maize grain yield but it did have a significant effect on crop grain and dry matter water use efficiency (WUE). Nevertheless, maize grain yields and WUE values were generally greater under tied-ridge tillage than under subsoiling-ripping and ox-plough tillages. The yields and WUE of cowpea under subsoiling-ripping tillage were less than those of ox-plough tillage. When averaged across the seasons and tillage systems, the cropping system with the manure treatment increased (P.0.05) maize grain yield, grain WUE and dry matter WUE by 36%, 30%, 26% respectively, compared to treatments without manure. Maize and cowpea when intercropped under ox-plough and ripping tillage systems did not have any yield advantage over the single crop

  20. Efeitos de sistemas de cultivo na densidade e macroporosidade do solo e no desenvolvimento radicular do milho em latossolo roxo Effects of tillage systems on bulk density, aeration porosity and root development of corn in a typic haplorthox soil

    Directory of Open Access Journals (Sweden)

    Paulo César Corsini

    1999-02-01

    Full Text Available Neste trabalho foram estudados os efeitos imediato e residual de dois sistemas de preparo na densidade e macroporosidade do solo e no desenvolvimento radicular do milho (Zea mays L., em camadas estruturalmente estabilizadas de um Latossolo Roxo, mantido por longo período sob plantio direto de milho. Os efeitos imediatos das operações envolvendo a subsolagem e a aração e gradagem aumentaram, em menos de um ano agrícola, a macroporosidade da camada superficial desse solo bem como o potencial de desenvolvimento radicular. Nesses tratamentos e nos três primeiros anos agrícolas, a adoção contínua do sistema de plantio direto diminuiu a porosidade de aeração do solo e o potencial de desenvolvimento radicular do milho. Os benefícios da manutenção desse sistema conservacionista nos valores de macroporosidade e densidade na camada superficial do solo iniciaram-se no quarto ano agrícola. A partir daí aumentaram, atingindo no oitavo ano agrícola consecutivo valores semelhantes aos imediatamente obtidos após as operações mecânicas realizadas na instalação do experimento. As relações entre desenvolvimento radicular, densidade e macroporosidade do solo foram estabelecidas por equações bem como por classes de desenvolvimento radicular.The objective of this study was to evaluate the immediate and the residual effects of soil preparation on bulk density, aeration porosity and root development relationships in stabilized structural layers of a typic Haplorthox soil due to long-term no-tillage system of corn (Zea mays L..The immediate effects of soil preparation to planting involving subsoiling, plowing, and disking improved soil macroporosity and root development for a short period of time. In these treatments and on the first three consecutive years, the adoption of continuous no-tillage management decreased soil macroporosity and root development. The long-term benefits of continuous no-tillage on soil macroporosity initiated at the

  1. Do Tillage Methods Affect Germination and Species Similarity of Soil Weed Seeds Bank?

    Directory of Open Access Journals (Sweden)

    Shahgholi Hassan

    2015-12-01

    Full Text Available Cultural practices such as tillage used for crop production influence the composition of the weed seed bank in the soil. In order to investigate the effects of different tillage methods on seed bank properties, species diversity and similarity, two laboratory and greenhouse experiments were carried out as randomized complete block design with four replications in 2011. Treatments included: once tillage per year (T1, twice tillage per year (T2, more than twice tillage (T3 and no tillage (T4. Laboratory results showed that the T3 and T4 treatments had the highest and the lowest observed seeds numbers, respectively. Between the laboratory observed weed seeds, the maximum weed seed numbers were Echinochloa crus-galli and Amaranthus retroflexus in the T3 treatment, while Chenopodium album, Polygonum aviculare and Cuscuta campestris had the highest seed numbers in the T2 treatment. At the greenhouse study, Chenopodium album, Amaranthus retroflexus and Hordeum morinum in the T2 treatment were dominant species. The highest diversity was observed in the T2 treatment, and Chenopodium album and Echinochloa crus-galli were dominant species in the T2 and T3 treatments. Maximum species similarity index was achieved from the T1 and T3 treatments. Thereby this study concluded that increasing of tillage number could affect the similarity index of weed seeds and subsequently alters the weed community composition.

  2. [Conservation tillage systems in North America and their significance for China].

    Science.gov (United States)

    Yang, Xueming; Zhang, Xiaoping; Fang, Huajun; Liang, Aizhen; Qi, Xiaoning; Wang, Yang

    2004-02-01

    Soil degradation through erosion and desertification reduces soil productivity, and is a serious problem in agricultural production of China. To avert our arable land from further degradation, soil management must be shifted from degrading tillage to conservation practices. Over viewing the technology used in the 20th century for controlling soil degradation from erosion, conservation tillage developed in the United States and adopted in South America and Africa is one of the most successful measures to overcome soil degradation problems. This paper reviewed the historical development and the current situation of conservation tillage systems used in North and South America, with special reference to their effects on soil erosion control and soil quality. The increasing adoption of conservation tillage systems in North and South America and Africa followed an enhanced awareness of the increasing risk of soil erosion and the high cost of fuel associated with conventional tillage. Many crucial points for successfully adopting conservation tillage systems were emphasized, such as equipment/tool development and chemical weed control. Adopting conservation tillage could provide China with low-priced means of reducing soil degradation and improving soil and water quality.

  3. Variations in thematic mapper spectra of soil related to tillage and crop residue management - Initial evaluation

    Science.gov (United States)

    Seeley, M. W.; Ruschy, D. L.; Linden, D. R.

    1983-01-01

    A cooperative research project was initiated in 1982 to study differences in thematic mapper spectral characteristics caused by variable tillage and crop residue practices. Initial evaluations of radiometric data suggest that spectral separability of variably tilled soils can be confounded by moisture and weathering effects. Separability of bare tilled soils from those with significant amounts of corn residue is enhanced by wet conditions, but still possible under dry conditions when recent tillage operations have occurred. In addition, thematic mapper data may provide an alternative method to study the radiant energy balance at the soil surface in conjunction with variable tillage systems.

  4. Efeitos de sistemas de preparo nas propriedades físicas de um Latossolo Vermelho distrófico Effects of tillage systems on the soil physical properties of a dystrophic Red Latosol

    Directory of Open Access Journals (Sweden)

    Karina Maria Vieira Cavalieri

    2006-02-01

    residue management are essential for the sustainability of cassava production in sandy and sandy loam soils of Northwestern Paraná State, Southern Brazil. The objective of this study was to evaluate the effects of different tillage systems used for planting cassava: no-tillage (NT, minimum tillage using chiseling (MT and conventional tillage with moldboard plow and disking (CT on some physical properties of a dystrophic Red Latosol. The following soil physical properties were evaluated in the 0-0.15 m and 0.15-0.30 m soil layers: soil bulk density (BD, soil water retention curve, soil resistance to penetration curve and least limiting water range (LLWR. Higher values of BD and soil resistance to penetration were verified in the NT and MT treatments. The soil water retention curve was only influenced by BD, which incorporated the effects of the soil tillage systems independent of sampled layers. The soil resistance curve to penetration was influenced by tillage systems and layers, indicating that the soil resistance to root penetration was higher in NT > MT > CT, and was accentuated at the 0.15-0.30 m depth. The increase in the BD led to a reduction in the LLWR due to the effects of soil resistance to penetration and air-filled porosity, which in turn determined the range of soil available water. Results indicated that LLWR value followed the sequence: PC = PM > PSR in the 0-0.15 m soil layer, and was not influenced by tillage systems in the 0.15-0.30 soil layer The critical bulk density value (BDc, the BD value at which LLWR = 0, was lower in NT and MT tillage systems compared with CT, therefore resulting in a smaller frequency of higher BD values than BDc in the soil under CT.

  5. Infiltration of surface mined land reclaimed by deep tillage treatments

    International Nuclear Information System (INIS)

    Chong, S.K.; Cowsert, P.

    1994-01-01

    Surface mining of coal leads to the drastic disturbance of soils. Compaction of replaced subsoil and topsoil resulting from hauling, grading, and leveling procedures produces a poor rooting medium for crop growth. Soil compaction results in high bulk density, low macroporosity, poor water infiltration capacity, and reduced elongation of plant roots. In the United States, Public Law 95-87 mandates that the rooting medium of mined soils have specific textural characteristics and be graded and shaped to a topography similar to premining conditions. Also, crop productivity levels equivalent to those prior to mining must be achieved, especially for prime farmland. Alleviation of compaction has been the major focus of reclamation, and recently new techniques to augment the rooting zone with deep-ripping and loosening equipment have come to the forefront. Several surface mine operators in the Illinois coal basin are using deep tillage equipment that is capable of loosening soils to greater depths than is possible with conventional farm tillage equipment. Information on the beneficial effects of these loosening procedures on soil hydrological properties, such as infiltration, runoff potential, erosion, and water retention, is extremely important for future mined land management. However, such information is lacking. In view of the current yield demonstration regulation for prime farmland and other unmined soils, it is important that as much information as possible be obtained concerning the effect of deep tillage on soil hydrologic properties. The objectives of this study are: (1) to compare infiltration rates and related soil physical properties of mined soils reclaimed by various deep tillage treatments and (2) to study the temporal variability of infiltration and related physical properties of the reclaimed mined soil after deep tillage treatment

  6. Tillage, crop residue, and nutrient management effects on soil organic carbon sequestration in rice-based cropping systems: a review

    Science.gov (United States)

    Sequestration of soil organic carbon (SOC) is one of the major agricultural strategies to mitigate greenhouse gas emissions, enhance food security, and improve agricultural sustainability. This paper synthesizes the much-needed state-of-knowledge on the effects of management practices, such as tilla...

  7. Nitrate Leaching From Grain Maize After Different Tillage Methods and Long/Short Term Cover Cropping

    DEFF Research Database (Denmark)

    Hansen, Elly Møller

    trial initiated in 1968 on a coarse sandy soil. The previous trial included spring sown crops undersown (with or without) perennial ryegrass (Lolium perenne L.) as cover crop, two N-rates (90 and 120 kg N ha-1) and different tillage methods (shallow tillage and ploughing autumn or spring). With maize......) previous history of long-term cover cropping, ii) soil tillage methods, iii) N rates and iv) present short-term use of cover cropping in maize. Preliminary results from 2009 – 2011 suggest that leaching after a history of cover cropping tended to be higher than after no history of cover cropping......, but the effect was insignificant. The effect of tillage and previous N rates were also insignificant but the present use of cover crops had a small but significant decreasing effect on leaching compared to no cover cropping. The cover crop was well established in both years but grew less vigorously during autumn...

  8. PORE SIZE DISTRIBUTION AND SOIL HYDRO PHYSICAL PROPERTIES UNDER DIFFERENT TILLAGE PRACTICES AND COVER CROPS IN A TYPIC HAPLUSULT IN NORTHERN NIGERIA

    Directory of Open Access Journals (Sweden)

    Halima Mohammed Lawal

    2017-05-01

    Full Text Available Tillage practices influence soil physical, chemical and biological qualities which in-turn alters plant growth and crop yield. In the Northern Guinea Savanna (NGS ecological zone of Nigeria, agricultural production is mainly constrained by low soil nutrient and water holding capacity, it is therefore, imperative to develop appropriate management practices that will give optimal soil hydro-physical properties for proper plant growth, effective soil and water management and environmental conservation. This study investigated the effect of three tillage practices (no till, reduced till and conventional till and four cover crops (Centrosema pascuorum, Macrotyloma uniflorum, Cucurbita maxima and Glyine max and a bare/control (no cover crop on some soil physical properties of a Typic Haplusult during the rainy seasons of 2011, 2012 and 2013 in Samaru, NGS ecological zone of Nigeria. The field trials were laid out in a split plot arrangement with tillage practices in the main plots and cover crops in the subplots, all treatments were replicated three times. Auger and core soil samples were collected at the end of each cropping season each year in three replicates from each treatment plot at four depths (0-5, 5-10, 10-15 and 15-20 cm. Particle size distribution, bulk density, total pore volume and water retention at various soil matric potentials were determined using standard methods. Data obtained were compared with optimum values and fitted into a RETC computer code for quantifying soil hydraulic behavior and physical quality. Results showed that different tillage practices had varied effect on soil physical properties. No-till had the highest water holding capacity at most suction points evaluated, it had 4.3 % and 12.9 % more soil moisture than the reduced till  and conventionally tilled systems across all matric potentials while Centrosema pascuorum (3.1% and Cucurbita maxima (5.5% were best among evaluated cover crops in retaining soil moisture

  9. Pitfalls in quantifying species turnover: the residency effect

    Directory of Open Access Journals (Sweden)

    Kevin Chase Burns

    2014-03-01

    Full Text Available The composition of ecological communities changes continuously through time and space. Understanding this turnover in species composition is a central goal in biogeography, but quantifying species turnover can be problematic. Here, I describe an underappreciated source of bias in quantifying species turnover, namely ‘the residency effect’, which occurs when the contiguous distributions of species across sampling domains are small relative to census intervals. I present the results of a simulation model that illustrates the problem theoretically and then I demonstrate the problem empirically using a long-term dataset of plant species turnover on islands. Results from both exercises indicate that empirical estimates of species turnover may be susceptible to significant observer bias, which may potentially cloud a better understanding of how the composition of ecological communities changes through time.

  10. Soil organic carbon sequestration and tillage systems in Mediterranean environments

    Science.gov (United States)

    Francaviglia, Rosa; Di Bene, Claudia; Marchetti, Alessandro; Farina, Roberta

    2016-04-01

    Soil carbon sequestration is of special interest in Mediterranean areas, where rainfed cropping systems are prevalent, inputs of organic matter to soils are low and mostly rely on crop residues, while losses are high due to climatic and anthropic factors such as intensive and non-conservative farming practices. The adoption of reduced or no tillage systems, characterized by a lower soil disturbance in comparison with conventional tillage, has proved to be positively effective on soil organic carbon (SOC) conservation and other physical and chemical processes, parameters or functions, e.g. erosion, compaction, ion retention and exchange, buffering capacity, water retention and aggregate stability. Moreover, soil biological and biochemical processes are usually improved by the reduction of tillage intensity. The work deals with some results available in the scientific literature, and related to field experiment on arable crops performed in Italy, Greece, Morocco and Spain. Data were organized in a dataset containing the main environmental parameters (altitude, temperature, rainfall), soil tillage system information (conventional, minimum and no-tillage), soil parameters (bulk density, pH, particle size distribution and texture), crop type, rotation, management and length of the experiment in years, initial SOCi and final SOCf stocks. Sampling sites are located between 33° 00' and 43° 32' latitude N, 2-860 m a.s.l., with mean annual temperature and rainfall in the range 10.9-19.6° C and 355-900 mm. SOC data, expressed in t C ha-1, have been evaluated both in terms of Carbon Sequestration Rate, given by [(SOCf-SOCi)/length in years], and as percentage change in comparison with the initial value [(SOCf-SOCi)/SOCi*100]. Data variability due to the different environmental, soil and crop management conditions that influence SOC sequestration and losses will be examined.

  11. MAIZE YIELD AND ITS STABILITY AS AFFECTED BY TILLAGE AND CROP RESIDUE MANAGEMENT IN THE EASTERN ROMANIAN DANUBE PLAIN

    Directory of Open Access Journals (Sweden)

    Alexandru COCIU

    2015-10-01

    Full Text Available Rainfed crop management systems need to be optimized to provide more resilient options in order to cope with projected climatic scenarios which are forecasting a decrease in mean precipitation and more frequent extreme drought periods in the Eastern Romanian Danube Plain. This research, carried out in the period of 2011-2014, had as main purpose the determination of influence of tillage practices and residue management on rainfall use efficiency, maize yield and its stability, in order to evaluate the advantages of conservation agriculture (CA in the time of stabilization of direct seeding effects, in comparison with traditional chisel tillage. The maize grain yields are presented for each crop management practices, as follows: (1 chisel tillage, retained crop residues being chopped and incorporated (ciz; (2 zero tillage, retained crop residue chopped and kept on the field in short flat condition (rvt; (3 zero tillage, crop residues kept on the field in short root-anchored condition (1/2rva, and (4 zero tillage, crop residues kept on the field in tall root-anchored condition (1/1rva. In 2012, a year with prolonged drought during vegetative growth, yield differences between zero tillage with short root-anchored residue retention (1/2rva and chisel tillage with residue incorporation (ciz were positive, up to 840 kg ha-1. In average over 2011-2014, conservation agriculture (CA practices had a yield advantage over traditional chisel tillage practice. Zero tillage with residue retention used rainfall more efficiently so suggesting that it is a more resilient agronomic system than traditional (conventional practices involving chisel tillage with residue incorporation.

  12. Runoff amount and quality as influenced by tillage and fertilizer management choices in a Cecil soil

    Science.gov (United States)

    Tillage and fertilizer choices and their interactions have varying impacts on levels and qualities of runoff from agricultural fields. We quantified runoff, sediment loss, concentrations and loads of ammonium-nitrogen (NH4-N), nitrate-nitrogen (NO3-N), dissolved reactive phosphorus (PO4-P) and total...

  13. Effects of Plant Residues in Two Types of Soil Texture on Soil characteristics and corn (Zea mays L. NS640 Yield in a Reduced -Tillage cropping System

    Directory of Open Access Journals (Sweden)

    E Hesami

    2018-05-01

    Full Text Available Introduction The impact of agronomy on the subsequent product in rotational cropping systems depends on factors such as plant type, duration of crop growth, soil moisture content, tillage type, irrigation method, the amount of nitrogen fertilizer, quantity and quality of returned crop residues to the soil. Prior cultivated crops improve the next crop yield by causing different conditions (nitrogen availability, organic matter and volume of available water in soil. This study was conducted due to importance of corn cultivation in Khuzestan and necessity of increasing the soil organic matter, moisture conservation and in the other hand the lack of sufficient information about the relationship between soil texture, type of preparatory crop in low-tillage condition and some soil characteristics and corn growth habits. The purpose of this experiment was to evaluate the effect of residue of preparatory crops in low plowing condition in two soil types on corn yield and some soil characteristics. Materials and Methods This experiment was carried out at Shooshtar city located in Khuzestan province. An experiment was performed by combined analysis in randomized complete block design in two fields and in two consecutive years with four replications. Two kinds of soil texture including: clay loam and clay sand. Five preparatory crops including: broad bean, wheat, canola, cabbage and fallow as control assigned as sub plots. SAS Ver. 9.1 statistical software was used for analysis of variance and comparison of means. Graphs were drawn using MS Excel software. All means were compared by Duncan test at 5% probability level. Results and Discussion The soil texture and the type of preparatory crop influenced the characteristics of the soil and corn grain yield. Returning the broad bean residue into two types of soil caused the highest grain yield of corn 10128.6 and 9547.9 kgha-1, respectively. The control treatment in sandy loam texture had the lowest corn seed

  14. 3D Structure of Tillage Soils

    Science.gov (United States)

    González-Torre, Iván; Losada, Juan Carlos; Falconer, Ruth; Hapca, Simona; Tarquis, Ana M.

    2015-04-01

    Soil structure may be defined as the spatial arrangement of soil particles, aggregates and pores. The geometry of each one of these elements, as well as their spatial arrangement, has a great influence on the transport of fluids and solutes through the soil. Fractal/Multifractal methods have been increasingly applied to quantify soil structure thanks to the advances in computer technology (Tarquis et al., 2003). There is no doubt that computed tomography (CT) has provided an alternative for observing intact soil structure. These CT techniques reduce the physical impact to sampling, providing three-dimensional (3D) information and allowing rapid scanning to study sample dynamics in near real-time (Houston et al., 2013a). However, several authors have dedicated attention to the appropriate pore-solid CT threshold (Elliot and Heck, 2007; Houston et al., 2013b) and the better method to estimate the multifractal parameters (Grau et al., 2006; Tarquis et al., 2009). The aim of the present study is to evaluate the effect of the algorithm applied in the multifractal method (box counting and box gliding) and the cube size on the calculation of generalized fractal dimensions (Dq) in grey images without applying any threshold. To this end, soil samples were extracted from different areas plowed with three tools (moldboard, chissel and plow). Soil samples for each of the tillage treatment were packed into polypropylene cylinders of 8 cm diameter and 10 cm high. These were imaged using an mSIMCT at 155keV and 25 mA. An aluminium filter (0.25 mm) was applied to reduce beam hardening and later several corrections where applied during reconstruction. References Elliot, T.R. and Heck, R.J. 2007. A comparison of 2D and 3D thresholding of CT imagery. Can. J. Soil Sci., 87(4), 405-412. Grau, J, Médez, V.; Tarquis, A.M., Saa, A. and Díaz, M.C.. 2006. Comparison of gliding box and box-counting methods in soil image analysis. Geoderma, 134, 349-359. González-Torres, Iván. Theory and

  15. Experimental analysis of CO2 emissions from agricultural soils subjected to five different tillage systems in Lithuania

    International Nuclear Information System (INIS)

    Buragienė, Sidona; Šarauskis, Egidijus; Romaneckas, Kęstutis; Sasnauskienė, Jurgita; Masilionytė, Laura; Kriaučiūnienė, Zita

    2015-01-01

    Intensive agricultural production strongly influences the global processes that determine climate change. Thus, tillage can play a very important role in climate change. The intensity of soil carbon dioxide (CO 2 ) emissions, which contribute to the greenhouse effect, can vary depending on the following factors: the tillage system used, meteorological conditions (which vary in different regions of the world), soil properties, plant residue characteristics and other factors. The main purpose of this research was to analyse and assess the effects of autumn tillage systems with different intensities on CO 2 emissions from soils during different seasons and under the climatic conditions of Central Lithuania. The research was conducted at the Experimental Station of Aleksandras Stulginskis University from 2009 to2012; and in 2014. The soils at the experimental site were classified as Eutric Endogleyic Planosol (Drainic). The investigations were conducted using five tillage systems with different intensities, typical of the Baltic Region. Deep conventional ploughing was performed at a depth of 230–250 mm, shallow ploughing was conducted at a depth of 120–150 mm, deep loosening was conducted at depths of 250–270 mm, and shallow loosening was conducted at depths of 120–150 mm. The fifth system was a no-tillage system. Overall, autumn tillage resulted in greater CO 2 emissions from the soil over both short- and long-term periods under the climatic conditions of Central Lithuania, regardless of the tillage system applied. The highest soil CO 2 emissions were observed for the conventional deep ploughing tillage system, and the lowest emissions were observed for the no-tillage system. The meteorological conditions greatly influenced the CO 2 emissions from the soil during the spring. Soil CO 2 emissions were enhanced as precipitation and the air and soil temperatures increased. Long-term investigations regarding the dynamics of CO 2 emissions from soils during the

  16. Warmer and Wetter Soil Stimulates Assimilation More than Respiration in Rainfed Agricultural Ecosystem on the China Loess Plateau: The Role of Partial Plastic Film Mulching Tillage.

    Science.gov (United States)

    Gong, Daozhi; Hao, Weiping; Mei, Xurong; Gao, Xiang; Liu, Qi; Caylor, Kelly

    2015-01-01

    Effects of agricultural practices on ecosystem carbon storage have acquired widespread concern due to its alleviation of rising atmospheric CO2 concentrations. Recently, combining of furrow-ridge with plastic film mulching in spring maize ecosystem was widely applied to boost crop water productivity in the semiarid regions of China. However, there is still limited information about the potentials for increased ecosystem carbon storage of this tillage method. The objective of this study was to quantify and contrast net carbon dioxide exchange, biomass accumulation and carbon budgets of maize (Zea maize L.) fields under the traditional non-mulching with flat tillage (CK) and partial plastic film mulching with furrow-ridge tillage (MFR) on the China Loess Plateau. Half-hourly net ecosystem CO2 exchange (NEE) of both treatments were synchronously measured with two eddy covariance systems during the growing seasons of 2011 through 2013. At same time green leaf area index (GLAI) and biomass were also measured biweekly. Compared with CK, the warmer and wetter (+1.3°C and +4.3%) top soil at MFR accelerated the rates of biomass accumulation, promoted greater green leaf area and thus shortened the growing seasons by an average value of 10.4 days for three years. MFR stimulated assimilation more than respiration during whole growing season, resulting in a higher carbon sequestration in terms of NEE of -79 gC/m2 than CK. However, after considering carbon in harvested grain (or aboveground biomass), there is a slight higher carbon sink (or a stronger carbon source) in MFR due to its greater difference of aboveground biomass than that of grain between both treatments. These results demonstrate that partial plastic film mulched furrow-ridge tillage with aboveground biomass exclusive of grain returned to the soil is an effective way to enhance simultaneously carbon sequestration and grain yield of maize in the semiarid regions.

  17. Warmer and Wetter Soil Stimulates Assimilation More than Respiration in Rainfed Agricultural Ecosystem on the China Loess Plateau: The Role of Partial Plastic Film Mulching Tillage.

    Directory of Open Access Journals (Sweden)

    Daozhi Gong

    Full Text Available Effects of agricultural practices on ecosystem carbon storage have acquired widespread concern due to its alleviation of rising atmospheric CO2 concentrations. Recently, combining of furrow-ridge with plastic film mulching in spring maize ecosystem was widely applied to boost crop water productivity in the semiarid regions of China. However, there is still limited information about the potentials for increased ecosystem carbon storage of this tillage method. The objective of this study was to quantify and contrast net carbon dioxide exchange, biomass accumulation and carbon budgets of maize (Zea maize L. fields under the traditional non-mulching with flat tillage (CK and partial plastic film mulching with furrow-ridge tillage (MFR on the China Loess Plateau. Half-hourly net ecosystem CO2 exchange (NEE of both treatments were synchronously measured with two eddy covariance systems during the growing seasons of 2011 through 2013. At same time green leaf area index (GLAI and biomass were also measured biweekly. Compared with CK, the warmer and wetter (+1.3°C and +4.3% top soil at MFR accelerated the rates of biomass accumulation, promoted greater green leaf area and thus shortened the growing seasons by an average value of 10.4 days for three years. MFR stimulated assimilation more than respiration during whole growing season, resulting in a higher carbon sequestration in terms of NEE of -79 gC/m2 than CK. However, after considering carbon in harvested grain (or aboveground biomass, there is a slight higher carbon sink (or a stronger carbon source in MFR due to its greater difference of aboveground biomass than that of grain between both treatments. These results demonstrate that partial plastic film mulched furrow-ridge tillage with aboveground biomass exclusive of grain returned to the soil is an effective way to enhance simultaneously carbon sequestration and grain yield of maize in the semiarid regions.

  18. Use of multispectral Ikonos imagery for discriminating between conventional and conservation agricultural tillage practices

    Science.gov (United States)

    Vina, Andres; Peters, Albert J.; Ji, Lei

    2003-01-01

    There is a global concern about the increase in atmospheric concentrations of greenhouse gases. One method being discussed to encourage greenhouse gas mitigation efforts is based on a trading system whereby carbon emitters can buy effective mitigation efforts from farmers implementing conservation tillage practices. These practices sequester carbon from the atmosphere, and such a trading system would require a low-cost and accurate method of verification. Remote sensing technology can offer such a verification technique. This paper is focused on the use of standard image processing procedures applied to a multispectral Ikonos image, to determine whether it is possible to validate that farmers have complied with agreements to implement conservation tillage practices. A principal component analysis (PCA) was performed in order to isolate image variance in cropped fields. Analyses of variance (ANOVA) statistical procedures were used to evaluate the capability of each Ikonos band and each principal component to discriminate between conventional and conservation tillage practices. A logistic regression model was implemented on the principal component most effective in discriminating between conventional and conservation tillage, in order to produce a map of the probability of conventional tillage. The Ikonos imagery, in combination with ground-reference information, proved to be a useful tool for verification of conservation tillage practices.

  19. Grassland soil tillage by three implements in an Ultisol and its physical and hydropedological implications

    Directory of Open Access Journals (Sweden)

    Manuel E. Camacho

    2015-11-01

    Full Text Available A field study was conducted to test the effects of soil tillage with 3 different implements on compaction, physical and hydropedological properties of an Ultisol under cattle production, located in San Mateo, Alajuela. An area of approximately 10 000 m2 was selected and divided into 16 plots (650 m2 each and was tilled with 3 different implements corresponding to the treatments, following an unrestricted random experimental design, with a plot as experimental unit. Soil without tillage (T, tillage by spader plow (PM, tillage by chisel plow (C or tillage by subsoiler (S were established as treatments. Forty days after tillage treatments, soil penetration resistance every 5 cm up to 50 cm deep was assessed, and gravimetric moisture content, bulk and particle density, water infiltration and hydraulic conductivity, all of them up to the first 10 cm deep, all of them were measured. Soil compaction, expressed as soil penetration resistance, was reduced by tillage treatments; the lowest values for soil compaction were found in the spader plow treatment (PM. This same treatment enhanced cumulated infiltration (38.70±3.60 mm at 150 min significantly, comparing with those obtained in T treatment (0.09±0.02 mm at 150 min. No significant differences were found among tillage treatments for bulk density, total porosity and airspace, but comparing with control treatment (T they were found. Subsoiler treatment (S favored the highest values for hydraulic conductivity, but no significant differences with the other treatments were found (p>0.05.

  20. Long-term impact of reduced tillage and residue management on soil carbon stabilization: Implications for conservation agriculture on contrasting soils

    OpenAIRE

    Chivenge, P.P.; Murwira, H.K.; Giller, K.E.; Mapfumo, P.; Six, J.

    2007-01-01

    Metadata only record The long-term effects of tillage system and residue management on soil organic carbon stabilization are studied in two tropical soils in Zimbabwe, a red clay and a sandy soil. The four tillage systems evaluated were conventional tillage (CT), mulch ripping (MR), clean ripping (CR) and tied ridging (TR). Soil organic carbon (SOC) content was measured for each size fraction as well as total SOC. Based on the findings, the authors conclude that residue management - mainta...

  1. Carbon fractions and soil fertility affected by tillage and sugarcane residue management an Xanthic Udult

    Directory of Open Access Journals (Sweden)

    Iara Maria Lopes

    2017-10-01

    Full Text Available The gradual change in management practices in sugarcane (Saccharum spp. production from burning straw to a green harvesting system, as well as the use of minimum soil tillage during field renovation, may affect soil fertility and soil organic matter (SOM contents. The objectives of this work were to investigate the influence of sugar cane production systems on: (1 soil fertility parameters; (2 on physical carbon fractions; (3 and on humic substance fractions, in a long-term experiment, comparing two soil tillage and two residue management systems an Xanthic Udult, in the coastal tableland region of Espírito Santo State, Brazil. The treatments consisted of plots (conventional tillage (CT or minimum tillage (MT and subplots (residue burned or unburned at harvesting, with five replicates The highest values of Ca2+ + Mg2+ and total organic carbon (TOC were observed in the MT system in all soil layers, while high values of K+ were observed in the 0.1-0.2 m layer. The CT associated with the burned residue management negatively influenced the TOC values, especially in the 0.1-0.2 and 0.2-0.4 m layers. The carbon in the humin fraction and organic matter associated with minerals were significantly different among the tillage systems; the MT showed higher values than the CT. However, there were no significant differences between the sugarcane residue management treatments. Overall, fractioning the SOM allowed for a better understanding of tillage and residue management systems effects on the soil properties.

  2. Infiltration in reclaimed mined land ameliorated with deep tillage treatments

    International Nuclear Information System (INIS)

    Chong, S.K.; Cowsert, P.T.

    1997-01-01

    Reclamation of mined land with heavy machinery can result in soil compaction, which increases soil bulk density and reduces porosity, water infiltrability, root elongation and crop productivity. This paper examines the effect on infiltration in reclaimed surface mined land of a deep tillage treatment, and the subsequent changes in infiltration after the amelioration. The experiment was conducted at the Horse Creek Mine near Conant, Ferry County, IL, USA

  3. Quantifying Update Effects in Citizen-Oriented Software

    Directory of Open Access Journals (Sweden)

    Ion Ivan

    2009-02-01

    Full Text Available Defining citizen-oriented software. Detailing technical issues regarding update process in this kind of software. Presenting different effects triggered by types of update. Building model for update costs estimation, including producer-side and consumer-side effects. Analyzing model applicability on INVMAT – large scale matrix inversion software. Proposing a model for update effects estimation. Specifying ways for softening effects of inaccurate updates.

  4. Quantifying and modeling birth order effects in autism.

    Directory of Open Access Journals (Sweden)

    Tychele Turner

    Full Text Available Autism is a complex genetic disorder with multiple etiologies whose molecular genetic basis is not fully understood. Although a number of rare mutations and dosage abnormalities are specific to autism, these explain no more than 10% of all cases. The high heritability of autism and low recurrence risk suggests multifactorial inheritance from numerous loci but other factors also intervene to modulate risk. In this study, we examine the effect of birth rank on disease risk which is not expected for purely hereditary genetic models. We analyzed the data from three publicly available autism family collections in the USA for potential birth order effects and studied the statistical properties of three tests to show that adequate power to detect these effects exist. We detect statistically significant, yet varying, patterns of birth order effects across these collections. In multiplex families, we identify V-shaped effects where middle births are at high risk; in simplex families, we demonstrate linear effects where risk increases with each additional birth. Moreover, the birth order effect is gender-dependent in the simplex collection. It is currently unknown whether these patterns arise from ascertainment biases or biological factors. Nevertheless, further investigation of parental age-dependent risks yields patterns similar to those observed and could potentially explain part of the increased risk. A search for genes considering these patterns is likely to increase statistical power and uncover novel molecular etiologies.

  5. The Urban Forest Effects (UFORE) model: quantifying urban forest structure and functions

    Science.gov (United States)

    David J. Nowak; Daniel E. Crane

    2000-01-01

    The Urban Forest Effects (UFORE) computer model was developed to help managers and researchers quantify urban forest structure and functions. The model quantifies species composition and diversity, diameter distribution, tree density and health, leaf area, leaf biomass, and other structural characteristics; hourly volatile organic compound emissions (emissions that...

  6. Chain Risk Model for quantifying cost effectiveness of phytosanitary measures

    NARCIS (Netherlands)

    Benninga, J.; Hennen, W.H.G.J.; Schans, van de J.

    2010-01-01

    A Chain Risk Model (CRM) was developed for a cost effective assessment of phytosanitary measures. The CRM model can be applied to phytosanitary assessments of all agricultural product chains. In CRM, stages are connected by product volume flows with which pest infections can be spread from one stage

  7. Quantifying the effects of IT-governance rules

    NARCIS (Netherlands)

    Verhoef, C.

    2007-01-01

    Via quantitative analyses of large IT-portfolio databases, we detected unique data patterns pointing to certain IT-governance rules and styles, plus their sometimes nonintuitive and negative side-effects. We grouped the most important patterns in seven categories and highlighted them separately.

  8. Quantifying the effect of investors' attention on stock market.

    Directory of Open Access Journals (Sweden)

    Zhen-Hua Yang

    Full Text Available The investors' attention has been extensively used to predict the stock market. Different from existing proxies of the investors' attention, such as the Google trends, Baidu index (BI, we argue the collective attention from the stock trading platforms could reflect the investors' attention more closely. By calculated the increments of the attention volume for each stock (IAVS from the stock trading platforms, we investigate the effect of investors' attention measured by the IAVS on the movement of the stock market. The experimental results for Chinese Securities Index 100 (CSI100 show that the BI is significantly correlated with the returns of CSI100 at 1% significance level only in 2014. However, it should be emphasized that the correlation of the new proposed measure, namely IAVS, is significantly at 1% significance level in 2014 and 2015. It shows that the effect of the measure IAVS on the movement of the stock market is more stable and significant than BI. This study yields important invest implications and better understanding of collective investors' attention.

  9. Quantifying the effect of investors' attention on stock market.

    Science.gov (United States)

    Yang, Zhen-Hua; Liu, Jian-Guo; Yu, Chang-Rui; Han, Jing-Ti

    2017-01-01

    The investors' attention has been extensively used to predict the stock market. Different from existing proxies of the investors' attention, such as the Google trends, Baidu index (BI), we argue the collective attention from the stock trading platforms could reflect the investors' attention more closely. By calculated the increments of the attention volume for each stock (IAVS) from the stock trading platforms, we investigate the effect of investors' attention measured by the IAVS on the movement of the stock market. The experimental results for Chinese Securities Index 100 (CSI100) show that the BI is significantly correlated with the returns of CSI100 at 1% significance level only in 2014. However, it should be emphasized that the correlation of the new proposed measure, namely IAVS, is significantly at 1% significance level in 2014 and 2015. It shows that the effect of the measure IAVS on the movement of the stock market is more stable and significant than BI. This study yields important invest implications and better understanding of collective investors' attention.

  10. Quantifying the effect of investors’ attention on stock market

    Science.gov (United States)

    Yang, Zhen-Hua; Liu, Jian-Guo; Yu, Chang-Rui; Han, Jing-Ti

    2017-01-01

    The investors’ attention has been extensively used to predict the stock market. Different from existing proxies of the investors’ attention, such as the Google trends, Baidu index (BI), we argue the collective attention from the stock trading platforms could reflect the investors’ attention more closely. By calculated the increments of the attention volume for each stock (IAVS) from the stock trading platforms, we investigate the effect of investors’ attention measured by the IAVS on the movement of the stock market. The experimental results for Chinese Securities Index 100 (CSI100) show that the BI is significantly correlated with the returns of CSI100 at 1% significance level only in 2014. However, it should be emphasized that the correlation of the new proposed measure, namely IAVS, is significantly at 1% significance level in 2014 and 2015. It shows that the effect of the measure IAVS on the movement of the stock market is more stable and significant than BI. This study yields important invest implications and better understanding of collective investors’ attention. PMID:28542216

  11. Quantifying the effect of colorization enhancement on mammogram images

    Science.gov (United States)

    Wojnicki, Paul J.; Uyeda, Elizabeth; Micheli-Tzanakou, Evangelia

    2002-04-01

    Current methods of radiological displays provide only grayscale images of mammograms. The limitation of the image space to grayscale provides only luminance differences and textures as cues for object recognition within the image. However, color can be an important and significant cue in the detection of shapes and objects. Increasing detection ability allows the radiologist to interpret the images in more detail, improving object recognition and diagnostic accuracy. Color detection experiments using our stimulus system, have demonstrated that an observer can only detect an average of 140 levels of grayscale. An optimally colorized image can allow a user to distinguish 250 - 1000 different levels, hence increasing potential image feature detection by 2-7 times. By implementing a colorization map, which follows the luminance map of the original grayscale images, the luminance profile is preserved and color is isolated as the enhancement mechanism. The effect of this enhancement mechanism on the shape, frequency composition and statistical characteristics of the Visual Evoked Potential (VEP) are analyzed and presented. Thus, the effectiveness of the image colorization is measured quantitatively using the Visual Evoked Potential (VEP).

  12. Propriedades químicas e fauna do solo influenciadas pela calagem em sistema semeadura direta Effects of liming on chemical properties and soil fauna in no-tillage system

    Directory of Open Access Journals (Sweden)

    Henrique Cesar Almeida

    2007-10-01

    Full Text Available Este trabalho objetivou avaliar o efeito da calagem e sua influência sobre atributos químicos e de fauna do solo em um Cambissolo sob sistema de semeadura direta. O experimento vem sendo conduzido em Lages, SC, desde maio de 2001. Os tratamentos foram: semeadura direta com calcário incorporado na dose de 1 SMP (SD-inc e superficial nas doses de 1/5 SMP (SD-1/5sup e 1/2 SMP (SD-1/2sup. Como padrão, utilizou-se solo sem cultivo e sem aplicação de calcário, e uma área de pastagem perene com calcário incorporado na dose de 1 SMP (PI-inc. O solo foi amostrado nas camadas de 0-5; 5-10; 10-20cm para análise de Ca2+, Mg+2, Al3+, pH em água e em CaCl2; e de 0-10cm para carbono orgânico total e fauna do solo. A aplicação superficial de calcário no sistema de semeadura direta na maior dose (1/2 SMP elevou os teores de Ca2+ até 10cm de profundidade e de Mg+2 até a camada de 10 a 20cm. A abundância e a diversidade da fauna edáfica foram maiores nas áreas sob semeadura direta e pastagem, em relação ao solo sem cultivo, mostrando sensibilidade às alterações advindas do manejo do solo, mas sem correlação direta com as modificações químicas decorrentes da calagem.This research was aimed at evaluating the effect of liming and its influence on chemistry and fauna properties of a Cambisol under no-tillage system. The experiment has been carried out in Lages, SC, southern Brazil, since May 2001. The treatments were: no-tillage with incorporated lime in the rate of 1 SMP (NT-inc; superficial liming in the rate of 1/5 SMP (NT-1/5sup, and 1/2 SMP (NT-1/2sup. As control treatment, bare soil without cultivation without lime application (BS, and plots with perennial pasture with incorporate lime in the rate of 1 SMP (Pp-inc were used. Soil samples were collected in the layers of 0-5; 5-10; 10-20cm depth for analysis of Ca2+, Mg+2, Al3+, water and CaCl2 pH. Total organic carbon and soil fauna were analysed in the layer 0-10cm. The superficial

  13. Quantifying effects of oxidant air pollutants on agricultural crops

    Energy Technology Data Exchange (ETDEWEB)

    Medeiros, W H; Moskowitz, P D

    1983-01-01

    Estimating risks of air pollution damage to agricultural crops requires identifying crop location and size, likely doses, models for translating dose to response, and measures of response appropriate for economic analysis. Assessment of risk requires compatible data sets for each of these variables. Analysis of air pollution mixtures suggests that oxidant crop damage is caused by three compounds: ozone, nitrogen oxides, and peroxyacetylnitrates. The phytotoxicity of ozone, the most prevalent photochemical oxidant, has been studied more extensively than the other two oxidants, and its effects on vegetation are best understood. Response of vegetation to air pollutants was first characterized by foliar or visible injury. Subsequent research indicated that foliar injury did not translate directly into reduced plant growth or yield, which can be measured. Response to air pollutants may be influenced by physical, biological, and environmental factors. Inherent genetic resistance is probably the most important single factor affecting plant response, although environmental factors influencing stomatal aperture may also be important. For several crops open-top chamber studies and cross sectional analyses of field data provide adequate information to develop dose-response functions. All of these studies have both strengths and weaknesses. Although a number of different models exist for selected crops, there is no single biological or statistical criterion which identifies the best or most accurate model.

  14. Quantifying the Intercontinental and Global Reach and Effects of Pollution

    Science.gov (United States)

    Chatfield, Robert B.; Guo, Zitan

    2000-01-01

    The Atmospheric Chemistry Modeling Group is participating in an international effort to explore the projected interactions of the atmosphere with biota, human activity, and the natural environment over the next three decades. The group uses computer simulations and statistical analyses to compare theory and observations of the composition of the lower atmosphere. This study of global habitability change is part of a more ambitious activity to understand global habitability. This broad planetary understanding is central to planetary habitability, biomarker detection, and similar aspects of Astrobiology. The group has made highly detailed studies of immense intercontinental plumes that affect the chemistry of the global atmosphere, especially the region below the ozone (O3) layer whose chemical composition defines the conditions for healthy humans and the biosphere. For some decades there has been concern about the pollution from cities and industrial burning and its possible effect in increasing smog ozone, not only in continental regions, but also in plumes that spread downwind. Recently, there has been new concern about another kind of pollution plume. Projections for a greatly expanded aircraft fleet imply that there will be plumes of nitrogen oxides (NO(x)) from jet exhaust in the Northern Hemisphere downwind of major air traffic routes. Both of these are tied to large-scale O3 in the troposphere, where it is toxic to humans and plant tissues.

  15. Mineralogy and phosphorus adsorption in soils of south and central-west Brazil under conventional and no-tillage systems

    Directory of Open Access Journals (Sweden)

    Jessé Rodrigo Fink

    2014-02-01

    Full Text Available The low phosphorus availability in tropical and subtropical soils, normally related to adsorption of phosphate to the minerals surfaces, can be attenuated when organic matter (OM accumulates in the soils. Herein, we report the results of long-term experiments (18–32 years aimed at quantifying the maximum phosphorus adsorption capacity (MPAC and its determinant mineralogical variables in Brazilian soils and at assessing the effect of no-tillage (NT in mitigating the phosphorus adsorption of soils. The MPAC of soils ranged from 297 to 4,561 mg kg-1 in the 0.00–0.10 m layer and from 285 to 4,961 mg kg-1 in the 0.10–0.20 m layer. The MPAC was correlated with the concentrations of iron oxides, goethite and ferrihydrite, gibbsite/(gibbsite+kaolinite ratio and the specific surface area. The OM increased in the 0.00–0.10 m layer of NT soils, which was not reflected on the decrease of MPAC for the no-tillage soils.

  16. Inoculum Potential of Fusarium spp. Relates to Tillage and Straw Management in Norwegian Fields of Spring Oats

    Science.gov (United States)

    Hofgaard, Ingerd S.; Seehusen, Till; Aamot, Heidi U.; Riley, Hugh; Razzaghian, Jafar; Le, Vinh H.; Hjelkrem, Anne-Grete R.; Dill-Macky, Ruth; Brodal, Guro

    2016-01-01

    The increased occurrence of Fusarium-mycotoxins in Norwegian cereals over the last decade, is thought to be caused by increased inoculum resulting from more cereal residues at the soil surface as a result of reduced tillage practices. In addition, weather conditions have increasingly promoted inoculum development and infection by Fusarium species. The objective of this work was to elucidate the influence of different tillage regimes (autumn plowing; autumn harrowing; spring plowing; spring harrowing) on the inoculum potential (IP) and dispersal of Fusarium spp. in spring oats. Tillage trials were conducted at two different locations in southeast Norway from 2010 to 2012. Oat residues from the previous year’s crop were collected within a week after sowing for evaluation. IP was calculated as the percentage of residues infested with Fusarium spp. multiplied by the proportion of the soil surface covered with residues. Fusarium avenaceum and F. graminearum were the most common Fusarium species recovered from oat residues. The IP of Fusarium spp. was significantly lower in plowed plots compared to those that were harrowed. Plowing in either the autumn or spring resulted in a low IP. Harrowing in autumn was more effective in reducing IP than the spring harrowing, and IP levels for the spring harrowed treatments were generally higher than all other tillage treatments examined. Surprisingly low levels of F. langsethiae were detected in the residues, although this species is a common pathogen of oat in Norway. The percentage of the residues infested with F. avenaceum, F. graminearum, F. culmorum, and F. langsethiae generally related to the quantity of DNA of the respective Fusarium species determined using quantitative PCR (qPCR). Fusarium dispersal, quantified by qPCR analysis of spore trap samples collected at and after heading, generally corresponded to the IP. Fusarium dispersal was also observed to increase after rainy periods. Our findings are in line with the

  17. Inoculum potential of Fusarium spp. relates to tillage and straw management in Norwegian fields of spring oats

    Directory of Open Access Journals (Sweden)

    Ingerd Skow Hofgaard

    2016-04-01

    Full Text Available The increased occurrence of Fusarium-mycotoxins in Norwegian cereals over the last decade, is thought to be caused by increased inoculum resulting from more cereal residues at the soil surface as a result of reduced tillage practices. In addition, weather conditions have increasingly promoted inoculum development and infection by Fusarium species. The objective of this work was to elucidate the influence of different tillage regimes (autumn plowing; autumn harrowing; spring plowing; spring harrowing on the inoculum potential (IP and dispersal of Fusarium spp. in spring oats. Tillage trials were conducted at two different locations in southeast Norway from 2010 to 2012. Oat residues from the previous year’s crop were collected within a week after sowing for evaluation. IP was calculated as the percentage of residues infested with Fusarium spp. multiplied by the proportion of the soil surface covered with residues. F. avenaceum and F. graminearum were the most common Fusarium species recovered from oat residues. The IP of Fusarium spp. was significantly lower in plowed plots compared to those that were harrowed. Plowing in either the autumn or spring resulted in a low IP. Harrowing in autumn was more effective in reducing IP than the spring harrowing, and IP levels for the spring harrowed treatments were generally higher than all other tillage treatments examined. Surprisingly low levels of F. langsethiae were detected in the residues, although this species is a common pathogen of oat in Norway. The percentage of the residues infested with F. avenaceum, F. graminearum, F. culmorum and F. langsethiae generally related to the quantity of DNA of the respective Fusarium species determined using qPCR. Fusarium dispersal, quantified by quantitative PCR analysis of spore trap samples collected at and after heading, generally corresponded to IP. Fusarium dispersal was also observed to increase after rainy periods. Our findings are in line with the

  18. Determination of crop residues and the physical and mechanical properties of soil in different tillage systems

    Directory of Open Access Journals (Sweden)

    P Ahmadi Moghaddam

    2016-04-01

    Full Text Available Introduction: Monitoring and management of soil quality is crucial for sustaining soil function in ecosystem. Tillage is one of the management operations that drastically affect soil physical quality. Conservation tillage methods are one of the efficient solutions in agriculture to reduce the soil erosion, air pollution, energy consumption, and the costs, if there is a proper management on the crop residues. One of the serious problems in agriculture is soil erosion which is rapidly increased in the recent decades as the intensity of tillage increases. This phenomenon occurs more in sloping lands or in the fields which are lacking from crop residues and organic materials. The conservation tillage has an important role in minimizing soil erosion and developing the quality of soil. Hence, it has attracted the attention of more researchers and farmers in the recent years. Materials and Methods: In this study, the effect of different tillage methods has been investigated on the crop residues, mechanical resistance of soil, and the stability of aggregates. This research was performed on the agricultural fields of Urmia University, located in Nazloo zone in 2012. Wheat and barley were planted in these fields, consecutively. The soil texture of these fields was loamy clay and the factorial experiments were done in a completely randomized block design. In this study, effect of three tillage systems including tillage with moldboard (conventional tillage, tillage with disk plow (reduced tillage, chisel plow (minimum tillage and control treatment on some soil physical properties was investigated. Depth is second factor that was investigated in three levels including 0-60, 60-140, and 140-200 mm. Moreover, the effect of different percentages of crop residues on the rolling resistance of non-driving wheels was studied in a soil bin. The contents of crop residues have been measured by using the linear transects and image processing methods. In the linear

  19. The Effects of Rape Residue Mulching on Net Global Warming Potential and Greenhouse Gas Intensity from No-Tillage Paddy Fields

    Science.gov (United States)

    Zhang, Zhi-Sheng; Cao, Cou-Gui; Guo, Li-Jin; Li, Cheng-Fang

    2014-01-01

    A field experiment was conducted to provide a complete greenhouse gas (GHG) accounting for global warming potential (GWP), net GWP, and greenhouse gas intensity (GHGI) from no-tillage (NT) paddy fields with different amounts of oilseed rape residue mulch (0, 3000, 4000, and 6000 kg dry matter (DM) ha−1) during a rice-growing season after 3 years of oilseed rape-rice cultivation. Residue mulching treatments showed significantly more organic carbon (C) density for the 0–20 cm soil layer at harvesting than no residue treatment. During a rice-growing season, residue mulching treatments sequestered significantly more organic C from 687 kg C ha−1 season−1 to 1654 kg C ha−1 season−1 than no residue treatment. Residue mulching significantly increased emissions of CO2 and N2O but decreased CH4 emissions. Residue mulching treatments significantly increased GWP by 9–30% but significantly decreased net GWP by 33–71% and GHGI by 35–72% relative to no residue treatment. These results suggest that agricultural economic viability and GHG mitigation can be achieved simultaneously by residue mulching on NT paddy fields in central China. PMID:25140329

  20. The effects of rape residue mulching on net global warming potential and greenhouse gas intensity from no-tillage paddy fields.

    Science.gov (United States)

    Zhang, Zhi-Sheng; Cao, Cou-Gui; Guo, Li-Jin; Li, Cheng-Fang

    2014-01-01

    A field experiment was conducted to provide a complete greenhouse gas (GHG) accounting for global warming potential (GWP), net GWP, and greenhouse gas intensity (GHGI) from no-tillage (NT) paddy fields with different amounts of oilseed rape residue mulch (0, 3000, 4000, and 6000 kg dry matter (DM) ha(-1)) during a rice-growing season after 3 years of oilseed rape-rice cultivation. Residue mulching treatments showed significantly more organic carbon (C) density for the 0-20 cm soil layer at harvesting than no residue treatment. During a rice-growing season, residue mulching treatments sequestered significantly more organic C from 687 kg C ha(-1) season(-1) to 1654 kg C ha(-1) season(-1) than no residue treatment. Residue mulching significantly increased emissions of CO2 and N2O but decreased CH4 emissions. Residue mulching treatments significantly increased GWP by 9-30% but significantly decreased net GWP by 33-71% and GHGI by 35-72% relative to no residue treatment. These results suggest that agricultural economic viability and GHG mitigation can be achieved simultaneously by residue mulching on NT paddy fields in central China.

  1. Long-term impact of reduced tillage and residue management on soil carbon stabilization: Implications for conservation agriculture on contrasting soil

    NARCIS (Netherlands)

    Chivenge, P.P.; Murwira, H.K.; Giller, K.E.; Mapfumo, P.; Six, J.

    2007-01-01

    Residue retention and reduced tillage are both conservation agricultural management options that may enhance soil organic carbon (SOC) stabilization in tropical soils. Therefore, we evaluated the effects of long-term tillage and residue management on SOC dynamics in a Chromic Luvisol (red clay soil)

  2. Response of water use efficiency and carbon emission to no-tillage and winter wheat genotypes in the North China Plain.

    Science.gov (United States)

    Ren, Yujie; Gao, Chao; Han, Huifang; Li, Quanqi

    2018-04-20

    No-tillage management practices reduce net CO 2 losses from farmland and keep soil from degrading, but also decrease winter wheat grain yield and water use efficiency (WUE) in the North China Plain (NCP). Suitable management practices, namely, the choice of genotypes, could enhance crop yield and WUE; however, how the WUE and CO 2 exchange responds to no-tillage practices and winter wheat genotypes remains unclear. In the 2015-2016 and 2016-2017 winter wheat growing seasons in the NCP, a field experiment was carried out, and tested two tillage methods (no-tillage with mulching and conventional tillage) and two winter wheat genotypes ('Tainong 18' and 'Jimai 22'). The goal of the study was to identify the relationship between winter wheat grain yield, water consumption, and carbon emissions in no-tillage practices. The results showed that, compared to conventional tillage, no-tillage significantly reduced the net CO 2 -C cumulative emissions and water consumption; however, the grain yield was significantly reduced by 6.8% and 12.0% in the first and second growing seasons, respectively. Compared with Jimai 22, Tainong 18 had a compensatory effect on the yield reduction caused by no-tillage. As a result, the yield carbon utilization efficiency (R) and WUE were the highest in no-tillage with Tainong 18 (NT18), and the carbon emission per unit water consumption was the lowest in NT18. The results support the idea that a combination of no-tillage with genotype can improve the regulation of soil carbon emissions and water consumption of winter wheat, thus, providing theoretical support for sustainable crop production and soil development in the NCP. Copyright © 2018 Elsevier B.V. All rights reserved.

  3. Sanitary state and yielding of spring barley as dependent on soil tillage method

    Directory of Open Access Journals (Sweden)

    Tomasz P. Kurowski

    2012-12-01

    Full Text Available The effects of traditional tillage cultivation (control treatment, no tillage (instead of tillage the soil was loosened with scruff, and direct sowing (with a special drill into unploughed soil on the health of spring barley cultivar. Klimek were compared in three-field crop rotation (field bean, winter wheat, spring barley in an experiment performed in the years 1997-1999 on the soil of a good wheat complex. The results of phytopathological observations carried out over the vegetation season are presented in the form of an injury index. The following diseases were recorded on spring barley: net blotch (Drechslera teres - net type and spot type, powdery mildew (Blumeria graminis, leaf blotch (Rhynchosporium secalis, eyespot (Tapesia yallundae and foot rot (fungal complex. Tillage system had no a significant influence on the occurrence of both types of net blotch. The intensity of powdery mildew and leaf blotch was the highest in the case of traditional tillage cultivation, and the lowest - in that of no tillage. Direct sowing was conductive to the development of eyespot, and no tillage - to foot rot. Fungi of the genus Fusarium, mainly F. culmorum, and the species Bipolaris sorokiniana, were isolated most frequently from infested stem bases. The weather conditions differed during spring barley grown in the three years analyzed. Mean air temperature in 1997 and 1998 was similar to the many-year average for the city of Olsztyn and its surroundings (13.8°C. In the vegetation season 1999 mean air temperature reached 14.6°C, and was considerably higher than the many-year average. Taking into account total precipitation and distribution in the three-year experimental cycle, 1997 and 1998 can be considered average, and 1999 - wet.The weather conditions had a significant effect on the intensity of all diseases observed on spring barley. The highest yield grain was obtained in the case of traditional tillage cultivation (on average 3.06 t·ha-1 for the

  4. Water erosion and soil water infiltration in different stages of corn development and tillage systems

    OpenAIRE

    Daniel F. de Carvalho; Eliete N. Eduardo; Wilk S. de Almeida; Lucas A. F. Santos; Teodorico Alves Sobrinho

    2015-01-01

    ABSTRACTThis study evaluated soil and water losses, soil water infiltration and infiltration rate models in soil tillage systems and corn (Zea mays, L.) development stages under simulated rainfall. The treatments were: cultivation along contour lines, cultivation down the slope and exposed soil. Soil losses and infiltration in each treatment were quantified for rains applied using a portable simulator, at 0, 30, 60 and 75 days after planting. Infiltration rates were estimated using the models...

  5. Cowpea production as affected by dry spells in no-tillage and conventional crop systems

    Directory of Open Access Journals (Sweden)

    Rômulo Magno Oliveira de Freitas

    2013-12-01

    Full Text Available The objective of this study was to evaluate the effect of different periods of water shortage in no-tillage and conventional crop systems on cowpea yield components and grain yield in the Mossoró-RN region. For this, an experiment was conducted using two tillage systems (conventional and no-tillage subjected to periods of irrigation suspension (2; 6; 10; 14; 18 end 22 days, started at flowering (34 days after sowing. Plants were harvested 70 days after sowing, and the studied variables were: Pods length (CV, number of grains per pod (NGV, number of pods per plant (NPP, the hundred grains weight (PCG and grain yield (kg ha-1. The no-tillage system is more productive than the conventional under both irrigation and water stress treatments. The water stress length affected grain yield and all yield components studied in a negative way, except for the hundred grains weight. Among the systems studied, the no-tillage provides higher values for the yield components, except the hundred grains weight.

  6. Efeito de três sistemas de preparo do solo sobre a rentabilidade econômica da mandioca (Manihot esculenta Crantz = Effects of three tillage systems on economic profitability of cassava crop (Manihot esculenta Crantz

    Directory of Open Access Journals (Sweden)

    Manoel Genildo Pequeno

    2007-07-01

    Full Text Available O objetivo deste estudo foi avaliar a rentabilidade econômica da cultura damandioca em três sistemas de preparo de solo durante os anos agrícolas de 1999/2000 a2002/2003, em Araruna, Estado do Paraná. O delineamento experimental utilizado foi o deblocos completos casualizados, com oito repetições. Os tratamentos foram constituídos deplantio direto; preparo mínimo (escarificação e preparo convencional (aração + gradagemniveladora. A força de tração e o consumo de combustível requeridos nas operações depreparo do solo e de plantio da mandioca foram maiores no sistema de preparoconvencional. Os maiores custos com combustível, preparo do solo e plantio da mandioca, ecusto operacional relativo às culturas de inverno e à cultura da mandioca, bem como a maiorrenda bruta foram observados no sistema de preparo convencional, seguidos pelo preparomínimo e plantio direto. A maior renda líquida e a melhor relação benefício/custo foramobservadas no sistema de preparo convencional que proporcionou maior produtividade deraízes tuberosas em relação aos sistemas de preparo mínimo e de plantio direto.The objective of this paper was to evaluate the economicprofitability of cassava crop submitted to the three soil tillage systems during the years1999/2000 to 2002/2003, in Araruna, state of Parana. The treatments consisted of three soiltillage systems: no-tillage, minimum tillage using chiseling, and conventional tillage withmoldboard plow and disking, arranged in a randomized complete blocks with eightreplications. The traction strength and fuel consumption in the soil tillage and in the cassavasowed operation were more required in the conventional tillage system. The conventionaland the minimum tillage systems showed the highest costs for fuel, soil tillage and cassavasowed. They also presented the highest gross income. The greatest net income and the bestbenefit/cost relation were observed in the conventional tillage system, which

  7. Energy balance, costs and CO2 analysis of tillage technologies in maize cultivation

    International Nuclear Information System (INIS)

    Šarauskis, Egidijus; Buragienė, Sidona; Masilionytė, Laura; Romaneckas, Kęstutis; Avižienytė, Dovile; Sakalauskas, Antanas

    2014-01-01

    To achieve energy independence, Lithuania and other Baltic countries are searching for new ways to produce energy. Maize is a crop that is suitable for both food and forage, as well as for the production of bioenergy. The objective of this work was to assess the energy efficiency of maize cultivation technologies in different systems of reduced tillage. The experimental research and energy assessment was carried out for five different tillage systems: DP (deep ploughing), SP (), DC (deep cultivation), SC (shallow cultivation) and NT (no tillage). The assessment of the fuel inputs for these systems revealed that the greatest amount of diesel fuel (67.2 l ha −1 ) was used in the traditional DP system. The reduced tillage systems required 12–58% less fuel. Lower fuel consumption reduces the costs of technological operations and reduces CO 2 emissions, which are associated with the greenhouse effect. The agricultural machinery used in reduced tillage technologies emits 107–223 kg ha −1 of CO 2 gas into the environment, whereas DP emits 253 kg ha −1 of CO 2 . The energy analysis conducted in this study showed that the greatest total energy input (approximately 18.1 GJ ha −1 ) was associated with the conventional deep-ploughing tillage technology. The energy inputs associated with the reduced-tillage technologies, namely SP, DC and SC, ranged from 17.1 to 17.6 GJ ha −1 . The lowest energy input (16.2 GJ ha −1 ) was associated with the NT technology. Energy efficiency ratios for the various technologies were calculated as a function of the yield of maize grain and biomass. The best energy balance and the highest energy efficiency ratio (14.0) in maize cultivation was achieved with the NT technology. The energy efficiency ratios for DP, SP, DC and SC were 12.4, 13.4, 11.3 and 12.0, respectively. - Highlights: • Energetical and economic analysis of maize cultivation was done. • Reduced tillage technology reduces working time, fuel consumption

  8. A multiple soil ecosystem services approach to evaluate the sustainability of reduced tillage systems

    Science.gov (United States)

    Pérès, Guénola; Menasseri, Safya; Hallaire, Vincent; Cluzeau, Daniel; Heddadj, Djilali; Cotinet, Patrice; Manceau, Olivier; Pulleman, Mirjam

    2017-04-01

    reduced tillage systems improved soil ecosystem services such as soil biodiversity, water regulation (quantity, quality), carbon storage and soil stability; however, the effects on crop production were more variable (-10% to +7 % range), strongly depending on crop type and agricultural practices (fertilisation, rotation, cover crop). Sociological approach showed that saving labour time and fuel costs were the main motivations for change. Agronomic and environmental benefits are not the trigger but are increasingly recognized and contribute to the maintenance of the practice. Farmers also expressed a need for stronger networking and technical advice, which plays a crucial role. Scientists and experts raise awareness, support collective learning and provide instrumental. Recommendations were provided for sustainable soil management aiming at ecological intensification of agricultural land.

  9. Minidisk against ring infiltrometer measurements to assess the saturated hydraulic conductivity in Mediterranean vineyards (Vitis vinifera L.) under Tillage and No-Tillage managements

    Science.gov (United States)

    Burguet, Maria; Di Prima, Simone; Prosdocimi, Massimo; Taguas, Encarnación V.; Cerdà, Artemi

    2016-04-01

    Vineyard is one of the main crops in the Mediterranean region and it forms, along with wheat and olive, what it is known as the 'Mediterranean triad'. According to the Food and Agriculture Organization of the United Nations (FAO, 2010), the European Union has 4.5 million hectares of land occupied by vineyards. Out of all, the Mediterranean region has the largest total area of vineyards. France, Italy and Spain together are responsible for 48% of global wine production. In Spain, the total surface occupied by vineyards is 1.048.104 ha (Ministry of Agriculture, Food and Environment, 2009), which is translated in a 13% of world total (Wine Institute, 2014). In terms of environmental factors, vineyards are a source of sediments and water due to the tillage and the soil compaction, the lack of vegetation cover and the soil organic matter depletion (Novara et al., 2011; Lieskovsky' et al., 2014; Rodrigo Comino et al., 2015). The infiltration capacity of soils is a key component of the hydrological cycle that can control the non-sustainable rates of runoff and erosion (Cerdà, 1997,1999). In this way research focused on the soil hydrological properties will bring knowledge on how to control the high erosion rates (Cammeraat et al., 2010). Saturated hydraulic conductivity, ks, is the most determining physical parameter in terms of quantifying the components of the global water balance as it interferes in all those processes which are related with water and solute movement and transport through the soil. ks values are required for an adequate modelling of the infiltration and runoff generation processes. However, it is a variable with high variability when it comes to agricultural soils due to different soil managements and the fact that the soil is not a continuous media (Polo et al., 2003). For instance, Leonard and Andrieux (1998) reported in a study done in untilled vineyards in France high differences in infiltration rates through the use of rainfall simulations, which

  10. Relating soil microbial activity to water content and tillage-induced differences in soil structure

    DEFF Research Database (Denmark)

    Schjønning, Per; Thomsen, Ingrid Kaag; Petersen, Søren O

    2011-01-01

    Several studies have identified optima in soil water content for aerobic microbial activity, and this has been ascribed to a balance between gas and solute diffusivity as limiting processes. We investigated the role of soil structure, as created by different tillage practices (moldboard ploughing......, MP, or shallow tillage, ST), in regulating net nitrification, applied here as an index of aerobic microbial activity. Intact soil cores were collected at 0–4 and 14–18 cm depth from a fine sandy (SAND) and a loamy (LOAM) soil. The cores were drained to one of seven matric potentials ranging from − 15...... content to a maximum and then decreased. This relationship was modelled with a second order polynomium. Model parameters did not show any tillage effect on the optimum water content, but the optimum coincided with a lower matric potential in ST (SAND: − 140 to –197 hPa; LOAM: − 37 to − 65 hPa) than in MP...

  11. Translocation of Soil Particles during Secondary Soil Tillage along Contour Lines

    Directory of Open Access Journals (Sweden)

    Novák Petr

    2018-04-01

    Full Text Available A high percentage of arable land and erosion risk on agricultural land are typical of current agriculture. While tillage erosion is a less frequently studied issue, it impacts vast areas of agricultural land. Not all relationships between cultivation equipment, the gradient of the plot and other factors have been known until now. Intensive soil tillage can be a crucial erosive factor mainly when the cultivation equipment moves in a fall line direction. Nevertheless, even when the equipment moves along contour lines, soil particles can be translocated perpendicular to the direction of the equipment movement (in a fall line direction. This phenomenon has not yet been adequately studied. For measurements, a field trial with secondary tillage of soil was laid out (a seedbed preparation implement was used. The objective of the trial was to evaluate the effect of the working tools of the cultivation equipment on the crosswise and lengthwise translocation of soil particles during soil tillage. Aluminium cubes, with a side length of 16 mm, were used as tracers. Before the operation, the tracers were inserted in a row perpendicular (at a right angle to a direction of the equipment passes. After the equipment passes, position of tracers was evaluated within a two-axis grid. The trial was performed at three gradients of the plot (2°, 6° and 11°. For each gradient, the 1-pass, 2-pass and 3-pass treatments were tested. The equipment always moved along the plot contour line. After the equipment passes in all treatments, all tracers were localized on an orthogonal grid. The results of the trial demonstrate the effect of the slope gradient on the crosswise translocation of particles during secondary tillage of soil in the slope direction. The tillage equipment translocated particles in the fall line direction even if it passed along the contour line. With the increasing intensity of passes, the effect of the equipment on crosswise translocation increases

  12. Species composition and density of weeds in a wheat crop depending on the soil tillage system in crop rotation

    Directory of Open Access Journals (Sweden)

    P. Yankov

    2015-03-01

    Full Text Available Abstract. The investigation was carried out in the trial field of Dobrudzha Agricultural Institute, General Toshevo on slightly leached chernozem soil type. For the purposes of this investigation, variants from a stationary field experiment initiated in 1987 and based on various soil tillage tools and operations were analyzed. The species composition and density of weeds were followed in a wheat crop grown after grain maize using the following soil tillage systems: plowing at 24 – 26 cm (for maize – disking at 10 – 12 cm (for wheat; cutting at 24 – 26 cm (for maize – cutting at 8 – 10 cm (for wheat; disking at 10 – 12 cm (for maize – disking at 10 – 12 cm (for wheat; no-tillage (for maize – no-tillage (for wheat.Weed infestation was read at the fourth rotation since the initiation of the trial. The observations were made in spring before treatment of the crop with herbicides. The soil tillage system had a significant effect on the species composition and density of weeds in the field with wheat grown after previous crop maize. The long-term alternation of plowing with disking in parallel with the usage of chemicals for weed control lead to lower weed infestation of the weed crop. The lower weed density after this soil tillage system was not related to changes in the species composition and the relative percent of the individual species in the total weed infestation. The long-term application in crop rotation of systems without turning of the soil layer and of minimal and no-tillage increased the amount of weeds. The reason is the greater variability of weed species which typically occur after shallow soil tillage.

  13. Relations between soil surface roughness, tortuosity, tillage treatments, rainfall intensity and soil and water losses from a red yellow latosol

    Directory of Open Access Journals (Sweden)

    Julieta Bramorski

    2012-08-01

    Full Text Available The soil surface roughness increases water retention and infiltration, reduces the runoff volume and speed and influences soil losses by water erosion. Similarly to other parameters, soil roughness is affected by the tillage system and rainfall volume. Based on these assumptions, the main purpose of this study was to evaluate the effect of tillage treatments on soil surface roughness (RR and tortuosity (T and to investigate the relationship with soil and water losses in a series of simulated rainfall events. The field study was carried out at the experimental station of EMBRAPA Southeastern Cattle Research Center in São Carlos (Fazenda Canchim, in São Paulo State, Brazil. Experimental plots of 33 m² were treated with two tillage practices in three replications, consisting of: untilled (no-tillage soil (NTS and conventionally tilled (plowing plus double disking soil (CTS. Three successive simulated rain tests were applied in 24 h intervals. The three tests consisted of a first rain of 30 mm/h, a second of 30 mm/h and a third rain of 70 mm/h. Immediately after tilling and each rain simulation test, the surface roughness was measured, using a laser profile meter. The tillage treatments induced significant changes in soil surface roughness and tortuosity, demonstrating the importance of the tillage system for the physical surface conditions, favoring water retention and infiltration in the soil. The increase in surface roughness by the tillage treatments was considerably greater than its reduction by rain action. The surface roughness and tortuosity had more influence on the soil volume lost by surface runoff than in the conventional treatment. Possibly, other variables influenced soil and water losses from the no-tillage treatments, e.g., soil type, declivity, slope length, among others not analyzed in this study.

  14. Zero tillage: A potential technology to improve cotton yield

    Directory of Open Access Journals (Sweden)

    Abbas Hafiz Ghazanfar

    2016-01-01

    Full Text Available Zero tillage technology revealed with no use of any soil inverting technique to grow crops. The crop plant seed is planted in the soil directly after irrigation to make the soil soft without any replenishing in soil layers. A study was conducted to evaluate cotton genotypes FH-114 and FH-142 for the consecutive three years of growing seasons from 2013-15. The seed of both genotypes was sown with two date of sowing, 1 March and 1 May of each three years of sowing under three tillage treatments (zero tillage, minimum tillage and conventional tillage in triplicate completely randomized split-split plot design. It was found from results that significant differences were recorded for tillage treatments, date of sowing, genotypes and their interactions. Multivariate analysis was performed to evaluate the yield and it attributed traits for potential of FH-114 and FH-142 cotton genotypes. The genotype FH-142 was found with higher and batter performance as compared to FH-114 under zero tillage, minimum tillage and conventional tillage techniques. The traits bolls per plant, boll weight, fibre fineness, fibre strength, plant height, cotton yield per plant and sympodial branches per plant were found as most contributing traits towards cotton yield and production. It was also found that FH-142 gives higher output in terms of economic gain under zero tillage with 54% increase as compared to conventional tillage technique. It was suggested that zero tillage technology should be adopted to improve cotton yield and quality. It was also recommended that further study to evaluate zero tillage as potential technology should be performed with different regions, climate and timing throughout the world.

  15. Soil and crop residue CO2-C emission under tillage systems in sugarcane-producing areas of southern Brazil

    Directory of Open Access Journals (Sweden)

    Luís Gustavo Teixeira

    2013-10-01

    Full Text Available Appropriate management of agricultural crop residues could result in increases on soil organic carbon (SOC and help to mitigate gas effect. To distinguish the contributions of SOC and sugarcane (Saccharum spp. residues to the short-term CO2-C loss, we studied the influence of several tillage systems: heavy offset disk harrow (HO, chisel plow (CP, rotary tiller (RT, and sugarcane mill tiller (SM in 2008, and CP, RT, SM, moldboard (MP, and subsoiler (SUB in 2009, with and without sugarcane residues relative to no-till (NT in the sugarcane producing region of Brazil. Soil CO2-C emissions were measured daily for two weeks after tillage using portable soil respiration systems. Daily CO2-C emissions declined after tillage regardless of tillage system. In 2008, total CO2-C from SOC and/or residue decomposition was greater for RT and lowest for CP. In 2009, emission was greatest for MP and CP with residues, and smallest for NT. SOC and residue contributed 47 % and 41 %, respectively, to total CO2-C emissions. Regarding the estimated emissions from sugarcane residue and SOC decomposition within the measurement period, CO2-C factor was similar to sugarcane residue and soil organic carbon decomposition, depending on the tillage system applied. Our approach may define new emission factors that are associated to tillage operations on bare or sugarcane-residue-covered soils to estimate the total carbon loss.

  16. The evaluation of meta-analysis techniques for quantifying prescribed fire effects on fuel loadings.

    Science.gov (United States)

    Karen E. Kopper; Donald McKenzie; David L. Peterson

    2009-01-01

    Models and effect-size metrics for meta-analysis were compared in four separate meta-analyses quantifying surface fuels after prescribed fires in ponderosa pine (Pinus ponderosa Dougl. ex Laws.) forests of the Western United States. An aggregated data set was compiled from eight published reports that contained data from 65 fire treatment units....

  17. Quantifying the effects of pesticide exposure on annual reproductive success of birds (presentation)

    Science.gov (United States)

    The Markov chain nest productivity model (MCnest) was developed for quantifying the effects of specific pesticide‐use scenarios on the annual reproductive success of simulated populations of birds. Each nesting attempt is divided into a series of discrete phases (e.g., egg ...

  18. Quantifying the effects of pesticide exposure on annual reproductive success of birds

    Science.gov (United States)

    The Markov chain nest productivity model (MCnest) was developed for quantifying the effects of specific pesticide-use scenarios on the annual reproductive success of simulated populations of birds. Each nesting attempt is divided into a series of discrete phases (e.g., egg layin...

  19. Enhanced computational methods for quantifying the effect of geographic and environmental isolation on genetic differentiation

    NARCIS (Netherlands)

    Botta, Filippo; Eriksen, Casper; Fontaine, Michael Christophe; Guillot, Gilles

    2015-01-01

    In a recent paper, Bradburd et al. (2013) proposed a model to quantify the relative effect ofgeographic and environmental distance on genetic differentiation. Here, we enhance this method in several ways. 1. We modify the covariance model so as to fit better with mainstream geostatistical models and

  20. Responses by earthworms to reduced tillage in herbicide tolerant maize and Bt maize cropping systems

    DEFF Research Database (Denmark)

    Krogh, P. H.; Griffiths, B.; Demsar, D.

    2007-01-01

    -toxin producing transgenic maize line MON810 was studied for 1 year. At a Danish study site, Foulum (Jutland), one year of Bt corn was followed by 2 years of herbicide tolerant corn. At the French study site the most prominent effects observed were due to the tillage method where RT significantly reduced...

  1. Water stability of soil aggregates in different systems of Chernozem tillage

    Directory of Open Access Journals (Sweden)

    Jaroslava Bartlová

    2011-01-01

    Full Text Available Effects of various agrotechnical measures on macrostructural changes in the ploughing layer and subsoil were studied within the period of 2008–2010. Soil macrostructure was evaluated on the base of water stability of soil aggregates. Altogether three variants of soil tillage were established, viz. ploughing to the depth of 0.22 m (Variant 1, deep soil loosening to the depth of 0.35–0.40 m (Variant 2, and shallow tillage to the depth of 0.15 m (Variant 3. Experiments were established on a field with Modal Chernozem in the locality Hrušovany nad Jevišovkou (maize-growing region, altitude of 210 m, average annual sum of precipitation 461 mm. In the first experimental year, winter rape was the cultivated crop and it was followed by winter wheat, maize and spring wheat in subsequent years. The aim of this study was to evaluate effects of different methods of tillage on water stability of soil aggregates and on yields of individual crops. An overall analysis of results revealed a positive effect of cultivation without ploughing on water stability of soil aggregates. In the variant with ploughing was found out a statistically significant decrease of this stability. At the same time it was also found out that both minimum tillage and deep soil loosening showed a positive effect on yields of crops under study (above all of maize and winter wheat.

  2. Reduced tillage and cover crops as a strategy for mitigating atmospheric CO2 increase through soil organic carbon sequestration in dry Mediterranean agroecosystems.

    Science.gov (United States)

    Almagro, María; Garcia-Franco, Noelia; de Vente, Joris; Boix-Fayos, Carolina; Díaz-Pereira, Elvira; Martínez-Mena, María

    2016-04-01

    The implementation of sustainable land management (SLM) practices in semiarid Mediterranean agroecosystems can be beneficial to maintain or enhance levels of soil organic carbon and mitigate current atmospheric CO2 increase. In this study, we assess the effects of different tillage treatments (conventional tillage (CT), reduced tillage (RT), reduced tillage combined with green manure (RTG), and no tillage (NT)) on soil CO2 efflux, aggregation and organic carbon stabilization in two semiarid organic rainfed almond (Prunus dulcis Mill., var. Ferragnes) orchards located in SE Spain Soil CO2 efflux, temperature and moisture were measured monthly between May 2012 and December 2014 (site 1), and between February 2013 and December 2014 (site 2). In site 1, soil CO2 efflux rates were also measured immediately following winter and spring tillage operations. Aboveground biomass inputs were estimated at the end of the growing season in each tillage treatment. Soil samples (0-15 cm) were collected in the rows between the trees (n=4) in October 2012. Four aggregate size classes were distinguished by sieving (large and small macroaggregates, free microaggregates, and free silt plus clay fraction), and the microaggregates occluded within macroaggregates (SMm) were isolated. Soil CO2efflux rates in all tillage treatments varied significantly during the year, following changes during the autumn, winter and early spring, or changes in soil moisture during late spring and summer. Repeated measures analyses of variance revealed that there were no significant differences in soil CO2 efflux between tillage treatments throughout the study period at both sites. Average annual values of C lost by soil respiration were slightly but not significantly higher under RT and RTG treatments (492 g C-CO2 m-2 yr-1) than under NT treatment (405 g C-CO2 m-2 yr-1) in site 1, while slightly but not significantly lower values were observed under RT and RTG treatments (468 and 439 g C-CO2 m-2 yr-1

  3. GRANULOMETRIC AND HUMIC FRACTIONS CARBON STOCKS OF SOIL ORGANIC MATTER UNDER NO-TILLAGE SYSTEM IN UBERABA, BRAZIL

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    Marcos Gervasio Pereira

    2011-12-01

    Full Text Available The cover plant use preceding grain crops in Cerrado soil can increase the carbon stocks of chemical and physical fractions of soil organic matter (SOM. The present study aimed to quantify the carbon stocks of SOM granulometric and humic fractions in a Cerrado area under no-tillage system with different cover plant, and compare the results with those from conventional tillage and fallow areas, in Uberaba, MG, Brazil. The implemented cover crops were: millet, tropical grass and sunn hemp. Furthermore, an area was used in fallow and another as a control area (conventional tillage. After cover crop removal, the areas were subdivided for the corn and soybean plantation. Soil samples were collected in the 0.0-0.025, 0.025-0.05, 0.05-0.10 and 0.10-0.20 m depths, with posterior quantification of total organic carbon (TOC levels and chemical and granulometric fractionation of SOM. Humic acid carbon (C-HAF, fulvic acids (C-FAF and humin (C-HUM were quantified through these fractionations. The granulometric fractions consisted in particulate organic matter (POM and mineral organic matter (MOM. Using the carbon levels for each fraction, the respective stocks for each depth were calculated, including the 0.0-0.20 m layer. In the 0.0-0.20 m layer, TOC had the highest stocks for the millet area. The highest POM stocks were found for the corn plantation over sunn hemp and the fallow and soybean area over millet and tropical grass (0.0-0.20 m. In relation to the MOM stocks, the highest values were observed in the areas with millet, sunn hemp and tropical (palisade grass, all superior to those found in the conventional tillage and fallow areas, independent of evaluated culture (0.10-0.20 m. The highest C-HUM stocks were observed in the area with tropical grass (0.025-0.05 m and areas with tropical grass and sunn hemp (0.10-0.20 m, when compared to conventional tillage, independent of evaluated culture (corn and soybean. The highest C-FAH stocks in the depth of 0

  4. Quantifying the Effects of Historical Land Cover Conversion Uncertainty on Global Carbon and Climate Estimates

    Science.gov (United States)

    Di Vittorio, A. V.; Mao, J.; Shi, X.; Chini, L.; Hurtt, G.; Collins, W. D.

    2018-01-01

    Previous studies have examined land use change as a driver of global change, but the translation of land use change into land cover conversion has been largely unconstrained. Here we quantify the effects of land cover conversion uncertainty on the global carbon and climate system using the integrated Earth System Model. Our experiments use identical land use change data and vary land cover conversions to quantify associated uncertainty in carbon and climate estimates. Land cover conversion uncertainty is large, constitutes a 5 ppmv range in estimated atmospheric CO2 in 2004, and generates carbon uncertainty that is equivalent to 80% of the net effects of CO2 and climate and 124% of the effects of nitrogen deposition during 1850-2004. Additionally, land cover uncertainty generates differences in local surface temperature of over 1°C. We conclude that future studies addressing land use, carbon, and climate need to constrain and reduce land cover conversion uncertainties.

  5. Conservation tillage impacts on soil, crop and the environment

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    Mutiu Abolanle Busari

    2015-06-01

    Full Text Available There is an urgent need to match food production with increasing world population through identification of sustainable land management strategies. However, the struggle to achieve food security should be carried out keeping in mind the soil where the crops are grown and the environment in which the living things survive. Conservation agriculture (CA, practising agriculture in such a way so as to cause minimum damage to the environment, is being advocated at a large scale world-wide. Conservation tillage, the most important aspect of CA, is thought to take care of the soil health, plant growth and the environment. This paper aims to review the work done on conservation tillage in different agro-ecological regions so as to understand its impact from the perspectives of the soil, the crop and the environment. Research reports have identified several benefits of conservation tillage over conventional tillage (CT with respect to soil physical, chemical and biological properties as well as crop yields. Not less than 25% of the greenhouse gas effluxes to the atmosphere are attributed to agriculture. Processes of climate change mitigation and adaptation found zero tillage (ZT to be the most environmental friendly among different tillage techniques. Therefore, conservation tillage involving ZT and minimum tillage which has potential to break the surface compact zone in soil with reduced soil disturbance offers to lead to a better soil environment and crop yield with minimal impact on the environment. Keywords: Atmosphere, Greenhouse gases, Conservation tillage, Sustainable crop yield

  6. Morphology and stability of aggregates of an Oxisol according to tillage system and gypsum application

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    Fábio Régis de Souza

    2012-12-01

    Full Text Available Morphological characterization and aggregate stability is an important factor in evaluating management systems. The aim of this paper is to evaluate the stability and morphology of the aggregates of a dystrophic Oxisol managed with no-tillage and conventional tillage with and without the residual action of gypsum. The experimental design was randomized blocks arranged in split-split plot, where the treatments were two soil management systems (plots with 0 and 2000 kg ha-1 of gypsum (subplots and five depths (0-0.05, 0.05-0.10, 0.10-0.15, 0.15-0.20 and 0.20-0.30 m as the subsubplots, with four replications. The aggregate morphology was determined through images and later evaluated by the Quantporo software. Stability was determined by the wet method. The results showed that the no-tillage system, with or without gypsum residual effect, provided the aggregates with the largest geometric diameters. The combination of no-tillage system and the gypsum residual effect provided rougher aggregates.

  7. Impact of no-till and conventional tillage practices on soil chemical properties

    International Nuclear Information System (INIS)

    Aziz, A.; Bangash, N.

    2015-01-01

    There is a global concern about progressive increase in the emission of greenhouse gases especially atmosphere CO/sub 2/. An increasing awareness about environmental pollution by CO/sub 2/ emission has led to recognition of the need to enhance soil C sequestration through sustainable agricultural management practices. Conservation management systems such as no-till (NT) with appropriate crop rotation have been reported to increase soil organic C content by creating less disturbed environment. The present study was conducted on Vanmeter farm of The Ohio State University South Centers at Piketon Ohio, USA to estimate the effect of different tillage practices with different cropping system on soil chemical properties. Tillage treatments were comprised of conventional tillage (CT) and No-till (NT).These treatments were applied under continuous corn (CC), corn-soybean (CS) and corn soybean-wheat-cowpea (CSW) cropping system following randomized complete block design. No-till treatment showed significant increase in total C (30%), active C (10%), and passive salt extractable (18%) and microwave extractable C (8%) and total nitrogen (15%) compared to conventional tillage practices. Total nitrogen increased significantly 23 % in NT over time. Maximum effect of no-till was observed under corn-soybean-wheat-cowpea crop rotation. These findings illustrated that no-till practice could be useful for improving soil chemical properties. (author)

  8. TILLAGE AND DYNAMICS OF INORGANIC NITROGEN IN ECOLOGICAL AND INTEGRATION MANAGEMENT SYSTEMS

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    J SMATANA

    2002-05-01

    Full Text Available During the period of 1991-1993 in the field experiment, the effect of different soil management (tillage 0,24 m and tillage 0,12-0,15 m in ecological and integration management system on changes of inorganic nitrogen (Nan = N-NH4 + + N-NO3 - content in the soil layer from 0 up to 0,6 m of the soil depth (0,00-0,30 m and 0,30- 0,60 m were studied. Trials were held in a warm climatic zone of the South – Western Slovakia on the brown soil. Different soil management systems (tillage 0,24 m and tillage 0,12-0,15 m considerably did not affected ammonification and nitrification processes in the soil. The sustainability of minimalization via shallow ploughing is not excluded, on the contrary this minimalization may have high a positive influence on economic saving the energy, labour costs, etc. The quantitative and qualitative changes of studied form of N were significantly effected by weather and soil depth. Soil content of N-NH4 + and N-NO3 - was in negative correlation with soil depth.

  9. Quantifying scaling effects on satellite-derived forest area estimates for the conterminous USA

    Science.gov (United States)

    Daolan Zheng; L.S. Heath; M.J. Ducey; J.E. Smith

    2009-01-01

    We quantified the scaling effects on forest area estimates for the conterminous USA using regression analysis and the National Land Cover Dataset 30m satellite-derived maps in 2001 and 1992. The original data were aggregated to: (1) broad cover types (forest vs. non-forest); and (2) coarser resolutions (1km and 10 km). Standard errors of the model estimates were 2.3%...

  10. Traffic Safety and Vehicle Choice: Quantifying the Effects of the "Arms Race" on American Roads

    OpenAIRE

    Li, Shanjun

    2009-01-01

    The increasing market share of light trucks in the U.S. in recent years has been characterized as an “arms race” where individual purchase of light trucks for better self-protection in collisions nevertheless leads to worse traffic safety for the society. This paper investigates the interrelation between traffic safety and vehicle choice by quantifying the effects of the arms race on vehicle demand, producer performance, and traffic safety. The empirical analysis shows that the accident exter...

  11. EFECTOS A LARGO PLAZO DE LA LABRANZA CONVENCIONAL Y LA SIEMBRA DIRECTA SOBRE LAS PROPIEDADES FÍSICAS DE UN ARGIUDOL TÍPICO DE LA PAMPA ONDULADA ARGENTINA LONG TERM EFFECTS OF NO TILLAGE AND CONVENTIONAL TILLAGE IN A TYPIC ARGIUDOLL OF THE ARGENTINA ROLLING PAMPA

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    Ramiro Ramírez Pisco

    2006-06-01

    Full Text Available Una creciente proporción de argiudoles franco limosos es manejada con siembra directa, lo cual genera incertidumbre en cuanto a la posible evolución a largo plazo de las propiedades físicas. En Pergamino, el INTA posee ensayos de labranzas donde los suelos son manejados con labranza convencional (LC y con siembra directa (SD continua desde hace 16 años. En estas parcelas fueron evaluadas la densidad aparente (cilindro, la resistencia (medida en laboratorio a distintos contenidos hídricos, la distribución de tamaño de poros (desorción de agua en mesa de tensión, la conductividad hidráulica saturada K sat (cilindros en laboratorio, y la estabilidad de agregados. Los resultados fueron comparados con un suelo no degradado (reserva botánica. Los parámetros más sensibles fueron la conductividad hidráulica y la inestabilidad de agregados cuyos valores fueron respectivamente de 1,41- 0,16 mm h-1 y 2,78 mm bajo LC, y de 23,61- 4,61 mm h-1 y 1,07 mm bajo SD. En este tratamiento el suelo recuperó su distribución original bimodal de poros, con prevalecía de las clases > 100 mm y 50- 20 mm.No tillage is applied to an increasing proportion of silty loam argiudolls. little is known about the possible longterm evolution of soil physical properties. In Pergamino, INTA has 16 yr field trials for comparing soil behavior under longterm conventional tillage (CT and no tillage (NT. In these treatments soil bulk density (cores, resistance (measured in the laboratory at different water contents, pore size distribution (water desorption in the tension table, saturated hydraulic conductivity, K sat (measured in the laboratory, and aggregate instability were determined. Results were compared to a nondegraded condition (a botanic reserve. Soil K sat and aggregate instability were the most sensitive parameters, which were respectively 1,41 - 0,16 mm h-1 and 1,07 mm under CT and 23,61 - 4,61 mm h-1 and 1,07 mm under NT. In this treatment soil recovered its

  12. Experimental analysis of CO{sub 2} emissions from agricultural soils subjected to five different tillage systems in Lithuania

    Energy Technology Data Exchange (ETDEWEB)

    Buragienė, Sidona [Institute of Agricultural Engineering and Safety, Aleksandras Stulginskis University, Studentu str. 15A, LT-53361 Akademija, Kaunas distr. (Lithuania); Šarauskis, Egidijus, E-mail: egidijus.sarauskis@asu.lt [Institute of Agricultural Engineering and Safety, Aleksandras Stulginskis University, Studentu str. 15A, LT-53361 Akademija, Kaunas distr. (Lithuania); Romaneckas, Kęstutis, E-mail: kestas.romaneckas@asu.lt [Institute of Agroecosystems and Soil Science, Aleksandras Stulginskis University, Studentu str. 11, Akademija LT-53361, Kaunas dist. (Lithuania); Sasnauskienė, Jurgita, E-mail: jurgita.sasnauskiene@asu.lt [Institute of Environment and Ecology, Aleksandras Stulginskis University, Studentu str. 11, Akademija LT-53361, Kaunas dist. (Lithuania); Masilionytė, Laura, E-mail: laura.masilionyte@gmail.com [Joniskelis Experimental Station, Lithuanian Research Centre for Agriculture and Forestry, Joniskelis, LT-39301 Pasvalys distr. (Lithuania); Kriaučiūnienė, Zita, E-mail: zita.kriauciuniene@asu.lt [Experimental Station, Aleksandras Stulginskis University, Rapsu str. 7, LT-53363 Noreikiskes, Kaunas distr. (Lithuania)

    2015-05-01

    Intensive agricultural production strongly influences the global processes that determine climate change. Thus, tillage can play a very important role in climate change. The intensity of soil carbon dioxide (CO{sub 2}) emissions, which contribute to the greenhouse effect, can vary depending on the following factors: the tillage system used, meteorological conditions (which vary in different regions of the world), soil properties, plant residue characteristics and other factors. The main purpose of this research was to analyse and assess the effects of autumn tillage systems with different intensities on CO{sub 2} emissions from soils during different seasons and under the climatic conditions of Central Lithuania. The research was conducted at the Experimental Station of Aleksandras Stulginskis University from 2009 to2012; and in 2014. The soils at the experimental site were classified as Eutric Endogleyic Planosol (Drainic). The investigations were conducted using five tillage systems with different intensities, typical of the Baltic Region. Deep conventional ploughing was performed at a depth of 230–250 mm, shallow ploughing was conducted at a depth of 120–150 mm, deep loosening was conducted at depths of 250–270 mm, and shallow loosening was conducted at depths of 120–150 mm. The fifth system was a no-tillage system. Overall, autumn tillage resulted in greater CO{sub 2} emissions from the soil over both short- and long-term periods under the climatic conditions of Central Lithuania, regardless of the tillage system applied. The highest soil CO{sub 2} emissions were observed for the conventional deep ploughing tillage system, and the lowest emissions were observed for the no-tillage system. The meteorological conditions greatly influenced the CO{sub 2} emissions from the soil during the spring. Soil CO{sub 2} emissions were enhanced as precipitation and the air and soil temperatures increased. Long-term investigations regarding the dynamics of CO{sub 2

  13. Soil CO 2 fluxes from direct seeding rice fields under two tillage practices in central China

    Science.gov (United States)

    Li, Cheng-fang; Kou, Zhi-kui; Yang, Jin-hua; Cai, Ming-li; Wang, Jin-ping; Cao, Cou-gui

    2010-07-01

    Agricultural practices affect the production and emission of carbon dioxide (CO 2) from paddy soils. It is crucial to understand the effects of tillage and N fertilization on soil CO 2 flux and its influencing factors for a better comprehension of carbon dynamics in subtropical paddy ecosystems. A 2-yr field study was conducted to assess the effects of tillage (conventional tillage [CT] and no-tillage [NT]) and N fertilization (0 and 210 kg N ha -1) on soil CO 2 fluxes during the 2008 and 2009 rice growing seasons in central China. Treatments were established following a split-plot design of a randomized complete block with tillage practices as the main plot and N fertilizer level as the split-plot treatment. The soil CO 2 fluxes were measured 24 times in 2008 and 17 times in 2009. N fertilization did not affect soil CO 2 emissions while tillage affected soil CO 2 emissions, where NT had similar soil CO 2 emissions to CT in 2008, but in 2009, NT significantly increased soil CO 2 emissions. Cumulative CO 2 emissions were 2079-2245 kg CO 2-C ha -1 from NT treatments, and 2084-2141 kg CO 2-C ha -1 from CT treatments in 2008, and were 1257-1401 kg CO 2-C ha -1 from NT treatments, and 1003-1034 kg CO 2-C ha -1 from CT treatments in 2009, respectively. Cumulative CO 2 emissions were significantly related to aboveground biomass and soil organic C. Before drainage of paddy fields, soil CO 2 fluxes were significantly related to soil temperature with correlation coefficients ( R) of 0.67-0.87 in 2008 and 0.69-0.85 in 2009; moreover, the Q 10 values ranged from 1.28 to 1.55 and from 2.10 to 5.21 in 2009, respectively. Our results suggested that NT rice production system appeared to be ineffective in decreasing carbon emission, which suggested that CO 2 emissions from integrated rice-based system should be taken into account to assess effects of tillage.

  14. Oslo traffic study - part 2: quantifying effects of traffic measures using individual exposure modeling

    International Nuclear Information System (INIS)

    Clench-Aas, J.; Bartonova, A.; Klaeboe, R.; Kolbenstvedt, M.

    2000-01-01

    In quantifying the benefits of air pollution reduction measures, it is desirable to compare the size of the benefits with the effects of other individual confounding factors such as smoking or passive smoking. The effect of pollution is rarely very large and in order to quantify it, exposure estimating procedures must be as accurate as possible. Dispersion models, run for hourly time intervals and controlled by measurements, are therefore used to provide estimates for specific receptor points. Results of three consecutive cross-sectional investigations in an area of Oslo characterized by heavy traffic are presented. The study was designed to provide repeated information on the effects of traffic diversion measures on the self-reporting of symptoms of reduced health of 1100 adults living in Oslo. The principal source of air pollution in Oslo is vehicular traffic. The primary pollutants of interest are nitrogen dioxide (NO 2 ) and respirable particles (PM 2.5 and PM 10 ). The mean hourly concentration of exposure was estimated at each participant's home by means of a time-dependent finite dispersion model combined with subgrid models to describe the source contribution to the grid concentrations. The study controlled the confounding factors. Using the symptom fatigue, the study illustrates that by controlling the changes in population composition, estimated exposure-effect relationships for health symptoms allow the effect of the studied traffic measures on the population to be evaluated. Since the method is based on individual estimates of exposure to different pollutants, it allows standardizing the exposure to compare effects of different pollutants. The study offers a methodology that is useful in evaluating the benefits of measures by both being able to quantify and compare the effects of different compounds and effects on different population sub-groups. (author)

  15. Weed-Species Abundance and Diversity Indices in Relation to Tillage Systems and Fertilization

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    Ilias S. Travlos

    2018-04-01

    Full Text Available Weeds pose a major threat to world agriculture by reducing detrimentally crop yield and quality. However, at the same time, weeds are major interacting components of the agroecosystems. Abundance and diversity of weeds vary significantly among the several communities. In order to evaluate each community's structure and the interactions among them, several population indices are used as key tools. In parallel, various cultivation and land management strategies, such as tillage and fertilization, are commonly used in terms of integrated weed management. Estimating the response of weed species on those practices is crucial for both biodiversity maintenance and alternative weed control methods. Many experiments have confirmed the fundamental role of tillage intensity and nutrition supply in weed species' abundance and diversity. For instance, in some studies, the abundance of perennial weeds was doubled under reduced tillage intensity. In addition, higher values of Shannon-Weiner and Pielou indices were reported in the PK fertilization treatment compared to the control and NK fertilization treatments. The objective of this paper is to provide a brief overview of the key results of these experiments and summarize the part of the literature related to the effect of tillage systems and fertilization on weed species abundance and diversity. Such knowledge could contribute to the sound design and implementation of integrated weed management programs which in turn may lead to a decrease in the density of serious and noxious weeds and an increase in the overall balance of agroecosystems.

  16. Differential responses of nitrate reducer community size, structure, and activity to tillage systems.

    Science.gov (United States)

    Chèneby, D; Brauman, A; Rabary, B; Philippot, L

    2009-05-01

    The main objective of this study was to determine how the size, structure, and activity of the nitrate reducer community were affected by adoption of a conservative tillage system as an alternative to conventional tillage. The experimental field, established in Madagascar in 1991, consists of plots subjected to conventional tillage or direct-seeding mulch-based cropping systems (DM), both amended with three different fertilization regimes. Comparisons of size, structure, and activity of the nitrate reducer community in samples collected from the top layer in 2005 and 2006 revealed that all characteristics of this functional community were affected by the tillage system, with increased nitrate reduction activity and numbers of nitrate reducers under DM. Nitrate reduction activity was also stimulated by combined organic and mineral fertilization but not by organic fertilization alone. In contrast, both negative and positive effects of combined organic and mineral fertilization on the size of the nitrate reducer community were observed. The size of the nitrate reducer community was a significant predictor of the nitrate reduction rates except in one treatment, which highlighted the inherent complexities in understanding the relationships the between size, diversity, and structure of functional microbial communities along environmental gradients.

  17. Efeito de cargas aplicadas e profundidades de semeadura no desenvolvimento da cultura do feijão em sistema plantio direto Effect of loads applied and depths of sowing in the development of bean culture in no-tillage system

    Directory of Open Access Journals (Sweden)

    Alcir José Modolo

    2010-06-01

    Full Text Available Dentre os fatores primordiais para a germinação estão a umidade, a temperatura e a aeração do solo. É importante citar que esses fatores são diretamente influenciados pelo estado de compactação do solo ao redor da semente. Objetivou-se, neste trabalho, estudar os efeitos da combinação entre profundidades de semeadura e cargas aplicadas pela roda compactadora da semeadora-adubadora sobre o desenvolvimento da cultura do feijão, em sistema plantio direto. Foi utilizado o esquema fatorial no delineamento em blocos ao acaso, composto por doze tratamentos (três profundidades de semeadura e quatro níveis de cargas aplicadas pela roda compactadora e quatro repetições. Os resultados mostraram que a profundidade de semeadura influenciou, significativamente, o índice de velocidade de emergência, os estandes inicial e final de plantas e o rendimento da cultura. As diferentes cargas aplicadas pela roda compactadora não influenciaram significativamente as variáveis avaliadas.Among the primordial factors for the germination are humidity, temperature, and aeration of the soil. It is important to mention that these factors are directly influenced by the soil compaction state around the seed. The present paper had the aim of studying the effects of the combination between depths of sowing and loads applied by press wheel of the seeder upon the development of bean culture, in a no-tillage system. Factor schedule was applied to the delineation in random blocks composed by twelve treatments (three depths of sowing and four levels of loads applied by the press wheel and four replications. The results showed that depth of sowing significantly influenced the index of emergency speed, the initial and final stands of plants and yield of culture. The different loads applied for the press wheel did not significantly influence the evaluated variables.

  18. Perdas de solo e nutrientes num latossolo vermelho-amarelo ácrico típico, com diferentes sistemas de preparo e sob chuva natural Soil and nutrient losses under different tillage systems in a clayey oxisol under natural rainfall

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    Marcelo Henrique Siqueira Leite

    2009-06-01

    Full Text Available O processo erosivo é a principal causa de degradação dos solos, trazendo, como consequência, prejuízos ao setor agrícola e ao meio ambiente, com reflexos econômicos e também sociais. Este trabalho foi realizado com o objetivo de avaliar as perdas de solo e nutrientes em diferentes sistemas de preparo num Latossolo Vermelho-Amarelo ácrico típico. Foram instaladas cinco parcelas experimentais contendo os seguintes tratamentos: preparo convencional e cultivo morro abaixo (CMA; preparo convencional e plantio em nível (CEN; preparo com uma grade aradora e uma niveladora e plantio em nível (CNiv; preparo com duas gradagens niveladoras, plantio em nível (NA e cultivo mínimo em nível (CMN. As perdas de solo foram determinadas pelo método direto durante o ciclo da cultura de algodão, de dezembro de 2005 a junho de 2006. A cada coleta foram retiradas amostras de solo para quantificar as perdas dos nutrientes N, P, K e carbono orgânico (C-org nos sedimentos. A diminuição no revolvimento do solo proporcionou menores perdas de sedimento, nutrientes e C-org, destacando o CMN como o mais eficiente. As perdas de N, P, K e C-org nos sedimentos apresentaram tendências semelhantes às das perdas de solo, e N, P e K variaram conforme as adubações utilizadas. O C-org foi encontrado em maior quantidade no sedimento. A taxa de infiltração básica (TIB expressou diferença entre os tratamentos na seguinte ordem em valores crescentes: CMA CNiv NA Erosion is the main cause of soil degradation, and it leads to adverse effects to agriculture and environment, with social and economic implications. The objective of this study was to evaluate soil and nutrient losses in different soil tillage systems in a typic Acric Red-Yellow Latosol (Oxisol. On five plots with the following soil tillage treatments were evaluated: conventional tillage and down-slope tillage (CMA; conventional tillage and contour seeding (CEN; tillage with one passage of heavy disk

  19. Water deficit stress effects on corn (Zea mays, L.) root: shoot ratio

    Science.gov (United States)

    A study was conducted at Akron, CO, USA, on a Weld silt loam in 2004 to quantify the effects of water deficit stress on corn (Zea mays, L.) root and shoot biomass. Corn plants were grown under a range of soil bulk density and water conditions caused by previous tillage, crop rotation, and irrigation...

  20. Quantifying the Effects of Biofilm on the Hydraulic Properties of Unsaturated Soils

    Science.gov (United States)

    Volk, E.; Iden, S.; Furman, A.; Durner, W.; Rosenzweig, R.

    2017-12-01

    Quantifying the effects of biofilms on hydraulic properties of unsaturated soils is necessary for predicting water and solute flow in soil with extensive microbial presence. This can be relevant to bioremediation processes, soil aquifer treatment and effluent irrigation. Previous works showed a reduction in the hydraulic conductivity and an increase in water content due to the addition of biofilm analogue materials. The objective of this research is to quantify soil hydraulic properties of unsaturated soil (water retention and hydraulic conductivity) using real soil biofilm. In this work, Hamra soil was incubated with Luria Broth (LB) and biofilm-producing bacteria (Pseudomonas Putida F1). Hydraulic conductivity and water retention were measured by the evaporation method, Dewpoint method and a constant head permeameter. Biofilm was quantified using viable counts and the deficit of TOC. The results show that the presence of biofilms increases soil retention in the `dry' range of the curve and reduces the hydraulic conductivity (see figure). This research shows that biofilms may have a non-negligible effect on flow and transport in unsaturated soils. These findings contribute to modeling water flow in biofilm amended soil.

  1. No-tillage and fertilization management on crop yields and nitrate leaching in North China Plain

    Science.gov (United States)

    Huang, Manxiang; Liang, Tao; Wang, Lingqing; Zhou, Chenghu

    2015-01-01

    A field experiment was performed from 2003 to 2008 to evaluate the effects of tillage system and nitrogen management regimes on crop yields and nitrate leaching from the fluvo-aquic soil with a winter wheat (Triticum aestivum L.)–maize (Zea mays L.) double-cropping system. The tillage systems consisted of conventional tillage (CT) and no-tillage (NT). Three nitrogen management regimes were included: 270 kg N ha−1 of urea for wheat and 225 kg N ha−1 of urea for maize (U), 180 kg N ha−1 of urea and 90 kg N ha−1 of straw for wheat and 180 kg N of urea and 45 kg N ha−1 of straw for maize (S), 180 kg N ha−1 of urea and 90 kg N ha−1 of manure for wheat and 180 kg N ha−1 of urea and 45 kg N ha−1 of manure for maize (M). An array of tension-free pan lysimeters (50 cm × 75 cm) were installed (1.2 m deep) to measure water flow and -N movement. No significant effect of the N management regime on yields of winter wheat and maize grain was found in the 5-year rotation. Tillage systems had significant influences on -N leaching from the second year and thereafter interacted with N management regimes on -N loads during all maize seasons. The average yield-scaled -N leaching losses were in order of CTS leaching losses while sustaining crop grain yields. Considering the lower costs, NTS could be a potential alternative to decrease yield-scaled -N leaching losses and improve soil fertility while maintaining crop yield for the winter wheat–maize double-cropping systems in the North China Plain. PMID:25859321

  2. Seedling emergence response of rare arable plants to soil tillage varies by species.

    Science.gov (United States)

    Torra, Joel; Recasens, Jordi; Royo-Esnal, Aritz

    2018-01-01

    Very little information is available on emergence of rare arable plants (RAP) in relation to soil disturbance and seed burial conditions in Europe. This information is essential to design conservation and soil management strategies to prevent the decline of these species in agroecosystems. The objective of this research was to investigate the effect of soil cultivation with burial time on the emergence and seed persistence of RAP. Seeds of 30 RAP species were collected from Spanish arable fields and subjected to two tillage treatments: (a) no soil disturbance, and (b) autumnal soil disturbance down to 10 cm depth every year. The treatments simulated no-till and tilled (disking), respectively. In plots under no-till, RAP seeds were sown at 1-cm depth. In the tilled plots, seeds were sown homogeneously mixed in the top 1-10 cm of soil. The trial was established every two consecutive seasons, and each trial was maintained for two years. Annual cumulative plant emergence was calculated each year; whereas the first trial was monitored for a third year to estimate seed longevity using a persistence index. The response in emergence of the 30 RAP to annual tillage varied among species. With burial time (number of years), higher emergence was observed for seeds sown in tilled soil. This was true across all species, and with strong season effects. The persistence index was correlated with seed weight, species with bigger seeds had low persistence indices while no pattern was observed for small seeded species. Most RAP species, particularly those with high persistence, showed induction of secondary dormancy processes, highlighting the importance of tillage to promote RAP emergence, and hence, seed bank replenishment. Therefore, as time passes the absence of soil tillage may represent a driver of RAP seed bank decline for those species with secondary dormancy processes. In conclusion, it is important to design soil management strategies, such as regular tillage to promote

  3. Improving maize productivity through tillage and nitrogen management

    African Journals Online (AJOL)

    Continuous cultivation of fields with same implement (cultivator) creates a hard pan in the subsoil which adversely affects crop productivity. In addition to tillage, nitrogen management is a key factor for better crop growth and yield. Impact of different tillage systems and nitrogen management on yield attributes and grain yield ...

  4. Quantifying Transmission.

    Science.gov (United States)

    Woolhouse, Mark

    2017-07-01

    Transmissibility is the defining characteristic of infectious diseases. Quantifying transmission matters for understanding infectious disease epidemiology and designing evidence-based disease control programs. Tracing individual transmission events can be achieved by epidemiological investigation coupled with pathogen typing or genome sequencing. Individual infectiousness can be estimated by measuring pathogen loads, but few studies have directly estimated the ability of infected hosts to transmit to uninfected hosts. Individuals' opportunities to transmit infection are dependent on behavioral and other risk factors relevant given the transmission route of the pathogen concerned. Transmission at the population level can be quantified through knowledge of risk factors in the population or phylogeographic analysis of pathogen sequence data. Mathematical model-based approaches require estimation of the per capita transmission rate and basic reproduction number, obtained by fitting models to case data and/or analysis of pathogen sequence data. Heterogeneities in infectiousness, contact behavior, and susceptibility can have substantial effects on the epidemiology of an infectious disease, so estimates of only mean values may be insufficient. For some pathogens, super-shedders (infected individuals who are highly infectious) and super-spreaders (individuals with more opportunities to transmit infection) may be important. Future work on quantifying transmission should involve integrated analyses of multiple data sources.

  5. Earthworms influenced by reduced tillage, conventional tillage and energy forest in Swedish agricultural field experiments

    Energy Technology Data Exchange (ETDEWEB)

    Lagerloef, Jan (SLU, Department of Ecology, Swedish University of Agricultural Sciences, Uppsala (Sweden)), Email: Jan.Lagerlof@ekol.slu.se; Paalsson, Olof; Arvidsson, Johan (SLU, Department of Soil and Environment, Swedish University of Agricultural Sciences, Uppsala (Sweden))

    2012-03-15

    We compared earthworm density, depth distribution and species composition in three soil cultivation experiments including the treatments ploughless tillage and mouldboard ploughing. Sampling was done in September 2005 and for one experiment also in 1994. By yearly sampling 1995-2005, earthworms in an energy forest of Salix viminalis were compared with those in an adjacent arable field. Sampling method was digging of soil blocks and hand sorting and formalin sampling in one cultivation experiment. Both methods were used in the energy forest and arable land comparison. In two soil cultivation experiments, highest abundances or biomass were found in ploughless tillage. Earthworm density was higher in the upper 10 cm, especially in the ploughless tillage. Earthworm density was significantly higher in the energy forest than in the arable field. Formalin sampling revealed c. 36% of the earthworm numbers found by digging in the energy forest and gave almost no earthworms in the arable field. In all treatments with soil cultivation, species living and feeding in the rhizosphere and soil dominated. One such species, Allolobophora chlorotica, was more abundant under mouldboard ploughing than ploughless tillage. Lumbricus terrestris, browsing on the surface and producing deep vertical burrows, was more common in the ploughless tillage. Species living and feeding close to the soil surface were almost only found in the energy forest, which had not been soil cultivated since 1984. The findings support earlier studies pointing out possibilities to encourage earthworms by reduced soil cultivation. This is one of the first published studies that followed earthworm populations in an energy forest plantation during several years. Explanation of earthworm reactions to management and environmental impacts should be done with consideration of the ecology of species or species groups. Earthworm sampling by formalin must always be interpreted with caution and calibrated by digging and

  6. Fabrication and evaluation of a reservoir tillage machine to reduce runoff from farms with sprinkler irrigation systems

    Directory of Open Access Journals (Sweden)

    M. A Rostami

    2016-09-01

    performance, two factors contain of machine speed (in three levels of 5, 7.5 and 10 km h-1 and Arm's length (in two levels of 30 and 40 cm were evaluated. The machine was evaluated based on a completely randomized block factorial design with three replications. Effects of these factors on depth, distance and volume of basins and runoff were evaluated. Results and Discussion Mean comparisons of depth, distance and size of reservoirs in different machine forward speed and different Arm's length are summarized in Table 1 and 2. The results showed that the effect of arm length and forward speed on changes in the depth and volume of the reservoirs were significant at the probability level of one percent but changes of the distance between the reservoirs was only affected by Arm's length. The results also showed that increasing the forward speed from 5 to 10 km h-1 and increase the Arm's length from 30 to 40 cm increased depth, distance and volume of reservoirs. Reservoir tillage practices were control runoff in all plots. Conclusions In this research project, a reservoir tillage machine was built and assessed. Tillage unit of this machine is similar to the spider wheel. By this machine the small holes generated in the ground periodically. For evaluation of machine performance, effect of two factors, including machine speed and arm's length on depth, distance and volume of the basins were evaluated. The results showed that increasing the ground speed from 5 to 10 km h-1 and increase the arm's length from 30 to 40 cm increased depth, distance and volume of reservoirs. Reservoir tillage practices were controlled runoff in all plots.

  7. Forms of phosphorus in an oxisol under different soil tillage systems and cover plants in rotation with maize

    Directory of Open Access Journals (Sweden)

    Arminda Moreira de Carvalho

    2014-06-01

    Full Text Available Phosphorus fractions play a key role in sustaining the productivity of acid-savanna Oxisols and are influenced by tillage practices. The aim of this study was to quantify different P forms in an Oxisol (Latossolo Vermelho-Amarelo from the central savanna region of Brazil under management systems with cover crops in maize rotation. Three cover crops (Canavalia brasiliensis, Cajanus cajan (L., and Raphanus sativus L. were investigated in maize rotation systems. These cover crops were compared to spontaneous vegetation. The inorganic forms NaHCO3-iP and NaOH-iP represented more than half of the total P in the samples collected at the depth of 5-10 cm during the rainy season when the maize was grown. The concentration of inorganic P of greater availability (NaHCO3-iP and NaOH-iP was higher in the soil under no-tillage at the depth of 5-10 cm during the rainy season. Concentrations of organic P were higher during the dry season, when the cover crops were grown. At the dry season, organic P constituted 70 % of the labile P in the soil planted to C. cajan under no-tillage. The cover crops were able to maintain larger fractions of P available to the maize, resulting in reduced P losses to the unavailable pools, mainly in no-tillage systems.

  8. Enhanced computational methods for quantifying the effect of geographic and environmental isolation on genetic differentiation

    DEFF Research Database (Denmark)

    Botta, Filippo; Eriksen, Casper; Fontaine, Michaël C.

    2015-01-01

    1. In a recent paper, Bradburd et al. (Evolution, 67, 2013, 3258) proposed a model to quantify the relative effect of geographic and environmental distance on genetic differentiation. Here, we enhance this method in several ways. 2. We modify the covariance model so as to fit better with mainstre...... available as an R package called sunder. It takes as input georeferenced allele counts at the individual or population level for co-dominant markers. Program homepage: http://www2.imm.dtu.dk/~gigu/Sunder/....

  9. Quantifying the effect of sorption and bioavailability of hydrophobic organic contaminants

    International Nuclear Information System (INIS)

    Zhang, W.; Bouwer, E.; Cunningham, A.

    1994-01-01

    In-situ bioremediation has been applied successfully at a few sites. Several restrictions presently exist which could greatly limit the effectiveness of this promising technology. Hydrophobic organic contaminants tend to sorb onto soil. However, microorganisms are most effective in utilizing substrates from the aqueous phase. Sorption tends to separate the direct contact between microorganisms and contaminants necessary for biodegradation to occur. A series of experiments, which represented scenarios with fast sorption/desorption, slow sorption/desorption, mass transfer across boundary layer and mass transfer within attached microorganisms (biofilm), was conducted to demonstrate the concentration effect and the mass transfer effect. A method has been developed to quantify bioavailability of organic contaminants in aquatic environments. Bioavailability Factor (B f ), a dimensionless parameter derived from mathematical models and verified by experimental results, has been formulated to describe the impact of equilibrium sorption, nonequilibrium sorption, and mass transfer processes on the rate and extent of biodegradation of petroleum hydrocarbons

  10. Optimize the cost of cultivation with using low-tillage in the wheat fields of Tehran province

    OpenAIRE

    KAMALI, Hossein; PARHIZGAR, Mohammad Mahdi

    2015-01-01

    Abstract. In appropriate patterns of tillage in wheat, three methods commonly cultivated as a maximum for tillage, planting a multifunctional device as minimum tillage and direct seeding cultivation system as no tillage operations together are comparable. Analysis of variance and mean cost of land preparation and time spent on the three methods of tillage operations shows that maximum conventional tillage and planting allocated to the most and direct seeding without tillage operations allocat...

  11. Short-Term Effects of Tillage Practices on Soil Organic Carbon Turnover Assessed by δ 13C Abundance in Particle-Size Fractions of Black Soils from Northeast China

    Science.gov (United States)

    Zhang, Xiaoping; Chen, Xuewen

    2014-01-01

    The combination of isotope trace technique and SOC fractionation allows a better understanding of SOC dynamics. A five-year tillage experiment consisting of no-tillage (NT) and mouldboard plough (MP) was used to study the changes in particle-size SOC fractions and corresponding δ 13C natural abundance to assess SOC turnover in the 0–20 cm layer of black soils under tillage practices. Compared to the initial level, total SOC tended to be stratified but showed a slight increase in the entire plough layer under short-term NT. MP had no significant impacts on SOC at any depth. Because of significant increases in coarse particulate organic carbon (POC) and decreases in fine POC, total POC did not remarkably decrease under NT and MP. A distinct increase in silt plus clay OC occurred in NT plots, but not in MP plots. However, the δ 13C abundances of both coarse and fine POC increased, while those of silt plus clay OC remained almost the same under NT. The C derived from C3 plants was mainly associated with fine particles and much less with coarse particles. These results suggested that short-term NT and MP preferentially enhanced the turnover of POC, which was considerably faster than that of silt plus clay OC. PMID:25162052

  12. TILLAGE EROSION: THE PRINCIPLES, CONTROLLING FACTORS AND MAIN IMPLICATIONS FOR FUTURE RESEARCH

    Directory of Open Access Journals (Sweden)

    Agnieszka Wysocka-Czubaszek

    2014-10-01

    Full Text Available Tillage erosion is one of the major contributors to landscape evolution in hummocky agricultural landscapes. This paper summarizes the available data describing tillage erosion caused by hand-held or other simple tillage implements as well as tools used in typical conventional agriculture in Europe and North America. Variations in equipment, tillage speed, depth and direction result in a wide range of soil translocation rates observed all over the world. The variety of tracers both physical and chemical gives a challenge to introduce the reliable model predicting tillage erosion, considering the number and type of tillage operation in the whole tillage sequence.

  13. Can conservation agriculture improve phosphorus (P) availability in weathered soils? Effects of tillage and residue management on soil P status after 9 years in a Kenyan Oxisol

    NARCIS (Netherlands)

    Margenot, Andrew; Paul, B.K.; Pulleman, M.M.; Parikh, Sanjai; Fonte, Steven J.

    2017-01-01

    The widespread promotion of conservation agriculture (CA) in regions with weathered soils prone to phosphorus (P) deficiency merits explicit consideration of its effect on P availability. A long-term CA field trial located on an acid, weathered soil in western Kenya was evaluated for effects of

  14. Energy indices in irrigated wheat production under conservation and conventional tillage and planting methods

    OpenAIRE

    S. M Hosseini; S Afzalinia; K Mollaei

    2016-01-01

    Introduction: Conservation tillage system was recommended for soil erosion control in North America for the first time 60 years ago (Wang et al., 2006). Using this tillage system including minimum and zero tillage has been rapidly developed in recent years. Thearea covered by zero tillage in 2006 was 95 million ha all over the world (Dumanski et al., 2006). In addition to saving soil and water resources, conservation tillage system reduces energy consumption and improves energy indices by com...

  15. Quantifying biostabilisation effects of biofilm-secreted and extracted extracellular polymeric substances (EPSs) on sandy substrate

    Science.gov (United States)

    van de Lageweg, Wietse I.; McLelland, Stuart J.; Parsons, Daniel R.

    2018-03-01

    Microbial assemblages (biofilms) preferentially develop at water-sediment interfaces and are known to have a considerable influence on sediment stability and erodibility. There is potential for significant impacts on sediment transport and morphodynamics, and hence on the longer-term evolution of coastal and fluvial environments. However, the biostabilisation effects remain poorly understood and quantified due to the inherent complexity of biofilms and the large spatial and temporal (i.e. seasonality) variations involved. Here, we use controlled laboratory tests to systematically quantify the effects of natural biofilm colonisation as well as extracted extracellular polymeric substances (EPSs) on sediment stability. Extracted EPSs may be useful to simulate biofilm-mediated biostabilisation and potentially provide a method of speeding up timescales of physical modelling experiments investigating biostabilisation effects. We find a mean biostabilisation effect due to natural biofilm colonisation and development of almost 4 times that of the uncolonised sand. The presented cumulative probability distribution of measured critical threshold for erosion of colonised sand reflects the large spatial and temporal variations generally seen in natural biostabilised environments. For identical sand, engineered sediment stability from the addition of extracted EPSs compares well across the measured range of the critical threshold for erosion and behaves in a linear and predictable fashion. Yet, the effectiveness of extracted EPSs to stabilise sediment is sensitive to the preparation procedure, time after application and environmental conditions such as salinity, pH and temperature. These findings are expected to improve biophysical experimental models in fluvial and coastal environments and provide much-needed quantification of biostabilisation to improve predictions of sediment dynamics in aquatic ecosystems.

  16. Chemical and physical soil attributes in integrated crop-livestock system under no-tillage

    OpenAIRE

    Silva,Hernani Alves da; Moraes,Anibal de; Carvalho,Paulo César de Faccio; Fonseca,Adriel Ferreira da; Caires,Eduardo Fávero; Dias,Carlos Tadeu dos Santos

    2014-01-01

    Although integrated crop-livestock system (ICLS) under no-tillage (NT) is an attractive practice for intensify agricultural production, little regional information is available on the effects of animal grazing and trampling, particularly dairy heifers, on the soil chemical and physical attributes. The objective of this study was to evaluate the effects of animal grazing on the chemical and physical attributes of the soil after 21 months of ICLS under NT in a succession of annual winter pastur...

  17. Temporal Dynamics of Soil Microbial Communities below the Seedbed under Two Contrasting Tillage Regimes

    OpenAIRE

    Florine Degrune; Florine Degrune; Nicolas Theodorakopoulos; Gilles Colinet; Marie-Pierre Hiel; Marie-Pierre Hiel; Bernard Bodson; Bernard Taminiau; Georges Daube; Micheline Vandenbol; Martin Hartmann

    2017-01-01

    Agricultural productivity relies on a wide range of ecosystem services provided by the soil biota. Plowing is a fundamental component of conventional farming, but long-term detrimental effects such as soil erosion and loss of soil organic matter have been recognized. Moving towards more sustainable management practices such as reduced tillage or crop residue retention can reduce these detrimental effects, but will also influence structure and function of the soil microbiota with direct conseq...

  18. Quantifying the effects of soil temperature, moisture and sterilization on elemental mercury formation in boreal soils.

    Science.gov (United States)

    Pannu, Ravinder; Siciliano, Steven D; O'Driscoll, Nelson J

    2014-10-01

    Soils are a source of elemental mercury (Hg(0)) to the atmosphere, however the effects of soil temperature and moisture on Hg(0) formation is not well defined. This research quantifies the effect of varying soil temperature (278-303 K), moisture (15-80% water filled pore space (WFPS)) and sterilization on the kinetics of Hg(0) formation in forested soils of Nova Scotia, Canada. Both, the logarithm of cumulative mass of Hg(0) formed in soils and the reduction rate constants (k values) increased with temperature and moisture respectively. Sterilizing soils significantly (p soils and our results highlight two key processes: (i) a fast abiotic process that peaks at 45% WFPS and depletes a small pool of Hg(0) and; (ii) a slower, rate limiting biotic process that generates a large pool of reducible Hg(II). Copyright © 2014 Elsevier Ltd. All rights reserved.

  19. Quantifying food intake in socially housed monkeys: social status effects on caloric consumption

    Science.gov (United States)

    Wilson, Mark E.; Fisher, Jeff; Fischer, Andrew; Lee, Vanessa; Harris, Ruth B.; Bartness, Timothy J.

    2008-01-01

    Obesity results from a number of factors including socio-environmental influences and rodent models show that several different stressors increase the preference for calorically dense foods leading to an obese phenotype. We present here a non-human primate model using socially housed adult female macaques living in long-term stable groups given access to diets of different caloric density. Consumption of a low fat (LFD; 15% of calories from fat) and a high fat diet (HFD; 45% of calories from fat) was quantified by means of a custom-built, automated feeder that dispensed a pellet of food when activated by a radiofrequency chip implanted subcutaneously in the animal’s wrist. Socially subordinate females showed indices of chronic psychological stress having reduced glucocorticoid negative feedback and higher frequencies of anxiety-like behavior. Twenty-four hour intakes of both the LFD and HFD were significantly greater in subordinates than dominates, an effect that persisted whether standard monkey chow (13% of calories from fat) was present or absent. Furthermore, although dominants restricted their food intake to daylight, subordinates continued to feed at night. Total caloric intake was significantly correlated with body weight change. Collectively, these results show that food intake can be reliably quantified in non-human primates living in complex social environments and suggest that socially-subordinate females consume more calories, suggesting this ethologically relevant model may help understand how psychosocial stress changes food preferences and consumption leading to obesity. PMID:18486158

  20. Quantifying the interplay between environmental and social effects on aggregated-fish dynamics.

    Directory of Open Access Journals (Sweden)

    Manuela Capello

    Full Text Available Demonstrating and quantifying the respective roles of social interactions and external stimuli governing fish dynamics is key to understanding fish spatial distribution. If seminal studies have contributed to our understanding of fish spatial organization in schools, little experimental information is available on fish in their natural environment, where aggregations often occur in the presence of spatial heterogeneities. Here, we applied novel modeling approaches coupled to accurate acoustic tracking for studying the dynamics of a group of gregarious fish in a heterogeneous environment. To this purpose, we acoustically tracked with submeter resolution the positions of twelve small pelagic fish (Selar crumenophthalmus in the presence of an anchored floating object, constituting a point of attraction for several fish species. We constructed a field-based model for aggregated-fish dynamics, deriving effective interactions for both social and external stimuli from experiments. We tuned the model parameters that best fit the experimental data and quantified the importance of social interactions in the aggregation, providing an explanation for the spatial structure of fish aggregations found around floating objects. Our results can be generalized to other gregarious species and contexts as long as it is possible to observe the fine-scale movements of a subset of individuals.

  1. Tillage and straw mulching impacts on grain yield and water use efficiency of spring maize in Northern Huang-Huai-Hai Valley

    Institute of Scientific and Technical Information of China (English)

    Zhiqiang Tao; Congfeng Li; Jingjing Li; Zaisong Ding; Jie Xu; Xuefang Sun; Peilu Zhou; Ming Zhao

    2015-01-01

    A two-year field experiment (2012–2013) was conducted to investigate the effects of two tillage methods and five maize straw mulching patterns on the yield, water consumption, and water use efficiency (WUE) of spring maize (Zea mays L.) in the northern Huang–Huai–Hai valley of China. Compared to rotary tillage, subsoil tillage resulted in decreases in water consumption by 6.3–7.8% and increases in maize yield by 644.5–673.9 kg ha−1, soil water content by 2.9–3.0%, and WUE by 12.7–15.2%. Chopped straw mulching led to higher yield, soil water content, and WUE as well as lower water consumption than prostrate whole straw mulching. Mulching with 50%chopped straw had the largest positive effects on maize yield, soil water content, and WUE among the five mulching treatments. Tillage had greater influence on maize yield than straw mulching, whereas straw mulching had greater influence on soil water content, water consumption, and WUE than tillage. These results suggest that 50%chopped straw mulching with subsoil tillage is beneficial in spring maize production aiming at high yield and high WUE in the Huang–Huai–Hai valley.

  2. Quantifying Direct and Indirect Effects of Elevated CO2 on Ecosystem Response

    Science.gov (United States)

    Fatichi, S.; Leuzinger, S.; Paschalis, A.; Donnellan-Barraclough, A.; Hovenden, M. J.; Langley, J. A.

    2015-12-01

    Increasing concentrations of atmospheric carbon dioxide are expected to affect carbon assimilation, evapotranspiration (ET) and ultimately plant growth. Direct leaf biochemical effects have been widely investigated, while indirect effects, although documented, are very difficult to quantify in experiments. We hypothesize that the interaction of direct and indirect effects is a possible reason for conflicting results concerning the magnitude of CO2 fertilization effects across different climates and ecosystems. A mechanistic ecohydrological model (Tethys-Chloris) is used to investigate the relative contribution of direct (through plant physiology) and indirect (via stomatal closure and thus soil moisture, and changes in Leaf Area Index, LAI) effects of elevated CO2 across a number of ecosystems. We specifically ask in which ecosystems and climate indirect effects are expected to be largest. Data and boundary conditions from flux-towers and free air CO2 enrichment (FACE) experiments are used to force the model and evaluate its performance. Numerical results suggest that indirect effects of elevated CO2, through water savings and increased LAI, are very significant and sometimes larger than direct effects. Indirect effects tend to be considerably larger in water-limited ecosystems, while direct effects correlate positively with mean air temperature. Increasing CO2 from 375 to 550 ppm causes a total effect on Net Primary Production in the order of 15 to 40% and on ET from 0 to -8%, depending on climate and ecosystem type. The total CO2 effect has a significant negative correlation with the wetness index and positive correlation with vapor pressure deficit. These results provide a more general mechanistic understanding of relatively short-term (less than 20 years) implications of elevated CO2 on ecosystem response and suggest plausible magnitudes for the expected changes.

  3. Integrated Palmer Amaranth Management in Glufosinate-Resistant Cotton: II. Primary, Secondary and Conservation Tillage

    Directory of Open Access Journals (Sweden)

    Michael G. Patterson

    2013-01-01

    Full Text Available A three year field experiment was conducted to evaluate the role of soil inversion, cover crops and spring tillage methods for Palmer amaranth between-row (BR and within-row (WR management in glufosinate-resistant cotton. Main plots were two soil inversion treatments: fall inversion tillage (IT and non-inversion tillage (NIT. Subplots were three cover treatments: crimson clover, cereal rye or none (i.e., winter fallow; and the sub subplots were four secondary spring tillage methods: disking followed by (fb cultivator (DCU, disking fb chisel plow (DCH, disking fb disking (DD and no tillage (NT. Averaged over years and soil inversion, the crimson clover produced maximum cover biomass (4390 kg ha−1 fb cereal rye (3698 kg ha−1 and winter fallow (777 kg ha−1. Two weeks after planting (WAP and before the postemergence (POST application, Palmer amaranth WR and BR density were two- and four-times less, respectively, in IT than NIT. Further, Palmer amaranth WR and BR density were reduced two-fold following crimson clover and cereal rye than following winter fallow at 2 WAP. Without IT, early season Palmer amaranth densities were 40% less following DCU, DCH and DD, when compared with IT. Following IT, no spring tillage method improved Palmer amaranth control. The timely application of glufosinate + S-metolachlor POST tank mixture greatly improved Palmer amaranth control in both IT and NIT systems. The highest cotton yields were obtained with DD following cereal rye (2251 kg ha−1, DD following crimson clover (2213 kg ha−1 and DD following winter fallow (2153 kg ha−1. On average, IT cotton yields (2133 kg ha−1 were 21% higher than NIT (1766 kg ha−1. Therefore, from an integrated weed management standpoint, an occasional fall IT could greatly reduce Palmer amaranth emergence on farms highly infested with glyphosate-resistant Palmer amaranth. In addition, a cereal rye or crimson clover cover crop can effectively reduce early season Palmer

  4. New Concept of Cultivation Using Limited Strip-Tillage with Strip Shallow Irrigation

    Directory of Open Access Journals (Sweden)

    Yazid Ismi Intara

    2014-04-01

    Full Text Available Normal 0 false false false IN X-NONE X-NONE Dry land is one of land resources which potentially used for food crop cultivation, especially in the areas which have light to medium technical obstacles. The development of technology to improve soil quality in marginal lands to be productive lands is still widely open for agricultural development in Indonesia. Rooting medium quality can be improved by changing soil tillage method and observing the proper crop irrigation technology. It can be the solution for crop cultivation in clay loam soil. This study aimed to obtain water movement model in a minimally-tilled clay soil with strip shallow irrigation. The concept is limited soil-tillage with strip shallow irrigation method, water supply technique, and crop water requirement. Method used in this study includes developing water movement model (software development in a minimally-tilled clay soil with subsurface irrigation. In the final stages, research also conducted water movement analysis testing apparatus in the laboratory, field validation of the subsurface irrigation performance, and cultivation technique testing to chili pepper growth (Capsicum annuumL.. The development of water movement simulation on a limited strip-tillage with subsurface irrigation uses the concept to quantify the amount of water in the soil. The analysis of movement pattern was demonstrated on contour patterns. It showed that the wetting process can reach depth zone – 5 cm to the rooting zone. It was an important discovery on the development of minimum stripe tillage soil with subsurface irrigation. Specifically, it can be concluded that: the result of fitting by eyes to diffusivity graphic and water content obtained the required parameter values for soil physical properties. It was then simulated on horizontal water movement model on a minimum strip-tillage with strip shallow irrigation /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso

  5. Quantifying the effects of ecological constraints on trait expression using novel trait-gradient analysis parameters.

    Science.gov (United States)

    Ottaviani, Gianluigi; Tsakalos, James L; Keppel, Gunnar; Mucina, Ladislav

    2018-01-01

    Complex processes related to biotic and abiotic forces can impose limitations to assembly and composition of plant communities. Quantifying the effects of these constraints on plant functional traits across environmental gradients, and among communities, remains challenging. We define ecological constraint ( C i ) as the combined, limiting effect of biotic interactions and environmental filtering on trait expression (i.e., the mean value and range of functional traits). Here, we propose a set of novel parameters to quantify this constraint by extending the trait-gradient analysis (TGA) methodology. The key parameter is ecological constraint, which is dimensionless and can be measured at various scales, for example, on population and community levels. It facilitates comparing the effects of ecological constraints on trait expressions across environmental gradients, as well as within and among communities. We illustrate the implementation of the proposed parameters using the bark thickness of 14 woody species along an aridity gradient on granite outcrops in southwestern Australia. We found a positive correlation between increasing environmental stress and strength of ecological constraint on bark thickness expression. Also, plants from more stressful habitats (shrublands on shallow soils and in sun-exposed locations) displayed higher ecological constraint for bark thickness than plants in more benign habitats (woodlands on deep soils and in sheltered locations). The relative ease of calculation and dimensionless nature of C i allow it to be readily implemented at various scales and make it widely applicable. It therefore has the potential to advance the mechanistic understanding of the ecological processes shaping trait expression. Some future applications of the new parameters could be investigating the patterns of ecological constraints (1) among communities from different regions, (2) on different traits across similar environmental gradients, and (3) for the same

  6. Quantifying the Combined Effect of Radiation Therapy and Hyperthermia in Terms of Equivalent Dose Distributions

    International Nuclear Information System (INIS)

    Kok, H. Petra; Crezee, Johannes; Franken, Nicolaas A.P.; Stalpers, Lukas J.A.; Barendsen, Gerrit W.; Bel, Arjan

    2014-01-01

    Purpose: To develop a method to quantify the therapeutic effect of radiosensitization by hyperthermia; to this end, a numerical method was proposed to convert radiation therapy dose distributions with hyperthermia to equivalent dose distributions without hyperthermia. Methods and Materials: Clinical intensity modulated radiation therapy plans were created for 15 prostate cancer cases. To simulate a clinically relevant heterogeneous temperature distribution, hyperthermia treatment planning was performed for heating with the AMC-8 system. The temperature-dependent parameters α (Gy −1 ) and β (Gy −2 ) of the linear–quadratic model for prostate cancer were estimated from the literature. No thermal enhancement was assumed for normal tissue. The intensity modulated radiation therapy plans and temperature distributions were exported to our in-house-developed radiation therapy treatment planning system, APlan, and equivalent dose distributions without hyperthermia were calculated voxel by voxel using the linear–quadratic model. Results: The planned average tumor temperatures T90, T50, and T10 in the planning target volume were 40.5°C, 41.6°C, and 42.4°C, respectively. The planned minimum, mean, and maximum radiation therapy doses were 62.9 Gy, 76.0 Gy, and 81.0 Gy, respectively. Adding hyperthermia yielded an equivalent dose distribution with an extended 95% isodose level. The equivalent minimum, mean, and maximum doses reflecting the radiosensitization by hyperthermia were 70.3 Gy, 86.3 Gy, and 93.6 Gy, respectively, for a linear increase of α with temperature. This can be considered similar to a dose escalation with a substantial increase in tumor control probability for high-risk prostate carcinoma. Conclusion: A model to quantify the effect of combined radiation therapy and hyperthermia in terms of equivalent dose distributions was presented. This model is particularly instructive to estimate the potential effects of interaction from different treatment

  7. Quantifying mediating effects of endogenous estrogen and insulin in the relation between obesity, alcohol consumption, and breast cancer

    DEFF Research Database (Denmark)

    Hvidtfeldt, Ulla A; Gunter, Marc J; Lange, Theis

    2012-01-01

    Increased exposure to endogenous estrogen and/or insulin may partly explain the relationship of obesity, physical inactivity, and alcohol consumption and postmenopausal breast cancer. However, these potential mediating effects have not been formally quantified in a survival analysis setting....

  8. Earthworm populations are affected from Long-Term Crop Sequences and Bio-Covers under No-Tillage

    Science.gov (United States)

    Earthworms are crucial for improving soil biophysical properties in cropping systems. Consequently, effects of cropping rotation and bio-covers were assessed on earthworm populations under no-tillage sites. Main effects of 6 different cropping sequences [corn (Zea mays), cotton (Gossypium hirsutum),...

  9.  The effect of context in children's interpretations of universally-quantified sentences

    DEFF Research Database (Denmark)

    Drozd, Kenneth

    2006-01-01

    This chapter investigates the effects of perceptual and discourse context on children's Exhaustive Pairing interpretation of universally quantified sentences. Two experiments compared the predictions of two recent accounts of Exhaustive Pairing. In one account, Crain et al. (1996) arge that child......This chapter investigates the effects of perceptual and discourse context on children's Exhaustive Pairing interpretation of universally quantified sentences. Two experiments compared the predictions of two recent accounts of Exhaustive Pairing. In one account, Crain et al. (1996) arge...

  10. A Mathematical Model Quantifies Proliferation and Motility Effects of TGF-β on Cancer Cells

    Directory of Open Access Journals (Sweden)

    Shizhen Emily Wang

    2009-01-01

    Full Text Available Transforming growth factor (TGF-β is known to have properties of both a tumour suppressor and a tumour promoter. While it inhibits cell proliferation, it also increases cell motility and decreases cell–cell adhesion. Coupling mathematical modelling and experiments, we investigate the growth and motility of oncogene-expressing human mammary epithelial cells under exposure to TGF-β. We use a version of the well-known Fisher–Kolmogorov equation, and prescribe a procedure for its parametrisation. We quantify the simultaneous effects of TGF-β to increase the tendency of individual cells and cell clusters to move randomly and to decrease overall population growth. We demonstrate that in experiments with TGF-β treated cells in vitro, TGF-β increases cell motility by a factor of 2 and decreases cell proliferation by a factor of 1/2 in comparison with untreated cells.

  11. Tuning and Quantifying Steric and Electronic Effects of N-Heterocyclic Carbenes

    KAUST Repository

    Falivene, Laura

    2014-07-12

    This chapter states that the main handles for tuning steric and electronic effects are the substituents on N atoms, the nature of the C4-C5 bridge (either saturated or unsaturated), and the substituents on the C4 and C5 atoms. The initial intuition that steric properties of N-heterocyclic carbenes (NHCs) could be modulated and could impact catalytic behavior stimulated the development of steric descriptors to quantify the steric requirement of different NHCs and, possibly, to compare them with tertiary phosphines. NHCs can be classified as typically strong σ-basic/π-acid ligands, although they have been also shown to exhibit reasonable π-basic properties. This electronic modularity allows NHC ligands to adapt flexibly to different chemical environments represented by a transition metal and the other ligands. © 2014 Wiley-VCH Verlag GmbH & Co. KGaA. All rights reserved.

  12. Quantifying Diurnal Cloud Radiative Effects by Cloud Type in the Tropical Western Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Burleyson, Casey D.; Long, Charles N.; Comstock, Jennifer M.

    2015-06-01

    Cloud radiative effects are examined using long-term datasets collected at the three Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facilities in the tropical western Pacific. We quantify the surface radiation budget, cloud populations, and cloud radiative effects by partitioning the data by cloud type, time of day, and as a function of large scale modes of variability such as El Niño Southern Oscillation (ENSO) phase and wet/dry seasons at Darwin. The novel facet of our analysis is that we break aggregate cloud radiative effects down by cloud type across the diurnal cycle. The Nauru cloud populations and subsequently the surface radiation budget are strongly impacted by ENSO variability whereas the cloud populations over Manus only shift slightly in response to changes in ENSO phase. The Darwin site exhibits large seasonal monsoon related variations. We show that while deeper convective clouds have a strong conditional influence on the radiation reaching the surface, their limited frequency reduces their aggregate radiative impact. The largest source of shortwave cloud radiative effects at all three sites comes from low clouds. We use the observations to demonstrate that potential model biases in the amplitude of the diurnal cycle and mean cloud frequency would lead to larger errors in the surface energy budget compared to biases in the timing of the diurnal cycle of cloud frequency. Our results provide solid benchmarks to evaluate model simulations of cloud radiative effects in the tropics.

  13. Effect of Simulated Tillage in Combination with Post-Shattering Temperature Conditions on Senna obtusifolia and Xanthium strumarium Seed Survival, Seedling Emergence and Seedbank Potential

    Directory of Open Access Journals (Sweden)

    Taghi Bararpour

    2018-04-01

    Full Text Available Two of the most troublesome weeds in soybean, cotton, and corn in cropping systems of mid-south United States (US are Senna obtusifolia and Xanthium strumarium. Understanding their population dynamics, particularly weed seedling emergence patterns, is important for the timely implementation and the success of weed management strategies. Identifying the sources of variation of emergence patterns could greatly improve our ability to predict emergence timing. A three-years field study was conducted to determine the effect of environmental conditions on S. obtusifolia and X. strumarium seedling emergence and seedbank potential. The experiment was conducted with two seed sources; X. strumarium burs and S. obtusifolia seeds from a single maternal plant source, and X. strumarium burs and S. obtusifolia seeds from multiple maternal plant sources, both being exposed either to 5 cm burial depth (buried or left on the soil surface (soil surface in the fallow or planted in spring after their storage under chilled (chill or room temperature (no chill conditions. X. strumarium and S. obtusifolia seedling emergence was lower from burs and seeds that were planted in the soil in September as compared with the chill and/or no chill seeds/burs stored for six months. X. strumarium seedling emergence was reduced from 37 to 1% when burs were left on the soil surface when compared to buried burs. S. obtusifolia seedling emergence was reduced from 47 to 13% when seeds were left on the soil surface as compared to buried. At the end of the experimental period, the soil seedbank of X. strumarium had been significantly depleted, whereas the remaining seeds of S. obtusifolia were viable.

  14. Tillage and planting density affect the performance of maize hybrids in Chitwan, Nepal

    Directory of Open Access Journals (Sweden)

    Tika Baladur Karki

    2015-12-01

    Full Text Available To find out whether the different tillage methods at different planting densities affect the performance of maize hybrids, an experiment was carried out at National Maize Research Program, Rampur during spring season of 2013 and 2014. The experiment was laid out in strip plot design with three replications having 12 treatments. The vertical factor was tillage with conservation tillage (No Tillage + residue=NT and conventional tillage (CT and the horizontal factor were genotypes (Rampur Hybrid-2 and RML-32/RML-17 and in split planting geometries (75cm × 25cm =53333 plants/ha, 70cm × 25cm=57142 plant/ha and 60cm ×25cm= 66666 plants/ha. In both the years, the highest number of cobs (73,177 and 67638/ha was recorded at planting density of 66666/ha. NT had the highest no of kernel rows/cob (14.01 as against 12.12 in CT in 2014. The highest number of kernels (27.3 and 29.29 per row was recorded in NT during 2013 and 2014 respectively. Similarly, in 2014, the highest number of kernels were found in RML-32/RMl-17 (29.17/row and planting density of 53333/ha (28.46/row. In 2013, RML-32/RML-17 produced the highest test weight of 363.94g over the Rampur hybrid-2 with 362.17g. Significantly the highest grain yield of 9240.00 kg/ha in 2013 and 7459.80 kg/ha in 2014 at planting geometry of 65cm ×25cm were recorded. No effects was found by tillage methods for grain yields of maize in 2013, but was found in 2014 (7012.18 kg in NT compared to 6037.59 kg/ha in CT. NT and wider spaced crop matured earlier in both the years; however Rampur hybrid-2 matured earlier to RML-32/RML-17 in 2013. In 2014, harvest index of 47.85 % was recorded in planting geometry of 66666/ha, the highest benefit cost ratio of 1.36 was worked out in NT and 1.46 at the density of 66666/ha. The highest value of 2.46% of soil organic matter was recorded in NT as compared to 2.43% in CT.

  15. Influence of Tillage and Mulch on Soil Physical Properties and ...

    African Journals Online (AJOL)

    ... (M0); rice straw, (MRice); wheat straw, (MWheat); plastic sheet, (MPlastic) at 4 t ... Happy seeder and deep tillage along with plastic mulch have positive impact ... use efficiency and yield parameters by creating a favorable soil environment.

  16. Precise tillage systems for enhanced non-chemical weed management

    NARCIS (Netherlands)

    Kurstjens, D.A.G.

    2007-01-01

    Soil and residue manipulation can assist weed management by killing weeds mechanically, interfering in weed lifecycles, facilitating operations and enhancing crop establishment and growth. Current tillage systems often compromise these functions, resulting in heavy reliance on herbicides,

  17. Evaluation of Conservation Tillage Techniques for Maize Production ...

    African Journals Online (AJOL)

    conservation tillage techniques and evaluate the impacts of the system on ... biological soil manipulation to optimize conditions for seed germination, emergence and ..... planting and weeding operations as total expense and sales from maize ...

  18. Haplic Chernozem Properties as Affected by Different Tillage Systems

    Directory of Open Access Journals (Sweden)

    Magdalena Hábová

    2016-01-01

    Full Text Available During 2007–2011 we assessed content and quality of humic substances with relationship to soil structure. Object of study was Haplic Chernozem (Hrušovany nad Jevišovkou, Czech Republic under three different tillage systems: – conventional ploughing to a depth of 0.22 m (CP; – reduced tillage with shallow harrowing to a depth of 0.15 m (RTSH; – reduced tillage with subsoiling to a depth of 0.35–0.40 m (RTS. Isolation of humic acids was made according to IHSS standard method using spectrometer Shimadzu 8700. Aggregates stability was determined by wet sieving method. Results showed that macrostructure stability was directly connected with time of sampling and content and quality of humic substances. After five years of experiment statistically significant differences in humic substances content were found. The highest structure stability, quantity and quality of humic substances were achieved under reduced tillage with shallow harrowing.

  19. Artificial neural network approach for mapping contrasting tillage practices

    Science.gov (United States)

    Tillage information is crucial for environmental modeling as it directly affects evapotranspiration, infiltration, runoff, carbon sequestration, and soil losses due to wind and water erosion from agricultural fields. However, collecting this information can be time consuming and costly. Remote sensi...

  20. Low-order non-spatial effects dominate second-order spatial effects in the texture quantifier analysis of 18F-FDG-PET images.

    Directory of Open Access Journals (Sweden)

    Frank J Brooks

    Full Text Available There is increasing interest in applying image texture quantifiers to assess the intra-tumor heterogeneity observed in FDG-PET images of various cancers. Use of these quantifiers as prognostic indicators of disease outcome and/or treatment response has yielded inconsistent results. We study the general applicability of some well-established texture quantifiers to the image data unique to FDG-PET.We first created computer-simulated test images with statistical properties consistent with clinical image data for cancers of the uterine cervix. We specifically isolated second-order statistical effects from low-order effects and analyzed the resulting variation in common texture quantifiers in response to contrived image variations. We then analyzed the quantifiers computed for FIGOIIb cervical cancers via receiver operating characteristic (ROC curves and via contingency table analysis of detrended quantifier values.We found that image texture quantifiers depend strongly on low-effects such as tumor volume and SUV distribution. When low-order effects are controlled, the image texture quantifiers tested were not able to discern only the second-order effects. Furthermore, the results of clinical tumor heterogeneity studies might be tunable via choice of patient population analyzed.Some image texture quantifiers are strongly affected by factors distinct from the second-order effects researchers ostensibly seek to assess via those quantifiers.

  1. Quantifying Matter

    CERN Document Server

    Angelo, Joseph A

    2011-01-01

    Quantifying Matter explains how scientists learned to measure matter and quantify some of its most fascinating and useful properties. It presents many of the most important intellectual achievements and technical developments that led to the scientific interpretation of substance. Complete with full-color photographs, this exciting new volume describes the basic characteristics and properties of matter. Chapters include:. -Exploring the Nature of Matter. -The Origin of Matter. -The Search for Substance. -Quantifying Matter During the Scientific Revolution. -Understanding Matter's Electromagnet

  2. Thermal infrared images to quantify thermal ablation effects of acid and base on target tissues

    Science.gov (United States)

    Liu, Ran; Wang, Jia; Liu, Jing

    2015-07-01

    Hyperthermia (42-46°C), treatment of tumor tissue through elevated temperature, offers several advantages including high cost-effectiveness, highly targeted ablation and fewer side effects and hence higher safety level over traditional therapies such as chemotherapy and radiotherapy. Recently, hyperthermia using heat release through exothermic acid-base neutralization comes into view owing to its relatively safe products of salt and water and highly confined ablation. However, lack of quantitative understanding of the spatial and temporal temperature profiles that are produced by simultaneous diffusion of liquid chemical and its chemical reaction within tumor tissue impedes the application of this method. This article is dedicated to quantify thermal ablation effects of acid and base both individually and as in neutralization via infrared captured thermal images. A theoretical model is used to approximate specific heat absorption rate (SAR) based on experimental measurements that contrast two types of tissue, normal pork and pig liver. According to the computation, both pork and liver tissue has a higher ability in absorbing hydrochloric acid (HCl) than sodium hydroxide, hence suggesting that a reduced dosage for HCl is appropriate in a surgery. The heating effect depends heavily on the properties of tissue types and amount of chemical reagents administered. Given thermal parameters such as SAR for different tissues, a computational model can be made in predicting temperature transitions which will be helpful in planning and optimizing surgical hyperthermia procedures.

  3. Item Response Theory to Quantify Longitudinal Placebo and Paliperidone Effects on PANSS Scores in Schizophrenia.

    Science.gov (United States)

    Krekels, Ehj; Novakovic, A M; Vermeulen, A M; Friberg, L E; Karlsson, M O

    2017-08-01

    As biomarkers are lacking, multi-item questionnaire-based tools like the Positive and Negative Syndrome Scale (PANSS) are used to quantify disease severity in schizophrenia. Analyzing composite PANSS scores as continuous data discards information and violates the numerical nature of the scale. Here a longitudinal analysis based on Item Response Theory is presented using PANSS data from phase III clinical trials. Latent disease severity variables were derived from item-level data on the positive, negative, and general PANSS subscales each. On all subscales, the time course of placebo responses were best described with Weibull models, and dose-independent functions with exponential models to describe the onset of the full effect were used to describe paliperidone's effect. Placebo and drug effect were most pronounced on the positive subscale. The final model successfully describes the time course of treatment effects on the individual PANSS item-levels, on all PANSS subscale levels, and on the total score level. © 2017 The Authors CPT: Pharmacometrics & Systems Pharmacology published by Wiley Periodicals, Inc. on behalf of American Society for Clinical Pharmacology and Therapeutics.

  4. Thermal infrared images to quantify thermal ablation effects of acid and base on target tissues

    Directory of Open Access Journals (Sweden)

    Ran Liu

    2015-07-01

    Full Text Available Hyperthermia (42-46°C, treatment of tumor tissue through elevated temperature, offers several advantages including high cost-effectiveness, highly targeted ablation and fewer side effects and hence higher safety level over traditional therapies such as chemotherapy and radiotherapy. Recently, hyperthermia using heat release through exothermic acid-base neutralization comes into view owing to its relatively safe products of salt and water and highly confined ablation. However, lack of quantitative understanding of the spatial and temporal temperature profiles that are produced by simultaneous diffusion of liquid chemical and its chemical reaction within tumor tissue impedes the application of this method. This article is dedicated to quantify thermal ablation effects of acid and base both individually and as in neutralization via infrared captured thermal images. A theoretical model is used to approximate specific heat absorption rate (SAR based on experimental measurements that contrast two types of tissue, normal pork and pig liver. According to the computation, both pork and liver tissue has a higher ability in absorbing hydrochloric acid (HCl than sodium hydroxide, hence suggesting that a reduced dosage for HCl is appropriate in a surgery. The heating effect depends heavily on the properties of tissue types and amount of chemical reagents administered. Given thermal parameters such as SAR for different tissues, a computational model can be made in predicting temperature transitions which will be helpful in planning and optimizing surgical hyperthermia procedures.

  5. Thermal infrared images to quantify thermal ablation effects of acid and base on target tissues

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Ran, E-mail: jliubme@tsinghua.edu.cn, E-mail: liuran@tsinghua.edu.cn; Liu, Jing, E-mail: jliubme@tsinghua.edu.cn, E-mail: liuran@tsinghua.edu.cn [Department of Biomedical Engineering, School of Medicine, Tsinghua University, Beijing 100084 (China); Wang, Jia [Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2015-07-15

    Hyperthermia (42-46°C), treatment of tumor tissue through elevated temperature, offers several advantages including high cost-effectiveness, highly targeted ablation and fewer side effects and hence higher safety level over traditional therapies such as chemotherapy and radiotherapy. Recently, hyperthermia using heat release through exothermic acid-base neutralization comes into view owing to its relatively safe products of salt and water and highly confined ablation. However, lack of quantitative understanding of the spatial and temporal temperature profiles that are produced by simultaneous diffusion of liquid chemical and its chemical reaction within tumor tissue impedes the application of this method. This article is dedicated to quantify thermal ablation effects of acid and base both individually and as in neutralization via infrared captured thermal images. A theoretical model is used to approximate specific heat absorption rate (SAR) based on experimental measurements that contrast two types of tissue, normal pork and pig liver. According to the computation, both pork and liver tissue has a higher ability in absorbing hydrochloric acid (HCl) than sodium hydroxide, hence suggesting that a reduced dosage for HCl is appropriate in a surgery. The heating effect depends heavily on the properties of tissue types and amount of chemical reagents administered. Given thermal parameters such as SAR for different tissues, a computational model can be made in predicting temperature transitions which will be helpful in planning and optimizing surgical hyperthermia procedures.

  6. Microbial community responses to soil tillage and crop rotation in a corn/soybean agroecosystem.

    Science.gov (United States)

    Smith, Chris R; Blair, Peter L; Boyd, Charlie; Cody, Brianne; Hazel, Alexander; Hedrick, Ashley; Kathuria, Hitesh; Khurana, Parul; Kramer, Brent; Muterspaw, Kristin; Peck, Charles; Sells, Emily; Skinner, Jessica; Tegeler, Cara; Wolfe, Zoe

    2016-11-01

    The acreage planted in corn and soybean crops is vast, and these crops contribute substantially to the world economy. The agricultural practices employed for farming these crops have major effects on ecosystem health at a worldwide scale. The microbial communities living in agricultural soils significantly contribute to nutrient uptake and cycling and can have both positive and negative impacts on the crops growing with them. In this study, we examined the impact of the crop planted and soil tillage on nutrient levels, microbial communities, and the biochemical pathways present in the soil. We found that farming practice, that is conventional tillage versus no-till, had a much greater impact on nearly everything measured compared to the crop planted. No-till fields tended to have higher nutrient levels and distinct microbial communities. Moreover, no-till fields had more DNA sequences associated with key nitrogen cycle processes, suggesting that the microbial communities were more active in cycling nitrogen. Our results indicate that tilling of agricultural soil may magnify the degree of nutrient waste and runoff by altering nutrient cycles through changes to microbial communities. Currently, a minority of acreage is maintained without tillage despite clear benefits to soil nutrient levels, and a decrease in nutrient runoff-both of which have ecosystem-level effects and both direct and indirect effects on humans and other organisms.

  7. Soil Biochemical Changes Induced by Poultry Litter Application and Conservation Tillage under Cotton Production Systems

    Directory of Open Access Journals (Sweden)

    Seshadri Sajjala

    2012-07-01

    Full Text Available Problems arising from conventional tillage (CT systems (such as soil erosion, decrease of organic matter, environmental damage etc. have led many farmers to the adoption of no-till (NT systems that are more effective in improving soil physical, chemical and microbial properties. Results from this study clearly indicated that NT, mulch tillage (MT, and winter rye cover cropping systems increased the activity of phosphatase, β-glucosidase and arylsulfatase at a 0–10 cm soil depth but decreased the activity of these enzymes at 10–20 cm. The increase in enzyme activity was a good indicator of intensive soil microbial activity in different soil management practices. Poultry litter (PL application under NT, MT, and rye cropping system could be considered as effective management practices due to the improvement in carbon (C content and the biochemical quality at the soil surface. The activities of the studied enzymes were highly correlated with soil total nitrogen (STN soil organic carbon (SOC at the 0–10 cm soil depth, except for acid phosphatase where no correlation was observed. This study revealed that agricultural practices such as tillage, PL, and cover crop cropping system have a noticeable positive effect on soil biochemical activities under cotton production.

  8. Using effect size to quantify plantar pressure asymmetry of gait of nondisabled adults and patients with hemiparesis.

    Science.gov (United States)

    Potdevin, François J; Femery, Virginie G; Decatoire, Aurélien; Bosquet, Laurent; Coello, Yann; Moretto, Pierre

    2007-01-01

    In the literature, numerous statistical analyses are used to quantify asymmetry in gait. This study tested the effect size (ES) statistic for quantifying asymmetry in nondisabled and pathological populations. The plantar pressure peaks on eight footprint locations of 27 nondisabled subjects and 18 patients with hemiparesis were bilaterally compared. Asymmetry quantifications were performed with ES and standard statistical tests (index of asymmetry, symmetry index, and ratio index). The results show an advantage in using ES to quantify asymmetry when confidence limits are also calculated. Conversely, traditional asymmetry indexes immediately implied asymmetry without statistical basis. These findings should be considered when one is attempting to diagnose pathological walking patterns or guide rehabilitation processes.

  9. Quantifying salinity and season effects on eastern oyster clearance and oxygen consumption rates

    Science.gov (United States)

    Casas, S.M.; Lavaud, Romain; LaPeyre, Megan K.; Comeau, L. A.; Filgueira, R.; LaPeyre, Jerome F.

    2018-01-01

    There are few data on Crassostrea virginica physiological rates across the range of salinities and temperatures to which they are regularly exposed, and this limits the applicability of growth and production models using these data. The objectives of this study were to quantify, in winter (17 °C) and summer (27 °C), the clearance and oxygen consumption rates of C. virginica from Louisiana across a range of salinities typical of the region (3, 6, 9, 15 and 25). Salinity and season (temperature and reproduction) affected C. virginica physiology differently; salinity impacted clearance rates with reduced feeding rates at low salinities, while season had a strong effect on respiration rates. Highest clearance rates were found at salinities of 9–25, with reductions ranging from 50 to 80 and 90 to 95% at salinities of 6 and 3, respectively. Oxygen consumption rates in summer were four times higher than in winter. Oxygen consumption rates were within a narrow range and similar among salinities in winter, but varied greatly among individuals and salinities in summer. This likely reflected varying stages of gonad development. Valve movements measured at the five salinities indicated oysters were open 50–60% of the time in the 6–25 salinity range and ~ 30% at a salinity of 3. Reduced opening periods, concomitant with narrower valve gap amplitudes, are in accord with the limited feeding at the lowest salinity (3). These data indicate the need for increased focus on experimental determination of optimal ranges and thresholds to better quantify oyster population responses to environmental changes.

  10. Quantifying effects of humans and climate on groundwater resources of Hawaii through sharp-interface modeling

    Science.gov (United States)

    Rotzoll, K.; Izuka, S. K.; Nishikawa, T.; Fienen, M. N.; El-Kadi, A. I.

    2016-12-01

    Some of the volcanic-rock aquifers of the islands of Hawaii are substantially developed, leading to concerns related to the effects of groundwater withdrawals on saltwater intrusion and stream base-flow reduction. A numerical modeling analysis using recent available information (e.g., recharge, withdrawals, hydrogeologic framework, and conceptual models of groundwater flow) advances current understanding of groundwater flow and provides insight into the effects of human activity and climate change on Hawaii's water resources. Three island-wide groundwater-flow models (Kauai, Oahu, and Maui) were constructed using MODFLOW 2005 coupled with the Seawater-Intrusion Package (SWI2), which simulates the transition between saltwater and freshwater in the aquifer as a sharp interface. This approach allowed coarse vertical discretization (maximum of two layers) without ignoring the freshwater-saltwater system at the regional scale. Model construction (FloPy3), parameter estimation (PEST), and analysis of results were streamlined using Python scripts. Model simulations included pre-development (1870) and recent (average of 2001-10) scenarios for each island. Additionally, scenarios for future withdrawals and climate change were simulated for Oahu. We present our streamlined approach and results showing estimated effects of human activity on the groundwater resource by quantifying decline in water levels, rise of the freshwater-saltwater interface, and reduction in stream base flow. Water-resource managers can use this information to evaluate consequences of groundwater development that can constrain future groundwater availability.

  11. A COMPARATIVE STUDY OF SIMULATION AND TIME SERIES MODEL IN QUANTIFYING BULLWHIP EFFECT IN SUPPLY CHAIN

    Directory of Open Access Journals (Sweden)

    T. V. O. Fabson

    2011-11-01

    Full Text Available Bullwhip (or whiplash effect is an observed phenomenon in forecast driven distribution channeland careful management of these effects is of great importance to managers of supply chain.Bullwhip effect refers to situations where orders to the suppliers tend to have larger variance thansales to the buyer (demand distortion and the distortion increases as we move up the supply chain.Due to the fact that demand of customer for product is unstable, business managers must forecast inorder to properly position inventory and other resources. Forecasts are statistically based and in mostcases, are not very accurate. The existence of forecast errors made it necessary for organizations tooften carry an inventory buffer called “safety stock”. Moving up the supply chain from the end userscustomers to raw materials supplier there is a lot of variation in demand that can be observed, whichcall for greater need for safety stock.This study compares the efficacy of simulation and Time Series model in quantifying the bullwhipeffects in supply chain management.

  12. Quantifying short run cost-effectiveness during a gradual implementation process.

    Science.gov (United States)

    van de Wetering, Gijs; Woertman, Willem H; Verbeek, Andre L; Broeders, Mireille J; Adang, Eddy M M

    2013-12-01

    This paper examines the short run inefficiencies that arise during gradual implementation of a new cost-effective technology in healthcare. These inefficiencies arise when health gains associated with the new technology cannot be obtained immediately because the new technology does not yet supply all patients, and when there is overcapacity for the old technology in the short run because the supply of care is divided among two mutually exclusive technologies. Such efficiency losses are not taken into account in standard textbook cost-effectiveness analysis in which a steady state is presented where costs and effects are assumed to be unchanging over time. A model is constructed to quantify such short run inefficiencies as well as to inform the decision maker about the optimal implementation pattern for the new technology. The model operates by integrating the incremental net benefit equations for both the period of co-existence of mutually exclusive technologies and the period after complete substitution of the old technology. It takes into account the rate of implementation of the new technology, depreciation of capital of the old technology as well as the demand curves for both technologies. The model is applied to the real world case of converting from screen film to digital mammography in the Netherlands.

  13. N{sub 2}O and CH{sub 4} emissions from a fallow–wheat rotation with low N input in conservation and conventional tillage under a Mediterranean agroecosystem

    Energy Technology Data Exchange (ETDEWEB)

    Tellez-Rio, Angela, E-mail: angela.tellez@upm.es [E.T.S.I. Agrónomos, Technical University of Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); García-Marco, Sonia [E.T.S.I. Agrónomos, Technical University of Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Navas, Mariela; López-Solanilla, Emilia [E.T.S.I. Agrónomos, Technical University of Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain); Centro de Biotecnología y Genómica de Plantas UPM-INIA. Dpto Biotecnología. E.T.S.I. Agrónomos. Technical University of Madrid. Campus Montegancedo, UPM. Autovía M-40, Salida 38 N, 36S. 28223 Pozuelo de Alarcón. Madrid (Spain); Tenorio, Jose Luis [Dpto. de Medio Ambiente, INIA. Ctra. de La Coruña km. 7.5, 28040 Madrid (Spain); Vallejo, Antonio [E.T.S.I. Agrónomos, Technical University of Madrid, Ciudad Universitaria s/n, 28040 Madrid (Spain)

    2015-03-01

    Conservation agriculture that includes no tillage (NT) or minimum tillage (MT) and crop rotation is an effective practice to increase soil organic matter in Mediterranean semiarid agrosystems. But the impact of these agricultural practices on greenhouse gases (GHGs), such as nitrous oxide (N{sub 2}O) and methane (CH{sub 4}), is variable depending mainly on soil structure and short/long-term tillage. The main objective of this study was to assess the long-term effect of three tillage systems (NT, MT and conventional tillage (CT)) and land-covers (fallow/wheat) on the emissions of N{sub 2}O and CH{sub 4} in a low N input agricultural system during one year. This was achieved by measuring crop yields, soil mineral N and dissolved organic C contents, and fluxes of N{sub 2}O and CH{sub 4}. Total cumulative N{sub 2}O emissions were not significantly different (P > 0.05) among the tillage systems or between fallow and wheat. The only difference was produced in spring, when N{sub 2}O emissions were significantly higher (P < 0.05) in fallow than in wheat subplots, and NT reduced N{sub 2}O emissions (P < 0.05) compared with MT and CT. Taking into account the water filled pore space (WFPS), both nitrification and denitrification could have occurred during the experimental period. Denitrification capacity in March was similar in all tillage systems, in spite of the higher DOC content maintained in the topsoil of NT. This could be due to the similar denitrifier densities, targeted by nirK copy numbers at that time. Cumulative CH{sub 4} fluxes resulted in small net uptake for all treatments, and no significant differences were found among tillage systems or between fallow and wheat land-covers. These results suggest that under a coarse-textured soil in low N agricultural systems, the impact of tillage on GHG is very low and that the fallow cycle within a crop rotation is not a useful strategy to reduce GHG emissions. - Highlights: • Tillage systems and land-covers with low N

  14. Preparo do solo em áreas de produção de grãos, silagem e pastejo: efeito na resistência tênsil e friabilidade de agregados Soil tillage in grain and silage-producing areas and pasture: effect on tensile strength and aggregate friability

    Directory of Open Access Journals (Sweden)

    Marina Araújo Bavoso

    2010-02-01

    ção da F. Os resultados demonstraram que a RT foi influenciada pelos sistemas de produção e tipos de preparo do solo. O menor valor de RT foi verificado no solo sob Pastejo, enquanto o Sistema Plantio Direto apresentou o maior valor de RT. A friabilidade não distinguiu os sistemas de produção e tipos de preparo de solo estudados.The understanding and quantification of soil use and management on the soil physical quality are important to develop and select sustainable agricultural systems. The purpose of this study was to evaluate the structural quality of a clayey Brazilian Oxisol under different production and soil tillage systems by measuring the tensile strength (TS and to quantify aggregate friability (F. The study was conducted in Castro, Paraná state, in southern Brazil, using three production systems and seven soil tillage types, in a randomized block design. The following production systems were evaluated: (PS I - ryegrass for soil cover (winter and corn for grain production (summer; (PS II ryegrass for haylage/silage and corn for grain production; and (PS III - ryegrass for grazing and corn for grain production. Seven types of soil tillage were evaluated in each system: (G1 - plow harrow in winter, depth 0.15 m; (G2 - plow harrow in winter and summer, depth 0.15 m; (Plow - disk plow, depth 0.20 m; (Laser wing subsoiler - subsoiler wing tips, to a depth of 0.45 m; (Subsoiler - subsoiler, depth 0.80 m; (Aerator - soil aerater Aeromix®; and (NT - No-tillage, where ryegrass was sown using a double disc and corn with a coulter. From each experimental plot soil blocks (0.20 x 0.15 x 0.07 m were taken which were broken up by hand in their natural aggregates. Then, the aggregates were air-dried for 24 h and passed through sieves with diameters of 12.5 and 19 mm. Forty aggregates from each block were selected and tested for indirect tension to determine TS and quantify F. TS was influenced by the production systems and soil tillage types. The lowest and the

  15. Which soil tillage is better in terms of the soil organic matter and soil structure changes?

    Directory of Open Access Journals (Sweden)

    VLADIMÍR ŠIMANSKÝ

    2016-06-01

    Full Text Available This study was performed to evaluate effects of minimum (MT and conventional tillage (CT on soil organic matter and soil structure in haplic Chernozems and mollic Fluvisols. The content of soil organic carbon (Corg as well as parameters of stability and vulnerability of soil structure were quantified. The results showed that soil type had statistically significant influence on Corg. In haplic Chernozems the Corg content near the surface (0–0.1 m was significantly higher under MT (by 6% compared to CT, however, in layer 0–0.3 m under CT the average Corg content was by 16% higher than under MT. In mollic Fulvisols under MT, the average Corg content (17.5 ± 5.4 g*kg-1 was significantly less for the 0–0.3 m layer than the CT (22.7 ± 0.4 g*kg-1. In Chernozems, total content of water-stable micro-aggregates (WSAmi was higher in MT (90.8% than in CT (69.5%. In mollic Fluvisols, the average content of WSAmi was higher in CT (62.5% than in MT (53.2%. The low aggregate stability and the high structure vulnerability were reflected also due to the high contents of WSAmi in both soils. The stability of aggregates was a higher in mollic Fluvisols than in haplic Chernozems. In haplic Chernozems, better soil structure stability was under CT than MT, on the other hand, in mollic Fluvisols, the average value of coefficient of aggregate stability was lower by 32% in CT than MT.

  16. Atrazine degradation and enzyme activities in an agricultural soil under two tillage systems.

    Science.gov (United States)

    Mahía, Jorge; Martín, Angela; Carballas, Tarsy; Díaz-Raviña, Montserrat

    2007-05-25

    The content of atrazine and its metabolites (hydroxyatrazine, deethylatrazine and deisopropylatrazine) as well as the activities of two soil enzymes (urease and beta-glucosidase) were evaluated in an acid agricultural soil, located in a temperate humid zone (Galicia, NW Spain), with an annual ryegrass-maize rotation under conventional tillage (CT) and no tillage (NT). Samples were collected during two consecutive years from the arable layer at two depths (0-5 cm and 5-20 cm) and different times after atrazine application. Hydroxyatrazine and deisopropylatrazine were the main metabolites resulting from atrazine degradation in the acid soil studied, the highest levels being detected in the surface layer of the NT treatment. A residual effect of atrazine was observed since hydroxyatrazine was detected in the arable layer (0-5 cm, 5-20 cm) even one year after the herbicide application. Soil enzyme activities in the upper 5 cm layer under NT were consistently higher than those in the same layer under CT. Urease and beta-glucosidase activities decreased with depth in the profile under NT but they did not show any differences between the two depths for the plots under CT. For both tillage systems enzyme activities also reflected temporal changes during the maize cultivation; however, no consistent effect of the herbicide application was observed.

  17. Dryland maize yields and water use efficiency in response to tillage/crop stubble and nutrient management practices in China

    NARCIS (Netherlands)

    Wang, X.B.; Dai, K.; Zhang, D.; Zhang, X.; Wang, Y.; Zhao, Q.; Cai, D.X.; Hoogmoed, W.B.; Oenema, O.

    2011-01-01

    Rainfed crop production in northern China is constrained by low and variable rainfall. This study explored the effects of tillage/crop residue and nutrient management practices on maize (Zea mays L.) yield, water use efficiency (WUE), and N agronomic use efficiency (NAE) at Shouyang Dryland Farming

  18. Sorghum-sudangrass responses to nitrogen and tillage following polyphenol-containing legumes, alfalfa, reed canarygrass, and kale

    Science.gov (United States)

    The collective effects of protein-binding polyphenols (PBP), preceding forage type, tillage, and fertilizer N on soil NO3-N production, N uptake, and dry matter yield (DMY) of N-demanding crops such as sorghum-sudangrass [SS, Sorghum bicolor (L.) Moench x S. sudanese Piper] are poorly understood. Th...

  19. Net global warming potential and greenhouse gas intensity influenced by irrigation, tillage, crop rotation, and nitrogen fertilization

    Science.gov (United States)

    Little information exists about sources and sinks of greenhouse gases (GHGs) affected by management practices to account for net emissions from agroecosystems. We evaluated the effects of irrigation, tillage, crop rotation, and N fertilization on net global warming potential (GWP) and greenhouse gas...

  20. Residue and soil carbon sequestration in relation to crop yield as affected by irrigation, tillage, cropping system and nitrogen fertilization

    Science.gov (United States)

    Information on management practices is needed to increase surface residue and soil C sequestration to obtain farm C credit. The effects of irrigation, tillage, cropping system, and N fertilization were evaluated on the amount of crop biomass (stems and leaves) returned to the soil, surface residue C...

  1. Soil carbon storage and stratification under different tillage/residue-management practices in double rice cropping system

    NARCIS (Netherlands)

    Chen, Z.; Zhang, H.; dikgwatlhe, S.B.; Xue, J.; Qiu, K.; Tang, H.; Chen, F.

    2015-01-01

    The importance of soil organic carbon (SOC) sequestration in agricultural soils as climate-change-mitigating strategy has become an area of focus by the scientific community in relation to soil management. This study was conducted to determine the temporal effect of different tillage systems and

  2. RNA Sequencing Analysis Reveals Transcriptomic Variations in Tobacco (Nicotiana tabacum Leaves Affected by Climate, Soil, and Tillage Factors

    Directory of Open Access Journals (Sweden)

    Bo Lei

    2014-04-01

    Full Text Available The growth and development of plants are sensitive to their surroundings. Although numerous studies have analyzed plant transcriptomic variation, few have quantified the effect of combinations of factors or identified factor-specific effects. In this study, we performed RNA sequencing (RNA-seq analysis on tobacco leaves derived from 10 treatment combinations of three groups of ecological factors, i.e., climate factors (CFs, soil factors (SFs, and tillage factors (TFs. We detected 4980, 2916, and 1605 differentially expressed genes (DEGs that were affected by CFs, SFs, and TFs, which included 2703, 768, and 507 specific and 703 common DEGs (simultaneously regulated by CFs, SFs, and TFs, respectively. GO and KEGG enrichment analyses showed that genes involved in abiotic stress responses and secondary metabolic pathways were overrepresented in the common and CF-specific DEGs. In addition, we noted enrichment in CF-specific DEGs related to the circadian rhythm, SF-specific DEGs involved in mineral nutrient absorption and transport, and SF- and TF-specific DEGs associated with photosynthesis. Based on these results, we propose a model that explains how plants adapt to various ecological factors at the transcriptomic level. Additionally, the identified DEGs lay the foundation for future investigations of stress resistance, circadian rhythm and photosynthesis in tobacco.

  3. Influence of Conservation Tillage on some Soil Physical Properties and Crop Yield in Vetch-Wheat Rotation in Dryland Cold Region

    Directory of Open Access Journals (Sweden)

    I Eskandari

    2017-10-01

    Full Text Available Introduction Winter wheat is an important, well-adapted grain crop under dryland condition of the northwest of Iran. Soil water is the most limiting resource for crop growth in dryland areas. Therefore, farmers need to use crop residues and minimum tillage to control the soil erosion and effectively store and to use the limited precipitation received for crop production. Crop rotation and tillage system could affect crop yield due to their effects on water conservation and soil chemical and physical properties. Galantini et al., (2000 studied the effect of crop rotation on wheat productivity in the Pampean semi-arid region of Argentina and found that a wheat–vetch (Vicia sativa L. rotation resulted in higher yield and protein content, and greater yield components than the other rotations.Payne et al. (2000 stated that where precipitation amount is marginal (400 mm, dry field pea offers a potential alternative to summer fallowing. The purpose of this study was to identify the optimal tillage system for increasing crop productivity in a vetch–wheat rotation in dryland farming of the northwest of Iran. Materials and Methods The field experiment was carried out from 2010 to 2014 at the Dryland Agricultural Research Station (latitude37° 12´N; longitude 46◦20´E; 1730 m a.s.l., 25 km east of Maragheh, East Azerbaijan Province, Iran. The long-term (10 years average precipitation, temperature and relative humidity of the station are 336.5 mm, 9.4 ◦C and 47.5%, respectively. The soil (Fine Mixed, Mesic, Vertic Calcixerepts, USDA system; Calcisols, FAO system at the study site had a clay loam texture in the 0–15 cm surface layer and a clay texture in the 15–80 cm depth. This study was conducted in vetch (Vicia pannonica- wheat (Triticum aestivum L. rotation. The experiment was arranged in a randomized complete block design with four replications. The tillage treatments consisted of (1 conventional tillage: moldboard plowing followed by one

  4. Quantifying the Effect of Soil Water Repellency on Infiltration Parameters Using a Dry Sand

    Science.gov (United States)

    Shillito, R.; Berli, M.; Ghezzehei, T. A.; Kaminski, E.

    2017-12-01

    Water infiltration into less than perfectly wettable soils has usually been considered an exceptional case—in fact, it may be the rule. Infiltration into soils exhibiting some degree of water repellency has important implications in agricultural irrigation, post-fire runoff, golf course and landscape management, and spill and contaminant mitigation. Beginning from fundamental principles, we developed a physically-based model to quantify the effect of water repellency on infiltration parameters. Experimentally, we used a dry silica sand and treated it to achieve various known degrees of water repellency. The model was verified using data gathered from multiple upward infiltration (wicking) experiments using the treated sand. The model also allowed us to explore the effect of initial soil moisture conditions on infiltration into water-repellent soils, and the physical interpretation of the simple water drop penetration time test. These results provide a fundamental step in the physically-based understanding of how water infiltrates into a less than perfectly wettable porous media.

  5. Quantifying Multiscale Habitat Structural Complexity: A Cost-Effective Framework for Underwater 3D Modelling

    Directory of Open Access Journals (Sweden)

    Renata Ferrari

    2016-02-01

    Full Text Available Coral reef habitat structural complexity influences key ecological processes, ecosystem biodiversity, and resilience. Measuring structural complexity underwater is not trivial and researchers have been searching for accurate and cost-effective methods that can be applied across spatial extents for over 50 years. This study integrated a set of existing multi-view, image-processing algorithms, to accurately compute metrics of structural complexity (e.g., ratio of surface to planar area underwater solely from images. This framework resulted in accurate, high-speed 3D habitat reconstructions at scales ranging from small corals to reef-scapes (10s km2. Structural complexity was accurately quantified from both contemporary and historical image datasets across three spatial scales: (i branching coral colony (Acropora spp.; (ii reef area (400 m2; and (iii reef transect (2 km. At small scales, our method delivered models with <1 mm error over 90% of the surface area, while the accuracy at transect scale was 85.3% ± 6% (CI. Advantages are: no need for an a priori requirement for image size or resolution, no invasive techniques, cost-effectiveness, and utilization of existing imagery taken from off-the-shelf cameras (both monocular or stereo. This remote sensing method can be integrated to reef monitoring and improve our knowledge of key aspects of coral reef dynamics, from reef accretion to habitat provisioning and productivity, by measuring and up-scaling estimates of structural complexity.

  6. Atmospheric LiDAR coupled with point measurement air quality samplers to measure fineparticulate matter (PM) emissions from agricultural operations. Part 2 of the California 2007 - 2008 Tillage Campaigns: Spring 2008 Data Analysis

    Science.gov (United States)

    Concern with health effects resulting from PM10 exposure is drawing increased regulatory scrutiny and research toward local agricultural tillage operations. To investigate the control effectiveness of one of the current Conservation Management Practices (CMPs) written for agricul...

  7. No tillage and liming reduce greenhouse gas emissions from poorly drained agricultural soils in Mediterranean regions

    International Nuclear Information System (INIS)

    García-Marco, Sonia; Abalos, Diego; Espejo, Rafael; Vallejo, Antonio; Mariscal-Sancho, Ignacio

    2016-01-01

    No tillage (NT) has been associated to increased N_2O emission from poorly drained agricultural soils. This is the case for soils with a low permeable Bt horizon, which generates a perched water layer after water addition (via rainfall or irrigation) over a long period of time. Moreover, these soils often have problems of acidity and require liming application to sustain crop productivity; changes in soil pH have large implications for the production and consumption of soil greenhouse gas (GHG) emissions. Here, we assessed in a split-plot design the individual and interactive effects of tillage practices (conventional tillage (CT) vs. NT) and liming (Ca-amendment vs. not-amendment) on N_2O and CH_4 emissions from poorly drained acidic soils, over a field experiment with a rainfed triticale crop. Soil mineral N concentrations, pH, temperature, moisture, water soluble organic carbon, GHG fluxes and denitrification capacity were measured during the experiment. Tillage increased N_2O emissions by 68% compared to NT and generally led to higher CH_4 emissions; both effects were due to the higher soil moisture content under CT plots. Under CT, liming reduced N_2O emissions by 61% whereas no effect was observed under NT. Under both CT and NT, CH_4 oxidation was enhanced after liming application due to decreased Al"3"+ toxicity. Based on our results, NT should be promoted as a means to improve soil physical properties and concurrently reduce N_2O and CH_4 emissions. Raising the soil pH via liming has positive effects on crop yield; here we show that it may also serve to mitigate CH_4 emissions and, under CT, abate N_2O emissions. - Highlights: • The effect of tillage and liming on GHG was studied in poorly drained acidic soils. • NT reduced N_2O emissions, global warming potential and greenhouse gases intensity. • Liming reduced N_2O and CH_4 emissions under CT; no effect was observed under NT. • NT and liming provide an opportunity for N_2O and CH_4 mitigation.

  8. No tillage and liming reduce greenhouse gas emissions from poorly drained agricultural soils in Mediterranean regions

    Energy Technology Data Exchange (ETDEWEB)

    García-Marco, Sonia, E-mail: sonia.garcia@upm.es [Departamento de Química y Tecnología de los Alimentos, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Abalos, Diego, E-mail: diego.abalosrodriguez@wur.nl [Departamento de Química y Tecnología de los Alimentos, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Espejo, Rafael, E-mail: rafael.espejo@upm.es [Departamento de Producción Agraria, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Vallejo, Antonio, E-mail: antonio.vallejo@upm.es [Departamento de Química y Tecnología de los Alimentos, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain); Mariscal-Sancho, Ignacio, E-mail: i.mariscal@upm.es [Departamento de Producción Agraria, E.T.S.I. Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Ciudad Universitaria, 28040 Madrid (Spain)

    2016-10-01

    No tillage (NT) has been associated to increased N{sub 2}O emission from poorly drained agricultural soils. This is the case for soils with a low permeable Bt horizon, which generates a perched water layer after water addition (via rainfall or irrigation) over a long period of time. Moreover, these soils often have problems of acidity and require liming application to sustain crop productivity; changes in soil pH have large implications for the production and consumption of soil greenhouse gas (GHG) emissions. Here, we assessed in a split-plot design the individual and interactive effects of tillage practices (conventional tillage (CT) vs. NT) and liming (Ca-amendment vs. not-amendment) on N{sub 2}O and CH{sub 4} emissions from poorly drained acidic soils, over a field experiment with a rainfed triticale crop. Soil mineral N concentrations, pH, temperature, moisture, water soluble organic carbon, GHG fluxes and denitrification capacity were measured during the experiment. Tillage increased N{sub 2}O emissions by 68% compared to NT and generally led to higher CH{sub 4} emissions; both effects were due to the higher soil moisture content under CT plots. Under CT, liming reduced N{sub 2}O emissions by 61% whereas no effect was observed under NT. Under both CT and NT, CH{sub 4} oxidation was enhanced after liming application due to decreased Al{sup 3+} toxicity. Based on our results, NT should be promoted as a means to improve soil physical properties and concurrently reduce N{sub 2}O and CH{sub 4} emissions. Raising the soil pH via liming has positive effects on crop yield; here we show that it may also serve to mitigate CH{sub 4} emissions and, under CT, abate N{sub 2}O emissions. - Highlights: • The effect of tillage and liming on GHG was studied in poorly drained acidic soils. • NT reduced N{sub 2}O emissions, global warming potential and greenhouse gases intensity. • Liming reduced N{sub 2}O and CH{sub 4} emissions under CT; no effect was observed under NT

  9. Towards risk-based drought management in the Netherlands: quantifying the welfare effects of water shortage

    Science.gov (United States)

    van der Vat, Marnix; Femke, Schasfoort; Rhee Gigi, Van; Manfred, Wienhoven; Nico, Polman; Joost, Delsman; den Hoek Paul, Van; Maat Judith, Ter; Marjolein, Mens

    2016-04-01

    It is widely acknowledged that drought management should move from a crisis to a risk-based approach. A risk-based approach to managing water resources requires a sound drought risk analysis, quantifying the probability and impacts of water shortage due to droughts. Impacts of droughts are for example crop yield losses, hydropower production losses, and water shortage for municipal and industrial use. Many studies analyse the balance between supply and demand, but there is little experience in translating this into economic metrics that can be used in a decision-making process on investments to reduce drought risk. We will present a drought risk analysis method for the Netherlands, with a focus on the underlying economic method to quantify the welfare effects of water shortage for different water users. Both the risk-based approach as well as the economic valuation of water shortage for various water users was explored in a study for the Dutch Government. First, an historic analysis of the effects of droughts on revenues and prices in agriculture as well as on shipping and nature was carried out. Second, a drought risk analysis method was developed that combines drought hazard and drought impact analysis in a probabilistic way for various sectors. This consists of a stepwise approach, from water availability through water shortage to economic impact, for a range of drought events with a certain return period. Finally, a local case study was conducted to test the applicability of the drought risk analysis method. Through the study, experience was gained into integrating hydrological and economic analyses, which is a prerequisite for drought risk analysis. Results indicate that the risk analysis method is promising and applicable for various sectors. However, it was also found that quantification of economic impacts from droughts is time-consuming, because location- and sector-specific data is needed, which is not always readily available. Furthermore, for some

  10. Quantifying soil burn severity for hydrologic modeling to assess post-fire effects on sediment delivery

    Science.gov (United States)

    Dobre, Mariana; Brooks, Erin; Lew, Roger; Kolden, Crystal; Quinn, Dylan; Elliot, William; Robichaud, Pete

    2017-04-01

    Soil erosion is a secondary fire effect with great implications for many ecosystem resources. Depending on the burn severity, topography, and the weather immediately after the fire, soil erosion can impact municipal water supplies, degrade water quality, and reduce reservoirs' storage capacity. Scientists and managers use field and remotely sensed data to quickly assess post-fire burn severity in ecologically-sensitive areas. From these assessments, mitigation activities are implemented to minimize post-fire flood and soil erosion and to facilitate post-fire vegetation recovery. Alternatively, land managers can use fire behavior and spread models (e.g. FlamMap, FARSITE, FOFEM, or CONSUME) to identify sensitive areas a priori, and apply strategies such as fuel reduction treatments to proactively minimize the risk of wildfire spread and increased burn severity. There is a growing interest in linking fire behavior and spread models with hydrology-based soil erosion models to provide site-specific assessment of mitigation treatments on post-fire runoff and erosion. The challenge remains, however, that many burn severity mapping and modeling products quantify vegetation loss rather than measuring soil burn severity. Wildfire burn severity is spatially heterogeneous and depends on the pre-fire vegetation cover, fuel load, topography, and weather. Severities also differ depending on the variable of interest (e.g. soil, vegetation). In the United States, Burned Area Reflectance Classification (BARC) maps, derived from Landsat satellite images, are used as an initial burn severity assessment. BARC maps are classified from either a Normalized Burn Ratio (NBR) or differenced Normalized Burned Ratio (dNBR) scene into four classes (Unburned, Low, Moderate, and High severity). The development of soil burn severity maps requires further manual field validation efforts to transform the BARC maps into a product more applicable for post-fire soil rehabilitation activities

  11. [Dynamics of aquic brown soil enzyme activities under no-tillage].

    Science.gov (United States)

    Liu, Xiumei; Li, Qi; Liang, Wenju; Jiang, Yong; Wen, Dazhong

    2006-12-01

    This paper studied the effects of no-tillage on the dynamics of invertase, urease and acid phosphatase activities in an aquic brown soil during maize growing season. The results showed that in 0 - 10 cm soil layer, the invertase activity at jointing, trumpet-shaped and ripening stages, urease activity at jointing and booting stages, and acid phosphatase activity at booting and ripening stages were significantly higher under no-tillage (NT) than under conventional tillage (CT). In 10 - 20 cm soil layer, the invertase activity at seedling, jointing and trumpet-shaped stages was significantly different between NT and CT, and the urease activity during whole growing season except at booting stage was significantly higher under NT than under CT. In 20 - 30 cm soil layer, the invertase activity during maize growing season was significantly lower under NT than under CT, and urease activity at seedling stage and acid phosphate activity at ripening stage were significantly different between these two treatments. Under NT, there was a decreasing trend of soil enzyme activities with increasing soil depth; while under CT, soil invertase and acid phosphatase activities increased, but urease activity decreased with increasing soil depth.

  12. Application limestone forms and doses for alfalfa in no-tillage system

    Directory of Open Access Journals (Sweden)

    Letícia Cristina Bertusso Toffolli

    Full Text Available Alfalfa (Medicago sativa L. requires good soil fertility. Brazil is characterized by acidic soils which reduce the potential of the crop. Generally, liming is incorporated into the soil, but in tillage systems it is inadvisable. This study aimed to evaluate the effects of the lime application method and dose on pH, Al+3, V % and Ca+Mg in the soil and on dry matter yield of alfalfa cultivated under a consolidated no-tillage system. The experiment was conducted at the Experimental Station of Paraná Agronomic Institute, located in Pato Branco city, in Paraná state. The plots consisted of the types of lime application (plowing+harrowing, subsoil and surface, the sub-plots was the lime dose (0, 2, 4, 6 and 8 Mg ha-1 and the sub-sub-plots were the sampled soil depth (0-5; 5-10; 10-20 and 20-30 cm. The results show the application of lime, even superficially, caused increases in pH, concentration of Ca and Mg and base saturation of the soil, while also reducing the concentration of Al, especially in the surface layers of the soil. The practice of plowing and harrowing or of subsoiling, with the aim of lime incorporation in a consolidated no-tillage system is unnecessary. If it is required, the application of lime to the soil should be done superficially for alfalfa cultivated in this system.

  13. Infiltration and Soil Loss Changes during the Growing Season under Ploughing and Conservation Tillage

    Directory of Open Access Journals (Sweden)

    Gergely Jakab

    2017-09-01

    Full Text Available Decreased water retention and increased runoff and soil loss are of special importance concerning soil degradation of hilly crop fields. In this study, plots under ploughing (conventional tillage (PT and conservation tillage (CT; 15 years were compared. Rainfall simulation on 6 m2 plots was applied to determine infiltration and soil loss during the growing season. Results were compared with those measured from 1200 m2 plots exposed to natural rainfalls in 2016. Infiltration was always higher under CT than PT, whereas the highest infiltration was measured under the cover crop condition. Infiltration under seedbed and stubble resulted in uncertainties, which suggests that natural pore formation can be more effective at improving soil drainage potential than can temporary improvements created by soil tillage operations. Soil erodibility was higher under PT for each soil status; however, the seedbed condition triggered the highest values. For CT, soil loss volume was only a function of runoff volume at both scales. Contrarily, on PT plots, some extreme precipitation events triggered extremely high soil loss owing to linear erosion, which meant no direct connection existed between the scales. Improved soil conditions due to conservation practice are more important for decreasing soil loss than the better surface conditions.

  14. Efeito de sistemas de produção mistos sob plantio direto sobre fertilidade do solo após oito anos Effect of mixed crop production systems under no-tillage on soil fertility after eight years

    Directory of Open Access Journals (Sweden)

    H. P. Santos

    2003-06-01

    Full Text Available Os atributos de solo relativos à sua fertilidade foram avaliados num Latossolo Vermelho distrófico típico, em Passo Fundo (RS, oito anos após o estabelecimento (1993 a 2000 de cinco sistemas de produção que integravam culturas produtoras de grãos, pastagens de inverno e pastagens perenes - sistema I (trigo/soja, aveia branca/soja e ervilhaca/milho; sistema II (trigo/soja, aveia branca/soja e pastagem de aveia preta + ervilhaca/milho; sistema III [pastagens perenes da estação fria (festuca + trevo branco + trevo vermelho + cornichão]; sistema IV [pastagens perenes da estação quente (pensacola + aveia preta + azevém + trevo branco + trevo vermelho + cornichão]; e sistema V (alfafa para feno, que foi acrescentado como tratamento adicional, com repetições em áreas contíguas ao experimento, em 1994. As áreas sob os sistemas III, IV e V retornaram ao sistema I, a partir do verão de 1996. As culturas, tanto de inverno como de verão, foram estabelecidas sob plantio direto. Os tratamentos foram distribuídos em blocos ao acaso com quatro repetições. Os valores de pH, de Al trocável, de Ca + Mg trocáveis, de matéria orgânica, de P extraível e de K trocável foram influenciados pelos sistemas de produção. Os sistemas de produção elevaram os níveis de matéria orgânica, de P extraível e de K trocável, principalmente na profundidade de solo de 0-5 cm. Os teores de matéria orgânica e os de Al trocável, de P extraível e de K trocável diminuíram da camada de 0-5 cm para a camada de 15-20 cm, enquanto para os valores de pH e de Ca + Mg trocáveis ocorreu o contrário.Soil fertility characteristics were evaluated on a typical dystrophic Red Latosol (Typic Haplorthox located in Passo Fundo, State of Rio Grande do Sul, Brazil, after eight years of use under mixed production systems (1993 to 2000. The effects of production systems integrating grain production with winter annual and perennial pastures under no-tillage were

  15. Nonclassical effects in plasmonics: an energy perspective to quantify nonclassical effects

    DEFF Research Database (Denmark)

    Yan, Wei; Mortensen, N. Asger

    2016-01-01

    of the nonclassical effects at different microscopic levels by contrasting the numerical results from the semiclassical hydrodynamic Drude model (HDM) and the microscopic random-phase approximation (RPA). The formal relation between the HDM and the RPA is also established for metals by exploring the limit...

  16. Quantifying the persistence of pro-smoking media effects on college students' smoking risk.

    Science.gov (United States)

    Setodji, Claude M; Martino, Steven C; Scharf, Deborah M; Shadel, William G

    2014-04-01

    To quantify the persistence of pro-smoking media exposure effects on college students' intentions to smoke and smoking refusal self-efficacy. A total of 134 college students (ages 18-24 years) were enrolled in an ecological momentary assessment study in which they carried handheld data collection devices for 3 weeks and reported their exposures to pro-smoking media as they occurred in the real world. Smoking intentions and smoking refusal self-efficacy were assessed after each exposure to pro-smoking media and at random prompts during each day of the 3-week assessment period. A generalized additive model was used to determine how long the effect of an exposure to pro-smoking media persisted. The effect of pro-smoking media exposures persisted for 7 days. After exposure, smoking intentions immediately increased (.56; 95% confidence interval [CI]: [.26, .87]) and then steadily decreased (-.12; 95% CI: [-.19, -.05]) each day for 7 days, while smoking refusal self-efficacy immediately decreased (-.42; 95% CI: [-.75, -.10]) and then steadily increased (.09; 95% CI: [.02, .16]) each day for 7 days. Daily changes occurring after 7 days were not statistically significant, suggesting that smoking intentions and refusal self-efficacy had stabilized and were no longer affected by pro-smoking media exposure. Exposures to pro-smoking media may have strong implications for emerging young adults smoking risk as the impact of an individual exposure appears to persist for at least a week. Copyright © 2014 Society for Adolescent Health and Medicine. All rights reserved.

  17. Quantifying the effect of riming on snowfall using ground-based observations

    Science.gov (United States)

    Moisseev, Dmitri; von Lerber, Annakaisa; Tiira, Jussi

    2017-04-01

    Ground-based observations of ice particle size distribution and ensemble mean density are used to quantify the effect of riming on snowfall. The rime mass fraction is derived from these measurements by following the approach that is used in a single ice-phase category microphysical scheme proposed for the use in numerical weather prediction models. One of the characteristics of the proposed scheme is that the prefactor of a power law relation that links mass and size of ice particles is determined by the rime mass fraction, while the exponent does not change. To derive the rime mass fraction, a mass-dimensional relation representative of unrimed snow is also determined. To check the validity of the proposed retrieval method, the derived rime mass fraction is converted to the effective liquid water path that is compared to microwave radiometer observations. Since dual-polarization radar observations are often used to detect riming, the impact of riming on dual-polarization radar variables is studied for differential reflectivity measurements. It is shown that the relation between rime mass fraction and differential reflectivity is ambiguous, other factors such as change in median volume diameter need also be considered. Given the current interest on sensitivity of precipitation to aerosol pollution, which could inhibit riming, the importance of riming for surface snow accumulation is investigated. It is found that riming is responsible for 5% to 40% of snowfall mass. The study is based on data collected at the University of Helsinki field station in Hyytiälä during U.S. Department of Energy Biogenic Aerosols Effects on Clouds and Climate (BAECC) field campaign and the winter 2014/2015. In total 22 winter storms were analyzed, and detailed analysis of two events is presented to illustrate the study.

  18. Quantifying Beetle-Mediated Effects on Gas Fluxes from Dung Pats

    Science.gov (United States)

    Penttilä, Atte; Slade, Eleanor M.; Simojoki, Asko; Riutta, Terhi; Minkkinen, Kari; Roslin, Tomas

    2013-01-01

    Agriculture is one of the largest contributors of the anthropogenic greenhouse gases (GHGs) responsible for global warming. Measurements of gas fluxes from dung pats suggest that dung is a source of GHGs, but whether these emissions are modified by arthropods has not been studied. A closed chamber system was used to measure the fluxes of carbon dioxide (CO2), methane (CH4) and nitrous oxide (N2O) from dung pats with and without dung beetles on a grass sward. The presence of dung beetles significantly affected the fluxes of GHGs from dung pats. Most importantly, fresh dung pats emitted higher amounts of CO2 and lower amounts of CH4 per day in the presence than absence of beetles. Emissions of N2O showed a distinct peak three weeks after the start of the experiment – a pattern detected only in the presence of beetles. When summed over the main grazing season (June–July), total emissions of CH4 proved significantly lower, and total emissions of N2O significantly higher in the presence than absence of beetles. While clearly conditional on the experimental conditions, the patterns observed here reveal a potential impact of dung beetles on gas fluxes realized at a small spatial scale, and thereby suggest that arthropods may have an overall effect on gas fluxes from agriculture. Dissecting the exact mechanisms behind these effects, mapping out the range of conditions under which they occur, and quantifying effect sizes under variable environmental conditions emerge as key priorities for further research. PMID:23940758

  19. Quantifying the effects of climate and post-fire landscape change on hydrologic processes

    Science.gov (United States)

    Steimke, A.; Han, B.; Brandt, J.; Som Castellano, R.; Leonard, A.; Flores, A. N.

    2016-12-01

    Seasonally snow-dominated, forested mountain watersheds supply water to many human populations globally. However, the timing and magnitude of water delivery from these watersheds has already and will continue to change as the climate warms. Changes in vegetation also affect the runoff response of watersheds. The largest driver of vegetation change in many mountainous regions is wildfire, whose occurrence is affected by both climate and land management decisions. Here, we quantify how direct (i.e. changes in precipitation and temperature) and indirect (i.e. changing fire regimes) effects of climate change influence hydrologic parameters such as dates of peak streamflow, annual discharge, and snowpack levels. We used the Boise River Basin, ID as a model laboratory to calculate the relative magnitude of change stemming from direct and indirect effects of climate change. This basin is relevant to study as it is well-instrumented and major drainages have experienced burning at different spatial and temporal intervals, aiding in model calibration. We built a hydrology-based integrated model of the region using a multiagent simulation framework, Envision. We used a modified HBV (Hydrologiska Byråns Vattenbalansavdelning) rainfall-runoff model and calibrated it to historic streamflow and snowpack observations. We combined a diverse set of climate projections with wildfire scenarios (low vs. high) representing two distinct intervals in the regional historic fire record. In fire simulations, we altered land cover coefficients to reflect a burned state post-fire, which decreased overall evapotranspiration rates and increased water yields. However, direct climate effects had a larger signal on annual variations of hydrologic parameters. By comparing and analyzing scenario outputs, we identified links and sensitivities between land cover and regional hydrology in the context of a changing climate, with potential implications for local land and water managers. In future

  20. Quantifying the effects of tempering on individual phase properties of DP980 steel with nanoindentation

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, G.; Zhang, F.; Ruimi, A.; Field, D. P.; Sun, X.

    2016-06-01

    We conduct a series of thermal and mechanical testing on a commercial dual phase (DP) 980 steel in order to quantify the effects of tempering on its individual phase properties. Tempering treatment is conducted at 250 °C and 400 °C for 60 minutes each. Ferrite and martensite grains are distinguished using electron backscatter diffraction (EBSD) and scanning probe microscopy (SPM), and the martensite volume fractions (MVF) are determined based on the image quality (IQ) map. Multi-scale indentation tests combined with a newly developed inverse method are used to obtain the individual phase flow properties in each tempered DP980 sample. The results show that, i) tempering significantly reduces martensite yield strength, while it only slightly reduces the ferrite yield strength; ii) tempering temperature has a more significant influence on the work hardening exponent of ferrite than that of martensite; iii) the elastic modulus of martensite is consistently higher than that of ferrite. As a validation, a simple rule of mixtures is used to verify the above-predicted individual phase flow stresses with the experimentally obtained overall true stress vs. true strain curves. The methodology and the corresponding results shown in this study can help guide the selection of tempering parameters in optimizing the mechanical properties of DP steels for their intended applications.

  1. ESR technique for noninvasive way to quantify cyclodextrins effect on cell membranes

    International Nuclear Information System (INIS)

    Grammenos, A.; Mouithys-Mickalad, A.; Guelluy, P.H.; Lismont, M.; Piel, G.; Hoebeke, M.

    2010-01-01

    Research highlights: → ESR: a new tool for cyclodextrins study on living cells. → Cholesterol and phospholipid extraction by Rameb in a dose- and time-dependent way. → Extracted phospholipids and cholesterol form stable aggregates. → ESR spectra show that lipid rafts are damaged by Rameb. → Quantification of the cholesterol extraction on cell membranes in a noninvasive way. -- Abstract: A new way to study the action of cyclodextrin was developed to quantify the damage caused on cell membrane and lipid bilayer. The Electron Spin Resonance (ESR) spectroscopy was used to study the action of Randomly methylated-beta-cyclodextrin (Rameb) on living cells (HCT-116). The relative anisotropy observed in ESR spectrum of nitroxide spin probe (5-DSA and cholestane) is directly related to the rotational mobility of the probe, which can be further correlated with the microviscosity. The use of ESR probes clearly shows a close correlation between cholesterol contained in cells and cellular membrane microviscosity. This study also demonstrates the Rameb ability to extract cholesterol and phospholipids in time- and dose-dependent ways. In addition, ESR spectra enabled to establish that cholesterol is extracted from lipid rafts to form stable aggregates. The present work supports that ESR is an easy, reproducible and noninvasive technique to study the effect of cyclodextrins on cell membranes.

  2. Quantifying the Effect of the Principal-Agent Problem on USResidential Energy Use

    Energy Technology Data Exchange (ETDEWEB)

    Murtishaw, Scott; Sathaye, Jayant

    2006-08-12

    The International Energy Agency (IEA) initiated andcoordinated this project to investigate the effects of market failures inthe end-use of energy that may isolate some markets or portions thereoffrom energy price signals in five member countries. Quantifying theamount of energy associated with market failures helps to demonstrate thesignificance of energy efficiency policies beyond price signals. In thisreport we investigate the magnitude of the principal-agent (PA) problemaffecting four of the major energy end uses in the U.S. residentialsector: refrigeration, water heating, space heating, and lighting. Usingdata from the American Housing Survey, we develop a novel approach toclassifying households into a PA matrix for each end use. End use energyvalues differentiated by housing unit type from the Residential EnergyConsumption Survey were used to estimate the final and primary energy useassociated with the PA problem. We find that the 2003 associated siteenergy use from these four end uses totaled over 3,400 trillion Btu,equal to 35 percent of the site energy consumed by the residentialsector.

  3. Quantifying the effects of land use and climate on Holocene vegetation in Europe

    Science.gov (United States)

    Marquer, Laurent; Gaillard, Marie-José; Sugita, Shinya; Poska, Anneli; Trondman, Anna-Kari; Mazier, Florence; Nielsen, Anne Birgitte; Fyfe, Ralph M.; Jönsson, Anna Maria; Smith, Benjamin; Kaplan, Jed O.; Alenius, Teija; Birks, H. John B.; Bjune, Anne E.; Christiansen, Jörg; Dodson, John; Edwards, Kevin J.; Giesecke, Thomas; Herzschuh, Ulrike; Kangur, Mihkel; Koff, Tiiu; Latałowa, Małgorzata; Lechterbeck, Jutta; Olofsson, Jörgen; Seppä, Heikki

    2017-09-01

    Early agriculture can be detected in palaeovegetation records, but quantification of the relative importance of climate and land use in influencing regional vegetation composition since the onset of agriculture is a topic that is rarely addressed. We present a novel approach that combines pollen-based REVEALS estimates of plant cover with climate, anthropogenic land-cover and dynamic vegetation modelling results. This is used to quantify the relative impacts of land use and climate on Holocene vegetation at a sub-continental scale, i.e. northern and western Europe north of the Alps. We use redundancy analysis and variation partitioning to quantify the percentage of variation in vegetation composition explained by the climate and land-use variables, and Monte Carlo permutation tests to assess the statistical significance of each variable. We further use a similarity index to combine pollen-based REVEALS estimates with climate-driven dynamic vegetation modelling results. The overall results indicate that climate is the major driver of vegetation when the Holocene is considered as a whole and at the sub-continental scale, although land use is important regionally. Four critical phases of land-use effects on vegetation are identified. The first phase (from 7000 to 6500 BP) corresponds to the early impacts on vegetation of farming and Neolithic forest clearance and to the dominance of climate as a driver of vegetation change. During the second phase (from 4500 to 4000 BP), land use becomes a major control of vegetation. Climate is still the principal driver, although its influence decreases gradually. The third phase (from 2000 to 1500 BP) is characterised by the continued role of climate on vegetation as a consequence of late-Holocene climate shifts and specific climate events that influence vegetation as well as land use. The last phase (from 500 to 350 BP) shows an acceleration of vegetation changes, in particular during the last century, caused by new farming

  4. Water-use efficiency of dryland wheat in response to mulching and tillage practices on the Loess Plateau

    Science.gov (United States)

    Wang, Li-Fang; Shangguan, Zhou-Ping

    2015-07-01

    Mulching and tillage are widely considered to be major practices for improving soil and water conservation where water is scarce. This paper studied the effects of FM (flat mulching), RFM (ridge-furrow mulching), SM (straw mulching), MTMC (mulching with two materials combined), MOM (mulching with other materials), NT (no-tillage) ST (subsoiling tillage) and RT (rotational tillage) on wheat yield based on a synthesis of 85 recent publications (including 2795 observations at 24 sites) in the Loess Plateau, China. This synthesis suggests that wheat yield was in the range of 259-7898 kg ha-1 for FM and RFM. The sequence of water use efficiency (WUE) effect sizes was similar to that of wheat yield for the practices. Wheat yields were more sensitive to soil water at planting covered by plastic film, wheat straw, liquid film, water-permeable plastic film and sand compared to NT, ST and RT. RFM and RT increased the yields of wheat by 18 and 15%, respectively, and corresponding for WUE by 20.11 and 12.50%. This synthesis demonstrates that RFM was better for avoiding the risk of reduced production due to lack of precipitation; however, under conditions of better soil moisture, RT and MTMC were also economic.

  5. Explaining Social Class Inequalities in Educational Achievement in the UK: Quantifying the Contribution of Social Class Differences in School "Effectiveness"

    Science.gov (United States)

    Hobbs, Graham

    2016-01-01

    There are large social class inequalities in educational achievement in the UK. This paper quantifies the contribution of one mechanism to the production of these inequalities: social class differences in school "effectiveness," where "effectiveness" refers to a school's impact on pupils' educational achievement (relative to…

  6. Influence of Tillage and Poultry Manure on the Physical Properties of ...

    African Journals Online (AJOL)

    User

    growth (Lampurlanes et al.,2001), grain yield and the ... Deep tillage improved the root length, root ... Data indicated that the deep tillage practice significantly improved the maize grain physical ... applied at the time of sowing while remaining.

  7. Mineralización bruta de nitrógeno bajo labranza convencional, siembra directa y pastura Gross nitrogen mineralization under conventional tillage, no tillage and pasture

    Directory of Open Access Journals (Sweden)

    Cecilia Videla

    2005-12-01

    de entre 0,47 y 0,97, significativos en todos los momentos. Después de cinco años de implantada, PP produjo un aumento en TMB con respecto a los manejos agrícolas, mientras que el mismo período bajo SD no mejoró las TMB respecto a la LC. Por otro lado, las TCB no presentaron diferencias en respuesta al manejo y ni PP ni SD mejoraron las TNB respecto a LC.The intensification of conventional agriculture in the southeastern Buenos Aires province (Argentine produced soil fertility degradation. No-tillage (SDagriculture and the inclusion of pastures (PP in crop rotations, represent management alternatives to reduce conventional tillage (LC effects. A laboratory experiment was carried out with the aims of: a studying nitrogen mineralization (TMB, nitrification (TNB and consumption (TCB gross rates in a Mollisol under LC, SD and PP and b quantifying the potentially mineralizable nitrogen through anaerobic incubation (NAN and its relation with mineralization rates. The studied soil was a Typic Argiudoll - Petrocalcic Paleudoll complex which had been under conventional tillage for 17 yr until 1994 when it was converted to three different soil management systems: continuous PP and continuous cropping under SD, and under LC. Gross processes were estimated through the 15N dilution technique, adding 15N-labeled (NH42SO4 (10% 15N at. exc. four times during an 35-d incubation period and NAN was determined through short anaerobic incubations. Gross N mineralization rates ranged between 0.17 and 1.36 mg N kg-1 day-1. The soil under PP treatment presented higher TMB than cropping managements. Gross consumption rates ranged between 0.47 and 3.21 mg N kg-1 day-1, being nitrification the most important consumption process for all three management systems (80 %. Cumulative mineralized N (P= 28.6 mg kg-1, SD= 19.7 mg kg-1 and LC= 10.8 mg kg-1 was different among management systems, whereas cumulative consumed N were not (P= 72.6 mg kg-1, SD= 56.9 mg kg-1 and LC= 74.1 mg kg-1. The soil

  8. Strip Tillage and Early-Season Broadleaf Weed Control in Seeded Onion (Allium cepa)

    OpenAIRE

    Sarah Gegner-Kazmierczak; Harlene Hatterman-Valenti

    2016-01-01

    Field experiments were conducted in 2007 and 2008 near Oakes, North Dakota (ND), USA, to evaluate if strip tillage could be incorporated into a production system of seeded onion (Allium cepa) to eliminate the standard use of a barley (Hordeum vulgare) companion crop with conventional, full width tillage, yet support common early-season weed control programs. A split-factor design was used with tillage (conventional and strip tillage) as the main plot and herbicide treatments (bromoxynil, DCPA...

  9. Conservation tillage versus conventional tillage on carbon stock in a Mediterranean dehesa (southern Spain)

    Science.gov (United States)

    Parras-Alcántara, Luis; Lozano-García, Beatriz

    2014-05-01

    Understanding soil dynamics is essential for making appropriate land management decisions, as soils can affect the carbon content from the atmosphere, emitting large quantities of CO2 or storing carbon. This property is essential for climate change mitigation strategies as agriculture and forestry soil management can affect the carbon cycle. The dehesa is a Mediterranean silvopastoral system formed by grasslands with scattered oaks (Quercus ilex or Q. suber). The dehesa is a pasture where the herbaceous layer is comprised of either cultivated cereals such as oat, barley and wheat or native vegetation dominated by annual species, which are used as grazing resources. In addition, the dehesa is a practice dedicated to the combined production of Iberian swine, sheep, fuel wood, coal and cork, as well as hunting. The dehesa is characterized by the preservation of forest oaks. In this work, we compared two management practices such as organic farming (OF) and conventional tillage (CT) on soil organic carbon stocks (SOC-S) in Cambisols (CM) and Leptosols (LP), and we analyzed the quality of these soils based on stratification ratio (SR) in a Mediterranean dehesa. MATERIAL AND METHODS An analysis of 85 soil profiles was performed in 2009 in Los Pedroches Valley (Cordoba, southern Spain). Two soil management practices were selected: OF (isolated trees of variable densities —15-25— trees ha-1, mostly holm and cork oaks, and patches of shrubs — cistaceae, fabaceae and lamiaceae— with a herbaceous pasture layer mostly composed of therophytic species and livestock are introduced to provide organic fertilizer to the soil, without ploughing and animal manure from the farms may be incorporated) for 20 years and CT (similar to OF, with ploughing —annual passes with a disc harrow and/or cultivator— is aimed at growing grain for livestock or at clearing the encroaching shrubs) in CM and LP. The dehesas studied were silvopastoral systems without cropping. Soil properties

  10. A Study to Quantify the Effectiveness of Daily Endorectal Balloon for Prostate Intrafraction Motion Management

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Ken Kang-Hsin, E-mail: wangken@uphs.upenn.edu [Department of Radiation Oncology, Hospital of University of Pennsylvania, Philadelphia, PA (United States); Vapiwala, Neha; Deville, Curtiland; Plastaras, John P.; Scheuermann, Ryan; Lin Haibo; Bar Ad, Voika; Tochner, Zelig; Both, Stefan [Department of Radiation Oncology, Hospital of University of Pennsylvania, Philadelphia, PA (United States)

    2012-07-01

    Purpose: To quantify intrafraction prostate motion between patient groups treated with and without daily endorectal balloon (ERB) employed during prostate radiotherapy and establish the effectiveness of the ERB. Methods: Real-time intrafraction prostate motion from 29 non-ERB (1,061 sessions) and 30 ERB (1,008 sessions) patients was evaluated based on three-dimensional (3D), left, right, cranial, caudal, anterior, and posterior displacements. The average percentage of time with 3D and unidirectional prostate displacements >2, 3, 4, 5, 6, 7, 8, 9, and 10 mm in 1-min intervals was calculated for up to 6 min of treatment time. The Kolmogorov-Smirnov method was used to evaluate the intrafraction prostate motion pattern between both groups. Results: Large 3D motion (up to 1 cm or more) was only observed in the non-ERB group. The motion increased as a function of elapsed time for displacements >2-8 mm for the non-ERB group and >2-4 mm for the ERB group (p < 0.05). The percentage time distributions between the two groups were significantly different for motion >5 mm (p < 0.05). The 3D symmetrical internal margin (IM) can be reduced from 5 to 3 mm (40% reduction), whereas the asymmetrical IM can be reduced from 3 to 2 mm (33% reduction) in cranial, caudal, anterior, and posterior for 6 min of treatment, when ERB is used. Beyond 6 min, the symmetrical 3D and asymmetrical cranial, caudal, anterior, and posterior IMs can be reduced from 9, 4, 7, 7, and 8 to 5, 2, 5, 3, and 4 mm, respectively (up to 57% reduction). Conclusion: The percentage of time that the prostate was displaced in any direction was less in the ERB group for almost all magnitudes of motion considered. The directional analysis shows that the ERB reduced IMs in almost all directions, especially the anterior-posterior direction.

  11. Final report: mathematical method for quantifying the effectiveness of management strategies.

    Energy Technology Data Exchange (ETDEWEB)

    Covan, John Morgan; Sena-Henderson, Lisa; Robinett, Rush D. III (.; ); Brewer, Jeffrey D.; Roginski, Robert J.; Cooper, James Arlin

    2005-10-01

    Large complex teams (e.g., DOE labs) must achieve sustained productivity in critical operations (e.g., weapons and reactor development) while maintaining safety for involved personnel, the public, and physical assets, as well as security for property and information. This requires informed management decisions that depend on tradeoffs of factors such as the mode and extent of personnel protection, potential accident consequences, the extent of information and physical asset protection, and communication with and motivation of involved personnel. All of these interact (and potentially interfere) with each other and must be weighed against financial resources and implementation time. Existing risk analysis tools can successfully treat physical response, component failure, and routine human actions. However, many ''soft'' factors involving human motivation and interaction among weakly related factors have proved analytically problematic. There has been a need for an effective software tool capable of quantifying these tradeoffs and helping make rational choices. This type of tool, developed during this project, facilitates improvements in safety, security, and productivity, and enables measurement of improvements as a function of resources expended. Operational safety, security, and motivation are significantly influenced by ''latent effects'', which are pre-occurring influences. One example of these is that an atmosphere of excessive fear can suppress open and frank disclosures, which can in turn hide problems, impede correction, and prevent lessons learned. Another is that a cultural mind-set of commitment, self-responsibility, and passion for an activity is a significant contributor to the activity's success. This project pursued an innovative approach for quantitatively analyzing latent effects in order to link the above types of factors, aggregating available information into quantitative metrics that can contribute to

  12. Users' reaction to the drought of 2014 in Lebanon; quantifying the effects

    Science.gov (United States)

    Farajalla, Nadim; Haydamous, Patricia; El Hajj, Rana

    2016-04-01

    A drought that Lebanon witnessed during the water cycle of 2013-2014 seemed to mimic the expected decrease in precipitation projected in one of the 2020 scenarios reported in Lebanon's second national communication to the United Nations Framework Convention on Climate Change. Nationally, data and assessment studies on drought impacts are generally lacking, and thus, this drought presented an opportunity to quantify drought effects. In the aim of understanding the effect drought has on the Lebanese economy, and its different sectors, a survey was conducted to set a baseline of the changes in the direct cost of water as well as other impacts that might have resulted on the water users. The survey reached out to different sectors to include the touristic establishments, industries, agriculture holders, and households. The sample selection and the data collection underwent several controls in order to ensure unbiased data. Moreover, a descriptive analysis was produced from the survey results, using STATA and Microsoft Excel. The main results have shown a shift of dependency towards water tankers during the drought season as opposed to the normal higher dependency on the public networks and private wells. Moreover, the cost incurred in general showed an average of 32% increase to the previous water bills across the different sectors, this in return is expected to have ripple effects on the national economy accounting for around 13.5% of GDP. However, the survey showed that little was done in terms of long term adaptation on the consumers' side, where most of the adaptation done included awareness campaigns for an economized water usage on the short term. The survey brought forward the un-preparedness of the country to react to such extreme events due to the absence of drought preparedness and management plan. . The results highlight the projected losses the country will have if no proper adaptation measures were taken. These impacts were caused by a one-year drought

  13. Interactions of tillage and cover crop on water, sediment, and pre-emergence herbicide loss in glyphosate-resistant cotton: implications for the control of glyphosate-resistant weed biotypes.

    Science.gov (United States)

    Krutz, L Jason; Locke, Martin A; Steinriede, R Wade

    2009-01-01

    The need to control glyphosate [N-(phosphonomethyl)glycine]-resistant weed biotypes with tillage and preemergence herbicides in glyphosate-resistant crops (GRCs) is causing a reduction in no-tillage hectarage thereby threatening the advances made in water quality over the past decade. Consequently, if environmental gains afforded by GRCs are to be maintained, then an in-field best management practice (BMP) compatible with tillage is required for hectarage infested with glyphosate-resistant weed biotypes. Thus, 1 d after a preemergent application of fluometuron [N,N-dimethyl-N'-(3-(trifluoromethyl)phenyl)urea] (1.02 kg ha(-1)) and metolachlor [2-chloro-N-(2-ethyl-6-methylphenyl)-N-(2-methoxy-1-methylethyl)acetamide] (1.18 kg ha(-1)) to a Dundee silt loam (fine-silty, mixed, active, thermic Typic Endoaqualf), simulated rainfall (60 mm h(-1)) was applied to 0.0002-ha microplots for approximately 1.25 h to elucidate tillage (no tillage [NT] and reduced tillage [RT])and cover crop (no cover [NC] and rye cover [RC]) effects on water, sediment, and herbicide loss in surface runoff. Regardless of tillage, RC delayed time-to-runoff 1.3-fold, reduced cumulative runoff volume 1.4-fold, and decreased cumulative sediment loss 4.7-fold. Cumulative fluometuron loss was not affected by tillage or cover crop. Conversely, total metolachlor loss was 1.3-fold lower in NT than RT and 1.4-fold lower in RC than NC. These data indicate that RC can be established in hectarage requiring tillage and potentially curtail water, sediment, and preemergence herbicide losses in the spring to levels equivalent to or better than that of NT, thereby protecting environmental gains provided by GRCs.

  14. Dynamics of soil organic carbon and microbial biomass carbon in relation to water erosion and tillage erosion.

    Science.gov (United States)

    Xiaojun, Nie; Jianhui, Zhang; Zhengan, Su

    2013-01-01

    Dynamics of soil organic carbon (SOC) are associated with soil erosion, yet there is a shortage of research concerning the relationship between soil erosion, SOC, and especially microbial biomass carbon (MBC). In this paper, we selected two typical slope landscapes including gentle and steep slopes from the Sichuan Basin, China, and used the (137)Cs technique to determine the effects of water erosion and tillage erosion on the dynamics of SOC and MBC. Soil samples for the determination of (137)Cs, SOC, MBC and soil particle-size fractions were collected on two types of contrasting hillslopes. (137)Cs data revealed that soil loss occurred at upper slope positions of the two landscapes and soil accumulation at the lower slope positions. Soil erosion rates as well as distribution patterns of the erosion is the major process of soil redistribution in the gentle slope landscape, while tillage erosion acts as the dominant process of soil redistribution in the steep slope landscape. In gentle slope landscapes, both SOC and MBC contents increased downslope and these distribution patterns were closely linked to soil redistribution rates. In steep slope landscapes, only SOC contents increased downslope, dependent on soil redistribution. It is noticeable that MBC/SOC ratios were significantly lower in gentle slope landscapes than in steep slope landscapes, implying that water erosion has a negative effect on the microbial biomass compared with tillage erosion. It is suggested that MBC dynamics are closely associated with soil redistribution by water erosion but independent of that by tillage erosion, while SOC dynamics are influenced by soil redistribution by both water erosion and tillage erosion.

  15. Energy balance and greenhouse gas emissions of dryland camelina as influenced by tillage and nitrogen

    International Nuclear Information System (INIS)

    Keshavarz-Afshar, Reza; Mohammed, Yesuf Assen; Chen, Chengci

    2015-01-01

    Despite the great potential of camelina (Camelina sativa L. Crantz) as a promising biofuel feedstock, in-farm energy flow of the crop and its associated environmental impacts has not received sufficient attention from researchers. In order to assess net energy gain and to identify energy saving and environmental friendly production operations, a two year study was conducted at central Montana. We investigated the effects of tillage method (CT (conventional tillage) vs. NT (no-tillage)) and N (nitrogen) fertilizer rate (0, 45, 90 kg N ha −1 ) on energy balance and GHG (greenhouse gas emission) of dryland camelina production. Results indicated that energy input and GHG emission were 5 and 8% lower in NT than in CT. Application of 45 and 90 kg N ha −1 increased camelina energy input by 186 and 365%, while increased energy output by only 21 and 64%, respectively. There was no significant difference in net energy gain in response to N fertilization, but lower energy efficiency in response to higher N inputs. Averaged across tillage systems, the GHG emission was 32.0 kg C eq ha −1 with 0 N applied, and the GHG emission increased by 206 and 389% when 45 and 90 kg N ha −1 was applied. Overall, N fertilizer had the biggest share in total energy input. Averaged over all experimental treatments, 14,945 MJ ha −1 net energy was obtained from camelina crop in this study which shows the potential of this crop as a bioenergy feedstock. Our result showed that implementation of NT is strongly recommendable for camelina production in this region. Moreover, improvement of N use efficiency has the highest priority to improve energy performance and reduce GHG emissions in camelina production. - Highlights: • Camelina produced 14,945 MJ ha −1 of net energy in this study. • No tillage operation reduced 5% energy input and 8% greenhouse gas emission. • Nitrogen fertilizer was the most energy-intensive input in camelina production.

  16. Influence of Soil Tillage Systems on Soil Respiration and Production on Wheat, Maize and Soybean Crop

    Science.gov (United States)

    Moraru, P. I.; Rusu, T.

    2012-04-01

    Soil respiration leads to CO2 emissions from soil to the atmosphere, in significant amounts for the global carbon cycle. Soil capacity to produce CO2 varies depending on soil, season, intensity and quality of agrotechnical tillage, soil water, cultivated plant, fertilizer etc. The data presented in this paper were obtained on argic-stagnic Faeoziom (SRTS, 2003). These areas were was our research, presents a medium multiannual temperature of 8.20C, medium of multiannual rain drowns: 613 mm. The experimental variants chosen were: A. Conventional system (CS): V1-reversible plough (22-25 cm)+rotary grape (8-10 cm); B. Minimum tillage system (MT): V2 - paraplow (18-22 cm) + rotary grape (8-10 cm); V3 - chisel (18-22 cm) + rotary grape (8-10 cm);V4 - rotary grape (10-12 cm); C. No-Tillage systems (NT): V5 - direct sowing. The experimental design was a split-plot design with three replications. In one variant the area of a plot was 300 m2. The experimental variants were studied in the 3 years crop rotation: maize - soy-bean - autumn wheat. To soil respiration under different tillage practices, determinations were made for each crop in four vegetative stages (spring, 5-6 leaves, bean forming, harvest) using ACE Automated Soil CO2 Exchange System. Soil respiration varies throughout the year for all three crops of rotation, with a maximum in late spring (1383 to 2480 mmoli m-2s-1) and another in fall (2141 to 2350 mmoli m-2s-1). The determinations confirm the effect of soil tillage system on soil respiration, the daily average is lower at NT (315-1914 mmoli m-2s-1), followed by MT (318-2395 mmoli m-2s-1) and is higher in the CS (321-2480 mmol m-2s-1). Productions obtained at MT and NT don't have significant differences at wheat and are higher at soybean. The differences in crop yields are recorded at maize and can be a direct consequence of loosening, mineralization and intensive mobilization of soil fertility. Acknowledgments: This work was supported by CNCSIS

  17. Soil surface roughness decay in contrasting climates, tillage types and management systems

    Science.gov (United States)

    Vidal Vázquez, Eva; Bertol, Ildegardis; Tondello Barbosa, Fabricio; Paz-Ferreiro, Jorge

    2014-05-01

    results indicate that two or more parameters may be needed to characterize the spatial variability of the soil surface microrelief and to best describe the roughness decay in agricultural soils under the various climatic and anthropogenic conditions studied. Then, rates of soil surface roughness decay were used to evaluate the susceptibility to degradation of the soil surface under the main tillage ands management types studied. Finally the effects of soil surface roughness on soil losses and water losses under typical tillage and management systems of the two contrasting regions studied were outlined.

  18. Can conservation tillage reduce N2O emissions on cropland transitioning to organic vegetable production?

    Science.gov (United States)

    Chen, Guihua; Kolb, Lauren; Cavigelli, Michel A; Weil, Ray R; Hooks, Cerruti R R

    2018-03-15

    Nitrous oxide (N 2 O) is an important greenhouse gas and a catalyst of stratospheric ozone decay. Agricultural soils are the source of 75% of anthropogenic N 2 O emissions globally. Recently, significant attention has been directed at examining effects of conservation tillage on carbon sequestration in agricultural systems. However, limited knowledge is available regarding how these practices impact N 2 O emissions, especially for organic vegetable production systems. In this context, a three-year study was conducted in a well-drained sandy loam field transitioning to organic vegetable production in the Mid-Atlantic coastal plain of USA to investigate impacts of conservation tillage [strip till (ST) and no-till (NT)] and conventional tillage (CT) [with black plastic mulch (CT-BP) and bare-ground (CT-BG)] on N 2 O emissions. Each year, a winter cover crop mixture (forage radish: Raphanus sativus var. longipinnatus, crimson clover: Trifolium incarnatum L., and rye: Secale cereale L.) was grown and flail-mowed in the spring. Nearly 80% of annual N 2 O-nitrogen (N) emissions occurred during the vegetable growing season for all treatments. Annual N 2 O-N emissions were greater in CT-BP than in ST and NT, and greater in CT-BG than in NT, but not different between CT-BG and CT-BP, ST and NT, or CT-BG and ST. Conventional tillage promoted N mineralization and plastic mulch increased soil temperature, which contributed to greater N 2 O-N fluxes. Though water filled porosity in NT was higher and correlated well with N 2 O-N fluxes, annual N 2 O-N emissions were lowest in NT suggesting a lack of substrates for nitrification and denitrification processes. Crop yield was lowest in NT in Year 1 and CT-BP in Year 3 but yield-scaled N 2 O-N emissions were consistently greatest in CT-BP and lowest in NT each year. Our results suggest that for coarse-textured soils in the coastal plain with winter cover crops, conservation tillage practices may reduce N 2 O emissions in organic

  19. Catch crop biomass production, nitrogen uptake and root development under different tillage systems

    DEFF Research Database (Denmark)

    Munkholm, Lars Juhl; Hansen, Elly Møller

    2012-01-01

    tinctoria L.), perennial ryegrass (RG) (Lolium perenne L.) and fodder radish (FR) (Raphanus sativus L.) under three tillage systems. For that, we used a tillage experiment established in 2002 on a Danish sandy loam. The tillage treatments were direct drilling (D), harrowing to 8–10 cm (H) and ploughing (P...

  20. Quantifying the effect of seasonal and vertical habitat tracking on planktonic foraminifera proxies

    Directory of Open Access Journals (Sweden)

    L. Jonkers

    2017-06-01

    Full Text Available The composition of planktonic foraminiferal (PF calcite is routinely used to reconstruct climate variability. However, PF ecology leaves a large imprint on the proxy signal: seasonal and vertical habitats of PF species vary spatially, causing variable offsets from annual mean surface conditions recorded by sedimentary assemblages. PF seasonality changes with temperature in a way that minimises the environmental change that individual species experience and it is not unlikely that changes in depth habitat also result from such habitat tracking. While this behaviour could lead to an underestimation of spatial or temporal trends as well as of variability in proxy records, most palaeoceanographic studies are (implicitly based on the assumption of a constant habitat. Up to now, the effect of habitat tracking on foraminifera proxy records has not yet been formally quantified on a global scale. Here we attempt to characterise this effect on the amplitude of environmental change recorded in sedimentary PF using core top δ18O data from six species. We find that the offset from mean annual near-surface δ18O values varies with temperature, with PF δ18O indicating warmer than mean conditions in colder waters (on average by −0.1 ‰ (equivalent to 0.4 °C per °C, thus providing a first-order quantification of the degree of underestimation due to habitat tracking. We use an empirical model to estimate the contribution of seasonality to the observed difference between PF and annual mean δ18O and use the residual Δδ18O to assess trends in calcification depth. Our analysis indicates that given an observation-based model parametrisation calcification depth increases with temperature in all species and sensitivity analysis suggests that a temperature-related seasonal habitat adjustment is essential to explain the observed isotope signal. Habitat tracking can thus lead to a significant reduction in the amplitude of recorded environmental change

  1. Real-time TaqMan polymerase chain reaction to quantify the effects ...

    African Journals Online (AJOL)

    TaqMan polymerase chain reaction was developed to quantify the number of Bifidobacterium. We used this assay to detect genomic DNA of Bifidobacterium in the intestinal tract digesta of piglets, including duodenum, jejunum, ileum, cecum and colon. Our results indicated that, developed new real-time quantitative PCR ...

  2. N-utilization in non-inversion tillage systems

    DEFF Research Database (Denmark)

    Hansen, Elly Møller; Munkholm, Lars Juhl; Olesen, Jørgen E

    2011-01-01

    When changing from ploughing to non-inversion tillage, N rates are of particular importance both for farmers and the environment. A tillage and fertilizer experiment was established in Denmark under temperate coastal climatic conditions to evaluate the N fertilizer responses on yields and N uptake......–30 kg N ha−1 of the total fertilizer N amount in autumn to autumn-sown crops (1.00NAut). In all the crop rotations, straw was chopped and retained after harvest. Different types of N fertilizer responses were observed in the six crops, but generally yields were lower with non-inversion tillage than...... with ploughing. On two occasions, yields in ploughed plots were significantly (p able to offset the growth reduction, which resulted from poor growth in patches probably caused...

  3. Tillage practices and identity formation in High Plains farming

    DEFF Research Database (Denmark)

    Strand, Katherine; Arnould, Eric; Press, Melea

    2014-01-01

    farming, recognition and denunciation of other farmers’ practices, and recognition and justification of their own contribute to identity formation. This research contributes to the ongoing discussion of how identity is formed through day-to-day activities in the material world. The plow creates divisions...... landscape. Specifically, they compare conservation tillage wedded to ‘modern’ ideologies of scientific farming with conventional tillage newly linked to beliefs about both organic and traditional farming, and examine how farmers use these different forms of tillage to create their identities. Roadside...... in the High Plains community between organic farmers who continue to rely on this implement in their material engagement with the land and the chemical farmers who distance their practices from the plow as they distinguish themselves as stewards of the soil....

  4. Weed seed germination in winter cereals under contrasting tillage systems

    DEFF Research Database (Denmark)

    Scherner, Ananda

    2015-01-01

    to accumulate in the top soil layer and timing of herbicide applications sometimes seems to target the emergence pattern of these weeds poorly. In contrast to the management of most diseases and pests, weed management should be considered in a time frame. The abilities to produce above and below ground...... of weeds. An important component in IWM is to understand and ultimately predict weed emergence patterns in relation to the cropping system and the tillage method applied. A better understanding of the cumulative emergence patterns of weed species in winter crops under different tillage regimes will help......Grass weeds and Gallium aparine are major weed problems in North European arable cropping systems with high proportions of winter crops, especially winter wheat (Clarke et al., 2000; Melander et al., 2008). Problems are accentuated where inverting tillage is omitted, as weed seeds tend...

  5. [Analysis of soil respiration and influence factors in wheat farmland under conservation tillage in southwest hilly region].

    Science.gov (United States)

    Zhang, Sai; Zhang, Xiao-Yu; Wang, Long-Chang; Luo, Hai-Xiu; Zhou, Hang-Fei; Ma, Zhong-Lian; Zhang, Cui-Wei

    2013-07-01

    In order to investigate the effect of conservation tillage on soil respiration in dry cropping farmland in southwest purple hilly region, the LI6400-09 respiratory chamber was adopted in the experiment conducted in the experimental field in Southwest University in Beibei, Chongqing. The respiration and the hydrothermal and biotic factors of soil were measured and analyzed during the growth period of wheat in the triple intercropping system of wheat/maize/soybean. There were four treatments including T (traditional tillage), R (ridge tillage), TS (traditional tillage + straw mulching) and RS (ridge tillage + straw mulching), which were all in triplicates. The results indicated that the soil respiration rate changed in the range of 1.100-2.508 micromol x (m2 x s)(-1) during the reproductive growth stage of wheat. There were significant differences in soil respiration rate among different treatments, which could be ranked as RS > R > TS > T. The soil temperature in the 10cm layer was ranked as T > R > TS > RS. The relationship between soil respiration and soil temperature fitted well with an exponential function, in which the Q10 values were 1.25, 1.20, 1.31 and 1.26, respectively. The soil moisture in the 5cm layer was ranked as TS > RS > T > R. The best fitting model between soil moisture and soil respiration was a parabolic curve, indicating the presence of soil moisture with the strongest soil respiration. The response threshold of wheat to soil moisture was 14.80%-17.47% during the reproductive stage. The dominant groups of soil animals were Collembola and Acarina, which were correlated with soil respiration to some extent. The correlation was high in the treatments T and R, ranged from 0.669-0.921, whereas there was no remarkable correlation in the other treatments.

  6. Quantifying the Road-Effect Zone: Threshold Effects of a Motorway on Anuran Populations in Ontario, Canada

    Directory of Open Access Journals (Sweden)

    Felix Eigenbrod

    2009-06-01

    Full Text Available The negative effect of roads on wildlife is recognized as a major contributor to the global biodiversity crisis, with anurans being among the most vulnerable groups overall. The "road-effect zone," i.e., the extent of significant ecological effects from the edge of a road (Forman and Alexander 1998, has important management implications, but has never been quantified for anurans. In the first study of its kind, we measured the extent and type of relationship underlying the road-effect zones of a motorway with a high proportion of heavy-truck traffic, particularly at night (Highway 401 for anuran species richness and relative abundance. We surveyed 34 ponds located 68-3262 m from the edge of the motorway, and used piecewise and linear regressions to determine if road-effect zones were clearly delineated by ecological thresholds. We found road-effect zones of 250-1000 m delineated by ecological thresholds for four of seven species and species richness, and road-effect zones of well beyond 1000 m best described by linear regressions for two species. The negative effect of Highway 401 was unexpectedly strong for four of seven species suggest that, in addition to road mortality, very high nighttime truck traffic can actually lead to reduced use of breeding habitat near the motorway either by acting as a barrier to forest habitat on the other side of the highway and/or because of traffic noise. Our results show that most anurans are likely to have reduced abundances near motorways, but that both the extent of the effect of this type of road and the underlying relationship vary considerably between species. Furthermore, the noise and/or barrier effect of very high nighttime traffic volumes can lead to negative effects of motorways even on species that are relatively unaffected by direct road mortality.

  7. Three-Dimensional, Transgenic Cell Models to Quantify Space Genotoxic Effects

    Science.gov (United States)

    Gonda, S. R.; Sognier, M. A.; Wu, H.; Pingerelli, P. L.; Glickman, B. W.; Dawson, David L. (Technical Monitor)

    1999-01-01

    The space environment contains radiation and chemical agents known to be mutagenic and carcinogenic to humans. Additionally, microgravity is a complicating factor that may modify or synergize induced genotoxic effects. Most in vitro models fail to use human cells (making risk extrapolation to humans more difficult), overlook the dynamic effect of tissue intercellular interactions on genotoxic damage, and lack the sensitivity required to measure low-dose effects. Currently a need exists for a model test system that simulates cellular interactions present in tissue, and can be used to quantify genotoxic damage induced by low levels of radiation and chemicals, and extrapolate assessed risk to humans. A state-of-the-art, three-dimensional, multicellular tissue equivalent cell culture model will be presented. It consists of mammalian cells genetically engineered to contain multiple copies of defined target genes for genotoxic assessment,. NASA-designed bioreactors were used to coculture mammalian cells into spheroids, The cells used were human mammary epithelial cells (H184135) and Stratagene's (Austin, Texas) Big Blue(TM) Rat 2 lambda fibroblasts. The fibroblasts were genetically engineered to contain -a high-density target gene for mutagenesis (60 copies of lacl/LacZ per cell). Tissue equivalent spheroids were routinely produced by inoculation of 2 to 7 X 10(exp 5) fibroblasts with Cytodex 3 beads (150 micrometers in diameter). at a 20:1 cell:bead ratio, into 50-ml HARV bioreactors (Synthecon, Inc.). Fibroblasts were cultured for 5 days, an equivalent number of epithelial cells added, and the fibroblast/epithelial cell coculture continued for 21 days. Three-dimensional spheroids with diameters ranging from 400 to 600 micrometers were obtained. Histological and immunohistochemical Characterization revealed i) both cell types present in the spheroids, with fibroblasts located primarily in the center, surrounded by epithelial cells; ii) synthesis of extracellular matrix

  8. Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs

    OpenAIRE

    Taylor, Michael P.

    2014-01-01

    Attempts to reconstruct the neutral neck posture of sauropod dinosaurs, or indeed any tetrapod, are doomed to failure when based only on the geometry of the bony cervical vertebrae. The thickness of the articular cartilage between the centra of adjacent vertebrae affects posture. It extends (raises) the neck by an amount roughly proportional to the thickness of the cartilage. It is possible to quantify the angle of extension at an intervertebral joint: it is roughly equal, in radians, to the ...

  9. Efecto acumulativo de la siembra directa sobre algunas características del suelo en la región semiárida central de Argentina Long term effect of no-tillage on some soil properties in the central semiarid region of Argentina

    Directory of Open Access Journals (Sweden)

    Adriana Abril

    2005-12-01

    Full Text Available La siembra directa (SD es relativamente reciente en Argentina, por lo que existen escasas posibilidades de evaluar cambios a largo plazo. Además, la mayoría de los trabajos han sido realizados en la región húmeda pampeana siendo escasas las referencias para la zona semiárida central, a pesar de que el incremento de la cobertura de rastrojo es particularmente útil en suelos con limitante de agua. En este trabajo se evaluó el efecto de la SD a largo plazo (5 y 10 años sobre: a características químicas (MO, N total y NO3-N y biológicas (actividad y biomasa microbiana del suelo; y b cantidad, fracciones identificables y composición química del rastrojo en dos tipos de ensayos: monocultivo de soja y rotación soja-maíz. La investigación fue realizada en la Estación Experimental Agropecuaria INTA Manfredi en la región semi-árida central. Los suelos bajo siembra directa, presentaron mayor contenido de MO y N total que los suelos control (labranza conservacionista. Las diferencias observados se incrementaron con el tiempo (10% y 20% a los 5 y 10 años, respectivamente. El contenido de NO3-N, y la biomasa y actividad microbiana mostraron alta variabilidad en ambas fechas de muestreo en relación a las condiciones climáticas. La cobertura del rastrojo fue mayor en rotación maíz-soja con antecesor maíz (2.473,9 g m-2 que en el monocultivo de soja (1.035,7 g m-2. La fracción del rastrojo no identificable fue muy importante en todos los tratamientos (rangos entre 2-10 t ha-1, lo que favorecería la formación de nuevo suelo superficial. Estos resultados sugieren que la liberación de nutrientes a partir de un abundante rastrojo en descomposición puede constuir una importante fuente de nutrientes, por lo que debería incluirse en los cálculos para requerimientos de fertilización de los cultivos.Evaluation of the effect of crop residues accumulation on soil under no-tillage cultivation is difficult in Argentina because the relative

  10. YIELD OF MAIZE (ZEA MAYS L. ON DIFFERENT SOIL TILLAGE VARIANTS

    Directory of Open Access Journals (Sweden)

    Danijel Jug

    2006-12-01

    Full Text Available Reduced tillage, as well as the most reduced tillage – No-till – every year are becoming more important in our region. Unfortunately, the areas under reduced tillage are still very small. In order to establish optimal system of reduced soil tillage, the experimental trials were set on Chernozem soil type in northern Baranja during three vege¬tation seasons (1998/1999-2000/2001 and five soil tillage systems: CT Conventional Tillage (primary soil tillage by moldboard ploughing at 30-35 cm depth, DH Multiple Diskharrowing at 10-15 cm as primary tillage, CH Chiseling and diskharrowing (chiseling at 30-35 cm and diskharrowing at 10-15 cm as primary tillage, PD One diskharro-wing pass (diskharrowing at 10-15 cm as primary tillage, and NT No-tillage system. The highest yields were recor¬ded at CT with three-year average of 9.29 t/ha, followed by CH with 8.37 t/ha, DH with 8.07 t/ha, PD with 6.99 t/ha, whereas the lowest yields were recorded at NT treatment, with three-year average of 5.94 t/ha. The highest profit was achieved at CT treatment (665,34 HRK/ha, followed by CH (189,24 HRK/ha, DH (77,20 HRK/ha, PD (-334,95 HRK/ha and NT (-459,81 HRK/ha.

  11. Rationally Managed Pastures Stock More Carbon than No-Tillage Fields

    Directory of Open Access Journals (Sweden)

    Hizumi L. S. Seó

    2017-12-01

    Full Text Available A significant share of Greenhouse Gases (GHG produced from agriculture comes from cattle farming. The reduction in GHG emissions from ruminants fed with grains has led some researchers to recommend such a diet as a means of mitigating emissions in the sector. A more accurate balance of emissions, however, must include the carbon (C stocked by feed crops. Within the grain production system, no-tillage (NT cultivation systems have a greater capacity to increase and store soil organic carbon (SOC. Within grazing management systems, the rotation used in Voisin's Rational Grazing (VRG allows the accumulation of SOC through root growth. The objective of this study was to assess the C stock of pasture under VRG and compare soil C stock between VRG pasture and fields under no-tillage management, in two seasons over a period of 1 year. The study included five dairy farms in Santa Catarina State, Brazil. In each property, we collected soil to quantify SOC from VRG pasture and NT fields, in summer and winter. In the pasture, to determine the total stock, we also collected samples from the aerial parts of plants and the roots. Further, we estimated how efficient would be producing milk from those pastures or from those crops. The VRG pasture showed a greater capacity to stock C in the soil than the no-tillage fields (VRG = 115.0 Mg C ha−1; NT = 92.5 Mg C ha−1; p < 0.00009, with the greatest difference at a depth of 0–10 cm (VRG = 41 Mg C ha−1; NT = 32 Mg C ha−1; p < 0.00008. In VRG, 95% of C was in the soil, 1% in the aerial part of plants, and 4% in the roots. On pasture was produced 0.15 kg of milk.kg−1 of C stored, and on NT system 0.13 kg of milk.kg−1 of C stored. In this study, we conclude that independent of season, the soil in well managed pastures had a greater stock of C, produced more milk and produced more milk.kg−1 of stored C than fields under NT management. Therefore, when comparing GHG emissions of ruminants with different

  12. Developments in conservation tillage in rainfed regions of North China

    NARCIS (Netherlands)

    Wang, X.B.; Cai, D.X.; Hoogmoed, W.B.; Oenema, O.; Perdok, U.D.

    2007-01-01

    Dryland regions in northern China account for over 50% of the nation's total area, where farming development is constrained by adverse weather, topography and water resource conditions, low fertility soils, and poor soil management. Conservation tillage research and application in dryland regions of

  13. Phosphorus Uptake and Partitioning in Maize as Affected by Tillage ...

    African Journals Online (AJOL)

    Higher phosphorus concentrations were found in the ears than in the shoots and leaves at physiological maturity. Tillage x phospho-rus interactions influenced phosphorus partitioning in the ears and the leaves on the Dystric Cam-bisol but not on the Ferric Acrisol. PUE in the plant parts were significantly higher under ...

  14. Tillage as a driver of change in weed communities

    NARCIS (Netherlands)

    Armengot, L.; Blanco-Moreno, J.M.; Bàrberi, P.; Bocci, G.; Carlesi, S.; Aendekerk, R.; Berner, A.; Celette, F.; Grosse, M.; Huiting, H.; Kranzler, A.; Luik, A.; Mäder, P.; Peigné, J.; Stoll, E.; Delfosse, P.; Sukkel, W.; Surböck, A.; Westaway, S.; Sans, F.X.

    2016-01-01

    The adoption of non-inversion tillage practices has been widely promoted due to their potential benefits in reducing energy consumption and greenhouse emissions as well as improving soil fertility. However, the lack of soil inversion usually increases weed infestations and changes the composition

  15. Study of the aging processes in polyurethane adhesives using thermal treatment and differential calorimetric, dielectric, and mechanical techniques ; 1, identifying the aging processes ; 2, quantifying the aging effect

    CERN Document Server

    Althouse, L P

    1979-01-01

    Study of the aging processes in polyurethane adhesives using thermal treatment and differential calorimetric, dielectric, and mechanical techniques ; 1, identifying the aging processes ; 2, quantifying the aging effect

  16. The influence of reduced tillage on water regime and nutrient leaching in a loamy soil

    OpenAIRE

    Baigys, Giedrius; Gaigalis, Kazimieras; Kutra, Ginutis

    2006-01-01

    The effect of tillage technologies and terms on soil moisture regime and nitrate leaching was studied in field trials carried out on 0.76-1.36-ha fields. The study site was arranged in Pikeliai village (Kėdainiai district). The soil prevailing in the study site is Endocalcari - Endohypogleic Cambisol, sandy light loam and sandy loam on deeper layers of sandy loam and sandy light loam. The arable horizon contains sandy light loam, which is characteristic of the soils prevailing in the Middle L...

  17. ECONOMICS RESULTS OF WHEAT PRODUCTION BY DIFFERENT SOIL TILLAGE WAYS

    Directory of Open Access Journals (Sweden)

    J. Kanisek

    2001-06-01

    Full Text Available Wheat consumption in the world increases and its importers are some European countries too. The present price of wheat grain will make selling at the market difficult for manufactures from the Republic of Croatia. Conditions and results of four year organizational - economical investigations of conventional and four ways of reduced soil tillage at wheat production are displayed in this paper. Total of 9.35 hours/ha of machinery work and 114.3 l/ha of fuel are consumed at conventional soil tillage. Total costs are 1660 DM/ha. Price of grain is 276.71 DM/t and profit amounts to 187.83 DM/ha. If the soil tillage is done by a disk harrow costs of the machinery work reduce to 471.36 DM/ha and profitability amounts to 16.5%. When soil tillage is done by multitiller with classical sowing, a yield of 5.65 t/ha st price of 273.37 DM/t and investment profitability 12.7% are obtained. Direct sowing by a Rotosem, without previous tillage, requires 11.66 hours/ha of human work and 7.18 hours/ha of machinery work. to meet the total costs 4.9 t/ha of grains need. In order to get equipment, 98 t of grains from land of 17.5 ha should be given annually during the period of 8 years. Plughing and sowing by Rotosem give 5.9 t/ha grains at price of 279.36 DM/t. Total energy cost at conventional production is 30085 and at reduced one it is 27972 MJ/ha.

  18. Quantifying the potential effects of high-volume water extractions on water resources during natural gas development: Marcellus Shale, NY

    Directory of Open Access Journals (Sweden)

    Laura C. Best

    2014-07-01

    New hydrological insights for the region: The potential effects of the withdrawal scenarios on both the water table and stream discharge were quantified. Based on these impact results, locations in the aquifer and stream networks were identified, which demonstrate particular vulnerability to increased withdrawals and their distribution. These are the locations of importance for planners and regulators who oversee water permitting, to reach a sustainable management of the water resources under changing conditions of energy and corresponding water demand.

  19. The occurrence of fungi on the stem base and roots of spring wheat (Triticum aestivum L. grown in monoculture depending on tillage systems and catch crops

    Directory of Open Access Journals (Sweden)

    Piotr Kraska

    2012-12-01

    Full Text Available The present study was carried out in the period 2006-2008 based on an experiment established in 2005. The study evaluated the effect of conservation and plough tillage as well as of four catch crops on the level of infection by fungal pathogens of the stem base and roots of the spring wheat cultivar ‘Zebra’ grown in monoculture. The species composition of fungi colonizing the stem base and roots of spring wheat was determined. The split-plot design of the experiment set up on rendzina soil included plough tillage and conservation tillage with autumn and spring disking of catch crops. The experiment used four methods for regeneration of the spring wheat monoculture stand using the following: undersown red clover and Westerwolds ryegrass crops as well as lacy phacelia and white mustard stubble crops. Plots without catch crops were the control treatment. Red clover and Westerwolds ryegrass catch crops as well as lacy phacelia and white mustard stubble crops had a significant effect on the decrease in the stem base and root infection index of spring wheat compared to the control without catch crops. The disease indices in the tillage treatments under evaluation did not differ significantly from one another. The stem base and roots of spring wheat were most frequently infected by fungi of the genus Fusarium, with F. culmorum being the dominant pathogen of cereals. Compared to conservation tillage, in plough tillage the pathogenic fungus Bipolaris sorokiniana was not found to occur on the stem base and roots. The Westerwolds ryegrass catch crop promoted the occurrence of F. culmorum, both on the stem base and roots of spring wheat.

  20. Response of CH4 and N2O emissions and wheat yields to tillage method changes in the North China plain.

    Directory of Open Access Journals (Sweden)

    Shenzhong Tian

    Full Text Available The objective of this study was to quantify soil methane (CH(4 and nitrous oxide (N(2O emissions when converting from minimum and no-tillage systems to subsoiling (tilled soil to a depth of 40 cm to 45 cm in the North China Plain. The relationships between CH(4 and N(2O flux and soil temperature, moisture, NH(4 (+-N, organic carbon (SOC and pH were investigated over 18 months using a split-plot design. The soil absorption of CH(4 appeared to increase after conversion from no-tillage (NT to subsoiling (NTS, from harrow tillage (HT to subsoiling (HTS and from rotary tillage (RT to subsoiling (RTS. N(2O emissions also increased after conversion. Furthermore, after conversion to subsoiling, the combined global warming potential (GWP of CH(4 and N(2O increased by approximately 0.05 kg CO(2 ha(-1 for HTS, 0.02 kg CO(2 ha(-1 for RTS and 0.23 kg CO(2 ha(-1 for NTS. Soil temperature, moisture, SOC, NH(4 (+-N and pH also changed after conversion to subsoiling. These changes were correlated with CH(4 uptake and N(2O emissions. However, there was no significant correlation between N(2O emissions and soil temperature in this study. The grain yields of wheat improved after conversion to subsoiling. Under HTS, RTS and NTS, the average grain yield was elevated by approximately 42.5%, 27.8% and 60.3% respectively. Our findings indicate that RTS and HTS would be ideal rotation tillage systems to balance GWP decreases and grain yield improvements in the North China Plain region.

  1. Quantified, Interactive Simulation of AMCW ToF Camera Including Multipath Effects.

    Science.gov (United States)

    Bulczak, David; Lambers, Martin; Kolb, Andreas

    2017-12-22

    In the last decade, Time-of-Flight (ToF) range cameras have gained increasing popularity in robotics, automotive industry, and home entertainment. Despite technological developments, ToF cameras still suffer from error sources such as multipath interference or motion artifacts. Thus, simulation of ToF cameras, including these artifacts, is important to improve camera and algorithm development. This paper presents a physically-based, interactive simulation technique for amplitude modulated continuous wave (AMCW) ToF cameras, which, among other error sources, includes single bounce indirect multipath interference based on an enhanced image-space approach. The simulation accounts for physical units down to the charge level accumulated in sensor pixels. Furthermore, we present the first quantified comparison for ToF camera simulators. We present bidirectional reference distribution function (BRDF) measurements for selected, purchasable materials in the near-infrared (NIR) range, craft real and synthetic scenes out of these materials and quantitatively compare the range sensor data.

  2. A new approach to quantify the additional effect of primary overloads on ratcheting

    International Nuclear Information System (INIS)

    Waeckel, N.; Faure, O.; Sperandio, M.; Cousin, M.; Taleb, L.

    1991-01-01

    Taking into account the temporary nature of overloads reduces the conservatism of the current RCC-MR rules for prevention of ratcheting. An empirical K factor determined by the BITUBE tests carried out at INSA LYON, permits to quantify the influence of short-term mechanical overloads by comparison with the case without overload. The prediction of ratcheting risks by the RCC-MR efficiency diagram using a fictitious increased primary load by a K-factor is more fitted to the design of structures submitted to seisms. From then on, taking advantage of the workability of the experimental device BITUBE a new tests program has begun to confirm the results expressed above. (author)

  3. Quantifying voids effecting delamination in carbon/epoxy composites: static and fatigue fracture behavior

    Science.gov (United States)

    Hakim, I.; May, D.; Abo Ras, M.; Meyendorf, N.; Donaldson, S.

    2016-04-01

    On the present work, samples of carbon fiber/epoxy composites with different void levels were fabricated using hand layup vacuum bagging process by varying the pressure. Thermal nondestructive methods: thermal conductivity measurement, pulse thermography, pulse phase thermography and lock-in-thermography, and mechanical testing: modes I and II interlaminar fracture toughness were conducted. Comparing the parameters resulted from the thermal nondestructive testing revealed that voids lead to reductions in thermal properties in all directions of composites. The results of mode I and mode II interlaminar fracture toughness showed that voids lead to reductions in interlaminar fracture toughness. The parameters resulted from thermal nondestructive testing were correlated to the results of mode I and mode II interlaminar fracture toughness and voids were quantified.

  4. Efeito residual do calcário sob diferentes modos de incorporação antes da instalação do sistema plantio direto Residual effect of lime under different types of incorporation before the installation of a no-tillage system

    Directory of Open Access Journals (Sweden)

    Renato de M. Prado

    2003-12-01

    Full Text Available A incorporação profunda do calcário no solo na época de instalação do sistema plantio direto, pode apresentar efeito residual prolongado no perfil beneficiando as culturas. O objetivo deste trabalho foi testar o efeito residual do calcário sob diferentes modos de incorporação quanto à produção da soja no terceiro ano agrícola em sistema de plantio direto. Para isso, conduziu-se um experimento, utilizando um Latossolo Vermelho distrófico, textura argilosa, em Uberlândia, MG. O delineamento estatístico foi o de blocos casualizados, em parcela subdividida. Nas parcelas foram aplicados os modos de incorporação do calcário: grade aradora pesada (14 discos de 34 polegadas e grade niveladora (60 discos de 22 polegadas; modo tradicional, com arado de disco (4 discos de 26 polegadas e grade niveladora; grade aradora superpesada (14 discos de 34 polegadas e grade niveladora e nas subparcelas aplicaram-se calcário dolomítico, nas doses de 0, 6,0 e 9,2 t ha-1. A incorporação do calcário ocorreu em maio/1995, e nos anos agrícolas subseqüentes cultivou-se a aveia-preta (1995/96 e o milho (1996/97 em sistema plantio direto. Avaliou-se, então, no ano agrícola 1997/98, o efeito residual do calcário na produção da soja. O calcário incorporado em camadas profundas na ocasião da instalação do sistema plantio direto exerceu efeito residual positivo na produção da soja. O modo de incorporação mais eficiente do calcário foi com uso da grade aradora superpesada e o menos eficiente com a grade aradora pesada.The deep incorporation of the lime at the time of installation of the no-tillage system may present a residual effect in the soil benfitial for the crops. The present work was conducted to test the residual effect of limestone incorporation on the production of the soybeans. For this purpose, an experiment was conducted on a clay textured distrophic Red Latosol, in Uberlândia, MG. A completely randomized block design in a

  5. Conservation Tillage on the Loess Plateau, China: Food security, Yes; Carbon sequestration, No?

    Science.gov (United States)

    Kuhn, Nikolaus; Hu, Yaxian; Xiao, Liangang; Greenwood, Phil; Bloemertz, Lena

    2015-04-01

    of NT in increasing SOC stocks to reduce net CO2 emissions. 2) In each soil layer, the total SOC stocks also declined over time. Such a decreasing trend suggests that the SOC sink was approaching its maximum capacity. This implies that the overall potential of NT in improving SOC stocks is apt to be over-estimated, if annual increases derived from short-term observation are linearly extrapolated to a long-term estimation. 3) Yields of NT increased evidently by 11.07% compared to CT. In particular, during years with precipitation food production falling below minimum thresholds to meet subsistence requirements, thereby increasing resilience to famine. Overall, conservation tillage (no-till) has great potential in stabilizing crop yield and thus ensuring local subsistence requirements on the China Loess Plateau. However, the potential of NT to sequestrate SOC is limited than often reported and has maximum capacity, and thus cannot be linearly extrapolated to estimate its effects on mitigating climate change.

  6. Strip Tillage and Early-Season Broadleaf Weed Control in Seeded Onion (Allium cepa

    Directory of Open Access Journals (Sweden)

    Sarah Gegner-Kazmierczak

    2016-03-01

    Full Text Available Field experiments were conducted in 2007 and 2008 near Oakes, North Dakota (ND, USA, to evaluate if strip tillage could be incorporated into a production system of seeded onion (Allium cepa to eliminate the standard use of a barley (Hordeum vulgare companion crop with conventional, full width tillage, yet support common early-season weed control programs. A split-factor design was used with tillage (conventional and strip tillage as the main plot and herbicide treatments (bromoxynil, DCPA, oxyfluorfen, and pendimethalin as sub-plots. Neither tillage nor herbicide treatments affected onion stand counts. Common lambsquarters (Chenopodium album densities were lower in strip tillage compared to conventional tillage up to three weeks after the post-emergence applied herbicides. In general, micro-rate post-emergence herbicide treatments provided greater early-season broadleaf weed control than pre-emergence herbicide treatments. Onion yield and grade did not differ among herbicide treatments because the mid-season herbicide application provided sufficient control/suppression of the early-season weed escapes that these initial weed escapes did not impact onion yield or bulb diameter. In 2007, onion in the strip tillage treatment were larger in diameter resulting in greater total and marketable yields compared to conventional tillage. Marketable onion yield was 82.1 Mg ha−1 in strip tillage and 64.9 Mg ha−1 in conventional tillage. Results indicate that strip tillage use in direct-seeded onion production was beneficial, especially when growing conditions were conducive to higher yields and that the use of strip tillage in onion may provide an alternative to using a companion crop as it did not interfere with either early-season weed management system.

  7. Effects of different soil management practices on soil properties and microbial diversity

    Science.gov (United States)

    Gajda, Anna M.; Czyż, Ewa A.; Dexter, Anthony R.; Furtak, Karolina M.; Grządziel, Jarosław; Stanek-Tarkowska, Jadwiga

    2018-01-01

    The effects of different tillage systems on the properties and microbial diversity of an agricultural soil was investigated. In doing so, soil physical, chemical and biological properties were analysed in 2013-2015, on a long-term field experiment on a loamy sand at the IUNG-PIB Experimental Station in Grabów, Poland. Winter wheat was grown under two tillage treatments: conventional tillage using a mouldboard plough and traditional soil tillage equipment, and reduced tillage based on soil crushing-loosening equipment and a rigid-tine cultivator. Chopped wheat straw was used as a mulch on both treatments. Reduced tillage resulted in increased water content throughout the whole soil profile, in comparison with conventional tillage. Under reduced tillage, the content of readily dispersible clay was also reduced, and, therefore, soil stability was increased in the toplayers, compared with conventional tillage. In addition, the beneficial effects of reduced tillage were reflected in higher soil microbial activity as measured with dehydrogenases and hydrolysis of fluorescein diacetate, compared with conventional tillage. Moreover, the polimerase chain reaction - denaturing gradient gel electrophoresis analysis showed that soil under reduced till-age had greater diversity of microbial communities, compared with conventionally-tilled soil. Finally, reduced tillage increased organic matter content, stability in water and microbial diversity in the top layer of the soil.

  8. Disponibilidade de água do solo ao milho cultivado sob sistemas de semeadura direta e preparo convencional Water availability to maize plants cultivated under no-tillage and conventional tillage systems

    Directory of Open Access Journals (Sweden)

    Mirta Teresinha Petry

    2007-06-01

    Full Text Available O objetivo deste trabalho foi quantificar o armazenamento, a disponibilidade e a extração de água no solo por plantas de milho irrigadas e submetidas a déficit hídrico terminal, cultivadas sob sistema de semeadura direta e preparo convencional. Foram realizados dois experimentos durante os anos agrícolas de 1999/00 e 2000/01, em área experimental do Departamento de Engenharia Rural da Universidade Federal de Santa Maria. Utilizou-se o delineamento experimental inteiramente casualizado, fatorial, com quatro repetições. Foram utilizados dois manejos da água de irrigação (fator A: irrigado e déficit hídrico terminal (plantas de milho foram submetidas a déficit hídrico terminal a partir dos 27 dias após a emergência; e dois sistemas de cultivo (fator B: semeadura direta e preparo convencional. Nas parcelas irrigadas, irrigações foram feitas para elevar o conteúdo de água no solo ao limite superior de disponibilidade de água às plantas, sempre que a evapotranspiração máxima acumulada da cultura do milho atingia 25 mm. O conteúdo de água no solo foi medido em três leituras semanais, para determinação da extração de água pelas plantas e disponibilidade de água às plantas de milho. Os resultados indicaram que a disponibilidade de água às plantas de milho foi similar nos sistemas semeadura direta e preparo convencional, em ambos os anos agrícolas avaliados. Plantas de milho cultivadas em preparo convencional extraíram maior quantidade de água, em ambos os anos, em relação à semeadura direta.The aim objective of this study was to quantify the soil water storage, plant-available water and extraction of soil water by corn plants under irrigation and terminal drought. Plants were cultivated under no-tillage and conventional tillage systems. Two experiments were conducted in the 1999/00 and 2000/01 growing season on an experimental field of the Agricultural Engineering Department of the Federal University of Santa

  9. Evaporação da água na superfície do solo em sistemas de plantio direto e preparo convencional Soil surface water evaporation under no-tillage and conventional tillage systems

    Directory of Open Access Journals (Sweden)

    Genei Antonio Dalmago

    2010-08-01

    Full Text Available Este trabalho teve por objetivos quantificar a evaporação da água na superfície do solo, em plantio direto e em preparo convencional, e avaliar o uso de microlisímetros de pesagem para medir esse processo. As medições foram feitas em campo, nos verões de 2001/2002, 2002/2003 e 2004/2005, em experimentos irrigados e não irrigados. Utilizaram-se delineamentos inteiramente casualizados, com quatro repetições, cujos tratamentos consistiram de sistemas de manejo do solo – plantio direto e preparo convencional –, e a presença ou ausência de cultivo de milho. Mediu-se a evaporação diária durante períodos de secagem do solo, entre precipitações ou irrigações consecutivas. Em experimentos sem irrigação, a evaporação acumulada foi maior sob plantio direto, na maioria dos períodos de medição, independentemente da presença da lavoura de milho. Nos experimentos com irrigação, a evaporação não apresentou diferenças regulares entre sistemas de manejo de solo. Normalmente, no início dos períodos de medição, com dois a cinco dias de secagem do solo, a evaporação foi maior em solo sob preparo convencional, tendo-se tornado maior em plantio direto, no restante do período de secagem. O emprego de microlisímetros de pesagem é eficiente para medir a evaporação na superfície do solo.This work aimed to quantify the evaporation of water on the soil surface under no-tillage and conventional tillage systems, and to evaluate the microlysimeters use to measure this process. Measurements were performed in the field, during the summers of 2001/2002, 2002/2003 and 2004/2005, in experiments with and without irrigation. Completely randomized designs were used, with four repetitions. The treatments consisted of no-tillage and conventional soil tillage systems, in the presence or absence of corn cultivation. Evaporation was measured daily, during drying periods between precipitations and consecutive irrigations. Without

  10. Quantifying the effect of colony size and food distribution on harvester ant foraging.

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    Tatiana P Flanagan

    Full Text Available Desert seed-harvester ants, genus Pogonomyrmex, are central place foragers that search for resources collectively. We quantify how seed harvesters exploit the spatial distribution of seeds to improve their rate of seed collection. We find that foraging rates are significantly influenced by the clumpiness of experimental seed baits. Colonies collected seeds from larger piles faster than randomly distributed seeds. We developed a method to compare foraging rates on clumped versus random seeds across three Pogonomyrmex species that differ substantially in forager population size. The increase in foraging rate when food was clumped in larger piles was indistinguishable across the three species, suggesting that species with larger colonies are no better than species with smaller colonies at collecting clumped seeds. These findings contradict the theoretical expectation that larger groups are more efficient at exploiting clumped resources, thus contributing to our understanding of the importance of the spatial distribution of food sources and colony size for communication and organization in social insects.

  11. Quantifying the Effect of Macroeconomic and Social Factors on Illegal E-Waste Trade.

    Science.gov (United States)

    Efthymiou, Loukia; Mavragani, Amaryllis; Tsagarakis, Konstantinos P

    2016-08-05

    As illegal e-waste trade has been significantly growing over the course of the last few years, the consequences on human health and the environment demand immediate action on the part of the global community. Though it is argued that e-waste flows from developed to developing countries, this subject seems to be more complex than that, with a variety of studies suggesting that income per capita is not the only factor affecting the choice of regions that e-waste is illegally shipped to. How is a country's economic and social development associated with illegal e-waste trade? Is legislation an important factor? This paper aims at quantifying macroeconomic (per capita income and openness of economy) and social (human development and social progress) aspects, based on qualitative data on illegal e-waste trade routes, by examining the percentage differences in scorings in selected indicators for all known and suspected routes. The results show that illegal e-waste trade occurs from economically and socially developed regions to countries with significantly lower levels of overall development, with few exceptions, which could be attributed to the fact that several countries have loose regulations on e-waste trade, thus deeming them attractive for potential illegal activities.

  12. Quantified, Interactive Simulation of AMCW ToF Camera Including Multipath Effects

    Directory of Open Access Journals (Sweden)

    David Bulczak

    2017-12-01

    Full Text Available In the last decade, Time-of-Flight (ToF range cameras have gained increasing popularity in robotics, automotive industry, and home entertainment. Despite technological developments, ToF cameras still suffer from error sources such as multipath interference or motion artifacts. Thus, simulation of ToF cameras, including these artifacts, is important to improve camera and algorithm development. This paper presents a physically-based, interactive simulation technique for amplitude modulated continuous wave (AMCW ToF cameras, which, among other error sources, includes single bounce indirect multipath interference based on an enhanced image-space approach. The simulation accounts for physical units down to the charge level accumulated in sensor pixels. Furthermore, we present the first quantified comparison for ToF camera simulators. We present bidirectional reference distribution function (BRDF measurements for selected, purchasable materials in the near-infrared (NIR range, craft real and synthetic scenes out of these materials and quantitatively compare the range sensor data.

  13. Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs

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    Michael P. Taylor

    2014-12-01

    Full Text Available Attempts to reconstruct the neutral neck posture of sauropod dinosaurs, or indeed any tetrapod, are doomed to failure when based only on the geometry of the bony cervical vertebrae. The thickness of the articular cartilage between the centra of adjacent vertebrae affects posture. It extends (raises the neck by an amount roughly proportional to the thickness of the cartilage. It is possible to quantify the angle of extension at an intervertebral joint: it is roughly equal, in radians, to the cartilage thickness divided by the height of the zygapophyseal facets over the centre of rotation. Applying this formula to published measurements of well-known sauropod specimens suggests that if the thickness of cartilage were equal to 4.5%, 10% or 18% of centrum length, the neutral pose of the Apatosaurus louisae holotype CM 3018 would be extended by an average of 5.5, 11.8 or 21.2 degrees, respectively, at each intervertebral joint. For the Diplodocus carnegii holotype CM 84, the corresponding angles of additional extension are even greater: 8.4, 18.6 or 33.3 degrees. The cartilaginous neutral postures (CNPs calculated for 10% cartilage—the most reasonable estimate—appear outlandish. But it must be remembered that these would not have been the habitual life postures, because tetrapods habitually extend the base of their neck and flex the anterior part, yielding the distinctive S-curve most easily seen in birds.

  14. Quantifying the effect of intervertebral cartilage on neutral posture in the necks of sauropod dinosaurs.

    Science.gov (United States)

    Taylor, Michael P

    2014-01-01

    Attempts to reconstruct the neutral neck posture of sauropod dinosaurs, or indeed any tetrapod, are doomed to failure when based only on the geometry of the bony cervical vertebrae. The thickness of the articular cartilage between the centra of adjacent vertebrae affects posture. It extends (raises) the neck by an amount roughly proportional to the thickness of the cartilage. It is possible to quantify the angle of extension at an intervertebral joint: it is roughly equal, in radians, to the cartilage thickness divided by the height of the zygapophyseal facets over the centre of rotation. Applying this formula to published measurements of well-known sauropod specimens suggests that if the thickness of cartilage were equal to 4.5%, 10% or 18% of centrum length, the neutral pose of the Apatosaurus louisae holotype CM 3018 would be extended by an average of 5.5, 11.8 or 21.2 degrees, respectively, at each intervertebral joint. For the Diplodocus carnegii holotype CM 84, the corresponding angles of additional extension are even greater: 8.4, 18.6 or 33.3 degrees. The cartilaginous neutral postures (CNPs) calculated for 10% cartilage-the most reasonable estimate-appear outlandish. But it must be remembered that these would not have been the habitual life postures, because tetrapods habitually extend the base of their neck and flex the anterior part, yielding the distinctive S-curve most easily seen in birds.

  15. Nitrogen gas emissions and nitrate leaching dynamics under different tillage practices based on data synthesis and process-based modeling

    Science.gov (United States)

    Huang, Y.; Ren, W.; Tao, B.; Zhu, X.

    2017-12-01

    Nitrogen losses from the agroecosystems have been of great concern to global changes due to the effects on global warming and water pollution in the form of nitrogen gas emissions (e.g., N2O) and mineral nitrogen leaching (e.g., NO3-), respectively. Conservation tillage, particularly no-tillage (NT), may enhance soil carbon sequestration, soil aggregation and moisture; therefore it has the potential of promoting N2O emissions and reducing NO3- leaching, comparing with conventional tillage (CT). However, associated processes are significantly affected by various factors, such as soil properties, climate, and crop types. How tillage management practices affect nitrogen transformations and fluxes is still far from clear, with inconsistent even opposite results from previous studies. To fill this knowledge gap, we quantitatively investigated gaseous and leaching nitrogen losses from NT and CT agroecosystems based on data synthesis and an improved process-based agroecosystem model. Our preliminary results suggest that NT management is more efficient in reducing NO3- leaching, and meanwhile it simultaneously increases N2O emissions by approximately 10% compared with CT. The effects of NT on N2O emissions and NO3- leaching are highly influenced by the placement of nitrogen fertilizer and are more pronounced in humid climate conditions. The effect of crop types is a less dominant factor in determining N2O and NO3- losses. Both our data synthesis and process-based modeling suggest that the enhanced carbon sequestration capacity from NT could be largely compromised by relevant NT-induced increases in N2O emissions. This study provides the comprehensive quantitative assessment of NT on the nitrogen emissions and leaching in agroecosystems. It provides scientific information for identifying proper management practices for ensuring food security and minimizing the adverse environmental impacts. The results also underscore the importance of suitable nitrogen management in the NT

  16. Evaluation of Net Primary Productivity and Carbon Allocation to Different Parts of Corn in Different Tillage and Nutrient Management Systems

    Directory of Open Access Journals (Sweden)

    esmat mohammadi

    2017-09-01

    Full Text Available Evaluation of net primary productivity and carbon allocation to different organs of corn under nutrient management and tillage systems Introduction Agriculture operations produce 10 to 20 percent of greenhouse gases. As a result of conventional operations of agriculture, greenhouse gases have been increased (Osborne et al., 2010. Therefor it is necessary to notice to carbon sequestration to reduce greenhouse gases emissions. In photosynthesis process, plants absorb CO2 and large amounts of organic carbon accumulate in their organs. Biochar is produced of pyrolysis of organic compounds. Biochar is an appropriate compound for improved of soil properties and carbon sequestration (Whitman and Lehmann, 2009; Smith et al., 2010. Conservation tillage has become an important technology in sustainable agriculture due to its benefits. So the aim of this study was to evaluate the effect of nutrient management and tillage systems on net primary production and carbon allocation to different organs of corn in Shahrood. Material and methods This study was conducted at the Shahrood University of Technology research farm. Experiment was done as split plot in randomized complete block design with three replications. Tillage systems with two levels (conventional tillage and minimum tillage were as the main factor and nutrient management in seven levels including (control, chemical fertilizer, manure, biochar, chemical fertilizer + manure, chemical fertilizer + biochar, manure + biochar were considered as sub plot. At the time of maturity of corn, was sampled from its aboveground and belowground biomasses. Carbon content of shoot, seed and root was considered almost 45 percent of yield of each of these biomasses and carbon in root exudates almost 65 percent of carbon in the root. Statistical analysis of the data was performed using SAS program. Comparison of means was conducted with LSD test at the 5% level. Results and discussion Effect of nutrient management was

  17. Soil erosion measurements under organic and conventional land use treatments and different tillage systems using micro-scale runoff plots and a portable rainfall simulator

    Science.gov (United States)

    Seitz, Steffen; Goebes, Philipp; Song, Zhengshan; Wittwer, Raphaël; van der Heijden, Marcel; Scholten, Thomas

    2015-04-01

    Soil erosion is a major environmental problem of our time and negatively affects soil organic matter (SOM), aggregate stability or nutrient availability for instance. It is well known that agricultural practices have a severe influence on soil erosion by water. Several long-term field trials show that the use of low input strategies (e.g. organic farming) instead of conventional high-input farming systems leads to considerable changes of soil characteristics. Organic farming relies on crop rotation, absence of agrochemicals, green manure and weed control without herbicides. As a consequence, SOM content in the top soil layer is usually higher than on arable land under conventional use. Furthermore, the soil surface is better protected against particle detachment and overland flow due to a continuous vegetation cover and a well-developed root system increases soil stability. Likewise, tillage itself can cause soil erosion on arable land. In this respect, conservation and reduced tillage systems like No-Till or Ridge-Till provide a protecting cover from the previous year's residue and reduce soil disturbance. Many studies have been carried out on the effect of farming practices on soil erosion, but with contrasting results. To our knowledge, most of those studies rely on soil erosion models to calculate soil erosion rates and replicated experimental field measurement designs are rarely used. In this study, we performed direct field assessment on a farming system trial in Rümlang, Switzerland (FAST: Farming System and Tillage experiment Agroscope) to investigate the effect of organic farming practises and tillage systems on soil erosion. A portable single nozzle rainfall simulator and a light weight tent have been used with micro-scale runoff plots (0.4 m x 0.4 m). Four treatments (Conventional/Tillage, Conventional/No-Tillage, Organic/Tillage, Organic/Reduced-tillage) have been sampled with 8 replications each for a total of 32 runoff plots. All plots have been

  18. Using Poisson mixed-effects model to quantify transcript-level gene expression in RNA-Seq.

    Science.gov (United States)

    Hu, Ming; Zhu, Yu; Taylor, Jeremy M G; Liu, Jun S; Qin, Zhaohui S

    2012-01-01

    RNA sequencing (RNA-Seq) is a powerful new technology for mapping and quantifying transcriptomes using ultra high-throughput next-generation sequencing technologies. Using deep sequencing, gene expression levels of all transcripts including novel ones can be quantified digitally. Although extremely promising, the massive amounts of data generated by RNA-Seq, substantial biases and uncertainty in short read alignment pose challenges for data analysis. In particular, large base-specific variation and between-base dependence make simple approaches, such as those that use averaging to normalize RNA-Seq data and quantify gene expressions, ineffective. In this study, we propose a Poisson mixed-effects (POME) model to characterize base-level read coverage within each transcript. The underlying expression level is included as a key parameter in this model. Since the proposed model is capable of incorporating base-specific variation as well as between-base dependence that affect read coverage profile throughout the transcript, it can lead to improved quantification of the true underlying expression level. POME can be freely downloaded at http://www.stat.purdue.edu/~yuzhu/pome.html. yuzhu@purdue.edu; zhaohui.qin@emory.edu Supplementary data are available at Bioinformatics online.

  19. Quantifying the Effectiveness of Dose Individualization by Simulation for a Drug With Moderate Pharmacokinetic Variability.

    Science.gov (United States)

    Liefaard, Lia; Chen, Chao

    2015-10-01

    Dose individualization can reduce variability in exposure. The objective of this work was to quantify, through pharmacokinetic (PK) simulation, the potential for reducing the variability in exposure by dose individualization for a drug with moderate PK variability between subjects and between occasions within a subject, and a narrow therapeutic window. Using a population PK model that includes between-subject and between-occasion variability for apparent clearance, individual PK profiles in a trial of 300 subjects after a test dose were simulated. From the simulated data, datasets were created mimicking various sampling regimens (from single predose sample to full profile samples over 12 hours) on 1 or more occasions (1, 2, 3, 5, or 10 visits). Using these datasets, individual apparent clearance values were estimated, which were then used to calculate an individualized dose for a predefined target area under the concentration-time curve (AUC), based on the available formulation strengths. The proportion of people whose mean AUC was within a predefined therapeutic AUC range was calculated for the test (before) and the individualized dose (after), and compared between the different sampling scenarios. The maximum increase in proportion of subjects with an AUC within the range was 20%. To achieve this benefit, PK samples over 4 hours from 100 dosing occasions were required. As a result of the dose adjustment, the AUC of 7.3% of the subjects moved from inside the therapeutic range to outside of the range. This work shows how modeling and simulation can help assess the benefit and risk of dose individualization for a compound with variability between subjects and between occasions. The framework can be applied to similar situations with a defined set of conditions (eg, therapeutic window, tablet strengths, and PK and/or pharmacodynamic sampling scheme) to inform dose change and to assess the utility of dose individualization against certain success criteria.

  20. Soybean root growth and crop yield in reponse to liming at the beginning of a no-tillage system

    Directory of Open Access Journals (Sweden)

    Edson Campanhola Bortoluzzi

    2014-02-01

    Full Text Available Analyzing the soil near crop roots may reveal limitations to growth and yield even in a no-tillage system. The purpose of the present study was to relate the chemical and physical properties of soil under a no-tillage system to soybean root growth and plant yield after five years of use of different types of limestone and forms of application. A clayey Oxisol received application of dolomitic and calcitic limestones and their 1:1 combination in two forms: surface application, maintained on the soil surface; and incorporated, applied on the surface and incorporated mechanically. Soil physical properties (resistance to mechanical penetration, soil bulk density and soil aggregation, soil chemical properties (pH, exchangeable cations, H+Al, and cation exchange capacity and plant parameters (root growth system, soybean grain yield, and oat dry matter production were evaluated five years after setting up the experiment. Incorporation of lime neutralized exchangeable Al up to a depth of 20 cm without affecting the soil physical properties. The soybean root system reached depths of 40 cm or more with incorporated limestone, increasing grain yield an average of 31 % in relation to surface application, which limited the effect of lime up to a depth of 5 cm and root growth up to 20 cm. It was concluded that incorporation of limestone at the beginning of a no-tillage system ensures a favorable environment for root growth and soybean yield, while this intervention does not show long-term effects on soil physical properties under no-tillage. This suggests that there is resilience in the physical properties evaluated.

  1. Iron oxides dynamics in a subtropical Brazilian Paleudult under long-term no-tillage management

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    Alberto Vasconcellos Inda

    2013-02-01

    Full Text Available Replacing conventional tillage (CT with no-tillage (NT management alters the pedoenvironment and the rate of topsoil processes, with possible effects on dissolution processes associated with iron oxides and therefore soil mineralogy. This study aimed to determine the effect of NT on the content and distribution of types of iron oxides in a Rhodic Paleudult in southern Brazil. Soil samples were collected at eight depths within the 0.00-0.80 m layer under CT and NT in a long-term experiment (21 years. Mineralogical identification was conducted by X-ray diffraction (XRD, and the Fe content related to specific types of iron oxides determined by selective dissolution and diffuse-reflectance spectroscopy. Kaolinite, quartz, goethite, hematite, and maghemite were identified in the clay fraction. In the NT-managed soil, there was a decrease in the content of crystalline iron oxides and an increase in the content of poorly crystalline iron oxides with increasing proximity to the soil surface. These results suggest that iron oxides are rearranged in this soil by reductive dissolution of the crystalline types and neoformation of metastable ferrihydrite in topsoil layers, which should be assessed further in laboratory studies.

  2. Mechanized farming in the humid tropics with special reference to soil tillage, workability and timeliness of farm operations : a case study for the Zanderij area of Suriname

    NARCIS (Netherlands)

    Goense, D.

    1987-01-01

    The reported investigations concern aspects of mechanized farming for the production of rainfed crops on the loamy soils of the Zanderij formation in Suriname and in particular, the effect of tillage on crop yield and soil properties, workability of field operations and timeliness of field

  3. Use of nitrogen from fertilizer and cover crops by upland rice in an Oxisol under no-tillage in the Cerrado

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Edson Cabral da; Muraoka, Takashi; Bendassolli, Jose Alberto, E-mail: edsoncabralsilva@gmail.com, E-mail: muraoka@cena.usp.br, E-mail: jab@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franzini, Vinicius Ide, E-mail: vinicius.franzini@embrapa.br [Embrapa Amazonia Oriental, Belem, PA (Brazil); Sakadevan, Karuppan, E-mail: K.Sakadevan@iaea.org [Joint FAO/IAEA, Division of Nuclear Techniques in Food and Agriculture, Soil and Water Management and Crop Nutrition Subprogram, Vienna International Centre, Vienna (Austria); Buzetti, Salatier; Arf, Orivaldo, E-mail: sbuzetti@agr.feis.unesp.br, E-mail: arf@agr.feis.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Ilha Solteira, SP (Brazil). Faculdade de Engenharia; Soares, Frederico Antonio Loureiro, E-mail: fredalsoares@hotmail.com [Instituto Federal Goiano, Rio Verde, GO (Brazil)

    2016-06-15

    The objective of this work was to evaluate the effects of cover crops on the yield of upland rice (Oryza sativa) grown under no-tillage system, in the presence and absence of N fertilizer, as well as to quantify, in the field, the use efficiency of N from urea and cover crops by upland rice, through the {sup 15}N isotope dilution technique. The field experiment was carried out in the municipality of Selviria, in the state of Mato Grosso do Sul, Brazil, in an Oxisol (Rhodic Hapludox) in the Cerrado (Brazilian savanna) region. The experimental design was a randomized complete block with 15 treatments and four replicates, in a 5 x 3 factorial arrangement. The treatments were four cover crops (Crotalaria juncea, Cajanus cajan, Mucuna pruriens, and Pennisetum glaucum) + spontaneous vegetation (fallow in off-season), combined with three forms of N fertilization: control treatment, without N fertilizer application; 20 kg ha{sup -1} N at sowing; and 20 kg ha{sup -1} N at sowing plus 60 kg ha{sup -1} N as topdressing. Rice is not affected by N fertilizer application as topdressing, when legume cover crops are used. The use of legume cover crops provides higher grain yield and use of fertilizer-N by rice than that of millet or fallow. Legume cover crops promote an effect equivalent to that of the application of 60 kg ha{sup -1} N as urea on rice yield. (author)

  4. Use of nitrogen from fertilizer and cover crops by upland rice in an Oxisol under no-tillage in the Cerrado

    International Nuclear Information System (INIS)

    Silva, Edson Cabral da; Muraoka, Takashi; Bendassolli, Jose Alberto; Franzini, Vinicius Ide; Sakadevan, Karuppan; Buzetti, Salatier; Arf, Orivaldo

    2016-01-01

    The objective of this work was to evaluate the effects of cover crops on the yield of upland rice (Oryza sativa) grown under no-tillage system, in the presence and absence of N fertilizer, as well as to quantify, in the field, the use efficiency of N from urea and cover crops by upland rice, through the 15 N isotope dilution technique. The field experiment was carried out in the municipality of Selviria, in the state of Mato Grosso do Sul, Brazil, in an Oxisol (Rhodic Hapludox) in the Cerrado (Brazilian savanna) region. The experimental design was a randomized complete block with 15 treatments and four replicates, in a 5 x 3 factorial arrangement. The treatments were four cover crops (Crotalaria juncea, Cajanus cajan, Mucuna pruriens, and Pennisetum glaucum) + spontaneous vegetation (fallow in off-season), combined with three forms of N fertilization: control treatment, without N fertilizer application; 20 kg ha -1 N at sowing; and 20 kg ha -1 N at sowing plus 60 kg ha -1 N as topdressing. Rice is not affected by N fertilizer application as topdressing, when legume cover crops are used. The use of legume cover crops provides higher grain yield and use of fertilizer-N by rice than that of millet or fallow. Legume cover crops promote an effect equivalent to that of the application of 60 kg ha -1 N as urea on rice yield. (author)

  5. Tillage and residue burning affects weed populations and seed banks.

    Science.gov (United States)

    Narwal, S; Sindel, B M; Jessop, R S

    2006-01-01

    An integrated weed management approach requires alternative management practices to herbicide use such as tillage, crop rotations and cultural controls to reduce soil weed seed banks. The objective of this study was to examine the value of different tillage practices and stubble burning to exhaust the seed bank of common weeds from the northern grain region of Australia. Five tillage and burning treatments were incorporated in a field experiment, at Armidale (30 degrees 30'S, 151 degrees 40'E), New South Wales, Australia in July 2004 in a randomized block design replicated four times. The trial was continued and treatments repeated in July 2005 with all the mature plants from the first year being allowed to shed seed in their respective treatment plots. The treatments were (i) no tillage (NT), (ii) chisel ploughing (CP), (iii) mould board ploughing (MBP), (iv) wheat straw burning with no tillage (SBNT) and (v) wheat straw burning with chisel ploughing (SBC). Soil samples were collected before applying treatments and before the weeds flowered to establish the seed bank status of the various weeds in the soil. Wheat was sown after the tillage treatments. Burning treatments were only initiated in the second year, one month prior to tillage treatments. The major weeds present in the seed bank before initiating the trial were Polygonum aviculare, Sonchus oleraceus and Avena fatua. Tillage promoted the germination of other weeds like Hibiscus trionum, Medicago sativa, Vicia sp. and Phalaris paradoxa later in the season in 2004 and Convolvulus erubescens emerged as a new weed in 2005. The MBP treatment in 2004 reduced the weed biomass to a significantly lower level of 55 g/m2 than the other treatments of CP (118 g/m2) and NT plots (196 g/m2) (P < 0.05). However, in 2005 SBC and MBP treatments were similar in reducing the weed biomass. In 2004, the grain yield trend of wheat was significantly different between CP and NT, and MBP and NT (P < 0.05) with maximum yield of 5898

  6. Planning soil tillage using quality function deployment (QFD

    Directory of Open Access Journals (Sweden)

    Milan Marcos

    2003-01-01

    Full Text Available The Brazilian forest sector represents about 4% of gross domestic product (GDP which is correspondent to US$ 21.0 billion. The natural forest area is approximately 4.8 million hectares and for the near future there will be a need to increase the planted area. To avoid or minimize the impact of mechanized practices on forest soils, the reduced tillage has been developed. The aim of this work is to define the technical priorities of the reduced tillage for eucalyptus seedlings, using quality function deployment (QDF. The design requirements classified as the most important to attend seedling demands were the furrow width and depth, and clod sizes. QFD has the potential to be applied to agro-forestry systems to translate plant demands into technical requirements.

  7. Tillage practices in the conterminous United States, 1989-2004-Datasets Aggregated by Watershed

    Science.gov (United States)

    Baker, Nancy T.

    2011-01-01

    This report documents the methods used to aggregate county-level tillage practices to the 8-digit hydrologic unit (HU) watershed. The original county-level data were collected by the Conservation Technology Information Center (CTIC). The CTIC collects tillage data by conducting surveys about tillage systems for all counties in the United States. Tillage systems include three types of conservation tillage (no-till, ridge-till, and mulch-till), reduced tillage, and intensive tillage. Total planted acreage for each tillage practice for each crop grown is reported to the CTIC. The dataset includes total planted acreage by tillage type for selected crops (corn, cotton, grain sorghum, soybeans, fallow, forage, newly established permanent pasture, spring and fall seeded small grains, and 'other' crops) for 1989-2004. Two tabular datasets, based on the 1992 enhanced and 2001 National Land Cover Data (NLCD), are provided as part of this report and include the land-cover area-weighted interpolation and aggregation of acreage for each tillage practice in each 8-digit HU watershed in the conterminous United States for each crop. Watershed aggregations were done by overlying the 8-digit HU polygons with a raster of county boundaries and a raster of either the enhanced 1992 or the 2001 NLCD for cultivated land to derive a county/land-cover area weighting factor. The weighting factor then was applied to the county-level tillage data for the counties within each 8-digit HU and summed to yield the total acreage of each tillage type within each 8-digit HU watershed.

  8. Assessment of tillage systems in organic farming: influence of soil structure on microbial biomass. First results

    OpenAIRE

    Vian, Jean François; Peigné, Joséphine; Chaussod, Rémi; Roger-Estrade, Jean

    2007-01-01

    Soil tillage modifies environmental conditions of soil microorganisms and their ability to release nitrogen. We compare the influence of reduced tillage (RT) and mouldboard ploughing (MP) on the soil microbial functioning in organic farming. In order to connect soil structure generated by these tillage systems on the soil microbial biomass we adopt a particular sampling scheme based on the morphological characterisation of the soil structure by the description of the soil profile. This method...

  9. Reduced tillage and green manures for sustainable cropping systems - Overview of the TILMAN-ORG project

    OpenAIRE

    Mäder, Paul

    2013-01-01

    Reduced tillage and green manures are environmentally friendly practices that increase levels of soil organic matter and biological activity, improve soil stability, and reduce fuel consumption and may mitigate the climate impact of crop production. The avoidance of deep ploughing is successfully practiced as no-tillage agriculture in conventional farming systems. However, these no-tillage systems rely on herbicides for weed control and mineral fertilisers for plant nutrients. As these inputs...

  10. Efeito de pastagens de inverno e de verão em características físicas de solo sob plantio direto Effect of annual winter and summer pastures on soil physical characteristics, under no-tillage

    Directory of Open Access Journals (Sweden)

    Silvio Tulio Spera

    2006-08-01

    Full Text Available Algumas características físicas de solo foram avaliadas após sete anos (1995 a 2001, num Latossolo Vermelho Distrófico, em Coxilha, RS, em seis sistemas de produção de grãos integrados com pastagens anuais de inverno e de verão e em floresta subtropical. As culturas, tanto de inverno como de verão, foram estabelecidas sob plantio direto. Mediante contrastes, foram comparados os valores das características físicas do solo em cada sistema nas camadas 0-0,05 e 0,10-0,15m. Nos sistemas I e II e na floresta, a densidade de solo e a resistência à penetração foram maiores na camada superficial em relação à camada mais profunda. No sistema II, porosidade total e microporosidade foram menores na camada superficial. O mesmo comportamento das características foi verificado na floresta subtropical para porosidade total e microporosidade. A floresta apresentou densidade de solo e resistência à penetração menores do que a maioria dos sistemas estudados em ambas as camadas, indicando que o solo, sob manejo antrópico, pode sofrer alterações nas características físicas. Os solos sob diferentes sistemas de produção, integrando lavoura e pecuária, apesar de apresentarem indícios de desestruturação, não atingiram níveis considerados críticos.Soil physical characteristics were evaluated, after seven years (1995 to 2001, on a typical Dystrophic Red Latosol located in Coxilha, State of Rio Grande do Sul, Brazil. Six systems integrating crop production with livestock and a subtropical forest were evaluated. Both winter and summer crops were seeded under no-tillage. Cropping systems and soil of different sampling depths were compared using the contrast procedure. In the I and II sistems and in the forest, the soil density and the resistance to penetration increased in the top layer (0-0,05m concerning the deeper layer (0,10-0,15m. In the II system, total porosity and microporosity decreased in the surface. In the subtropical forest

  11. Conventional tillage decreases the abundance and biomass of earthworms and alters their community structure in a global meta-analysis.

    Science.gov (United States)

    Briones, María Jesús I; Schmidt, Olaf

    2017-10-01

    The adoption of less intensive soil cultivation practices is expected to increase earthworm populations and their contributions to ecosystem functioning. However, conflicting results have been reported on the effects of tillage intensity on earthworm populations, attributed in narrative reviews to site-dependent differences in soil properties, climatic conditions and agronomic operations (e.g. fertilization, residue management and chemical crop protection). We present a quantitative review based on a global meta-analysis, using paired observations from 165 publications performed over 65 years (1950-2016) across 40 countries on five continents, to elucidate this long-standing unresolved issue. Results showed that disturbing the soil less (e.g. no-tillage and conservation agriculture [CA]) significantly increased earthworm abundance (mean increase of 137% and 127%, respectively) and biomass (196% and 101%, respectively) compared to when the soil is inverted by conventional ploughing. Earthworm population responses were more pronounced when the soil had been under reduced tillage (RT) for a long time (>10 years), in warm temperate zones with fine-textured soils, and in soils with higher clay contents (>35%) and low pH (earthworm population responses to RT. Additional meta-analyses confirmed that epigeic and, more importantly, the bigger-sized anecic earthworms were the most sensitive ecological groups to conventional tillage. In particular, the deep burrower Lumbricus terrestris exhibited the strongest positive response to RT, increasing in abundance by 124% more than the overall mean of all 13 species analysed individually. The restoration of these two important ecological groups of earthworms and their burrowing, feeding and casting activities under various forms of RT will ensure the provision of ecosystem functions such as soil structure maintenance and nutrient cycling by "nature's plough." © 2017 John Wiley & Sons Ltd.

  12. Quantifying the effects of promoting smokeless tobacco as a harm reduction strategy in the USA.

    Science.gov (United States)

    Mejia, Adrienne B; Ling, Pamela M; Glantz, Stanton A

    2010-08-01

    Snus (a form of smokeless tobacco) is less dangerous than cigarettes. Some health professionals argue that snus should be promoted as a component of a harm reduction strategy, while others oppose this approach. Major US tobacco companies (RJ Reynolds and Philip Morris) are marketing snus products as cigarette brand line extensions. The population effects of smokeless tobacco promotion will depend on the combined effects of changes in individual risk with population changes in tobacco use patterns. To quantitatively evaluate the health impact of smokeless tobacco promotion as part of a harm reduction strategy in the US. A Monte Carlo simulation of a decision tree model of tobacco initiation and use was used to estimate the health effects associated with five different patterns of increased smokeless tobacco use. With cigarette smoking having a health effect of 100, the base case scenario (based on current US prevalence rates) yields a total health effect of 24.2 (5% to 95% interval 21.7 to 26.5) and the aggressive smokeless promotion (less cigarette use and increased smokeless, health-concerned smokers switching to snus, smokers in smokefree environments switching to snus) was associated with a health effect of 30.4 (5% to 95% interval 25.9 to 35.2). The anticipated health effects for additional scenarios with lower rates of smokeless uptake also overlapped with the base case. Promoting smokeless tobacco as a safer alternative to cigarettes is unlikely to result in substantial health benefits at a population level.

  13. The Role of Government Policies in the Adoption of Conservation Tillage in China: A Theoretical Model

    Science.gov (United States)

    Ding, Ya

    2018-01-01

    In recent years, many areas of China have been facing increasing problems of soil erosion and land degradation. Conservation tillage, with both economic and ecological benefits, provides a good avenue for Chinese farmers to conserve land as well as secure food production. However, the adoption rate of conservation tillage systems is very low in China. In this paper, the author constructs a theoretical model to explain a farmer’s adoption decision of conservation tillage. The goal is to investigate potential reasons behind the low adoption rate and explores alternative policy tools that can help improve a farmer’s incentive to adopt conservation tillage in China.

  14. Performance of super hybrid rice cultivars grown under no-tillage and direct seeding

    Directory of Open Access Journals (Sweden)

    Min Huang

    2012-04-01

    Full Text Available Good progress has been made in the super hybrid rice (Oryza sativa L. breeding in China. However, rice yield not only depends on the genetic characteristics but also on the agronomic practices. No-tillage and direct seeding (NTDS is a simplified cultivation technology that greatly simplifies both land preparation and crop establishment. Aiming to determine the grain yield performance of super hybrid rice under NTDS and to identify critical factors that determine grain yield, field experiments were conducted in Nanxian, Hunan Province, China in 2009 and 2010. Two super hybrid cultivars, Liangyoupeijiu and Y-liangyou 1, were grown under conventional tillage and transplanting (CTTP and NTDS. Grain yield, yield components, biomass production, crop growth rate and biomass accumulation during sowing to heading (HD and HD to maturity were measured for each cultivar. There was no difference in grain yield under NTDS and CTTP. However, grain yield differed with cultivar and year. Y-liangyou 1 produced 4 % higher grain yield than Liangyoupeijiu in 2009, whereas in 2010 both cultivars yielded similarly. Grain yields of both cultivars were higher in 2009 than in 2010. Higher grain yield of Y-liangyou 1 in 2009 was associated with higher spikelet filling (spikelet filling percentage and grain weight, which resulted from higher biomass production. Crop growth rate after HD was critical for biomass production by the super hybrid rice. We suggest that increasing the crop growth rate after HD is an effective approach to increase grain yield of super hybrid rice under NTDS.

  15. Surface water ponding on clayey soils managed by conventional and conservation tillage in boreal conditions

    Directory of Open Access Journals (Sweden)

    L. ALAKUKKU

    2008-12-01

    Full Text Available Surface water ponding and crop hampering due to soil wetness was monitored in order to evaluate the effects of conservation tillage practices and perennial grass cover on soil infiltrability for five years in situ in gently sloping clayey fields. Thirteen experimental areas, each having three experimental fields, were established in southern Finland. The fields belonged to: autumn mouldboard ploughing (AP, conservation tillage (CT and perennial grass in the crop rotation (PG. In the third year, direct drilled (DD fields were established in five areas. Excluding PG, mainly spring cereals were grown in the fields. Location and surface area of ponded water (in the spring and autumn as well as hampered crop growth (during June-July were determined in each field by using GPS devices and GIS programs. Surface water ponding or crop hampering occurred when the amount of rainfall was clearly greater than the long-term average. The mean of the relative area of the ponded surface water, indicating the risk of surface runoff, and hampered crop growth was larger in the CT fields than in the AP fields. The differences between means were, however, not statistically significant. Complementary soil physical measurements are required to investigate the reasons for the repeated surface water ponding.;

  16. Rotavirus vaccine and diarrhea mortality: quantifying regional variation in effect size

    OpenAIRE

    Fischer Walker, Christa L; Black, Robert E

    2011-01-01

    Abstract Background Diarrhea mortality remains a leading cause of child death and rotavirus vaccine an effective tool for preventing severe rotavirus diarrhea. New data suggest vaccine efficacy may vary by region. Methods We reviewed published vaccine efficacy trials to estimate a regional-specific effect of vaccine efficacy on severe rotavirus diarrhea and hospitalizations. We assessed the quality of evidence using a standard protocol and conducted meta-analyses where more than 1 data point ...

  17. Quantifying effects of biodiversity on ecosystem functioning across times and places†

    Science.gov (United States)

    Isbell, Forest; Cowles, Jane; Dee, Laura E.; Loreau, Michel; Reich, Peter B.; Gonzalez, Andrew; Hector, Andy; Schmid, Bernhard

    2018-01-01

    Biodiversity loss decreases ecosystem functioning at the local scales at which species interact, but it remains unclear how biodiversity loss affects ecosystem functioning at the larger scales of space and time that are most relevant to biodiversity conservation and policy. Theory predicts that additional insurance effects of biodiversity on ecosystem functioning could emerge across time and space if species respond asynchronously to environmental variation and if species become increasingly dominant when and where they are most productive. Even if only a few dominant species maintain ecosystem functioning within a particular time and place, ecosystem functioning may be enhanced by many different species across many times and places (β-diversity). Here, we develop and apply a new approach to estimate these previously unquantified insurance effects of biodiversity on ecosystem functioning that arise due to species turnover across times and places. In a long-term (18-year) grassland plant diversity experiment, we find that total insurance effects are positive in sign and substantial in magnitude, amounting to 19% of the net biodiversity effect, mostly due to temporal insurance effects. Species loss can therefore reduce ecosystem functioning both locally and by eliminating species that would otherwise enhance ecosystem functioning across temporally fluctuating and spatially heterogeneous environments. PMID:29493062

  18. Rotavirus vaccine and diarrhea mortality: quantifying regional variation in effect size

    Directory of Open Access Journals (Sweden)

    Black Robert E

    2011-04-01

    Full Text Available Abstract Background Diarrhea mortality remains a leading cause of child death and rotavirus vaccine an effective tool for preventing severe rotavirus diarrhea. New data suggest vaccine efficacy may vary by region. Methods We reviewed published vaccine efficacy trials to estimate a regional-specific effect of vaccine efficacy on severe rotavirus diarrhea and hospitalizations. We assessed the quality of evidence using a standard protocol and conducted meta-analyses where more than 1 data point was available. Results Rotavirus vaccine prevented severe rotavirus episodes in all regions; 81% of episodes in Latin America, 42.7% of episodes in high-mortality Asia, 50% of episodes in sub-Saharan Africa, 88% of episodes low-mortality Asia and North Africa, and 91% of episodes in developed countries. The effect sizes observed for preventing severe rotavirus diarrhea will be used in LiST as the effect size for rotavirus vaccine on rotavirus-specific diarrhea mortality. Conclusions Vaccine trials have not measured the effect of vaccine on diarrhea mortality. The overall quality of the evidence and consistency observed across studies suggests that estimating mortality based on a severe morbidity reduction is highly plausible.

  19. Crop sequences in no-tillage system: effects on soil fertility and soybean, maize and rice yield Sequências de culturas em semeadura direta: efeitos sobre a fertilidade do solo e a produtividade de soja, milho e arroz

    Directory of Open Access Journals (Sweden)

    Adolfo Valente Marcelo

    2009-04-01

    Full Text Available Decomposing crop residues in no-tillage system can alter soil chemical properties, which may consequently influence the productivity of succession crops. The objective of this study was to evaluate soil chemical properties and soybean, maize and rice yield, grown in the summer, after winter crops in a no-tillage system. The experiment was carried out in Jaboticabal, SP, Brazil (21 ° 15 ' 22 '' S; 48 ° 18 ' 58 '' W on a Red Latosol (Oxisol, in a completely randomized block design, in strip plots with three replications. The treatments consisted of four summer crop sequences (maize monocrop, soybean monocrop, soybean/maize rotation and rice/bean/cotton rotation combined with seven winter crops (maize, sunflower, oilseed radish, pearl millet, pigeon pea, grain sorghum and sunn hemp. The experiment began in September 2002. After the winter crops in the 2005/2006 growing season and before the sowing of summer crops in the 2006/2007 season, soil samples were collected in the layers 0-2.5; 2.5-5.0; 5-10; 10-20; and 20-30 cm. Organic matter, pH, P, K+, Ca2+, Mg2+, and H + Al were determined in each soil sample. In the summer soybean/maize rotation and in maize the organic matter contents and P levels were lower, in the layers 0-10 cm and 0-20 cm, respectively. Summer rice/bean/cotton rotation increased soil K levels at 0-10 cm depth when sunn hemp and oilseed radish had previously been grown in the winter, and in the 0-2.5 cm layer for millet. Sunn hemp, millet, oilseed radish and sorghum grown in the winter increased organic matter contents in the soil down to 30 cm. Higher P levels were found at the depths 0-2.5 cm and 0-5 cm, respectively, when sunn hemp and oilseed radish were grown in the winter. Highest grain yields for soybean in monoculture were obtained in succession to winter oilseed radish and sunn hemp and in rotation with maize, after oilseed radish, sunn hemp and millet. Maize yields were highest in succession to winter oilseed radish

  20. Quantifying small molecule phenotypic effects using mitochondrial morpho-functional fingerprinting and machine learning

    Science.gov (United States)

    Blanchet, Lionel; Smeitink, Jan A. M.; van Emst-de Vries, Sjenet E.; Vogels, Caroline; Pellegrini, Mina; Jonckheere, An I.; Rodenburg, Richard J. T.; Buydens, Lutgarde M. C.; Beyrath, Julien; Willems, Peter H. G. M.; Koopman, Werner J. H.

    2015-01-01

    In primary fibroblasts from Leigh Syndrome (LS) patients, isolated mitochondrial complex I deficiency is associated with increased reactive oxygen species levels and mitochondrial morpho-functional changes. Empirical evidence suggests these aberrations constitute linked therapeutic targets for small chemical molecules. However, the latter generally induce multiple subtle effects, meaning that in vitro potency analysis or single-parameter high-throughput cell screening are of limited use to identify these molecules. We combine automated image quantification and artificial intelligence to discriminate between primary fibroblasts of a healthy individual and a LS patient based upon their mitochondrial morpho-functional phenotype. We then evaluate the effects of newly developed Trolox variants in LS patient cells. This revealed that Trolox ornithylamide hydrochloride best counterbalanced mitochondrial morpho-functional aberrations, effectively scavenged ROS and increased the maximal activity of mitochondrial complexes I, IV and citrate synthase. Our results suggest that Trolox-derived antioxidants are promising candidates in therapy development for human mitochondrial disorders.

  1. The Weeds Response to the Winter Vetch (Vicia villosa and Chicklingpea (Lathyrus sativus Cover Crops under Different Tillage Methods in Corn Fields

    Directory of Open Access Journals (Sweden)

    Javad Hamzei

    2017-01-01

    Full Text Available Introduction: Using cover crops in conservation tillage systems offers many advantages, one of which is weed control through physical and chemical interferences. Most of the benefits of cover crops are well known. They prevent form wind and water erosions, conserve soil moisture by reducing evaporation and increasing infiltration, increase the content of organic matter, increase fertility by recycling nutrients, add nitrogen if they are legumes, and improve soil structure. Proper cover crops can also suppress weed growth by allelopathic activities and light interference. They impact on environmental quality through the protection of surface water and groundwater, as well as eliminating the need for using preemergence herbicides. Either increase or decreases have been reported for crop yields when the crop residues remain on soil surface. No-till system has been reported to increase the presence of certain difficult to control weeds. Therefore, the aim of this study was to investigate the effect of tillage systems and cover crops on weed control and corn yield. Materials and Methods: Experiment was carried out as split plot based on randomized complete block design with three replications at the Bu-Ali Sina University in growing season of 2011. Tillage with moldboard, tillage with chisel (minimum tillage, and no tillage were considered as main plots and two cover crops, winter vetch and chicklingpea, chemical weed control and weed-infest treatment (control were considered as sub-plots. Cover crops were cultivated in late March 2011. In early June 2011, cover crops were harvested and were spread over the soil surface. The Plot size was 22.50 m-2. Five rows were in each plot with 75 cm intervals among rows and 18 cm among seedlings. 2 square were picked in the three central rows of each plot in order to determine the yield and yield components. From each plot three quadrants (1×1 mrandomly were picked and weeds and cover crops was separated. All

  2. Quantifying the effect of squirt flow dispersion from compliant clay porosity in clay bearing sandstones

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne; Fabricius, Ida Lykke

    2013-01-01

    Compliant porosity in the form of cracks is known to cause significant attenuation and velocity dispersion through pore pressure gradients and consequent relaxation, dubbed squirt flow. Squirt flow from cracks vanish at high confining stress due to crack closing. Studies on clay bearing sandstones......-squirt flow on the bulk modulus of a clay bearing sandstone. The predicted magnitude of the clay-squirt effect on the bulk modulus is compared with experimental data. The clay-squirt effect is found to possibly account for a significant portion of the deviances from Gassmann fluid substitution in claybearing...... sandstones....

  3. Quantifying the motion of magnetic particles in excised tissue: Effect of particle properties and applied magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, Sandip, E-mail: sandip.d.kulkarni@gmail.com [Fischell Department of Bioengineering, University of Maryland at College Park, MD 20742 (United States); Ramaswamy, Bharath; Horton, Emily; Gangapuram, Sruthi [Fischell Department of Bioengineering, University of Maryland at College Park, MD 20742 (United States); Nacev, Alek [Weinberg Medical Physics, LLC (United States); Depireux, Didier [The Institute for Systems Research, University of Maryland at College Park, MD 20742 (United States); Otomagnetics, LLC (United States); Shimoji, Mika [Fischell Department of Bioengineering, University of Maryland at College Park, MD 20742 (United States); Otomagnetics, LLC (United States); Shapiro, Benjamin [Fischell Department of Bioengineering, University of Maryland at College Park, MD 20742 (United States); The Institute for Systems Research, University of Maryland at College Park, MD 20742 (United States); Otomagnetics, LLC (United States)

    2015-11-01

    This article presents a method to investigate how magnetic particle characteristics affect their motion inside tissues under the influence of an applied magnetic field. Particles are placed on top of freshly excised tissue samples, a calibrated magnetic field is applied by a magnet underneath each tissue sample, and we image and quantify particle penetration depth by quantitative metrics to assess how particle sizes, their surface coatings, and tissue resistance affect particle motion. Using this method, we tested available fluorescent particles from Chemicell of four sizes (100 nm, 300 nm, 500 nm, and 1 μm diameter) with four different coatings (starch, chitosan, lipid, and PEG/P) and quantified their motion through freshly excised rat liver, kidney, and brain tissues. In broad terms, we found that the applied magnetic field moved chitosan particles most effectively through all three tissue types (as compared to starch, lipid, and PEG/P coated particles). However, the relationship between particle properties and their resulting motion was found to be complex. Hence, it will likely require substantial further study to elucidate the nuances of transport mechanisms and to select and engineer optimal particle properties to enable the most effective transport through various tissue types under applied magnetic fields.

  4. A comparative analysis to quantify the biogeochemical and biogeophysical cooling effects on climate of a white mustard cover crop

    Science.gov (United States)

    Ferlicoq, Morgan; Ceschia, Eric; Brut, Aurore; Tallec, Tiphaine; Carrer, Dominique; Pique, Gaetan; Ferroni, Nicole

    2017-04-01

    During the COP21, agriculture was recognised as a strategic sector and an opportunity to strengthen climate mitigation. In particular, the "4 per 1000" initiative relies upon solutions that refer to agro-ecology, conservation agriculture, … that could lead to increase carbon storage. Among those agro-ecology practices, including cover crops during fallow periods is considered as a fundamental agronomic lever for storing carbon. However, if biogeochemical benefits of cover-crops (CC) have already been addressed, their biogeophysical effects on climate have never been quantified and compared to biogeochemical effects. This comparative study (CC vs. bare soil), quantified and compared biogeochemical (including carbon storage) and biophysical effects (albedo and energy partitioning effect) of CC on climate. An experimental campaign was performed in 2013 in Southwest France, during the fallow period following a winter-wheat crop (and before a maize). The experimental plot was divided in two: the northern part was maintained in bare soil (BS) while white-mustard (WM) was grown during 3-months on the southern part. On each subplot, continuous measurements of CO2, latent and sensible fluxes (by eddy covariance) and solar radiation were acquired. Also, N2O emissions were measured by means of automatic chambers on each subplots. Moreover, by using a Life-Cycle-Analysis approach, each component of the greenhouse gas budget (GHGB) was quantified for each subplot, including emissions associated to field operations (FO). To quantify the albedo induced radiative forcing (RFα) caused by the white-mustard, the bare soil subplot was used as a reference state (IPCC, 2007). Finally, the net radiative forcing for each subplot was calculated as the sum of biogeochemical and biogeophysical (albedo effect) radiative forcing. The white-mustard allowed a net CO2 fixation of 63 g C-eq.m-2, corresponding to 20% of the net annual CO2 flux that year (-332 g C-eq.m-2). Through the WM seeds

  5. Estimating required information size by quantifying diversity in random-effects model meta-analyses

    DEFF Research Database (Denmark)

    Wetterslev, Jørn; Thorlund, Kristian; Brok, Jesper

    2009-01-01

    an intervention effect suggested by trials with low-risk of bias. METHODS: Information size calculations need to consider the total model variance in a meta-analysis to control type I and type II errors. Here, we derive an adjusting factor for the required information size under any random-effects model meta......-analysis. RESULTS: We devise a measure of diversity (D2) in a meta-analysis, which is the relative variance reduction when the meta-analysis model is changed from a random-effects into a fixed-effect model. D2 is the percentage that the between-trial variability constitutes of the sum of the between...... and interpreted using several simulations and clinical examples. In addition we show mathematically that diversity is equal to or greater than inconsistency, that is D2 >or= I2, for all meta-analyses. CONCLUSION: We conclude that D2 seems a better alternative than I2 to consider model variation in any random...

  6. A Computational Model Quantifies the Effect of Anatomical Variability on Velopharyngeal Function

    Science.gov (United States)

    Inouye, Joshua M.; Perry, Jamie L.; Lin, Kant Y.; Blemker, Silvia S.

    2015-01-01

    Purpose: This study predicted the effects of velopharyngeal (VP) anatomical parameters on VP function to provide a greater understanding of speech mechanics and aid in the treatment of speech disorders. Method: We created a computational model of the VP mechanism using dimensions obtained from magnetic resonance imaging measurements of 10 healthy…

  7. Tuning and Quantifying Steric and Electronic Effects of N-Heterocyclic Carbenes

    KAUST Repository

    Falivene, Laura; Poater, Albert; Cavallo, Luigi

    2014-01-01

    This chapter states that the main handles for tuning steric and electronic effects are the substituents on N atoms, the nature of the C4-C5 bridge (either saturated or unsaturated), and the substituents on the C4 and C5 atoms. The initial intuition

  8. Quantifying the effect of fuel reduction treatments on fire behavior in boreal forests

    Science.gov (United States)

    B.W. Butler; R.D. Ottmar; T.S. Rupp; R. Jandt; E. Miller; K. Howard; R. Schmoll; S. Theisen; R.E. Vihnanek; D. Jimenez

    2013-01-01

    Mechanical (e.g., shearblading) and manual (e.g., thinning) fuel treatments have become the preferred strategy of many fire managers and agencies for reducing fire hazard in boreal forests. This study attempts to characterize the effectiveness of four fuel treatments through direct measurement of fire intensity and forest floor consumption during a single prescribed...

  9. Quantifying flooding effects on har