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1

Recycling of crop residues for sustainable crop production in a wheat-peanut rotation system  

International Nuclear Information System (INIS)

Field experiments were conducted in a sandy soil at west Samalout, Minia, Egypt, from December 1996 to October 1999. The main objectives were (i) to examine long-term effects of applications of crop residues on crop nutrition, yields and soil fertility; (ii) to improve process-level understanding of nutrient flows through the use of isotopic techniques, and (iii) to enhance the efficiency of use of nutrients by a wheat-peanut rotation system. There were four treatments: (i) T1, 15N-labelled (NH4)2SO4, 60 kg N/ha at 9.82% 15N with unlabelled residues; (ii) T2, 15N-labelled wheat residues, 26 kg N/ha at 1.94% 15N a.e, applied at the end of the first season; (iii) T3, to generate unlabelled residues and yield; and (iv) T4, 15N-labelled (NH4)2SO4, 60 kg N/ha at 9.82% 15N atom excess, applied at the beginning of the first season, without residues. The Ndff recoveries during the first season in treatments T1 and T4 were 27% and 26% respectively, while 25% of the 15N remained in the soil for T1 and T4. Thus, the total amounts of 15N accounted for (in plant and soil) were 51% for T1 and 50% for T4. After the second crop, the total 15N recovery was 25% and 13% for T1 and T4, respectively. Application of the crop residues seemed to decrease N losses from the soil. Values for %N derived from labelled residues (%Ndfr) %N derived from labelled residues (%Ndfr) by wheat (T2) were 1.0% and 0.4% during seasons 3 and 5, respectively, while recoveries of %Ndfr by peanut from T2 treatments were 3.7, 4.1 and 0.3 during seasons 2, 4 and 6, respectively. In the following five seasons (peanut-wheat-peanut-wheat-peanut), total 15N recoveries by plant and soil were 67, 54, 34, 25 and 16%, respectively. (author)

2

[Nutrient management strategy of paddy rice-upland crop rotation system].  

Science.gov (United States)

Paddy rice-upland crop rotation system is a major cropping system in China, and practiced widely along the Yangtze River basin. A unique feature of this system is the annual conversion of soil from aerobic to anaerobic and then back to aerobic condition, which can result in the changes of soil physical, chemical, and biological prosperities among seasons, making a special agroecosystem. The major challenges faced by this system include declining or stagnating productivity, increasing shortage of irrigation water, improper management of nutrients, low efficiency of resource utilization, and environmental pollution. Based on an overview of the characteristics and problems of paddy rice-upland crop rotation system, this paper put forward a strategy of practicing integrated nutrient management to solve the contradictions between nutrient input, crop production and environmental risk. The key points of this strategy included nutrient management from the whole rotation system perspective, integrated use of nutrients from various sources (chemical fertilizers, organic fertilizers, and nutrients from the environment), synchronization of nutrient supply and crop nutrient demand, application of different management technologies based on the characteristics of different nutrient resources, and integration of nutrient management with other cropping system technologies like water saving and high-yielding cultivation, etc. PMID:18472447

Fan, Ming-Sheng; Jiang, Rong-Feng; Zhang, Fu-Suo; Lü, Shi-Hua; Liu, Xue-Jun

2008-02-01

3

Diversity of segetal weeds in pea (Pisum sativum L. depending on crops chosen for a crop rotation system  

Directory of Open Access Journals (Sweden)

Full Text Available This study, lasting from 1999 to 2006, was conducted at the Research Station in Tomaszkowo, which belongs to the University of Warmia and Mazury in Olsztyn. The experiment was set up on brown rusty soil classified as good rye complex 5 in the Polish soil valuation system. The analysis comprised weeds in fields sown with pea cultivated in two four-field crop rotation systems with a different first crop: A. potato – spring barley – pea – spring barley; B. mixture of spring barley with pea – spring barley – pea – spring barley. Every year, at the 2–3 true leaf stage of pea, the species composition and density of individual weed species were determined; in addition, before harvesting the main crop, the dry matter of weeds was weighed. The results were used to analyze the constancy of weed taxa, species diversity, and the evenness and dominance indices, to determine the relationships between all biological indicators analyzed and weather conditions, and to calculate the indices of similarity, in terms of species composition, density and biomass of weeds, between the crop rotations compared.The species richness, density and biomass of weeds in fields with field pea were not differentiated by the choice of the initial crop in a given rotation system. In the spring, the total number of identified taxa was 28 and it increased to 36 before the harvest of pea plants. Chenopodium album and Echinochloa crus-galli were the most numerous. Chenopodium album, Echinochloa crus-galli, Sonchus arvensis, Fallopia convolvulus and Viola arvensis were constant in all treatments, regardless of what the first crop in rotation was or when the observations were made.The species diversity and the evenness and species dominance indices varied significantly between years and dates of observations. Species diversity calculated on the basis of the density of weed species was higher in the rotation with a mixture of cereals and legumes, while that calculated on the basis of weed biomass was higher in the system with potato. The similarity indices, which express the convergence of floristic composition as well as of the density and biomass of weeds growing in pea fields in the two crop rotation systems compared, were within a broad range (42–86%. The biodiversity of weed communities was more closely correlated to total precipitation than to air temperature.

Marta K. Kostrzewska

2014-04-01

4

Evaluation of soil quality indicators in paddy soils under different crop rotation systems  

Science.gov (United States)

Evaluation of soil quality indicators in paddy soils under different crop rotation systems Soil quality, by definition, reflects the capacity to sustain plant and animal productivity, maintain or enhance water and air quality, and promote plant and animal health. Soil quality assessment is an essential issue in soil management for agriculture and natural resource protection. This study was conducted to detect the effects of four crop rotation systems (rice-rice-rice, soya-rice-rice, fallow-rice and pea-soya-rice) on soil quality indicators (soil moisture, porosity, bulk density, water-filled pore space, pH, extractable P, CEC, OC, OM, microbial respiration, active carbon) in paddy soils of Verona area, Northern Italy. Four adjacent plots which managed almost similarly, over five years were selected. Surface soil samples were collected from each four rotation systems in four times, during growing season. Each soil sample was a composite of sub-samples taken from 3 points within 350 m2 of agricultural land. A total of 48 samples were air-dried and passed through 2mm sieve, for some chemical, biological, and physical measurements. Statistical analysis was done using SPSS. Statistical results revealed that frequency distribution of most data was normal. The lowest CV% was related to pH. Analysis of variance (ANOVA) and comparison test showed that there are significant differences in soil quality indicators among crop rotation systems and sampling times. Results of multivariable regression analysis revealed that soil respiration had positively correlation coefficient with soil organic matter, soil moisture and cation exchange capacity. Overall results indicated that the rice rotation with legumes such as bean and soybean improved soil quality over a long time in comparison to rice-fallow rotation, and this is reflected in rice yield. Keywords: Soil quality, Crop Rotation System, Paddy Soils, Italy

Nadimi-Goki, Mandana; Bini, Claudio; Haefele, Stephan; Abooei, Monireh

2013-04-01

5

The response to P-Derived from phosphate rock and TSP by crops grown in a simulated crop rotation system  

International Nuclear Information System (INIS)

The response to P-Derived from phosphate rock and TSP by crops grown in a simulated crop rotation system. A green house experiment was carried out on a simulated crop rotation system of upland rice-soybean-mungbean to determine the effect of P-derived from different phosphate rock (PR) sources and TPS using 12P. The data obtained reveal that all the P-sources has a significant effect on the growth of all the there crops, expressed in dry weight, % P-total and total P-uptake (mg P pot-1). For the P-source it was shown that % P-derived from PR/TSP and their uptake (mg P pot-1) was quite high, showing that the PRs applied were of good reactivity. The residue of the PRs has also still a good effect on plant growth than that of TSP. The efficiency of PRs was far below that of TSP. This apparently was due to the high rate of application, ten times the rate of TSP

6

The Response to P-Derived from Phosphate Rock and TSP by Crops Grown in a Simulated Crop Rotation System  

International Nuclear Information System (INIS)

A green house experiment was carried out on a simulated crop rotation system of upland rice-soybean-mungbean to determine the effect of P-derived from different phosphate rock (PR) sources and TSP using 32P. The data obtained reveal that all the P-sources has a significant effect on the growth of all the three crops, expressed in dry weight, % P-total and total P-uptake (mg P pot-1). For the P-source it was shown that % P-derived from PR/TSP and their uptake (mg P pot-1) was quite high, showing that the PRs applied were of good reactivity. The residue of the PRs has also still a good effect on plant growth than that of TSP. The efficiency of PRs was far below that of TSP. This apparently was due to the high rate of application, ten times the rate of TSP. (author)

7

Energy crops in rotation. A review  

Energy Technology Data Exchange (ETDEWEB)

The area under energy crops has increased tenfold over the last 10 years, and there is large consensus that the demand for energy crops will further increase rapidly to cover several millions of hectares in the near future. Information about rotational systems and effects of energy crops should be therefore given top priority. Literature is poor and fragmentary on this topic, especially about rotations in which all crops are exclusively dedicated to energy end uses. Well-planned crop rotations, as compared to continuous monoculture systems, can be expected to reduce the dependence on external inputs through promoting nutrient cycling efficiency, effective use of natural resources, especially water, maintenance of the long-term productivity of the land, control of diseases and pests, and consequently increasing crop yields and sustainability of production systems. The result of all these advantages is widely known as crop sequencing effect, which is due to the additional and positive consequences on soil physical-chemical and biological properties arising from specific crops grown in the same field year after year. In this context, the present review discusses the potential of several rotations with energy crops and their possibilities of being included alongside traditional agriculture systems across different agro-climatic zones within the European Union. Possible rotations dedicated exclusively to the production of biomass for bioenergy are also discussed, as rotations including only energy crops could become common around bio-refineries or power plants. Such rotations, however, show some limitations related to the control of diseases and to the narrow range of available species with high production potential that could be included in a rotation of such characteristics. The information on best-known energy crops such as rapeseed (Brassica napus) and sunflower (Helianthus annuus) suggests that conventional crops can benefit from the introduction of energy crops in the rotation; furthermore, a considerable number of lesser-known energy crops such as biomass sorghum (Sorghum spp.), hemp (Cannabis sativa), kenaf (Hibiscus cannabinus), Ethiopian mustard (Brassica carinata) could be expected to lead to even greater benefits according to literature. Therefore, this review aimed at systematizing and reorganizing the existing and fragmentary information on these crops while stressing major knowledge gaps to be urgently investigated. (author)

Zegada-Lizarazu, Walter; Monti, Andrea [Department of Agroenvironmental Science and Technology, University of Bologna, Viale G. Fanin, 44 - 40127, Bologna (Italy)

2011-01-15

8

A systematic representation of crop rotations.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Crop rotations are allocations by growers of crop types to specific fields through time. This paper aims at presenting (i) a systematic and rigorous mathematical representation of crops rotations; and (ii) a concise mathematical framework to model crop rotations, which is useable on landscape scale modelling of agronomical practices. Rotations can be defined as temporal arrangements of crops and can be classified systematically according to their internal variability and cyc...

Castellazzi, M. S.; Wood, G. A.; Burgess, Paul J.; Morris, Joe; Conrad, K. F.; Perry, J. N.

2008-01-01

9

Short rotation Wood Crops Program  

Energy Technology Data Exchange (ETDEWEB)

This report synthesizes the technical progress of research projects in the Short Rotation Woody Crops Program for the year ending September 30, 1989. The primary goal of this research program, sponsored by the US Department of Energy's Biofuels and Municipal Waste Technology Division, is the development of a viable technology for producing renewable feedstocks for conversion to biofuels. One of the more significant accomplishments was the documentation that short-rotation woody crops total delivered costs could be $40/Mg or less under optimistic but attainable conditions. By taking advantage of federal subsidies such as those offered under the Conservation Reserve Program, wood energy feedstock costs could be lower. Genetic improvement studies are broadening species performance within geographic regions and under less-than-optimum site conditions. Advances in physiological research are identifying key characteristics of species productivity and response to nutrient applications. Recent developments utilizing biotechnology have achieved success in cell and tissue culture, somaclonal variation, and gene-insertion studies. Productivity gains have been realized with advanced cultural studies of spacing, coppice, and mixed-species trials. 8 figs., 20 tabs.

Wright, L.L.; Ehrenshaft, A.R.

1990-08-01

10

Short Rotation Crops in the United States  

Energy Technology Data Exchange (ETDEWEB)

The report is based primarily on the results of survey questions sent to approximately 60 woody and 20 herbaceous crop researchers in the United States and on information from the U.S. Department of Energy?s Bioenergy Feedstock Development Program. Responses were received from 13 individuals involved in woody crops research or industrial commercialization (with 5 of the responses coming from industry). Responses were received from 11 individuals involved in herbaceous crop research. Opinions on market incentives, technical and non-technical barriers, and highest priority research and development areas are summarized in the text. Details on research activities of the survey responders are provided as appendices to the paper. Woody crops grown as single-stem systems (primarily Populus and Eucalyptus species) are perceived to have strong pulp fiber and oriented strand board markets, and the survey responders anticipated that energy will comprise 25% or less of the utilization of single-stem short-rotation woody crops between now and 2010. The only exception was a response from California where a substantial biomass energy market does currently exist. Willows (Salix species) are only being developed for energy and only in one part of the United States at present. Responses from herbaceous crop researchers suggested frustration that markets (including biomass energy markets) do not currently exist for the crop, and it was the perception of many that federal incentives will be needed to create such markets. In all crops, responses indicate that a wide variety of research and development activities are needed to enhance the yields and profitability of the crops. Ongoing research activities funded by the U.S. Department of Energy?s Bioenergy Feedstock Development Program are described in an appendix to the paper.

Wright, L.L.

1998-06-04

11

7 CFR 205.205 - Crop rotation practice standard.  

Science.gov (United States)

...false Crop rotation practice standard. 205.205...Inspections, Marketing Practices), DEPARTMENT OF AGRICULTURE...205 Crop rotation practice standard. The producer...sod, cover crops, green manure crops, and...b) Provide for pest management in annual and...

2010-01-01

12

Maize response to different straw management and tillage systems under cereal crop rotation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of this study was to determine the effect of various straw management and tillage systems on the emergence, grain yield and cob characteristics of maize (Zea mays L.) under different cereal rotations on two soils (Orthic Luvisols) of loamy sand and sandy loam textures. The study was conducted in 1999, 2002 and 2003 in a micro-plot (1x1 m) experiment. Concrete walls, 120 cm deep, separated each plot of 1x1 m (five replicates). Straw management systems included: removed straw (RS) and l...

Biskupski, A.; Wa?…a?‚odek, S.; Lipiec, J.; Pabin, J.

2006-01-01

13

Agroforestry systems in northern Vietnam with Tephrosia candida as an alternative to short-fallow crop rotations  

Energy Technology Data Exchange (ETDEWEB)

Tephrosia candida was experimentally tested on-farm as an improved fallow species (TepFa), in hedgerows, (TepAl) and in a mulch transfer system (TepMu) in an upland rice (Oryza sativa) system on sloping land in northern Vietnam during the period 1996-1999. The objectives of this study were: (1) to investigate whether the existing monocropping (Mono) and short-fallow crop rotations (NaFa) are sustainable systems with respect to soil erosion and concomitant nutrient losses; (2) to determine whether agroforestry systems with Tephrosia (TepFa, TepAl, TepMu) can improve nutrient cycling and nutrient balances, for instance by preventing nutrient losses through erosion, as well as sustaining upland rice yields. A criteria system, including soil and nutrient losses, nutrient balances, changes of P-available pools, returns on labour and farmers' response, was used for comparing the systems tested. Only TepFa gave a positive input-output balance for both P and N. TepFa increased soil N and seemed to positively affect the release of soil labile P. However, the cost of Tephrosia seeds made the Net Present Value (NPV) of the Tephrosia fallow crop rotation system negative. TepMu increased upland rice yield by 50% compared to Mono. As a result, NPV was positive and sufficient rice for one more person could be produced per ha and year. However, the yield increase could cause a depletion of plant-available P, and the timing for pruning and mulching activities coincided with the farming activities in paddy fields. TepAl increased soil N, gave a neutral overall effect on crop yield but a negative NPV. NaFa gave a positive and highest NPV. In general, TepFa and TepMu were shown to increase crop yield per hectare with acceptable returns on labour and also to do better than Mono and NaFa with respect to preventing soil and nutrient losses through erosion. Recommendations are made for further research to focus on alternatives to maintain soil P, mechanisms of P pool reallocation and adoption potentials of the Tephrosia systems tested.

Hoang Fagerstroem, M.H. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Soil Sciences

2000-07-01

14

Regulation of Population Densities of Heterodera cajani and Other Plant-Parasitic Nematodes by Crop Rotations on Vertisols, in Semi-Arid Tropical Production Systems in India.  

Science.gov (United States)

The significance of double crop (intercrop and sequential crop), single crop (rainy season crop fallow from June to September), and rotations on densities of Heterodera cajani, Helicotylenchus retusus, and Rotylenchulus reniformis was studied on Vertisol (Typic Pellusterts) between 1987 and 1993. Cowpea (Vigna sinensis), mungbean (Phaseolus aureus), and pigeonpea (Cajanus cajan) greatly increased the population densities of H. cajani and suppressed the population densities of other plant-parasitic nematodes. Mean population densities of H. cajani were about 8 times lower in single crop systems than in double crop systems, with pigeonpea as a component intercrop. Plots planted to sorghum, safflower, and chickpea in the preceding year contained fewer H. cajani eggs and juveniles than did plots previously planted to pigeonpea, cowpea, or mungbean. Continuous cropping of sorghum in the rainy season and safflower in the post-rainy season markedly reduced the population density of H. cajani. Sorghum, safflower, and chickpea favored increased population densities of H. retusus. Adding cowpea to the system resulted in a significant increase in the densities of R. reniformis. Mean densities of total plant-parasitic nematodes were three times greater in double crop systems, with pigeonpea as a component intercrop than in single crop systems with rainy season fallow component. Cropping systems had a regulatory effect on the nematode populations and could be an effective nematode management tactic. Intercropping of sorghum with H. cajani tolerant pigeonpea could be effective in increasing the productivity of traditional production systems in H. cajani infested regions. PMID:19277141

Sharma, S B; Rego, T J; Mohiuddin, M; Rao, V N

1996-06-01

15

Impact of Minimum Tillage and Crop Rotation as Climate Change Adaptation Strategies on Farmer Welfare in Smallholder Farming Systems of Zambia  

Directory of Open Access Journals (Sweden)

Full Text Available Worldwide, climate change is currently recognized as one of the major challenges to increased food production. The agriculture sector is the main source of livelihoods, growth and foreign exchange earnings in many developing countries including Zambia. However, it is also a sector that is mostly vulnerable to effects of climate change. Smallholder farmers in Zambia have been adopting agricultural related adaptation strategies including minimum tillage and crop rotation to mitigate effects of climate change. There has been contentious debate on whether the two strategies (that are elements of conservation farming increase crop yields and incomes. Available literature heavily relies on biophysical experiments and show contradictions in the ability of these strategies to improve crop yields. Taking cognizance of the differences in socioeconomic circumstances of the farmers, the purpose of this study was to estimate the impact of minimum tillage and crop rotation on maize yields and incomes for farmers adopting the strategies. The study used cross sectional data collected in 2012/13 from 1231 households across six districts of Zambia and applied propensity score matching techniques and Heckman’s selection estimators to account for observed and unobserved heterogeneity between the adopters and non-adopters. The results showed that about 12 and 19% of the farmers have adopted minimum tillage and crop rotation respectively. The strategies improved on-farm maize productivity by about 26% to 38% for minimum tillage and 21% to 24% for crop rotation. Minimum tillage also improved total household maize production. On the other hand crop rotation did not significantly improve total maize production and gross income from the crop. This could reflect the small proportions of areas allocated to legumes versus the areas subsequently allocated to the maize crop during crop rotation. The impact of crop rotation on the staple maize crop could be boosted by encouraging farmers to increase the areas allocated to legumes. The legumes portfolio in the government sponsored input support programme should be increased. The results from this study generally confirm the potential direct role of agricultural related climate change adaptation strategies in improving crop productivity levels in small holder farming systems.

Elias Kuntashula

2014-07-01

16

Impacts of crop rotations on soil organic carbon sequestration  

Science.gov (United States)

Agricultural land use and crop rotations can greatly affect the amount of carbon sequestered in the soil. We developed a framework for modelling the impacts of crop rotations on soil carbon sequestration at the field scale with test case Flanders. A crop rotation geo-database was constructed covering 10 years of crop rotation in Flanders using the IACS parcel registration (Integrated Administration and Control System) to elicit the most common crop rotation on major soil types in Flanders. In order to simulate the impact of crop cover on carbon sequestration, the Roth-C model was adapted to Flanders' environment and coupled to common crop rotations extracted from the IACS geodatabases and statistical databases on crop yield. Crop allometric models were used to calculate crop residues from common crops in Flanders and subsequently derive stable organic matter fluxes to the soil (REGSOM). The REGSOM model was coupled to Roth-C model was run for 30 years and for all combinations of seven main arable crops, two common catch crops and two common dosages of organic manure. The common crops are winter wheat, winter barley, sugar beet, potato, grain maize, silage maize and winter rapeseed; the catch crops are yellow mustard and Italian ryegrass; the manure dosages are 35 ton/ha cattle slurry and 22 ton/ha pig slurry. Four common soils were simulated: sand, loam, sandy loam and clay. In total more than 2.4 million simulations were made with monthly output of carbon content for 30 years. Results demonstrate that crop cover dynamics influence carbon sequestration for a very large percentage. For the same rotations carbon sequestration is highest on clay soils and lowest on sandy soils. Crop residues of grain maize and winter wheat followed by catch crops contribute largely to the total carbon sequestered. This implies that agricultural policies that impact on agricultural land management influence soil carbon sequestration for a large percentage. The framework is therefore suited for further scenario analysis and impact assessment in order to support agri-environmental policy decisions.

Gobin, Anne; Vos, Johan; Joris, Ingeborg; Van De Vreken, Philippe

2013-04-01

17

Crop rotation impact on soil quality  

International Nuclear Information System (INIS)

l depth. The SBQ (23%), SCQ (16%), SPQ (7%) and SQI (15%) improved under CSW over time. The results imply that multiple cropping systems could be more effective for maintaining and enhancing soil quality than sole-cropping systems. (author)

18

Water erosion during a 17-year period under two crop rotations in four soil management systems on a Southbrazilian Inceptisol  

Science.gov (United States)

Soil erosion still remains a persistent issue in the world, and this in spite of the efforts to ameliorate soil management systems taken into account the point of view of environmental protection against soil losses. In South Brazil water erosion is mainly associated to rainfall events with a great volume and high intensity, which are more or less evenly distributed all over the year. Nowadays, direct drilling is the most widely soil management system used for the main crops of the region. However, some crops still are grown on conventionally tilled soils, which means mainly ploughing and harrowing and less frequently chisel ploughing. In Lages-Santa Catarina State, Brazil, a plot experiment under natural rain was started in 1992 on an Inceptisol with the aim of quantifying soil and water losses. Treatments included bare and vegetated plots. The crop succession was: oats (Avena strigosa), soybean (Glycine max), vetch (Vicia sativa), maize (Zea mays), fodder radish (Raphanus sativus) and beans (Phaseolus vulgaris). Soil tillage systems investigated in this study were: i) conventional tillage (CT), ii) reduced tillage (MT), iii) no tillage (NT) under crop rotation and iv) conventional tillage on bare soil (BS). Treatments CT and BS involved ploughing plus twice harrowing, whereas MT involved chisel ploughing plus harrowing. Rainfall erosivity from January 1 1992 to December 31 2009 was calculated. Soil losses from the BS treatment along the 17 year study period were higher than 1200 Mg ha-1. Crop cover significantly reduced erosion, so that under some crops soil losses in the CT treatment were 80% lower than in the BS treatment. In turn soil losses in the MT treatment, where tillage was performed by chiselling and harrowing, were on average about 50% lower than in the CT treatment. No tillage was the most efficient soil management system in reducing soil erosion, so that soil losses in the NT treatment were about 98% lower than in the BS treatment. The three vegetated treatments, CT, MT and NT showed a lower efficiency in reducing water losses than soil losses. Water losses by runoff during a number of events were of the same order of magnitude for all the management systems studied here; which was mainly true when the volume of rainfall was high and the lag between successive events was small. In general, soil losses in the autumn-winter seasons were lower than under the spring-summer seasons. Soil losses showed a positive correlation with rainfall erosivity. However, the degree of dependence between these two variables decreased as the efficiency of soil management in controlling soil erosion increased. The large soil and water losses in the BS and CT treatments suggest that there is a need to implement soil conservation measures in the study region. In this context soil conservation would take advantage from soil cover by previous crop residue as well as from terrace building. Acknowledgement: This work was partly supported by Spanish Ministry of Education (Project CGL2005-08219-C02).

Bertol, Ildegardis; Vidal Vázquez, Eva; Paz Ferreiro, Jorge

2010-05-01

19

ECONOMIC VIABILITY OF CROPS ROTATION AND GREEN MANURING PRECEDING THE CULTIVATION OF NO-TILL SYSTEM CORN IN THE CERRADO  

Directory of Open Access Journals (Sweden)

Full Text Available In search of minimizing the environmental impacts of agricultural production it is necessary the use of techniques which make larger production sustainability possible and bring economic return to the producer. In this context, the present work had the objective to evaluate, in a typical Cerrado soil, the economic viability of crops rotation and green manure (Cajanus cajan (L. Millsp; Crotalaria juncea (L.; Eleusine coracana (L.; Pennisetum americanum (L. or fallow land in the yield of corn cultivated in notill system. The production information used were collected in the 2003/2004 harvest, in a test carried out in Selvíria, Mato Grosso do Sul, and the costs of farm inputs and production price were obtained in September 2004. The method used was the Total Operational Cost. To determine the profit of the activity for each treatment were considered the gross revenue, the operational profit, the profitability index and the balance price. The corn in rotation system with soybean obtained larger grains yield and higher profitability. The use of green manure preceding the cultivation of the corn was proven economically viable, and the use of the C. juncea allowed larger economic return, without showing significant difference between the E. coracana and the P. americanumt.

AGUINALDO JOSÉ FREITAS LEAL

2005-12-01

20

7 CFR 205.205 - Crop rotation practice standard.  

Science.gov (United States)

The producer must implement a crop rotation including but not limited to sod, cover crops, green manure crops, and catch crops that provide the following functions that are applicable to the operation: (a) Maintain or improve soil organic matter...

2010-01-01

 
 
 
 
21

Impacts of projected climate change on productivity and nitrogen leaching of crop rotations in arable and pig farming systems in Denmark  

DEFF Research Database (Denmark)

The effects of projected changes in climate and atmospheric CO2 concentration on productivity and nitrogen (N) leaching of characteristic arable and pig farming rotations in Denmark were investigated with the FASSET simulation model. The LARS weather generator was used to provide climatic data for the baseline period (1961–90) and in combination with two regional circulation models (RCM) to generate climatic data under the Intergovernmental Panel on Climate Change (IPCC) A1B emission scenario for four different 20-year time slices (denoted by midpoints 2020, 2040, 2060 and 2080) for two locations in Denmark, differing in soil and climate, and representative of the selected production systems. The CO2 effects were modelled using projected CO2 concentrations for the A1B emission scenario. Crop rotations were irrigated (sandy soil) and unirrigated (sandy loam soil), and all included systems with and without catch crops, with field operation dates adapted to baseline and future climate change. Model projections showed an increase in the productivity and N leaching in the future that would be dependent on crop rotation and crop management, highlighting the importance of considering the whole rotation rather than single crops for impact assessments. Potato and sugar beet in arable farming and grain maize in pig farming contributed most to the productivity increase in the future scenarios. The highest productivity was obtained in the arable system on the sandy loam soil, with an increase of 20% on average in 2080 with respect to the baseline. Irrigation and fertilization rates would need to be increased in the future to achieve optimum yields. Growing catch crops reduces N leaching, but current catch crop management might not be sufficient to control the potential increase of leaching and more efficient strategies are required in the future. The uncertainty of climate change scenarios was assessed by using two different climate projections for predicting crop productivity and N leaching in Danish crop rotations, and this showed the consistency of the projected trends when used with the same crop model

Doltra, Jordi; Lægdsmand, Mette

2014-01-01

22

Grain legumes in organic cropping systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Grain legumes are valuable protein and energy sources in animal feeds and in human diets low in meat. Furthermore, grain legumes strongly benefit the cropping system, via biological fixation of atmospheric N2 - a fundamental process for maintaining soil fertility in organic farming systems. Other positive effects in the crop rotations are recycled N-rich crop residues and the break-crop effect in cereals-rich rotations. However, yield variability in grain legumes is well known and related to...

Hauggaard-nielsen, Henrik

2002-01-01

23

ECONOMIC VIABILITY OF CROPS ROTATION AND GREEN MANURING PRECEDING THE CULTIVATION OF NO-TILL SYSTEM CORN IN THE CERRADO  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In search of minimizing the environmental impacts of agricultural production it is necessary the use of techniques which make larger production sustainability possible and bring economic return to the producer. In this context, the present work had the objective to evaluate, in a typical Cerrado soil, the economic viability of crops rotation and green manure (Cajanus cajan (L.) Millsp; Crotalaria juncea (L.); Eleusine coracana (L.); Pennisetum americanum (L.)) or fallow land in the yield of c...

AGUINALDO JOSÉ FREITAS LEAL; EDSON LAZARINI; MARIA APARECIDA ANSELMO TARSITANO; MARCO EUSTÁQUIO DE SÁ; FRANCISCO GUILHIEN GOMES JÚNIOR

2005-01-01

24

Three-year measurements of nitrous oxide emissions from cotton and wheat-maize rotational cropping systems  

Science.gov (United States)

The remarkable expansion of fertilization and irrigation may stimulate nitrous oxide (N2O) emissions from cropping systems in northern China. High-resolution measurements were conducted in irrigated cotton and wheat-maize rotational systems in Shanxi Province, P.R. China, between 2007 and 2010 (three year-round crop cycles, hereinafter referred to as Y1, Y2 and Y3) to investigate the impacts of natural inter-annual variations and agricultural management on annual N2O emissions and direct emission factors (EFs). Overall, N2O emissions fluctuated diurnally, seasonally and inter-annually in the fertilized treatments. The hourly N2O fluxes closely followed the daily air temperature patterns. The daily mean fluxes corresponded to these hourly fluxes, which were observed between 09:00-10:00 and 19:00-20:00. An optimized sampling protocol could improve the reliability of discrete measurements when estimating cumulative emissions. The N2O emissions for the fertilized treatments were 2.7 ± 0.2 (Y1) and 1.6 ± 0.1 kg N ha-1 yr-1 (Y2) from the cotton field and 6.2 ± 0.4 (Y1), 4.5 ± 0.3 (Y2) and 4.5 ± 0.2 kg N ha-1 yr-1 (Y3) from the wheat-maize field. Peak N2O emissions after fertilization and irrigation/rainfall lasted one to three weeks and accounted for 16-55% of the annual emissions. Leaching losses were estimated at 10.4 ± 3.0 (Y1) and 12.5 ± 3.4 kg N ha-1 yr-1 (Y2), which accounted for 16-17% of the fertilizer-N applied to the cotton field. Annual N2O emissions did not increase with increasing fertilization rates or water inputs because significant amounts of fertilizer-N were lost through leaching. Background emissions amounted to one-third to one-half of the total N2O emissions from the fertilized treatments. The direct EFs were 2.2 ± 0.3% (Y1) and 0.9 ± 0.2% (Y2) in the cotton field and 1.3 ± 0.2% (Y1), 0.8 ± 0.1% (Y2) and 0.7 ± 0.1% (Y3) in the wheat-maize field. The large inter-annual variations in N2O emissions and direct EFs emphasize the importance of multiple-year continuous observations.

Liu, Chunyan; Yao, Zhisheng; Wang, Kai; Zheng, Xunhua

2014-10-01

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Dinâmica e contribuição da micorriza arbuscular em sistemas de produção com rotação de culturas / Dynamics and contribution of arbuscular mycorrhiza in culture systems with crop rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Rotação de culturas e variações sazonais podem promover alterações quantitativas e qualitativas na comunidade de fungos micorrízicos arbusculares nativos e na formação da micorriza arbuscular. Essa dinâmica foi avaliada, em campo, num Latossolo Vermelho, em relação ao tempo de cultivo e variação saz [...] onal, em sistemas de rotação de culturas. Em casa de vegetação, avaliou-se, em solo proveniente da área experimental, a contribuição da micorriza arbuscular no crescimento de soja e capim-andropógon utilizados na rotação. O número de esporos dos fungos aumentou no solo cultivado. O número de esporos e o porcentual de colonização radicular, inicialmente maiores sob pastagem, variaram de acordo com o tempo de cultivo, as estações seca e chuvosa, a cultura e o sistema de rotação utilizados. O número de gêneros e espécies aumentou com o tempo de cultivo e manejo de culturas e foi maior sob culturas anuais em rotação. A presença dos fungos no solo contribuiu no crescimento da soja e do capim-andropógon em 53% e 95%, respectivamente. A cultura e o sistema de cultivo são fatores determinantes para o enriquecimento do sistema com micorriza arbuscular. Abstract in english Crop rotation and seasonal variations can promote quantitative and qualitative changes in the indigenous arbuscular mycorrhizal fungi population in the soil and arbuscular mycorrhiza establishment. These fungi dynamics were evaluated in the field, in a Red Latosol, in relation to cropping time, seas [...] onal variation and rotation systems. The contribution of arbuscular mycorrhiza to the growth of andropogon grass and soybean, which were used in the systems, was evaluated in a greenhouse experiment using soil from the experimental area. The number of spores of the fungi increased in the cultivated soil. The spores number and percent root colonization varied according to cropping time, soil moisture, crops and rotation system and were, initially, higher under pasture. The number of genus and species increased according to cropping time and culture management and was higher under annual crops in rotation. The presence of these fungi in the soil contributed 53% and 95% to the growth of soybean and andropogon grass, respectively. Crops and cultivation system are crucial for the system's enrichment in arbuscular mycorrhiza.

Jeanne Christine Claessen de, Miranda; Lourival, Vilela; Leo Nobre de, Miranda.

26

Dinâmica e contribuição da micorriza arbuscular em sistemas de produção com rotação de culturas Dynamics and contribution of arbuscular mycorrhiza in culture systems with crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available Rotação de culturas e variações sazonais podem promover alterações quantitativas e qualitativas na comunidade de fungos micorrízicos arbusculares nativos e na formação da micorriza arbuscular. Essa dinâmica foi avaliada, em campo, num Latossolo Vermelho, em relação ao tempo de cultivo e variação sazonal, em sistemas de rotação de culturas. Em casa de vegetação, avaliou-se, em solo proveniente da área experimental, a contribuição da micorriza arbuscular no crescimento de soja e capim-andropógon utilizados na rotação. O número de esporos dos fungos aumentou no solo cultivado. O número de esporos e o porcentual de colonização radicular, inicialmente maiores sob pastagem, variaram de acordo com o tempo de cultivo, as estações seca e chuvosa, a cultura e o sistema de rotação utilizados. O número de gêneros e espécies aumentou com o tempo de cultivo e manejo de culturas e foi maior sob culturas anuais em rotação. A presença dos fungos no solo contribuiu no crescimento da soja e do capim-andropógon em 53% e 95%, respectivamente. A cultura e o sistema de cultivo são fatores determinantes para o enriquecimento do sistema com micorriza arbuscular.Crop rotation and seasonal variations can promote quantitative and qualitative changes in the indigenous arbuscular mycorrhizal fungi population in the soil and arbuscular mycorrhiza establishment. These fungi dynamics were evaluated in the field, in a Red Latosol, in relation to cropping time, seasonal variation and rotation systems. The contribution of arbuscular mycorrhiza to the growth of andropogon grass and soybean, which were used in the systems, was evaluated in a greenhouse experiment using soil from the experimental area. The number of spores of the fungi increased in the cultivated soil. The spores number and percent root colonization varied according to cropping time, soil moisture, crops and rotation system and were, initially, higher under pasture. The number of genus and species increased according to cropping time and culture management and was higher under annual crops in rotation. The presence of these fungi in the soil contributed 53% and 95% to the growth of soybean and andropogon grass, respectively. Crops and cultivation system are crucial for the system's enrichment in arbuscular mycorrhiza.

Jeanne Christine Claessen de Miranda

2005-10-01

27

Carbon footprints of crops from organic and conventional arable crop rotations – using a life cycle assessment approach  

DEFF Research Database (Denmark)

Many current organic arable agriculture systems are challenged by a dependency on imported livestock manure from conventional agriculture. At the same time organic agriculture aims at being climate friendly. A life cycle assessment is used in this paper to compare the carbon footprints of different organic arable crop rotations with different sources of N supply. Data from long-term field experiments at three different locations in Denmark were used to analyse three different organic cropping systems (‘Slurry’, ‘Biogas’ and ‘Mulching’), one conventional cropping system (‘Conventional’) and a “No input” system as reference systems. The ‘Slurry’ and ‘Conventional’ rotations received slurry and mineral fertilizer, respectively, whereas the ‘No input’ was unfertilized. The ‘Mulching’ and ‘Biogas’ rotations had one year of grass-clover instead of a faba bean crop. The grass-clover biomass was incorporated in the soil in the ‘Mulching’ rotation and removed and used for biogas production in the ‘Biogas’ rotation (and residues from biogas production were simulated to be returned to the field). A method was suggested for allocating effects of fertility building crops in life cycle assessments. The results showed significantly lower carbon footprint of the crops from the ‘Biogas’ rotation (assuming that biogas replaces fossil gas) whereas the remaining crop rotations had comparable carbon footprints per kg cash crop. The study showed considerable contributions caused by the green manure crop (grass-clover) and highlights the importance of analysing the whole crop rotation and including soil carbon changes when estimating carbon footprints of organic crops especially where green manure crops are included.

Knudsen, Marie Trydeman; Meyer-Aurich, A

2014-01-01

28

Rainfed intensive crop systems  

DEFF Research Database (Denmark)

This chapter focuses on the importance of intensive cropping systems in contributing to the world supply of food and feed. The impact of climate change on intensive crop production systems is also discussed.

Olesen, JØrgen E

2014-01-01

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Designing and testing crop rotations for organic farming. Proceedings from an international workshop  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Organic farming aims at establishing stable and harmonic farming systems, which integrate livestock and crop production. No industrial fertilisers, pesticides or growth regulators are used. The nutrient management is based on the use of animal manure, green manure, crop residues and on nitrogen fixation by legumes. Weeds, pests and diseases are controlled through the use of versatile crop rotations, mechanical weed control and a proper choice of varieties. The multifunctional crop rotati...

1999-01-01

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Atributos físicos do solo em sistemas de manejo de solo e de rotação de culturas Soil tillage and crop rotation systems on the soil physical attributes  

Directory of Open Access Journals (Sweden)

Full Text Available A compreensão e a quantificação do impacto do uso e manejo do solo na qualidade física são fundamentais no desenvolvimento de sistemas agrícolas sustentáveis. Com o objetivo de avaliar o efeito de sistemas de manejo de solo e de rotação de culturas sobre alguns atributos físicos de solo em um experimento instalado em 1985, em Latossolo Vermelho Distrófico típico argiloso, em Passo Fundo (RS, estudou-se a variação desses atributos entre 2001 e 2005. Os tratamentos consistiram de quatro modos de manejo de solo: 1 plantio direto (PD; 2 cultivo mínimo (CM; 3 preparo convencional de solo com arado e grade de discos (PCD e 4 preparo convencional de solo com arado de aivecas e grade de discos (PCA, e três sistemas de rotação de culturas: I (trigo/soja, II (trigo/soja e ervilhaca/milho ou sorgo e III (trigo/soja, aveia branca/soja e ervilhaca/milho ou sorgo. O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. A parcela foi constituída pelos sistemas de manejo de solo, e as subparcelas, pelos sistemas de rotação de culturas. Amostras de solo também foram coletadas em um fragmento de floresta subtropical adjacente ao experimento, como testemunha da condição original do solo. Os sistemas de manejo e de rotação de culturas influenciaram os atributos físicos do solo quando comparados entre si e com a condição sob floresta subtropical. Em quatro anos (2001 a 2005 ocorreram alterações significativas nos atributos físicos dos solos entre os distintos tipos de manejo. No sistema PD houve maior densidade de solo e microporosidade em comparação aos demais, principalmente na camada subsuperficial, e os sistemas de rotação de plantas não afetaram positivamente os atributos físicos de solo independentemente do tipo de manejo.Evaluation and quantification of soil use impact on its physical quality are important to achieve sustainable cropping systems. Soil physical attributes were assessed after twenty years of implementation (1985 to 2005 on a typical Dystrophic Red Latosol (Rodic Hapludox located in Passo Fundo, Rio Grande do Sul State, Brazil. Four soil tillage systems were evaluated: 1 no-tillage; 2 minimum tillage; 3 conventional tillage using a disk plow plus disk harrow, and 4 conventional tillage using a moldboard plow plus disk harrow. Three crop rotation systems were evaluated: I (wheat/soybean, II (wheat/soybean and common vetch/corn or sorghum, and III (wheat/soybean, common vetch/corn or sorghum and white oats/soybean. A randomized complete block design, with split-plots and three replicates, was used. The main plots were formed by the soil tillage systems, while split-plots were composed by crop rotation systems. As control, soil samples were collected in a subtropical forest fragment adjacent to the experiment. Soil tillage systems and crop rotation systems influenced soil physical parameters when compared to the samples collected in a fragment of subtropical forest. During four years (2001 to 2005 the physical attributes were altered among different soil tillage management. The no-tillage system (PD presented higher soil bulk density and microporosity in comparison to the other systems, mainly in 0.10 to 0.15 m layer, characterizing high soil compaction levels. Crop systems did not promote favorable changes in physical attributes independent of the type of soil management.

Silvio Tulio Spera

2009-01-01

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Design of an organic farming crop rotation experiment  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A field experiment is conducted which focuses on crop rotations for cereal production in organic farming. The objective of the experiment is to explore the possibilities for both short-term and long-term increases in organic cereal production through manipulation of crop rotation design on different soil types. This paper describes the design of a rather complex experiment, and later papers will describe and discuss the results. Three factors are included in the experiment in a factorial desi...

Olesen, Jørgen E.; Askegaard, Margrethe; Rasmussen, Ilse Ankær

2000-01-01

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Sistemas de preparo do solo e rotação de culturas na produtividade de milho, soja e trigo Tillage systems and crop rotation on yield of corn, soybean and wheat  

Directory of Open Access Journals (Sweden)

Full Text Available Com este trabalho, objetivou-se determinar quanto os sistemas de preparo do solo e as rotações de culturas afetam a produtividade de grãos do milho, da soja e do trigo. O experimento foi conduzido em um Latossolo Vermelho distrófico, em área irrigada por pivô central, na EMBRAPA Arroz e Feijão, em Santo Antônio de Goiás, GO, por seis anos, setembro de 1992 a setembro de 1998, durante os quais foram feitos 12 cultivos e comparados três sistemas de preparo do solo: a aração com arado de aiveca, realizada em novembro-dezembro e em maio-junho; b aração com grade aradora, em ambos os períodos, e c plantio direto e quatro rotações de cultura: 1 milho-feijão; 2 soja-trigo; 3 soja-trigo-soja-feijão-arroz-feijão e 4 milho-feijão-milho-feijão-arroz-feijão. As culturas de arroz, soja e milho, foram semeadas em novembro-dezembro e as de feijão e trigo, em maio-junho. Para efeito do estudo, consideraram-se somente as culturas do milho, da soja e do trigo. O sistema de preparo do solo não afetou a produtividade de soja mas, sim, a de milho e de trigo, tendo o preparo com arado propiciado maiores produtividades em comparação com o plantio direto. As diferenças entre o plantio direto e os demais sistemas de preparo do solo, com relação à produtividade acumulada relativa de milho, diminuíram com o tempo de cultivo. Não houve efeito da rotação de culturas sobre a produtividade das culturas estudadas.The objective of this study was to determine how much soil tillage and crop rotation affected grain yield of corn, soybean and wheat. The study was carried out at EMBRAPA (Rice and Beans, in Santo Antônio de Goiás, GO, Brazil, in a Red Latosol (Oxisol, under center pivot irrigation system, for six consecutive years. During the experimentation, 12 crops were cultivated. The tillage treatments were a moldboard plough, b harrow disc and c no-tillage. The crop rotations were 1 corn-bean, 2 soybean-wheat, 3 soybean-wheat-soybean-bean-upland rice-bean and 4 corn-bean-corn bean-upland rice-bean. Rice, soybean and corn were sown in November/December and bean and wheat in May/June. For this study, only corn, soybean and wheat were considered. Soil tillage affected corn and wheat yields but did not affect soybean yield. Corn and wheat yields under mouldboard plough were higher than under no-tillage. The differences among no-tillage and the other tillage systems in relation to relative accumulative corn yield decreased as the cultivation period increased. Crop rotations did not affect the crop yields.

Pedro M. da Silveira

2003-08-01

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Maize nitrogen fertilization in two crop rotation systems under no-till / Adubação nitrogenada para o milho em dois sistemas de rotação de culturas sob plantio direto  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Com o objetivo de avaliar o parcelamento de doses de nitrogênio (N), aplicadas na semeadura e em cobertura do milho, com e sem rotação de culturas, em semeadura direta, foi realizado um experimento com seis doses de N na semeadura (0, 20, 30, 40, 50 e 60 kg ha-1), combinadas com três doses em cobert [...] ura (40, 70, 100 kg ha-1) e dois sistemas de manejo: após cinco cultivos de milho e com rotação de culturas (milho+soja+aveia+soja+milho), em delineamento de blocos casualizados, com quatro repetições. O sistema de rotação de culturas proporcionou incremento de aproximadamente 7%, no rendimento de grãos, em relação ao da área sem rotação. O parcelamento da adubação nitrogenada, com doses acima de 39 e 54 kg ha-1, na semeadura, com 70 e 40 kg ha-1, em cobertura, respectivamente, resultou em produtividade superior à obtida com aplicação de 100 kg ha-1, em cobertura. O rendimento de grãos foi maior com o parcelamento da dose de 50 e 70 kg ha-1 de N, na semeadura e cobertura, em comparação com o obtido com o parcelamento de 20 e 100 kg ha-1, na semeadura e cobertura, respectivamente. A dose de 70 kg ha-1 de N em cobertura apresentou maior produtividade de grãos com menor custo, em comparação com os rendimentos e custos verificados em relação às doses de 40 e 100 kg ha-1. Abstract in english The objective of this study was to evaluate split nitrogen (N) fertilization of maize applied in band at sowing and top dressing with and without crop rotation, under no-till. The experiment was conducted with six N rates at sowing (0, 20, 30, 40, 50 and 60 kg ha-1) combined with three rates in top [...] dressing (40, 70, 100 kg ha-1) and two management systems: after five cropping sequences of maize and crop rotation (maize + soybean + oat + soybean + corn) in a randomized block design with four replications. The crop rotation system increased yield in approximately 7% in relation to the area without rotation. The split of nitrogen fertilization, in rates above 39 and 54 kg ha-1 at sowing and 70 and 40 kg ha-1 in top dressing, resulted in yield higher than that obtained with the application of 100 kg ha-1 in top dressing. Grain yield was higher with the rates 50 and 70 kg ha-1 of N compared with that obtained with 20 and 100 kg ha-1 at sowing and top dressing, respectively. The rate 70 kg ha-1 of N resulted in the highest yield at the lowest cost compared with the revenues and costs incurred with the rates 40 and 100 kg ha-1.

Maria do Carmo, Lana; Rodrigo Vianei, Czycza; Jean Sérgio, Rosset; Jucenei Fernando, Frandoloso.

2013-12-01

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Grain yield and agronomic traits in soybean according to crop rotation systems / Rendimento de grãos e características agronômicas de soja em função de sistemas de rotação de culturas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo deste trabalho foi avaliar o efeito dos sistemas de rotação de culturas (SRC) sobre o rendimento de grãos e as características agronômicas de soja no período de 1996/1997 a 2010/2011 em Latossolo Vermelho distrófico típico, na Embrapa Trigo, em Passo Fundo, RS. Foram comparados quatro tip [...] os de manejo de solo (TMS): 1) sistema plantio direto (SPD); 2) cultivo mínimo (CM); 3) preparo convencional de solo com arado de discos (PCD); e 4) preparo convencional de solo com arado de aivecas (PCA) e três SRC: sistema I (monocultura de trigo/monocultura de soja); sistema II (trigo/soja e ervilhaca/milho ou sorgo); e III (trigo/soja, aveia branca/soja e ervilhaca/milho ou sorgo). O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. A parcela foi constituída pelos TMS, e as subparcelas, pelos SRC. No presente trabalho serão abordados somente os dados sobre sistemas de rotação de culturas. A análise conjunta dos dados obtidos não indicou diferença entre os SRC em relação ao número de grãos por planta, à massa de mil grãos e à altura de inserção das primeiras vagens de soja. A rotação de culturas por um verão utilizando milho ou sorgo propicia maior rendimento de grãos de soja em comparação com os demais sistemas estudados e com a soja em monocultura. A combinação de sistemas conservacionistas (SPD e CM) e SRC favoreceu o maior rendimento de grãos de soja. Os menores rendimentos de grãos e massa de grãos ocorreram em monocultura de soja. Abstract in english The effects of crop rotation systems (CRS) on soybean yield and agronomic characteristics were evaluated from 1996/1997 to 2010/2011 at Embrapa Trigo, Passo Fundo (RS), Brazil. Four soil management systems (SMS) were compared, namely: 1) no tillage, 2) minimum tillage, 3) conventional tillage using [...] a disk plow and a disk harrow, and 4) conventional using a moldboard and a disk harrow - and three CRS: system I (wheat/soybean), system II (wheat/soybean and common vetch/corn or sorghum) and system III (wheat/soybean, white oats/soybean and common vetch/corn or sorghum). This is a split-plot, randomized, complete block design with three replications. SMS were assigned in the main plot and CRS systems in the split-plots. This work addressed only data on crop rotation systems. There were no significant differences between the CRS for number of grains per plant, 1,000 grain weight and first pod height in soybean. The crop rotation for a summer, with corn or sorghum, propitiates a higher soybean yield compared with the other systems and monoculture soybean. The combination of conservation systems (no tillage and minimum tillage) and CR resulted in a higher soybean yield. The lowest grain yield and grain weight per plant were obtained in monoculture soybean.

Henrique Pereira dos, Santos; Renato Serena, Fontaneli; João, Pires; Evandro Ademir, Lampert; Ana Maria, Vargas; Amauri Colet, Verdi.

35

Weed control through crop rotation and alternative management practices  

Directory of Open Access Journals (Sweden)

Full Text Available Economic as well as agricultural and socio-political changes have an impact on crop management and thus also on crop rotation design and the related effects on the weed flora. Likewise other changes in cultivation such as reduced tillage practices, earlier sowing date, etc. cause an increase in weed infestation resp. an increased use of herbicides and if so contribute to herbicide resistance. The positive effects of crop rotation, but also of alternative management practices such as choice of varieties, catch crops, mixed cropping, green chop, and the share of predators, as well as methods of direct non-chemical weed control are presented and discussed for both, conventional and organic farming. If alternative management methods should be more practiced, especially trade-offs need to be broken, or incentives be offered.

Böhm, Herwart

2014-02-01

36

Faba bean in cropping systems  

DEFF Research Database (Denmark)

The grain legume (pulse) faba bean (Vicia faba L.) is grown world-wide as a protein source for food and feed. At the same time faba bean offers ecosystem services such as renewable inputs of nitrogen (N) into crops and soil via biological N2 fixation, and a diversification of cropping systems. Even though the global average grain yield has almost doubled during the past 50 years the total area sown to faba beans has declined by 56% over the same period. The season-to-season fluctuations in grain yield of faba bean and the progressive replacement of traditional farming systems, which utilized legumes to provide N to maintain soil N fertility, with industrialized, largely cereal-based systems that are heavily reliant upon fossil fuels (=N fertilizers, heavy mechanization) are some of the explanations for this decline in importance. Past studies of faba bean in cropping systems have tended to focus on the effect of faba bean as a pre-crop in mainly cereal intensive rotations, whereas similar information on the effect of preceding crops on faba bean is lacking. Faba bean has the highest average reliance on N2 fixation for growth of the major cool season grain legumes. As a consequence the N benefit for following crops is often high, and several studies have demonstrated substantial savings (up to 100–200 kg N ha?1) in the amount of N fertilizer required to maximize the yield of crops grown after faba bean. There is, however, a requirement to evaluate the potential risks of losses of N from the plant–soil system associated with faba bean cropping via nitrate leaching or emissions of N2O to the atmosphere as a consequence of the rapid mineralization of N from its N-rich residues. It is important to develop improved preventive measures, such as catch crops, intercropping, or no-till technologies, in order to provide farmers with strategies to minimize any possible undesirable effects on the environment that might result from their inclusion of faba bean in cropping system. This needs to be combined with research that can lead to a reduction in the current extent of yield variability, so that faba bean may prove to be a key component of future arable cropping systems where declining supplies and high prices of fossil energy are likely to constrain the affordability and use of fertilizers. This will help address the increasing demand by consumers and governments for agriculture to reduce its impact on the environment and climate through new, more sustainable approaches to food production. The aims of this paper are to review the role of faba bean in global plant production systems, the requirements for optimal faba bean production and to highlight the beneficial effects of faba bean in cropping systems.

Hauggaard-Nielsen, Henrik

2010-01-01

37

Cereal-forage crop rotations and irrigation treatment effect on water use efficiency and crops sustainability in Mediterranean environment  

Directory of Open Access Journals (Sweden)

Full Text Available Agricultural systems based on crop rotations favour sustainability of cultivation and productivity of the crops. Wheat-forage crops rotations (annual winter binary mixture and perennial alfalfa meadow combined with irrigation are the agronomical techniques able to better exploit the weather resources in Mediterranean environments. The experiment aimed to study the effect of 18 years of combined effect of irrigation and continuous durum wheat and wheat-forage rotations on productivities of crops and organic matter of topsoil. The experiments were established through 1991-2008 under rainfed and irrigated treatments and emphasized on the effect of irrigation and continuous wheat and wheat-forage crop rotations on water use efficiency and sustainability of organic matter. The effect of irrigation increased 49.1% and 66.9% the dry matter of mixture and meadow, respectively. Continuous wheat rotation reduced seed yield, stability of production, crude protein characteristics of kernel and soil organic matter. The yearly gain in wheat after forage crops was 0.04 t (ha·yr-1 under rainfed and 0.07 t (ha·yr-1 under irrigation treatments. The crude protein and soil organic matter of wheat rotations, compared to those of continuous wheat under rainfed and irrigated was increase in term of point percentage by 0.8 and 0.5 in crude protein and 5.1 and 4.4 in organic matter, respectively. The rotations of mixture and meadow under both irrigated treatments increased the point of percentage of organic matter over continuous wheat (9.3.and 8.5 in mixture and 12.5 and 9.5 meadow under rainfed and irrigation, respectively. Irrigation reduce the impact of weather on crop growing reducing water use efficiency (mean over rotations for dry mater production (15.5 in meadow and 17.5 in mixture [L water (kg·dry·matter-1 ] and wheat seed yield. The effect of agronomic advantages achieved by forage crops in topsoil expire its effect after three years of continuous wheat rotation.

Pasquale Martiniello

2012-01-01

38

Environmental enhancement using short-rotation woody crops and perennial grasses as alternative agricultural crops  

Energy Technology Data Exchange (ETDEWEB)

Short-rotation woody crops and perennial grasses are grown as biomass feedstocks for energy and fiber. When replacing traditional row crops on similar lands, these alternative crops can provide multiple environmental benefits in addition to enhancing rural economies and providing valuable feedstock resources. The Department of Energy is supporting research to address how these crops can provide environmental benefits to soil, water and native wildlife species in addition to providing bioenergy feedstocks. Research is underway to address the potential for biomass crops to provide soil conservation and water quality improvements in crop settings. Replacement of traditional erosive row crops with biomass crops on marginal lands and establishment of biomass plantations as filter strips adjacent to streams and wetlands are being studied. The habitat value of different biomass crops for selected wildlife species is also under study. To date, these studies have shown that in comparison with row crops biomass plantings of both grass and tree crops increased biodiversity of birds; however, the habitat value of tree plantations is not equivalent to natural forests. The effects on native wildlife of establishing multiple plantations across a landscape are being studied. Combining findings on wildlife use of individual plantations with information on the cumulative effects of multiple plantations on wildlife populations can provide guidance for establishing and managing biomass crops to enhance biodiversity while providing biomass feedstocks. Data from site-specific environmental studies can provide input for evaluation of the probable effects of large-scale plantings at both landscape and regional levels of resolution.

Tolbert, V.R. [Oak Ridge National Lab., TN (United States); Schiller, A. [Oak Ridge Inst. for Science and Education, TN (United States)

1995-12-31

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Produtividade do algodoeiro herbáceo em plantio direto no Cerrado com rotação de culturas / Herbaceous cotton yield in no-till system in rainfed Savannah conditions with crop rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O experimento, instalado em um Latossolo Vermelho-Amarelo muito argiloso, teve o objetivo de avaliar o efeito da rotação de culturas na produtividade do algodoeiro herbáceo (Gossypium hirsutum L. r. latifolium Hutch) em plantio direto sob condições de sequeiro no Cerrado. O delineamento experimental [...] foi de blocos casualizados com cinco tratamentos e quatro repetições. Os tratamentos consistiram das rotações soja-milheto-soja-milheto-algodoeiro; soja-amaranto-soja-nabo forrageiro-soja-algodoeiro; soja-sorgo granífero-soja-sorgo granífero-algodoeiro; soja-aveia preta-soja-aveia preta-algodoeiro e soja-soja-algodoeiro. A maior produtividade do algodoeiro foi obtida com a rotação de soja e milheto, em que houve melhor controle de plantas daninhas. Abstract in english The experiment was carried out in a heavy red yellow latosol and aimed at evaluating crop rotation on herbaceous cotton yields in no-till system under rainfed Savannah conditions. The experimental design used was a completely randomised blocks with five treatments: soybean-millet-soybean-millet-cott [...] on; soybean-amaranth-soybean-forage radish-soybean-cotton; soybean-grain sorghum-soybean-grain sorghum-cotton; soybean-black rye-soybean-black rye-cotton and soybean-soybean-cotton and four replications. The highest cotton seed yield was obtained in the sequence soybean-millet-soybean-millet-cotton, in which best weed control also occurred.

José Carlos, Corrêa; Ravi Datt, Sharma.

2004-01-01

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Produtividade do algodoeiro herbáceo em plantio direto no Cerrado com rotação de culturas / Herbaceous cotton yield in no-till system in rainfed Savannah conditions with crop rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O experimento, instalado em um Latossolo Vermelho-Amarelo muito argiloso, teve o objetivo de avaliar o efeito da rotação de culturas na produtividade do algodoeiro herbáceo (Gossypium hirsutum L. r. latifolium Hutch) em plantio direto sob condições de sequeiro no Cerrado. O delineamento experimental [...] foi de blocos casualizados com cinco tratamentos e quatro repetições. Os tratamentos consistiram das rotações soja-milheto-soja-milheto-algodoeiro; soja-amaranto-soja-nabo forrageiro-soja-algodoeiro; soja-sorgo granífero-soja-sorgo granífero-algodoeiro; soja-aveia preta-soja-aveia preta-algodoeiro e soja-soja-algodoeiro. A maior produtividade do algodoeiro foi obtida com a rotação de soja e milheto, em que houve melhor controle de plantas daninhas. Abstract in english The experiment was carried out in a heavy red yellow latosol and aimed at evaluating crop rotation on herbaceous cotton yields in no-till system under rainfed Savannah conditions. The experimental design used was a completely randomised blocks with five treatments: soybean-millet-soybean-millet-cott [...] on; soybean-amaranth-soybean-forage radish-soybean-cotton; soybean-grain sorghum-soybean-grain sorghum-cotton; soybean-black rye-soybean-black rye-cotton and soybean-soybean-cotton and four replications. The highest cotton seed yield was obtained in the sequence soybean-millet-soybean-millet-cotton, in which best weed control also occurred.

José Carlos, Corrêa; Ravi Datt, Sharma.

 
 
 
 
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Evaluation of Maize Yield in an On-Farm Maize-Soybean and Maize-Lablab Crop Rotation Systems in the Northern Guinea Savanna of Nigeria  

Directory of Open Access Journals (Sweden)

Full Text Available An attempt was made to solving the problem of shortfall of fertilizer to maize production in the Northern Guinea Savanna (NGS of Nigeria by harnessing the potentials of legume/cereal crop rotation in on-farm trials. The yield of maize that succeeded two soybean varieties and Lablab in a two-cycle of soybean/maize and Lablab/maize crop rotation in NGS Nigeria was assessed in researcher-managed and farmer-managed plots. Though maize that followed the soybean received between 5 kg N ha-1 from improved soybean variety (TGx 1448-2E and 17 kg N ha-1 from farmer soybean variety (Samsoy-2 as N balance, this did not significantly (p = 0.05 affect the maize yields. The soybean shed 90-100% of its leaves at physiological maturity which resulted in about 110 kg N ha-1 N uptake. This source of N might be one of the factors responsible for the increase in maize yield that followed soybean (20 to 24% compared with continuous maize yield plot. Maize yield in previous Lablab plot was significantly (p = 0.05 higher than in all other treatments. Maize yield in farmer-managed plot ranged between 0.13 and 4.53 t ha-1, maize yield in researcher-managed plot was over 200% higher than maize yield in farmer-managed plot because of poor crop management on the part of the farmer.

J.A. Okogun

2007-01-01

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Potentials of RapidEye time series for improved classification of crop rotations in heterogeneous agricultural landscapes: experiences from irrigation systems in Central Asia  

Science.gov (United States)

In Central Asia, more than eight Million ha of agricultural land are under irrigation. But severe degradation problems and unreliable water distribution have caused declining yields during the past decades. Reliable and area-wide information about crops can be seen as important step to elaborate options for sustainable land and water management. Experiences from RapidEye classifications of crop in Central Asia are exemplarily shown during a classification of eight crop classes including three rotations with winter wheat, cotton, rice, and fallow land in the Khorezm region of Uzbekistan covering 230,000 ha of irrigated land. A random forest generated by using 1215 field samples was applied to multitemporal RapidEye data acquired during the vegetation period 2010. But RapidEye coverage varied and did not allow for generating temporally consistent mosaics covering the entire region. To classify all 55,188 agricultural parcels in the region three classification zones were classified separately. The zoning allowed for including at least three observation periods into classification. Overall accuracy exceeded 85 % for all classification zones. Highest accuracies of 87.4 % were achieved by including five spatiotemporal composites of RapidEye. Class-wise accuracy assessments showed the usefulness of selecting time steps which represent relevant phenological phases of the vegetation period. The presented approach can support regional crop inventory. Accurate classification results in early stages of the cropping season permit recalculation of crop water demands and reallocation of irrigation water. The high temporal and spatial resolution of RapidEye can be concluded highly beneficial for agricultural land use classifications in entire Central Asia.

Conrad, Christopher; Machwitz, Miriam; Schorcht, Gunther; Löw, Fabian; Fritsch, Sebastian; Dech, Stefan

2011-11-01

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

DEFF Research Database (Denmark)

Tillage and rotation are fundamental factors influencing soil quality and thus the sustainability of cropping systems. Many studies have focused on the effects of either tillage or rotation, but few have quantified the long term integrated effects of both. We studied the issue using a 30-year old 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 was visually evaluated in early June and mid October. Minimal disturbed soil cores collected in early June were used for X-ray CT scanning and to quantify water content and porosity. Soil friability was determined on the soil samples using a drop shatter test. Crop yield was determined and correlated to the soil quality estimates. We found significant effect of both rotation and tillage on visual soil structure at both times of assessment. Poor soil structure was found for NT except when combined with a diverse crop rotation (R6). The soil core pore characteristics data also displayed a significant effect of tillage but only a weak insignificant effect of rotation. The drop shatter results were in accordance with the visual assessment data. Crop yield correlated significantly with the visual soil structure scores. We conclude that a diverse crop rotation was needed for an optimal performance of NT for the studied soil.

Munkholm, Lars Juhl; Heck, R

2013-01-01

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Measurements in rotating systems  

International Nuclear Information System (INIS)

This paper considers a method of making measurements within a particular metric framework for a rotating system. The relationship between measurements made by observers at different points within a rotating system has been investigated. The first part of the paper considers the application of radar measurement to the rotating system. In the second part infinitesimal radar measurements are used to show that for an observer at a radius R within a rotating system, similar results are obtained, through the application of the metric, to those which would be obtained by the use of instantaneous rest frames. The overall aim of this paper is to clarify the interpretation of measurements made by a rotating observer when the metric approach to rotating systems is used. (author)

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Nitrogen cycling with oilseed radish cover crop in Indiana crop rotations  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Cover crop interest among Midwestern farmers has greatly increased over the past few years, with a focus on cover crops that can be successfully integrated into corn-soybean rotations. Oilseed radish (Raphanus sativus L.) is receiving attention due to its large fleshy taproot that winter-kills and is excellent at scavenging nitrogen (N) and penetrating deep into the subsoil. Although oilseed radish (OSR) can scavenge large quantities of N in the fall, its rapid decomposition in spring may rel...

Horton, Kaylissa A.

2013-01-01

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Environmental enhancement using short-rotation woody crops and perennial grasses as alternative agricultural crops  

Energy Technology Data Exchange (ETDEWEB)

Short-rotation woody crops and perennial grasses are grown as biomass feedstocks for energy and fiber. When replacing traditional row crops on similar lands, these alternative crops can provide multiple environmental benefits in addition to enhancing rural economies and providing valuable resources. The DOE is supporting research to address how these crops can provide environmental benefits to soil, water, and native wildlife species in addition to providing bioenergy feedstocks. Research is underway to address the potential for biomass crops to provide soils conservation and water quality improvements in crop settings. Replacement of traditional erosive row drops with biomass crops on marginal lands and establishment of biomass plantations as filter strips adjacent to streams and wetlands are being studied. The habitat value of different crops for wildlife species is also considered. Combining findings on wildlife use of individual plantations with information on the cumulative effects of multiple plantations on wildlife populations can provide guidance for establishing and managing biomass crops to enhance biodiversity while providing feedstocks. Data from site-specific environmental studies can provide input for evaluation of the effects of large-scale plantings at both landscape and regional levels of resolution.

Tolbert, V.R. [Oak Ridge National Lab., TN (United States); Schiller, A. [Oak Ridge Inst. for Science and Education, TN (United States)

1996-10-01

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Irrigation treatments, water use efficiency and crop sustainability in cereal-forage rotations in Mediterranean environment  

Directory of Open Access Journals (Sweden)

Full Text Available Agricultural systems based on crop rotation are beneficial to crop sustainability and productivity. Wheat-forage rotations combined with irrigation are the agronomic techniques best able to exploit Mediterranean environmental conditions. This paper describes a long-term field trial to ascertain the effect of combined irrigation and durum wheat-forage rotations on crop yield and soil chemical properties. The two forage crops: annual grass-clover winter binary mixture and perennial lucerne were carried out through 1991-2008 under rainfed and irrigated treatments. The experiments were used to highlight the effect of irrigation and wheat-forage crop rotations on water use efficiency (WUE and sustainability of organic matter (OM in topsoil. Irrigation increased the dry matter (DM of annual binary mixture and lucerne by 49.1% and 66.9%, respectively. Continuous wheat rotation reduced seed yield (SY, stability of production, and crude protein (CP characteristics of kernel and OM in topsoil. The yearly gain in wheat after forage crops was 0.04 t (ha yr-1 under rainfed and 0.07 t (ha yr-1 under irrigation treatments. The CP and soil OM of wheat forage crops rotations, compared with those of continuous wheat under rainfed and irrigated was a 0.8 and 0.5 % increase in CP and 5.1 and 4.4 in OM, respectively. The rotations of annual grass-clover winter binary mixture and lucerne meadow under both irrigated treatments increased the OM over continuous wheat (9.3 % and 8.5 in annual grass-clover winter binary mixture and 12.5 and 9.5 lucerne meadow under rainfed and irrigation, respectively. Irrigation reduced the impact of weather on crop growing, reducing water use efficiency (mean over rotations for DM production (15.5 in meadow and 17.5 in annual grass-clover winter binary mixture [L water (kg DM-1] and wheat SY. However, the agronomic benefits achieved by forage crops in topsoil are exhausted after three years of continuous wheat rotation.

Salvatore Claps

2012-10-01

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Potential biomass production of a short rotation crop in Portugal  

Digital Repository Infrastructure Vision for European Research (DRIVER)

There is a growing consensus that CO2 emissions from burning fossil fuels are altering the global climate. The Portuguese government aims to reduce national CO2 emissions by 8 %, at the levels of 1990, by 2012. The use of short rotation crops (SRC) such as willow and poplar as an energy source that produces very low net CO2 emissions could help meet these targets. In 2008, in the framework of the research project PTDC/AGR-CFL/64500/2006, a SRC crop was established in the Trás-os-Montes Regio...

Patri?cio, Maria Do Sameiro; Nunes, Lui?s; Saraiva, Daniel; Azevedo, Joa?o

2011-01-01

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Energy balance in rainfed herbaceous crops in a semiarid environment for a 15-year experiment. 2. Impact of crop rotations.  

Science.gov (United States)

Energy balances in agriculture production have been widely studied since the 1970s. Researchers have performed detailed energy balances for different crops and farm management systems all over the world in attempts to assess the efficiency and environmental impact of production systems. This work is part of a larger study assessing the effects of three farming systems (conventional, conservation with zero tillage, and organic) and four barley-based crop rotations (barley followed by fallow [B-F], barley in rotation with vetch for hay production [B-V] or sunflower [B-S], and barley monoculture [B-B]), on the energy balance of crop production under the semi-arid conditions over a 15 year period. However, the present work is focused on the crop rotation effect, so farming systems and years are averaged. Experiments were conducted at "La Higueruela" Experimental Farm (4°26' W, 40°04' N, altitude 450 m) (Spanish National Research Council, Santa Olalla, Toledo, central Spain). The climate is semi-arid Mediterranean, with an average seasonal rainfall of 480 mm irregularly distributed. The rotations were simultaneously duplicated to have all phases of each rotation present every year. Results were expressed with respect to one hectare and year for a complete rotation. The energy balance method used required the identification and quantification of all the inputs and outputs implied, and the conversion to energy values by corresponding coefficients. The parameters considered were (i) energy inputs (EI) (diesel, machines, fertilizers, herbicides, seeds) (ii) energy outputs (EO) (energy in the harvested biomass), (iii) net energy produced (NE) (EI - EO), (iv) the energy output/input ratio (O/I), and (v) energy productivity (EP) (Crop yield/EI). Total EI varied from 6.19 GJ ha-1 year-1 for B-F to 11.7 GJ ha-1 year-1 for B-B, that indicates that the energy requirements of barley monoculture (B-B) are almost double those when a fallow period is included in the rotation. Fertilizer was the main energy input, accounting from 52% in B-V to 62% in B-B. EO increased in the order B-B (19.1 GJ ha-1 year-1) ? B-F B-F > B-S > B-B (2.00), indicating the low energy use efficiency of barley monoculture. Vetch was the most energetically efficient crop (yield/input), a result of the low requirements for producing a unit of vetch hay. EP ranged from 360 kg GJ-1 for B-V to 137 kg GJ-1 for B-B. As conclusions and in terms of energy efficiency, cereal monoculture, independent of the crop management system used, appeared to be an energetically unsustainable practice. However, crop rotations, especially those that include a leguminous crop, increase energy efficiency.

Moreno, M. C.; Moreno, M. M.; Lacasta, C.; Tarquis, A. M.; Meco, R.

2012-04-01

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ESTABLISHMENT OF SHORT ROTATION WOODY CROP TRIALS IN ATLANTIC CANADA  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The purpose of this study was to analyze the establishment of short rotation plantations in the province of New Brunswick, in Atlantic Canada. Two bioenergy crops, willow and Miscanthus and their six clones (Salix Viminalis, Salix Eriocephala, Salix Miyabeana, Miscanthus M114, M115 and M116) were selected to this thesis and their survivals and costs were examined. The method in this study is a field test conducted in summer 2011. Materials include survival rates, soil analyses, diary note...

Malinen, Satu

2012-01-01

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CONVERSÃO E BALANÇO ENERGÉTICO DE SISTEMAS DE SUCESSÃO E DE ROTAÇÃO DE CULTURAS ENERGY CONVERSION AND BALANCE OF CROP SUCCESSION AND ROTATION SYSTEMS  

Directory of Open Access Journals (Sweden)

Full Text Available Do ponto de vista calórico, existem poucos trabalhos no Brasil estimando a conversão e o balanço energético. Neste estudo, avaliaram-se a conversão e o balanço energético de sete sistemas de rotação de culturas durante nove anos (1987 a 1995, em Passo Fundo, RS. Os sistemas foram constituídos por: sistema I (trigo/soja; sistema II (trigo/soja, de 1987 a 1989, e trigo/soja e ervilhaca/ milho ou sorgo, de 1990 a 1995; sistema III (trigo/soja, aveia preta ou aveia branca/soja e ervilhaca/milho ou sorgo; sistema IV (trigo/soja, aveia branca/soja, linho/soja e ervilhaca/milho, de 1987 a 1989, e trigo/soja, girassol ou aveia preta/soja, aveia branca/soja e ervilhaca/milho ou sorgo, de 1990 a 1995; sistema V (trigo/soja, trigo/soja, aveia preta ou aveia branca/soja e ervilhaca/milho ou sorgo; sistema VI (trigo/ soja, trigo/soja, aveia branca/soja, linho/soja e ervilhaca/milho, de 1987 a 1989, e trigo/soja, trigo/soja, girassol ou aveia preta/soja, aveia branca/soja e ervilhaca/milho ou sorgo, de 1990 a 1995; e VII (pousio de inverno/soja, de 1990 a 1995. No período agrícola de 1987 a 1989, não houve diferenças significativas entre os sistemas de rotação de culturas, em relação à conversão energética e ao balanço energético. Na média do período de 1990 a 1995, o sistema II (8,58 apresentou índice de conversão energética maior do que o do sistema I (5,61, e os demais sistemas não diferiram significativamente entre si. No mesmo período, o balanço energético para os sistemas II (20.938Mcal/ha, III (19.239Mcal/ha, IV (18.618Mcal/ha, V (19.646kg/Mcal e VI (18.702Mcal/ha foi superior ao do sistema VII (10.279Mcal/ha. A rotação de culturas foi mais eficiente, sem aumentar o consumo de energia não renovável.Energy conversion and balance of seven crop rotation systems for wheat were assessed from 1987 to 1995, in Passo Fundo, RS, Brazil. The following systems were evaluated: system I (wheat/soybean; system II (wheat/soybean, from 1987 to 1989, and wheat/soybean and common vetch/corn or sorghum, from 1990 to 1995; system III (wheat/soybean, black oats or white oats/soybean, and common vetch/corn or sorghum; system IV (wheat/soybean, white oats/soybean, flax/soybean, and common vetch/corn, from 1987 to 1989, and wheat/soybean, sunflower or black oats/soybean, white oats/soybean, and common vetch/corn or sorghum, from 1990 to 1995; system V (wheat/soybean, wheat/soybean, black oats or white oats/soybean, and common vetch/corn or sorghum; system VI (wheat/soybean, wheat/soybean, white oats/soybean, flax/soybean, and common vetch/corn, from 1987 to 1989, and wheat/soybean, wheat/soybean, sunflower or black oats/soybean, white oats/soybean, and common vetch/corn or sorghum, from 1990 to 1995; and VII (winter fallow/soybean, from 1990 to 1995. On the average from1987 to 1989, no significant differences among rotation systems were observed for energy conversion and energy balance rates. From 1990 to 1995, system II (8.58 showed greater energy conversion index than system I (5.61, and the remaining systems did not differ significantly among themselves. From 1990 to 1995, systems II (20,938Mcal/ha, III (19,239Mcal/ha, IV (18,618Mcal/ha, V (19.646Mcal/ha, and VI (18,702Mcal/ha showed greater energy balance, as compared to system VII (10.279kg/Mcal.

Henrique Pereira dos Santos

2001-04-01

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Nuclear methods for plant nutrient and water balance studies. Results of an FAO/IAEA regional technical co-operation programme on nuclear methods for plant nutrients and water balance studies under legume-cereal or fallow-cereal crop rotation systems implemented for Middle Eastern countries (1991-1994)  

International Nuclear Information System (INIS)

In semi-arid Middle Eastern countries, the increasing demand for food and other agricultural products calls for urgent measures to increase plant nutrient availability and water use efficiency. Water and plant nutrients are the two main crop yield limiting factors in these regions. Improved methods must be developed to sustain crop productivity of the legume-cereal rotation systems. It has been recognized for years that the growth of leguminous crops can improve the N status of the soil through biological nitrogen fixation (BNF). The conditions to improve the efficiency of the fixation process should be further investigated in order to fully benefit from this cheap N source. The BNF process is especially interesting for those areas facing limited fertilizer N availability or where the price of the fertilizers is too high for the farmers. In view of sustainable productivity, even with adequate supply of nutrients (nitrogen) and water, crop rotations have been promoted for years. However, the best rotation, taking into account the available nutrients and water in a specific place, is not always known. Furthermore, if a leguminous crop can be incorporated into a crop rotation system, free N is provided for this crop and some of it can serve as residual N for the next crop in the rotation. The use of 15N technology provides a unique tool to separately study the behaviour of fertilizer N as well as soil N. In addition, the quantification of residual fertilizer N is possible, as well as the quantification of BNF. Refs, figs, tabs

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EFFICIENCY OF FERTILIZATION AND SOIL CULTIVATION IN CROP ROTATION  

Directory of Open Access Journals (Sweden)

Full Text Available The experiment with the crop rotation: winter wheat, pea, corn, spring barley and cow-grass were founded in 2001- 2004. We examined the effect of the preceding crop, the soil cultivation and fertilization on yield of grain of the main product. The methods of soil cultivation: tillage to the depth of 0.25 m, to the depth of 0.15 m and cultivation where we used disk tools to the depth of 0.10 m. In the variants of fertilization had been used fertilization of the artificial fertilizer with the balance method and fertilization with the artificial fertilizer with the placement of the remains of the preceding crop. By grain corn were statistically significant yield achieved after the tillage to the depth of 0.25 m and 0.15 m. Spring barley reacted positive on the soil cultivation with disk tools. Yield of the winter wheat and the pea were not statistically significant. Fertilization affected statistically significant on yield of winter wheat. The effect of the artificial fertilizers and the residues of the preceding crop on yield of corn, spring barley and pea did not show statistically significant.

Eva CANDRÁKOVÁ

2009-03-01

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Efeito de manejos de solo e de rotação de culturas de inverno no rendimento e doenças de trigo / Effect of soil management and of crop rotation systems on wheat yield and diseases  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar os efeitos de sistemas de manejo de solo e de rotação de culturas de inverno sobre o rendimento de grãos e sobre doenças radiculares do trigo. Foram comparados quatro sistemas de manejo de solo: plantio direto, cultivo mínimo, preparo convencional do solo com ar [...] ado de discos mais grade de discos e preparo convencional de solo com arado de aivecas mais grade de discos. Na rotação de culturas, três sistemas foram utilizados: sistema I (trigo/soja), sistema II (trigo/soja e ervilhaca/milho ou sorgo) e sistema III (trigo/soja, aveia-preta ou aveia-branca/soja e ervilhaca/milho ou sorgo). O delineamento experimental foi em blocos ao acaso, com parcelas subdivididas e três repetições. A parcela principal foi constituída pelos sistemas de manejo de solo, e as subparcelas, pelos sistemas de rotação de culturas. O rendimento de grãos de trigo cultivado em plantio direto e em cultivo mínimo foi superior ao cultivado após preparo convencional do solo com arado de discos e com arado de aivecas. A rotação de culturas foi eficiente na redução de doenças do sistema radicular, resultando em aumento do rendimento de grãos de trigo. Abstract in english The effects of soil management systems and winter crop rotation on wheat yield and root diseases were assessed. No-tillage, minimum tillage,conventional tillage using a disc plow plus disc harrow, and tillage using a moldboard plow plus disc harrow were the soil managements compared. In crop rotatio [...] n, three systems were used:system I (wheat/soybean), system II (wheat/soybean and common vetch/corn or sorghum), and system III (wheat/soybean, black oats or white oats/soybean, and common vetch/corn or sorghum). A randomized block experimental design, with split-plots and three replicates, was used. The main plots were formed by the soil management systems, while the split-plots consisted of crop rotation systems. Yield of wheat grown under no-tillage and minimum tillage was higher than the yield of wheat grown under conventional soil tillage using either disc plow or moldboard plow. Crop rotation was efficient in reducing root diseases and in increasing wheat yield.

HENRIQUE PEREIRA DOS, SANTOS; JULIO CESAR BARRENECHE, LHAMBY; ARIANO MORAES, PRESTES; MARCOS ROBERTO DE, LIMA.

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INFLUÊNCIA DE CULTURAS DE INVERNO SOBRE O RENDIMENTO DE GRÃOS DE SOJA CULTIVADA EM SISTEMAS DE ROTAÇÃO DE CULTURAS / INFLUENCE OF WINTER CROPS ON SOYBEAN YIELD IN CROP ROTATION SYSTEMS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Durante nove anos, avaliou-se o efeito de diferentes culturas antecessoras sobre o rendimento de grãos e sobre a estatura de plantas de soja, na EMBRAPA-Centro Nacional de Pesquisa de Trigo (CNPT), em Passo Fundo, RS. Os tratamentos consistiram em sete sistemas de rotação de culturas, e a soja foi s [...] emeada em sucessão à aveia branca, à aveia preta, ao linho e ao trigo. Em 1990, foram adicionadas duas parcelas, uma para completar o sistema II e outra para pousio de inverno antecedendo a soja (sistema VII). As culturas de inverno foram estabelecidas com preparo convencional de solo, e as de verão, em plantio direto. O delineamento experimental foi blocos ao acaso, com três repetições, e parcelas com área útil de 30m². A soja cultivada após linho, na média do período de 1987 a 1989, nos sistemas IV e VI, apresentou menor estatura de plantas e menor rendimento de grãos. Nos períodos de 1990 a 1992 e de 1993 a 1995, não houve diferenças significativas entre tipo de cultura antecessora e rendimento de grãos. A soja cultivada após aveia branca, após aveia preta ou após trigo pode ser incluída, sem prejuízo, nos diferentes sistemas estudados. Abstract in english Different preceding crops on the yield and height of soybean plants was assessed during nine years at EMBRAPA-Centro Nacional de Pesquisa de Trigo (CNPT), in Passo Fundo, RS, Brazil. The treatments consisted of seven crop systems, and soybean was sown in succession to white oat, black oat, flax, and [...] wheat. Two plots were added in 1990; one to complement system II and the other as winter fallow preceding soybean (system VII). Winter crops were set up using conventional soil preparation, and summer crops were sown under no-tillage. An experimental design of blocks at random, with three replications and plots totalling 30m², was used. The grown soybean after flax, in the mean of the period 1987 to 1989, in systems IV and VI showed lower plant on height and lower yield. No significant differences were found on the evoluated preceding crops on the yield over the periods 1990 to 1992 and 1993 to 1995. The grown soybean after white oat, black oat or wheat may be included in the different systems studied without any adverse effect.

Henrique Pereira dos, Santos; Julio Cesar Barreneche, Lhamby.

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The Effects of Weed-Crop Competition on Nutrient Uptake as Affected by Crop Rotation and Fertilizers  

Directory of Open Access Journals (Sweden)

Full Text Available A field study at the Agricultural University of Timiriazev, Moscow, was conducted to determine the effect of crop rotation and Long-term fertilizer application on differences in the competitive ability of spring barley and weeds to nutrient uptake in 2004 and 2005. Spring barley was cultivated in continuous and in crop rotation with winter rye, potato, clover, flax and fallow, with and without NPK application since 1912. Spring barley, especially in no fertilizer plots grown in crop rotation has greater dry mass than spring barley grown in continuous. While dry weed mass markedly decreased in crop rotation. Decrease dry weeds mass was greater when NPK had applied. The statistical analyses show that when spring barley grew in competition with weeds in the no fertilizer plots, crop rotation significantly increased nutrient content in spring barley, but when fertilizer applied the content of N, P2O5 and K2O in barley did not change. Lowest weeds nutrient content observed where soil fertility was increased by crop rotation and NPK application. Crop rotation significantly increased total nutrient uptake of soils by spring barley, but decreased total nutrient uptake by weeds.

Hamid Reza Mohammaddoust-e-Chamanabad Mohammaddoust-e-Chamanabad

2007-01-01

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Carbon storage and recycling in short-rotation energy crops  

International Nuclear Information System (INIS)

Short-rotation energy crops can play a significant role in storing carbon compared to the agricultural land uses they would displace. However, the benefits from these plantations in avoiding further use of fossil fuel and in taking pressure off of native forests for energy uses provides longer term carbon benetfits than the plantation carbon sequestration itself. The fast growth and harvest frequency of plantations tends to limit the amount of above and below-ground carbon storage in them. The primary components of plantation carbon sequestering compared to sustained agricultural practices involve above-ground wood, possible increased soil carbon, litter layer formation, and increased root biomass. On the average, short-rotation plantations in total may increase carbon inventories by about 30 to 40 tonnes per hectare over about a 20- to 56-year period when displacing cropland. This is about doubling in storage over cropland and about one-half the storage in human-impacted forests. The sequestration benefit of wood energy crops over cropland would be negated in about 75 to 100 years by the use of fossil fuels to tend the plantations and handle biomass. Plantation interactions with other land uses and total landscape carbon inventory is important in assessing the relative role plantations play in terrestrial and atmospheric carbon dynamics. It is speculated that plantations, when viewed in this context. could trencrate a global leveling of net carbon emissions for approximately 10 to 20 years

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Carbon storage and recycling in short-rotation energy crops  

International Nuclear Information System (INIS)

Short-rotation energy crops can play a significant role in storing carbon compared to the agricultural land uses they would displace. However, the benefits from these plantations in avoiding further use of fossil fuels and in taking pressure off native forests for energy uses provides longer term carbon benefits than the plantation carbon sequestration itself. The fast growth and harvest frequency of plantations tends to limit the amount of above- and below-ground carbon storage in them. The primary components of plantation carbon sequestering compared to sustained agricultural practices involve above ground wood, possible increased soil carbon, litter layer formation, and increased root biomass. On the average, short-rotation plantations in total may increase carbon inventories by about 10 to 40 tonnes per hectare over about a 20 to 50 year period when displacing cropland. This is about doubling in storage over cropland and about one-half the storage in human-impacted forests. The sequestration benefit of wood energy crops over cropland would be negated in about 75 to 100 years by the use of fossil fuels to tend the plantations and handle biomass. Plantation interactions with other land uses and total landscape carbon inventory is important in assessing the relative role plantations play in terestrial and atmospheric carbon dynamics. It is speculated that plantations, when viewed in this context, could generate a global levelling of net carbon emissions for approximaling of net carbon emissions for approximately 10 to 20 years. 16 refs., 7 figs

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Soil organic carbon dynamics and crop yield for different crop rotations in a degraded ferruginous tropical soil in a semi-arid region: a simulation approach.  

Science.gov (United States)

In recent years, simulation models have been used as a complementary tool for research and for quantifying soil carbon sequestration under widely varying conditions. This has improved the understanding and prediction of soil organic carbon (SOC) dynamics and crop yield responses to soil and climate conditions and crop management scenarios. The goal of the present study was to estimate the changes in SOC for different cropping systems in West Africa using a simulation model. A crop rotation experiment conducted in Farakô-Ba, Burkina Faso was used to evaluate the performance of the cropping system model (CSM) of the Decision Support System for Agrotechnology Transfer (DSSAT) for simulating yield of different crops. Eight crop rotations that included cotton, sorghum, peanut, maize and fallow, and three different management scenarios, one without N (control), one with chemical fertilizer (N) and one with manure applications, were studied. The CSM was able to simulate the yield trends of various crops, with inconsistencies for a few years. The simulated SOC increased slightly across the years for the sorghum-fallow rotation with manure application. However, SOC decreased for all other rotations except for the continuous fallow (native grassland), in which the SOC remained stable. The model simulated SOC for the continuous fallow system with a high degree of accuracy normalized root mean square error (RMSE)=0·001, while for the other crop rotations the simulated SOC values were generally within the standard deviation (s.d.) range of the observed data. The crop rotations that included a supplemental N-fertilizer or manure application showed an increase in the average simulated aboveground biomass for all crops. The incorporation of this biomass into the soil after harvest reduced the loss of SOC. In the present study, the observed SOC data were used for characterization of production systems with different SOC dynamics. Following careful evaluation of the CSM with observed soil organic matter (SOM) data similar to the study presented here, there are many opportunities for the application of the CSM for carbon sequestration and resource management in Sub-Saharan Africa. PMID:22505776

Soler, C M Tojo; Bado, V B; Traore, K; Bostick, W McNair; Jones, J W; Hoogenboom, G

2011-10-01

60

Rotating Aperture System  

Science.gov (United States)

A rotating aperture system includes a low-pressure vacuum pumping stage with apertures for passage of a deuterium beam. A stator assembly includes holes for passage of the beam. The rotor assembly includes a shaft connected to a deuterium gas cell or a crossflow venturi that has a single aperture on each side that together align with holes every rotation. The rotating apertures are synchronized with the firing of the deuterium beam such that the beam fires through a clear aperture and passes into the Xe gas beam stop. Portions of the rotor are lapped into the stator to improve the sealing surfaces, to prevent rapid escape of the deuterium gas from the gas cell.

Rusnak, Brian (Livermore, CA); Hall, James M. (Livermore, CA); Shen, Stewart (Danville, CA); Wood, Richard L. (Santa Fe, NM)

2005-01-18

 
 
 
 
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Can non-inversion tillage and straw retainment reduce N leaching in cereal based crop rotations?  

DEFF Research Database (Denmark)

Finding ways of reducing nitrate leaching in Northern Europe has become an extremely important task, especially under the projected climate changes that are expected to exacerbate the problem. To this end, two field experiments were established under temperate coastal climate conditions to evaluate the effect of tillage, straw retainment and cropping sequences, including cover crops, on nitrate leaching. The experiments were established in autumn 2002 on a loamy sand with 92 g clay kg-1 and a sandy loam with 147 g clay kg-1. The tillage treatments were stubble cultivation to 8-10 cm or 3-4 cm, direct drilling, or ploughing to 20 cm. The hypothesis was that (i) decreasing soil tillage intensity would decrease leaching compared to ploughing, (ii) leaving straw in the field would decrease leaching compared to removing straw, and (iii) a spring/winter crop rotation with catch crops would be more efficient in reducing nitrate leaching than a winter crop rotation. Overall, we were not able to confirm the three hypotheses. The effect of soil tillage on leaching might be blurred because the studied crop rotations had a high proportion of winter crops and because catch crops were grown whenever the alternative would have been bare soil in autumn and winter. The spring/winter crop rotation with catch crops was not found to be more efficient in reducing nitrate leaching than the winter crop rotation. In contrast, in a single year the winter crop rotation showed significantly lower leaching than the spring/winter crop rotations, probably due to the spring/winter crop rotation including peas, which may be considered a high-risk crop. Our study highlights that management practices that improve biomass production throughout the year are crucial in order to tighten the nitrogen cycle and thereby reduce nitrate leaching.

Hansen, Elly MØller; Munkholm, Lars Juhl

2010-01-01

62

The Effect of Tobacco Monoculture and Crop Rotations on Tobacco Leaf Composition  

Directory of Open Access Journals (Sweden)

Full Text Available This paper presents the long-term results relating to the influence of different crop rotations and tobacco monoculture upon the chemical composition of flue-cured tobacco leaf. As a key crop, tobacco is included in all crop rotations. Considering the obtained results in the particular year’s tobacco growing in monoculture or in crop rotation mainly had significant effect on nicotine content in tobacco leaf including a 10-year average. A similar trend was also determined for the content of proteins. The content of total nitrogen and reducing sugars was mainly affected significantly by crop rotation as regards the particular years. Calcium and potassium ratio was also unfavorable, although both of them were significantly influenced by crop rotation. The same is true for magnesium in the particular years.

An?elko Butorac

2004-12-01

63

Diversifying crop rotations with temporary grasslands : potentials for weed mangement and farmland biodiversity  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Crop rotation may be used to prevent the continuous selection of particular weed species adapted to one crop type. This might be useful for weed management, economy in herbicide applications and promoting biodiversity. Common simple crop sequences might be diversified by introducing perennial forage crops. Impacts of such perennial crops on weeds were studied with four approaches : 1) Large-scale weed surveys in 632 fields in western France showed that weed species composition differed most s...

Meiss, Helmut

2010-01-01

64

Carbon stock and its compartments in a subtropical oxisol under long-term tillage and crop rotation systems Estoque e compartimentos de carbono em um latossolo vermelho subtropical sob diferentes sistemas de longo prazo de preparo e rotação de culturas  

Directory of Open Access Journals (Sweden)

Full Text Available Soil organic matter (SOM plays a crucial role in soil quality and can act as an atmospheric C-CO2 sink under conservationist management systems. This study aimed to evaluate the long-term effects (19 years of tillage (CT-conventional tillage and NT-no tillage and crop rotations (R0-monoculture system, R1-winter crop rotation, and R2- intensive crop rotation on total, particulate and mineral-associated organic carbon (C stocks of an originally degraded Red Oxisol in Cruz Alta, RS, Southern Brazil. The climate is humid subtropical Cfa 2a (Köppen classification, the mean annual precipitation 1,774 mm and mean annual temperature 19.2 ºC. The plots were divided into four segments, of which each was sampled in the layers 0-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30 m. Sampling was performed manually by opening small trenches. The SOM pools were determined by physical fractionation. Soil C stocks had a linear relationship with annual crop C inputs, regardless of the tillage systems. Thus, soil disturbance had a minor effect on SOM turnover. In the 0-0.30 m layer, soil C sequestration ranged from 0 to 0.51 Mg ha-1 yr-1, using the CT R0 treatment as base-line; crop rotation systems had more influence on soil stock C than tillage systems. The mean C sequestration rate of the cropping systems was 0.13 Mg ha-1 yr-1 higher in NT than CT. This result was associated to the higher C input by crops due to the improvement in soil quality under long-term no-tillage. The particulate C fraction was a sensitive indicator of soil management quality, while mineral-associated organic C was the main pool of atmospheric C fixed in this clayey Oxisol. The C retention in this stable SOM fraction accounts for 81 and 89 % of total C sequestration in the treatments NT R1 and NT R2, respectively, in relation to the same cropping systems under CT. The highest C management index was observed in NT R2, confirming the capacity of this soil management practice to improve the soil C stock qualitatively in relation to CT R0. The results highlighted the diversification of crop rotation with cover crops as a crucial strategy for atmospheric C-CO2 sequestration and SOM quality improvement in highly weathered subtropical Oxisols.A matéria orgânica do solo (MOS desempenha papel relevante na qualidade do solo e pode atuar como dreno de C-CO2 atmosférico em solos sob sistemas de manejo conservacionista. Este estudo foi realizado com o objetivo de investigar o efeito de longo prazo (19 anos de sistemas de preparo do solo (PC-preparo convencional e PD-plantio direto e de rotação de culturas (R0- sucessão de monoculturas, R1- rotação de culturas de inverno e R2- rotação intensiva de culturas no estoque de carbono (C orgânico total, particulado e associado a minerais de um Latossolo Vermelho, originalmente degradado, do Sul do Brasil. O clima é subtropical úmido Cfa 2, segundo a classificação de Köppen, com média anual de precipitação pluvial de 1.774 mm e média anual de temperatura de 19,2 ºC. As parcelas experimentais foram divididas em três segmentos, e em cada um destes foram coletadas amostras nas profundidades de 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,30 m. As amostras foram coletadas por meio da abertura manual de pequenas trincheiras. O estoque de C no solo apresentou relação linear com o aporte anual de C, independentemente do sistema de preparo investigado. Assim, o preparo do solo teve pequeno efeito no incremento da taxa de decomposição da MOS. Na camada de 0-0,30 m, a taxa de sequestro de C variou de zero a 0,51 Mg ha-1 ano-1 considerando o tratamento CT R0 como referência, sendo a rotação de culturas uma estratégia mais eficiente em determinar o acúmulo de C do que os sistemas de preparo. Na média dos sistemas de cultura, uma taxa de sequestro de C de 0,13 Mg ha-1ano-1 foi observada sob PD em relação ao PC. Isso é claro? Esse resultado foi determinado pelo maior aporte de C proporcionado pela melhoria da qualidade do solo em PD adotado por longo prazo. A fração particulada de C foi um indicador eficie

Ben-Hur Costa de Campos

2011-06-01

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Rendimento de soja em sistema de integração lavoura-pecuária: efeito de métodos e intensidades de pastejo Soybean yield in an animal-crop rotation system: effects of grazing methods and intensities  

Directory of Open Access Journals (Sweden)

Full Text Available Sistemas de integração lavoura-pecuária têm despertado o interesse de produtores que buscam a diversificação das atividades e o aumento da rentabilidade. O objetivo deste trabalho foi avaliar a influência de métodos e intensidades de pastejo de ovinos no rendimento da soja cultivada em dois espaçamentos entre linhas, em um sistema de integração lavoura-pecuária. O experimento foi conduzido no município de Eldorado do Sul - RS, na Estação Experimental Agronômica - UFRGS na safra 2003/2004, cujas coordenadas geográficas são 30005'22" S de latitude e 51039'08" W de longitude. O delineamento experimental foi em blocos casualizados num fatorial com duas intensidades de pastejo, baixa e moderada, dois métodos de pastejo, contínuo e rotacionado, e dois espaçamentos entre fileiras de soja, 0,2 e 0,4m, com quatro repetições. Uma área foi adicionada como testemunha sem pastejo. Avaliaram-se o rendimento e os componentes do rendimento da soja. A produção de soja foi superior nos tratamentos submetidos a pastejo em comparação aos não-pastejados. Dentre os pastejados, o rendimento de soja foi superior na intensidade de pastejo baixa em comparação com a intensidade moderada. A intensidade de pastejo utilizada no inverno é o principal determinante do sucesso desse sistema de integração lavoura-pecuária.Animal-crop rotation systems are fostering the interest of farmers searching for diversification and the increase of profitability. The experiment aimed to evaluate the influence of grazing methods and intensities applied on winter pastures grazed by lambs and its consequence for soybean yield cultivated in succession. This crop-animal rotation trial was conducted in 2003/2004 at UFRGS Agricultural Research Station (Universidade Federal do Rio Grande do Sul in Eldorado do Sul, Rio Grande do Sul state, Brazil, whose geographical coordinates are 30005'22" S latitude and 51039'08" W longitude. The experimental design was a randomized complete block arranged in a factorial with two grazing methods, continuous and rotational, two grazing intensities, low and moderate, and two soybean rows spacing, 0.2 and 0.4 m, with four replicates. An additional area was surveyed as a no grazing paddock reference and soybean yield attributes were evaluated. Soybean yield was superior in grazed areas (P<0.05 compared to non grazed ones. Among grazed treatments, soybean yield was superior (P<0.05 at low grazing intensity compared to moderate grazing intensity. The grazing intensity level used during winter is fundamental to the success of animal-crop rotation systems.

Robson Lunardi

2008-06-01

66

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

DEFF Research Database (Denmark)

Tillage and rotation are fundamental factors influencing soil quality and thus the sustainability of cropping systems. Many studies have focused on the effects of either tillage or rotation but few have quantified long term integrated effects tillage and rotation. We studied the issue using a 30 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 structural quality was visually evaluated early June and mid October. Minimal disturbed soil cores early June and these were used for X-ray CT scanning and more traditional analysis. Soil friability was determined on the soil samples using a drop shatter test. Crop yield was determined and correlated to the soil quality estimates. We found significant effect of both rotation and tillage on visual soil structure at both times of assessment. Poor soil structure was found for NT except when combined with a versatile crop rotation (R6). The soil core pore characteristics data also displayed a significant effect of tillage but only a weak insignificant effect of rotation. The drop shatter results were in accordance with the visual assessment data. Crop yield correlated significantly with the visual soil structure scores. We conclude that a versatile crop rotation was needed for an optimal performance of NT for the studied soil.

Munkholm, Lars Juhl; Heck, Richard

67

On the effect of crop rotation on artificially established weed species in two field experiments  

Directory of Open Access Journals (Sweden)

Full Text Available Several studies indicate links between regional occurrence of well adapted weed species and crop rotations. Monocultures or very short crop rotation, which increased in the past decades are crucial for the establishment and dispersion of problematic weed species. In this study the impact of crop rotation on the occurrence of the species Amaranthus retroflexus (L., Anchusa arvensis (L. M. Bieb., Echinochloa crus-galli (L., Galium aparine (L., Geranium pusillum (L., Sisymbrium officinale (L., Solanum nigrum (L., Stellaria media (L. Vill., Viola arvensis Murray is investigated in four crop rotations with varying potential of crop health risks. Therefore, maize (M, oilseed rape (WR and winter wheat [early sowing (WWF and late sowing (WWS] are cropped in four different rotations (M, WR – WWF, WR – M – WWS and WR – WWF – M – WWS at two study sites in Germany since year 2008 (Rostock and 2009 (Göttingen. At the start of the project selected weed species were sown into some plots in order to simulate an artificial similar weed pressure. In all plots weed species densities were counted before spraying in a standardized observation method. Analyses of four, respectively three years give evidences of crop specific effects regarding A. arvensis, E. crus-galli, G. pusillum, S. nigrum and S. media. Moreover, first effects of crop rotations on problematic weed species indicates that expanding crop rotations is a preventive tool to reduce weed densities.

Flucke, Christoph

2014-02-01

68

Desempenho agronômico da soja sob diferentes rotações e sucessões de culturas em sistema plantio direto / Agronomic performance of soybean in different rotations and successions of crops in no tillage system  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este trabalho faz parte de um projeto de longa duração que teve início em 1997 e envolve produção de grãos baseada em sistemas de rotação ou sucessão de culturas. O experimento foi desenvolvido no ano agrícola 2005/06, em LATOSSOLO VERMELHO Distroférrico, na Fazenda Experimental de Ciências Agrárias [...] da Universidade Federal da Grande Dourados - UFGD, em Dourados, Estado de Mato Grosso do Sul. O delineamento experimental foi em blocos casualizados com sete tratamentos e três repetições. Em cada parcela, foram semeadas mecanicamente 26 linhas de soja com 36 m de comprimento, espaçadas entre si por 0,45 m. Os tratamentos consistiram de sete sistemas de rotação ou sucessão, envolvendo espécies semeadas solteiras ou com misturas de espécies antecessoras a soja, constituindo os seguintes tratamentos: Sistema 1: crotalária+ervilhaca/soja; Sistema 2: ervilhaca+aveia+nabo/soja; Sistema 3: girassol/soja; Sistema 4: milheto/soja; Sistema 5: milho/soja; Sistema 6: trigo/soja e Sistema 7: aveia/soja. Foram avaliadas a altura de planta, altura de inserção da primeira vagem, número de ramificações por planta, número de vagens por planta, produtividade da soja, massa de 100 grãos. Concluiu-se que podem ser utilizadas várias espécies em rotação ou sucessão de cultura com a soja no sistema plantio direto consolidado, sem afetar os componentes de produção da leguminosa. Abstract in english This work is a part of a long-term project that began in 1997 and which involves grain production based on crop rotation or crop succession systems. The experiment was carried out in the 2005/06 season, in a Dystroferric Red Latosol, in the Agrarian Science Experimental Farm of Federal University of [...] Great Dourados - UFGD, in Dourados, Mato Grosso do Sul, Brazil. The experimental design was in randomized blocks with seven treatments and three replications. In each parcel, 26 rows of soybean were sowed, 36 m long, spaced 0.45 m apart. Treatments consisted of seven systems of rotation or succession, involving species that were sowed alone or mixed with species that preceded soybean, comprising the following treatments: System 1: crotalaria + vetch /soybean; System 2: vetch +oat + turnip/soybean; System 3: sunflower/soybean; System 4: millet/soybean; System 5: corn/soybean; System 6: wheat/soybean; and System 7: oat/soybean. Plant height, insertion height of first pod, number of plant ramifications, number of pods per plant, soybean yield, and mass of 100 grains were evaluated. It was concluded that in a no-tillage consolidated system, various species can be used in rotation or succession with soybean, without affecting the components of the leguminous yield.

Cinthia Raquel, Mancin; Luiz Carlos Ferreira de, Souza; José Oscar, Novelino; Marlene Estevão, Marchetti; Manoel Carlos, Gonçalves.

69

Cereal yield and quality as affected by N availability in organic and conventional crop rotations in Denmark  

DEFF Research Database (Denmark)

The effects of nitrogen (N) availability related to fertilizer type, catch crop management, and rotation composition on cereal yield and grain N were investigated in four organic and one conventional cropping systems in Denmark using the FASSET model. The four-year rotation studied was: spring barley–(faba bean or grass-clover)–potato–winter wheat. Experiments were done at three locations representative of the different soil types and climatic conditions in Denmark. The three organic systems that included faba bean as the N fixing crop comprised a system with manure (stored pig slurry) and undersowing catch crops (OF + C + M), a system with manure but without undersowing catch crops (OF ? C + M), and a system without manure and with catch crops (OF + C ? M). A grass-clover green manure was used as N fixing crop in the other organic system with catch crops (OG + C + M). Cuttings of grass-clover were removed from the plots and an equivalent amount of total-N in pig slurry was applied to the cropping system. Theconventional rotation included mineral fertilizer and catch crops (CF + C + F), although only non-legume catch crops were used. Measurements of cereal dry matter (DM) at harvest and of grain N contents were done in all plots. On average the FASSET model was able to predict the yield and grain N of cereals with a reasonable accuracy for the range of cropping systems and soil types studied, having a particularly good performance on winter wheat. Cereal yields were better on the more loamy soil. DM yield and grain N content were mainly influenced by the type and amount of fertilizer-N at all three locations. Although a catch crop benefit in terms of yield and grain N was observed in most of the cases, a limited N availability affected the cereal production in the four organic systems. Scenario analyses conducted with the FASSET model indicated the possibility of increasing N fertilization without significantly affecting N leaching if there is an adequate catch crop management. This would also improve yields of cereal production of organic farming in Denmark

Doltra, Jordi; Lægdsmand, Mette

2011-01-01

70

Atributos bioquímicos e químicos do solo rizosférico e não rizosférico de culturas em rotação no sistema de semeadura direta / Biochemical and chemical attributes of rhizospheric and non-rhizospheric soil in no till crop rotation system  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Sistemas autossustentáveis favorecem as populações microbianas devido à conservação e ao aumento da matéria orgânica no solo. Além disso, as plantas que fazem parte desses sistemas promovem o efeito rizosférico, por meio da zona de influência das raízes, que resulta no aumento da atividade e na modi [...] ficação da população microbiana. O objetivo deste trabalho foi avaliar o efeito da rotação de culturas de inverno sobre sequências de verão, em sistema de semeadura direta, nos atributos bioquímicos (amilase, urease, celulase e protease) e químicos (carbono orgânico total - COT, carboidratos totais e proteínas totais) em solo rizosférico (SR) e não rizosférico (SNR). Este estudo foi constituído de três culturas de inverno: milho (Zea mays L.), girassol (Helianthus anuus L.) e guandu (Cajanus cajan (L.) Millsp), que estavam em rotação sobre três sequências de verão: soja/soja (Glycine max L.), milho/milho e soja/milho, e duas posições no solo: solo aderido às raízes das plantas (SR) e solo da entrelinha de plantio (SNR). As atividades da amilase, celulase, protease e urease no SR foram 16, 85, 62 e 100 % maiores do que no SNR; para COT e proteínas totais a diferença foi de 21 %. Das culturas de inverno, o milho foi a que mais estimulou as atividades das enzimas amilase, celulase, urease e protease no SR, bem como a atividade das enzimas amilase, urease e protease no SNR. De modo geral, os teores de proteínas totais não foram influenciados pelas culturas de inverno e pelas sequências de verão; os carboidratos totais foram influenciados pelas culturas de inverno milho e girassol. Para o COT houve influência apenas da sequência de verão milho/milho. Os atributos bioquímicos e químicos avaliados neste estudo podem ser utilizados como indicadores das alterações no solo promovidas pelas culturas de inverno e pelas sequências de verão. Abstract in english Self-sustaining systems encourage microbial populations due to the conservation and improvement of organic matter in the soil. In addition, the plants constituents of these systems produce the rhizospheric effect through the influence zone of the roots, increasing activity and modifying the microbia [...] l population. The objective of this study was to evaluate the effect of winter crop rotation and summer crop sequences in a no tillage system, based on biochemical (amylase, urease, cellulase, and protease) and chemical (organic carbon, total carbohydrates, and total protein) characteristics in rhizospheric (SR) and non-rhizospheric soil (SNR). Three winter crops were studied: corn (Zea mays L.), sunflower (Helianthus anuus L.), and pigeon pea (Cajanus cajan (L.) Millsp), in rotation with three summer sequences: soybean/soybean (Glycine max L.), corn/corn, and soybean/corn. Samples were taken from soil adhering to the plant roots (SR) and from in-between the rows (SNR). The activities of amylase, cellulase, protease, and urease in SR were 16, 85, 62, and 100 % higher, respectively, than in SNR. For total organic carbon and total protein, the difference was 21 %. Of the winter crops, corn stimulated higher amylase, cellulase, protease, and urease activity in SR, as well as amylase, protease, and urease activity in SNR. The winter crops and the summer sequences did not affect total protein levels. The total carbohydrates were influenced by winter corn and sunflower crops. Only the summer corn/corn sequence influenced total organic carbon. The biochemical and chemical properties analyzed in this study can be used as indicators of changes in soil caused by winter crops and summer sequences.

Meire Aparecida Silvestrini, Cordeiro; José Eduardo, Corá; Ely, Nahas.

71

Yield trends in the long-term crop rotation with organic and inorganic fertilisers on Alisols in Mata (Rwanda)  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A crop rotation system with various species was established on «Alisols» at Mata grassland site, oriental side of Zaire-Nile Watershed Divide (CZN), Rwanda. Inorganic and organic fertilisers were applied in various plots led in randomised complete blocs with three replicates. Crop yield data were each season recorded over a 9-year period. Results showed that there was very low or no harvest in plots without fertilisers. Where fertilisers were applied, the yield generally increased but re...

Neel H.; Rutunga V.

2006-01-01

72

Nitrate leaching from organic arable crop rotations is mostly determined by autumn field management  

DEFF Research Database (Denmark)

Two main challenges facing organic arable farming are the supply of nitrogen (N) to the crop and the control of perennial weeds. Nitrate leaching from different organic arable crop rotations was investigated over three consecutive four-year crop rotations in a field experiment at three locations in Denmark (12 years in total). The experimental treatments were: (i) crop rotation, (ii) catch crop and (iii) animal manure. Nitrate leaching was estimated from measured soil nitrate concentration in ceramic suction cells and modelled drainage. There were significant effects on annual N leaching of location (coarse sand > loamy sand > sandy loam) and catch crops (without > with). Including a grass-clover green manure on 25% of the area did not increase N leaching compared with crop rotations without green manure. Also the application of animal manure did not influence N leaching, probably because even in the manured treatments the application rate was lower than crop demand. The results identify management of crop and soil during autumn as the main determinant of N leaching. Nitrate leaching was lowest for a catch crop soil cover during autumn and winter (avg. 20 kg N ha?1), a soil cover of weeds/volunteers had on avg. 30 kg N ha?1, and the largest N leaching losses were found after stubble cultivation (avg. 55 kg N ha?1). The N leaching losses increased with increasing number of autumn soil cultivations

Askegaard, M; Olesen, JØrgen E

2011-01-01

73

Effectiveness of the GAEC standard of cross compliance Crop rotations in maintaining organic matter levels in soils  

Directory of Open Access Journals (Sweden)

Full Text Available Our study was conducted in the framework of EFFICOND project, with the aim of evaluating the environmental effectiveness of GAEC (Good Agricultural and Environmental Conditions standards with particular focus to the maintenance of soil organic matter (SOM levels through the appropriate crop rotation. The study analyzed the effect of crop rotation on the build-up of soil organic matter in three different areas of Italy, located in the North (Lodi, Centre (Fagna, Firenze and South (Foggia of Italy, characterized by different climate, soil, and cropping systems. In the two experiments conducted in the South of Italy, in a dry Mediterranean climate, the stock of C was kept steady in most of the rotations compared with the monoculture of durum wheat. In such environment, with very dry and hot summers, introducing a year of fallow seems to improve SOM content, but these data need further investigation. In the Centre of Italy (Fagna, with less extreme climate than in Foggia, the effect of rotation compared to the monoculture of maize is negligible, but investigation on the soil organic matter composition, showed that in the rotation the SOM appeared to be more stable and, in the long term, probably more resistant to degradation. Eventually, experiments conducted in the North of Italy, showed that the monoculture, despite the application of FYM (Farm Yard Manure or semi-liquid manure, led to a decrease of SOM. To an increase of the rotation complexity, corresponded an increase in the stock of C in soil. Summarizing, results showed that crop rotation could guarantee the maintenance of SOM level, given that the input of C to the soil is maintained at a good level or, in other word, that productivity of the system is high. Other practices such as conservation tillage, appropriate management of residues, and manure application could enhance the positive effect of rotations. Moreover, preliminary investigation of soil microbial diversity, suggests the positive effect of rotations on soil biological fertility.

Roberta Farina

2011-09-01

74

Biomassa, atividade microbiana e FMA em rotação cultural milho/feijão-de-corda utilizando-se águas salinas / Biomass, microbial activity and AMF in crop rotation system of maize/cowpea using saline water  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar a influência da irrigação com água de alta e baixa salinidade sobre variáveis microbiológicas do solo em área submetida à rotação de cultura entre milho (Zea Mays L.) e feijão-de-corda (Vigna unguiculata L.). A área destinada ao experimento foi dividida em duas [...] subáreas, sendo realizados quatro cultivos: dois cultivos irrigados na estação seca e dois de sequeiro na estação chuvosa. O estudo foi conduzido em campo, utilizando-se o delineamento em blocos ao acaso, com cinco repetições. Nos cultivos irrigados foram usadas água com as seguintes condutividades elétricas (CEa): 0,8; 2,2; 3,6 e 5,0 dS m-1. Os cultivos de sequeiro foram realizados nas mesmas parcelas que foram cultivadas na estação seca, as quais permaneceram demarcadas e identificadas. No início e ao final de cada cultivo, foram coletadas amostras em duas subáreas na região radicular das plantas, no terço médio da fileira central de cada parcela. O aumento da salinidade da água de irrigação promoveu aumento do número total de esporos de fungos micorrízicos arbusculares FMA e reduziu a respiração basal do solo, o carbono da biomassa e o coeficiente metabólico microbiano (qCO2), principalmente na área cultivada com feijão-de-corda. O gênero Glomus respondeu por mais de 70% dos esporos totais encontrados, sendo que essa percentagem aumentou nos tratamentos com maior salinidade nos cultivos da estação seca. Os dados não evidenciaram qualquer efeito negativo da salinidade residual sobre as variáveis microbiológicas avaliadas, em função da irrigação com água salina durante os cultivos da estação seca. Abstract in english This work carred out the influence of irrigation with water of high and low salinity on soil microbial variables in area under the crop rotation between maize (Zea Mays L.) and cowpea (Vigna unguiculata L.). The area for the experiment was divided into two sub areas being made four crops, two crops [...] irrigated in the dry season and two dry in the rainy season. The study was conducted under field conditions using a randomized block design with five replications. In irrigated crops were used the following water with electrical conductivity (ECw): 0.8; 2.2; 3.6 and 5.0 dS m-1. The rainfed crops were conducted on the same plots that were cultivated during the dry season, which remained demarcated and identified. At the beginning and end of each crop were collected samples in two subareas in the region of root system plant, in the middle third of the central row of each plot. Increasing of salinity in irrigation water led to increase in the total number of spores and reduced soil basal respiration, biomass carbon and microbial metabolic coefficient (qCO2), mainly in the area cultivated with cowpea. The genus Glomus accounted for more than 70% of total spores found, and this percentage increased in treatments with high salinity in dry season crops. The data reveal no residual negative effect of salinity on the microbial variables assessed in function irrigation with saline water during the dry season crops.

Maria Eloneide de Jesus, Bezerra; Claudivan Feitosa de, Lacerda; Geocleber Gomes de, Sousa; Vânia Felipe Freire, Gomes; Paulo Furtado, Mendes Filho.

2010-12-01

75

Controle de plantas daninhas em feijão num sistema de rotação culturas em plantio direto Weed control in beans in a no-tillage crop rotation system  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi selecionar culturas de inverno para formação de cobertura morta que reduza a população de plantas daninhas na cultura do feijão (Phaseolus vulgaris. Ocupou-se o terreno durante o ano todo, com a sucessão, em plantio direto, de pousio ou cultura de inverno/feijão/cultura para silagem, estudando-se três modalidades de controle de plantas daninhas na cultura do feijão. A maior renda líquida acumulada após duas safras foi obtida com feijão semeado sobre palha de aveia-preta e controle de plantas daninhas com um gramicida pré-emergente, completando-se com capinas, quando necessário.This study was undertaken to select winter crops for mulching to reduce the weed infestation and to lower weed control costs in bean (Phaseolus vulgaris production. The soil was kept convered all the year under no-tillage with a sequence of a winter crop or fallow/beans/silage crop. Three weed control methods for beans were studied. After two complete crop sequences, the highest total net income was obtained with the beans directly drilled on the black oats (Avena strigosa mulching, spraying a pre-emergence grasskiller plus hoeing when needed.

Benedito N. Rodrigues

1995-01-01

76

The Effect of Crop Rotation, Mineral Fertilizer Application and Herbicide on Weed Control in Winter Rye  

Directory of Open Access Journals (Sweden)

Full Text Available The recent years' problems of herbicide use have led a growing number of researchers to seek alternative methods that are less reliant on herbicides. This research was conducted to determine the effect of long-term crop rotation, mineral fertilizer and herbicide on the weed infestation and grain yield of winter rye during 2004 and 2005 at the long-term experimental site of the University of Timiriazev, Moscow. Treatments were control (no weed control, herbicide, combined fertilizer (NPK and NPK plus herbicide in field winter rye cultivated in continuous and crop rotation with other crops since 1912. Crop rotation significantly decreased weed density and dry mass. Long-term NPK application significantly decreased weed density, but had not any effect on weed dry mass. Crop rotation, NPK application and herbicide increased ground crop cover and decreased ground weed cover. In continuous crop, weed ground cover was 10 % in control plot and 3.33 % in plots where NPK was applied. Data showed that long-term crop rotation and NPK application can reduce weed infestation and increase grain yield of winter rye.

H Mohamad Dost CHamanabad

2009-04-01

77

IMPACT OF GROWING CROPS AND DIFFERENT WATER LOADINGS ON THE FEATURES OF DARK CHESTNUT SOILS IN RICE ROTATIONS ??????? ????????????? ??????? ? ????????? ?????? ???????? ?? ???????? ?????-?????????? ???? ? ??????? ????????????  

Directory of Open Access Journals (Sweden)

Full Text Available The article gives a general assessment for meliorative state of soils at the rice irrigation systems in the Ros-tov region. The indices of soil salinity, alkalinity, sodicity, calium content in soil exchangeable com-plex of dark chestnut soils at different crop rotations and water loadings are afforded

Mironchenko M. S.

2013-03-01

78

Efeito de sistemas de manejo de solo e de rotação de culturas na fertilidade do solo, após vinte anos Soil tillage and crop rotation systems on soil fertility attributes after twenty years  

Directory of Open Access Journals (Sweden)

Full Text Available No Brasil, ainda são escassos os estudos disponíveis com experimentos de longa duração em sistemas de manejo de solo e de rotação de culturas. Após vinte anos (1985 a 2005, a fertilidade de solo foi avaliada, em Latossolo Vermelho distrófico típico, em Passo Fundo (RS, em quatro sistemas de manejo de solo (SMSs - 1 plantio direto (PD, 2 cultivo mínimo (CM, 3 preparo convencional de solo com arado de discos e com grade de discos (PCD e 4 preparo convencional de solo com arado de aivecas e com grade de discos (PCA - e em três sistemas de rotação de culturas (SRCs: I (trigo/soja, II (trigo/soja e ervilhaca/milho e III (trigo/soja, ervilhaca/milho e aveia branca/soja, incluindo como testemunha um fragmento adjacente de floresta subtropical (FST. O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. As parcelas (4 x 90 m no total de 12, foram constituídas pelos SMSs, e as subparcelas, pelos SRCs (4 x 10 m, no total de 72. Os valores de pH, carbono, P extraível e K disponível diferiram entre os SMSs. No PD, houve acúmulo de carbono orgânico, P e K, na camada superficial. Não houve diferença do nível de matéria orgânica (MOS entre PD e FST, em todas as camadas estudadas. O nível de MOS e os teores de P e K foram mais elevados na camada 0-0,05 m, quando comparados com os observados de 0,15-0,20 m de profundidade, sob PD e nas rotações II e III. Observou-se que em FST os valores de pH, Ca, P e de K foram menores do que os dos SMSs e SRCs.Long term field studies on crop rotation and soil tillage systems under Brazilian conditions are scarce. Soil fertility characteristics were assessed after twenty years (1985 to 2005 on a typical dystrophic Red Latosol located in Passo Fundo, in Rio Grande do Sul, the southernmost state of Brazil. Four soil tillage systems (STS - 1 no-tillage, 2 minimum tillage, 3 conventional tillage using disk plow followed by disk harrow, and 4 conventional tillage using moldboard plow followed by disk harrow - and three crop rotation systems (CRS: I (wheat/soybean, II (wheat/soybean and common vetch/corn, and III (wheat/soybean, common vetch/corn, and white oat/soybean were evaluated, including as check a fragment of subtropical forest (FST. A randomized complete block design, with split-plots and three replicates, was used. The main field plots (4 x 90 m in a total of 12, were the soil tillage systems, whereas the subplots (4 x 10 m, in a total of 72 comprised the crop rotation systems. Values of soil pH, soil organic carbon, extractable P, and exchangeable K were affected by soil tillage systems (STSs. Higher levels of soil organic matter and contents of soil carbon, extractable P, and exchangeable K were observed in the 0-0,05 m layer for the no-tillage system. No statistical differences were found in soil organic matter levels between no-tillage and tropical forest, in any soil layer. Values of soil organic matter, P, and K were higher in the 0-0,05 m layer, when compared to the ones observed in the 0,15-0,20 m layer, in no-tillage and II and III CRSs. Values of pH, Ca, P, and K observed in all STSs and CRSs were higher than in the tropical forest area.

Henrique Pereira dos Santos

2008-01-01

79

Efeito de sistemas de manejo de solo e de rotação de culturas na fertilidade do solo, após vinte anos / Soil tillage and crop rotation systems on soil fertility attributes after twenty years  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese No Brasil, ainda são escassos os estudos disponíveis com experimentos de longa duração em sistemas de manejo de solo e de rotação de culturas. Após vinte anos (1985 a 2005), a fertilidade de solo foi avaliada, em Latossolo Vermelho distrófico típico, em Passo Fundo (RS), em quatro sistemas de manejo [...] de solo (SMSs) - 1) plantio direto (PD), 2) cultivo mínimo (CM), 3) preparo convencional de solo com arado de discos e com grade de discos (PCD) e 4) preparo convencional de solo com arado de aivecas e com grade de discos (PCA) - e em três sistemas de rotação de culturas (SRCs): I (trigo/soja), II (trigo/soja e ervilhaca/milho) e III (trigo/soja, ervilhaca/milho e aveia branca/soja), incluindo como testemunha um fragmento adjacente de floresta subtropical (FST). O delineamento experimental foi em blocos completos ao acaso, com parcelas subdivididas e três repetições. As parcelas (4 x 90 m) no total de 12, foram constituídas pelos SMSs, e as subparcelas, pelos SRCs (4 x 10 m), no total de 72. Os valores de pH, carbono, P extraível e K disponível diferiram entre os SMSs. No PD, houve acúmulo de carbono orgânico, P e K, na camada superficial. Não houve diferença do nível de matéria orgânica (MOS) entre PD e FST, em todas as camadas estudadas. O nível de MOS e os teores de P e K foram mais elevados na camada 0-0,05 m, quando comparados com os observados de 0,15-0,20 m de profundidade, sob PD e nas rotações II e III. Observou-se que em FST os valores de pH, Ca, P e de K foram menores do que os dos SMSs e SRCs. Abstract in english Long term field studies on crop rotation and soil tillage systems under Brazilian conditions are scarce. Soil fertility characteristics were assessed after twenty years (1985 to 2005) on a typical dystrophic Red Latosol located in Passo Fundo, in Rio Grande do Sul, the southernmost state of Brazil. [...] Four soil tillage systems (STS) - 1) no-tillage, 2) minimum tillage, 3) conventional tillage using disk plow followed by disk harrow, and 4) conventional tillage using moldboard plow followed by disk harrow - and three crop rotation systems (CRS): I (wheat/soybean), II (wheat/soybean and common vetch/corn), and III (wheat/soybean, common vetch/corn, and white oat/soybean) were evaluated, including as check a fragment of subtropical forest (FST). A randomized complete block design, with split-plots and three replicates, was used. The main field plots (4 x 90 m) in a total of 12, were the soil tillage systems, whereas the subplots (4 x 10 m), in a total of 72 comprised the crop rotation systems. Values of soil pH, soil organic carbon, extractable P, and exchangeable K were affected by soil tillage systems (STSs). Higher levels of soil organic matter and contents of soil carbon, extractable P, and exchangeable K were observed in the 0-0,05 m layer for the no-tillage system. No statistical differences were found in soil organic matter levels between no-tillage and tropical forest, in any soil layer. Values of soil organic matter, P, and K were higher in the 0-0,05 m layer, when compared to the ones observed in the 0,15-0,20 m layer, in no-tillage and II and III CRSs. Values of pH, Ca, P, and K observed in all STSs and CRSs were higher than in the tropical forest area.

Henrique Pereira dos, Santos; Silvio Tulio, Spera; Gilberto Omar, Tomm; Rainoldo Alberto, Kochann; Alexandre, Ávila.

80

Economics of Rainfed Cropping Systems: Northeast Thailand  

Science.gov (United States)

Using a computer model to simulate effective rainfall, it is shown that a flexible rainfed cropping system based on a legume crop planted before rice has a greater expected return than present subsistent rainfed cropping systems. Combining a legume crop intercropped with cassava or kenaf further increases the expected returns yet maintains the stability of the new system. Further research is required to bring the farmer's yields up to match experiment station results and to facilitate effective transfer policies.

Johnson, Sam H., III; Charoenwatana, Terd

1981-06-01

 
 
 
 
81

Soil salinization and maize and cowpea yield in the crop rotation system using saline waters / Salinização do solo e produtividade de milho e feijão caupi em sistema de rotação cultural utilizando águas salinas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A utilização de águas salinas bem como o reúso de águas de drenagem na irrigação dependem de estratégias de longo prazo que garantam a sustentabilidade socioeconômica e ambiental dos sistemas agrícolas. Neste trabalho, avaliaram-se os efeitos da irrigação com água salina na estação seca e com água d [...] e baixa salinidade na estação chuvosa sobre o acúmulo de sais no solo e a produtividade de milho e feijão-de-corda em sistema de rotação. O experimento foi conduzido em campo, utilizando-se do delineamento em blocos ao acaso, com cinco repetições. O primeiro cultivo foi instalado durante a estação seca de 2007, com a cultura do milho irrigada com água de diferentes salinidades (0,8; 2,2; 3,6 e 5,0 dS m-1). As plantas foram coletadas aos 90 dias após a semeadura (DAS), sendo realizadas as avaliações: crescimento vegetativo, produção de grãos por planta, matéria seca de 1.000 grãos e produtividade. Durante a estação chuvosa de 2008, foi cultivado o feijão caupi nas mesmas parcelas que foram cultivadas com milho. Ao final do ciclo, as plantas foram coletadas, sendo realizadas avaliações de crescimento vegetativo e produtividade. Amostras de solo foram coletadas antes e após o cultivo do milho e ao final do cultivo com feijão caupi. A salinidade da água de irrigação acima 2,2 dS m-1 reduziu a produtividade do milho durante o período seco. Os elevados totais de precipitação pluviométrica durante a estação chuvosa proporcionaram a lixiviação dos sais acumulados durante o cultivo na estação seca e eliminaram os possíveis efeitos negativos da salinidade sobre o feijão caupi. Porém, o feijão caupi apresentou um comportamento atípico com uma expressiva proporção de massa vegetativa e baixa produção de vagens, o que reduziu a eficiência dessa estratégia de rotação de culturas, nas condições do presente estudo. Abstract in english The use of saline water and the reuse of drainage water for irrigation depend on long-term strategies that ensure the sustainability of socio-economic and environmental impacts of agricultural systems. In this study, it was evaluated the effects of irrigation with saline water in the dry season and [...] fresh water in the rainy season on the soil salt accumulation yield of maize and cowpea, in a crop rotation system. The experiment was conducted in the field, using a randomized complete block design, with five replications. The first crop was installed during the dry season of 2007, with maize irrigated with water of different salinities (0.8, 2.2, 3.6 and 5.0 dS m-1). The maize plants were harvested at 90 days after sowing (DAS), and vegetative growth, dry mass of 1000 seeds and grain yield were evaluated. The same plots were utilized for the cultivation of cowpea, during the rainy season of 2008. At the end of the crop, cycle plants of this species were harvested, being evaluated the vegetative growth and plant yield. Soil samples were collected before and after maize and cowpea cultivation. The salinity of irrigation water above 2.2 dS m-1 reduced the yield of maize during the dry season. The high total rainfall during the rainy season resulted in leaching of salts accumulated during cultivation in the dry season, and eliminated the possible negative effects of salinity on cowpea plants. However, this crop showed atypical behavior with a significant proportion of vegetative mass and low pod production, which reduced the efficiency of this strategy of crop rotation under the conditions of this study.

Claudivan F., Lacerda; Geocleber G., Sousa; Francisco L. B., Silva; Francisco V. A., Guimarães; Giovana L., Silva; Lourival F., Cavalcante.

82

Carbon stock and its compartments in a subtropical oxisol under long-term tillage and crop rotation systems / Estoque e compartimentos de carbono em um latossolo vermelho subtropical sob diferentes sistemas de longo prazo de preparo e rotação de culturas  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A matéria orgânica do solo (MOS) desempenha papel relevante na qualidade do solo e pode atuar como dreno de C-CO2 atmosférico em solos sob sistemas de manejo conservacionista. Este estudo foi realizado com o objetivo de investigar o efeito de longo prazo (19 anos) de sistemas de preparo do solo (PC- [...] preparo convencional e PD-plantio direto) e de rotação de culturas (R0- sucessão de monoculturas, R1- rotação de culturas de inverno e R2- rotação intensiva de culturas) no estoque de carbono (C) orgânico total, particulado e associado a minerais de um Latossolo Vermelho, originalmente degradado, do Sul do Brasil. O clima é subtropical úmido Cfa 2, segundo a classificação de Köppen, com média anual de precipitação pluvial de 1.774 mm e média anual de temperatura de 19,2 ºC. As parcelas experimentais foram divididas em três segmentos, e em cada um destes foram coletadas amostras nas profundidades de 0-0,05, 0,05-0,10, 0,10-0,20 e 0,20-0,30 m. As amostras foram coletadas por meio da abertura manual de pequenas trincheiras. O estoque de C no solo apresentou relação linear com o aporte anual de C, independentemente do sistema de preparo investigado. Assim, o preparo do solo teve pequeno efeito no incremento da taxa de decomposição da MOS. Na camada de 0-0,30 m, a taxa de sequestro de C variou de zero a 0,51 Mg ha-1 ano-1 considerando o tratamento CT R0 como referência, sendo a rotação de culturas uma estratégia mais eficiente em determinar o acúmulo de C do que os sistemas de preparo. Na média dos sistemas de cultura, uma taxa de sequestro de C de 0,13 Mg ha-1ano-1 foi observada sob PD em relação ao PC. Isso é claro? Esse resultado foi determinado pelo maior aporte de C proporcionado pela melhoria da qualidade do solo em PD adotado por longo prazo. A fração particulada de C foi um indicador eficiente da qualidade dos sistemas de manejo, enquanto o C orgânico associado aos minerais foi um importante dreno de C-CO2 atmosférico nesse Latossolo argiloso. A retenção de C nessa fração estável da MOS contribuiu com 81 e 89 % do total de C sequestrado no solo em PD, nos sistemas R1 e R2, respectivamente. O maior índice de manejo de C foi verificado sob PD R2, confirmando o potencial de práticas de manejo em melhorar qualitativamente o C armazenado no solo, em relação ao PC R0. Esses resultados mostram que a diversificação da rotação de culturas, notadamente com a inclusão de plantas de cobertura, é uma importante estratégia para o sequestro de C-CO2 atmosférico e melhoria da qualidade da MOS em Latossolos subtropicais intemperizados. Abstract in english Soil organic matter (SOM) plays a crucial role in soil quality and can act as an atmospheric C-CO2 sink under conservationist management systems. This study aimed to evaluate the long-term effects (19 years) of tillage (CT-conventional tillage and NT-no tillage) and crop rotations (R0-monoculture sy [...] stem, R1-winter crop rotation, and R2- intensive crop rotation) on total, particulate and mineral-associated organic carbon (C) stocks of an originally degraded Red Oxisol in Cruz Alta, RS, Southern Brazil. The climate is humid subtropical Cfa 2a (Köppen classification), the mean annual precipitation 1,774 mm and mean annual temperature 19.2 ºC. The plots were divided into four segments, of which each was sampled in the layers 0-0.05, 0.05-0.10, 0.10-0.20, and 0.20-0.30 m. Sampling was performed manually by opening small trenches. The SOM pools were determined by physical fractionation. Soil C stocks had a linear relationship with annual crop C inputs, regardless of the tillage systems. Thus, soil disturbance had a minor effect on SOM turnover. In the 0-0.30 m layer, soil C sequestration ranged from 0 to 0.51 Mg ha-1 yr-1, using the CT R0 treatment as base-line; crop rotation systems had more influence on soil stock C than tillage systems. The mean C sequestration rate of the cropping systems was 0.13 Mg ha-1 yr-1 higher in NT than CT. This result w

Ben-Hur Costa de, Campos; Telmo Jorge Carneiro, Amado; Cimélio, Bayer; Rodrigo da Silveira, Nicoloso; Jackson Ernani, Fiorin.

83

Soil properties, crop production and greenhouse gas emissions in organic and conventional cropping systems  

DEFF Research Database (Denmark)

Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr-old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots on 19 September 2007, 14 April 2008 and 22 September 2008, i.e. before, during, and after the growth season. The soils were analyzed for multiple attributes: total soil organic carbon (SOC), total N, microbial biomass N (MBN), potentially mineralizable N (PMN), and levels of potential ammonium oxidation (PAO) and denitrifying enzyme activity (DEA). In situ measurements of soil heterotrophic carbon dioxide (CO2) respiration and nitrous oxide emissions were conducted in plots with winter wheat. In April 2008, prior to field operations, intact soil cores were collected at two depths (0–5 and 5–10 cm) in plots under winter wheat. Water retention characteristics of each core were determined and used to calculate relative gas diffusivity (DP/Do). Finally, crop growth was monitored and grain yields measured at harvest maturity. The different management strategies between 1997 and 2007 led to soil carbon inputs that were on average 18–68% and 32–91% higher in the organic than inorganic fertilizer-based rotations for the sampled winter wheat and spring barley crops, respectively. Nevertheless, SOC levels in 2008 were similar across systems. The cumulative soil respiration for the period February to August 2008 ranged between 2 and 3 t CO2–C ha?1 and was correlated (r = 0.95) with average C inputs. In the organic cropping systems, pig slurry application and inclusion of catch crops generally increased soil respiration, PMN and PAO. At field capacity, relative gas diffusivity at 0–5 cm depth was >50% higher in the organic than the inorganic fertilizer-based system (P < 0.05). Crop yields in 2008 were generally lower in the low-input organic rotations than in the high-input inorganic fertilizer-based system; only spring barley in rotations with pig slurry application and incorporation of a catch crop prior to sowing obtained grain yields similar to levels achieved in the system where inorganic fertilizer was applied. These results suggest that within organic cropping systems, both microbial activity and crop yields could be enhanced through inclusion of catch crops. However, the timing of catch crop incorporation is critical.

Chirinda, Ngonidzashe; Olesen, JØrgen E

2010-01-01

84

SOIL PHYSICAL QUALITY INDICES UNDER TECHNICAL CROP ROTATION  

Directory of Open Access Journals (Sweden)

Full Text Available The multiple processes which assists in the physical indices evolution of soil quality, within technical rotation are correlated, this being materialized in their hierarchization to the different integration levels and structural functional organization of the soil system. More pronounced, the technical anthropic modifications affect the levels aggregate – horizon – profile (pedon being concretized in the agrogen layer compaction and profile stratification. Integrated index of the agrogen modifications are characteristic for the pore space, specially the volume, size, pore space stability and continuity.

Gheorghe Jigau

2011-12-01

85

Management of Lesion Nematodes and Potato Early Dying with Rotation Crops  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soil-incorporated rotation/green manure crops were evaluated for management of potato early dying caused by Verticillium dahliae and Pratylenchus penetrans. After two years of rotation/green manure and a subsequent potato crop, P. penetrans numbers were less after ‘Saia’ oat/‘Polynema’ marigold, ‘Triple S’ sorghum-sudangrass, or ‘Garry’ oat than ‘Superior’ potato or ‘Humus’ rapeseed. The area under the disease progress curve (AUDPC) for early dying was lowest after Sai...

Lamondia, J. A.

2006-01-01

86

Influence of Rotation Crops on the Strawberry Pathogens Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Field microplot, small plot, and greenhouse experiments were conducted to determine the effects of rotation crops on Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae populations. Extraction of P. penetrans from roots and soil in microplots and field plots planted to rotation crops was highest for Garry oat, lowest for Triple S sorgho-sudangrass and Saia oat, and intermediate for strawberry, buckwheat, and canola. Isolation of R. fragariae from bait roots was highest for st...

Lamondia, J. A.

1999-01-01

87

Increasing cropping system diversity balances productivity, profitability and environmental health.  

Science.gov (United States)

Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain crop productivity. To test this, we conducted a field study from 2003-2011 in Iowa that included three contrasting systems varying in length of crop sequence and inputs. We compared a conventionally managed 2-yr rotation (maize-soybean) that received fertilizers and herbicides at rates comparable to those used on nearby farms with two more diverse cropping systems: a 3-yr rotation (maize-soybean-small grain + red clover) and a 4-yr rotation (maize-soybean-small grain + alfalfa-alfalfa) managed with lower synthetic N fertilizer and herbicide inputs and periodic applications of cattle manure. Grain yields, mass of harvested products, and profit in the more diverse systems were similar to, or greater than, those in the conventional system, despite reductions of agrichemical inputs. Weeds were suppressed effectively in all systems, but freshwater toxicity of the more diverse systems was two orders of magnitude lower than in the conventional system. Results of our study indicate that more diverse cropping systems can use small amounts of synthetic agrichemical inputs as powerful tools with which to tune, rather than drive, agroecosystem performance, while meeting or exceeding the performance of less diverse systems. PMID:23071739

Davis, Adam S; Hill, Jason D; Chase, Craig A; Johanns, Ann M; Liebman, Matt

2012-01-01

88

Nitrous oxide emissions from crop rotations including wheat, oilseed rape and dry peas  

Science.gov (United States)

Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas (GHG), originate from soils at a global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes can reduce N fertilizer use, and possibly N2O emissions. Nevertheless, the decomposition of crop organic matter during the crop cycle and residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity) and from the subsequent crops in comparison with N2O emissions from wheat and oilseed rape crops, fertilized or not, in various rotations. A field experiment was conducted over 4 consecutive years to compare the emissions during the pea crop, in comparison with those during the wheat (fertilized or not) or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly due to the site's soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after the pea crop. These results should be confirmed over a wider range of soil types. Nevertheless, they demonstrate the absence of N2O emissions linked to the symbiotic N fixation process, and allow us to estimate the decrease in N2O emissions by 20-25% through including one pea crop in a three-year rotation. On a larger scale, this reduction of GHG emissions at field level has to be added to the decrease due to the reduced production and transport of the N fertilizer not applied to the pea crop.

Jeuffroy, M. H.; Baranger, E.; Carrouée, B.; de Chezelles, E.; Gosme, M.; Hénault, C.; Schneider, A.; Cellier, P.

2013-03-01

89

Tracking nitrogen losses in a greenhouse crop rotation experiment in North China using the EU-Rotate{sub N} simulation model  

Energy Technology Data Exchange (ETDEWEB)

Vegetable production in China is associated with high inputs of nitrogen, posing a risk of losses to the environment. Organic matter mineralisation is a considerable source of nitrogen (N) which is hard to quantify. In a two-year greenhouse cucumber experiment with different N treatments in North China, non-observed pathways of the N cycle were estimated using the EU-Rotate{sub N} simulation model. EU-Rotate{sub N} was calibrated against crop dry matter and soil moisture data to predict crop N uptake, soil mineral N contents, N mineralisation and N loss. Crop N uptake (Modelling Efficiencies (ME) between 0.80 and 0.92) and soil mineral N contents in different soil layers (ME between 0.24 and 0.74) were satisfactorily simulated by the model for all N treatments except for the traditional N management. The model predicted high N mineralisation rates and N leaching losses, suggesting that previously published estimates of N leaching for these production systems strongly underestimated the mineralisation of N from organic matter. - The EU-Rotate{sub N} model can satisfactorily simulate crop N uptake and N{sub min} dynamics in a typical greenhouse cucumber production system of North China

Guo Ruiying [Ministry of Education Key Laboratory of Arid and Grassland Ecology, School of Life Sciences, Lanzhou University, No. 222 Tianshui Nanlu, Lanzhou 730000, Gansu Province (China); Nendel, Claas, E-mail: nendel@zalf.d [Institute for Landscape Systems Analysis, Leibniz-Center for Agricultural Landscape Research, Eberswalder Strasse 84, 15374 Muencheberg (Germany); Rahn, Clive [Warwick HRI, Wellesbourne CV35 9EF (United Kingdom); Jiang Chunguang; Chen Qing [College of Resources and Environmental Sciences, China Agricultural University, No. 2 Yuanmingyuan Xilu, Haidian, Beijing 100193 (China)

2010-06-15

90

Management of lesion nematodes and potato early dying with rotation crops.  

Science.gov (United States)

Soil-incorporated rotation/green manure crops were evaluated for management of potato early dying caused by Verticillium dahliae and Pratylenchus penetrans. After two years of rotation/green manure and a subsequent potato crop, P. penetrans numbers were less after 'Saia' oat/'Polynema' marigold, 'Triple S' sorghum-sudangrass, or 'Garry' oat than 'Superior' potato or 'Humus' rapeseed. The area under the disease progress curve (AUDPC) for early dying was lowest after Saia oat/marigold, and tuber yields were greater than continuous potato after all crops except sorghum-sudangrass. Saia oat/marigold crops resulted in the greatest tuber yields. After one year of rotation/green manure, a marigold crop increased tuber yields and reduced AUDPC and P. penetrans. In the second potato crop after a single year of rotation, plots previously planted to marigolds had reduced P. penetrans densities and AUDPC and increased tuber yield. Rapeseed supported more P. penetrans than potato, but had greater yields. After two years of rotation/green manure crops and a subsequent potato crop, continuous potato had the highest AUDPC and lowest tuber weight. Rotation with Saia oats (2 yr) and Rudbeckia hirta (1 yr) reduced P. penetrans and increased tuber yields. AUDPC was lowest after R. hirta. Two years of sorghum-sudangrass did not affect P. penetrans, tuber yield or AUDPC. These results demonstrate that P. penetrans may be reduced by one or two years of rotation to non-host or antagonistic plants such as Saia oat, Polynema marigold, or R. hirta and that nematode control may reduce the severity of potato early dying. PMID:19259461

Lamondia, J A

2006-12-01

91

Effects of broad-leaf crop frequency in various rotations on soil organic C and N, and inorganic N in a Dark Brown soil  

Directory of Open Access Journals (Sweden)

Full Text Available The objective of this study was to determine the impact of frequency of broad-leaf crops canola and pea in various crop rotations on pH, total organic C (TOC, total organic N (TON, light fraction organic C (LFOC and light fraction organic N (LFON in the 0 - 7.5 and 7.5 - 15 cm soil depths in autumn 2009 after 12 years (1998-2009 on a Dark Brown Chernozem (Typic Boroll loam at Scott, Saskatchewan, Canada. The field ex-periment contained monoculture canola (herbicide tolerant and blackleg resistant hybrid and monoculture pea compared with rotations that contained these crops every 2-, 3-, and 4-yr with wheat. There was no effect of crop rotation duration and crop phase on soil pH. Mass of TOC and TON in the 0 - 15 cm soil was greater in canola phase than pea phase in the 1-yr (monoculture and 2-yr crop rotations, while the opposite was true in the 3-yr and 4-yr crop rotations. Mass of TOC and TON (averaged across crop phases, in soil generally increased with increasing crop rotation duration, with the maximum in the 4-yr rotation while no difference in the 1-yr and 2-yr rotations. Mass of LFOC and LFON in soil was greater in canola phase than pea phase in the 1-yr, 2-yr and 3-yr rotations, but the opposite was true in the 4-yr rotation. There was no consistent effect of crop rotation duration on mass of LFOC and LFON. The N balance sheet over the 1998 to 2009 period indicated large amounts of unaccounted N for monoculture pea, suggesting a great potential for N loss from the soil-plant system in this treatment through nitrate leaching and/or denitrification. In conclusion, the findings suggest that the quantity of organic C and N can be maximized by increasing duration of crop rotation and by including hybrid canola in the rotation.

Sukhdev S. Malhi

2012-10-01

92

Soil enzyme activities under long-term tillage and crop rotation systems in subtropical agro-ecosystems Atividade enzimática em solo sob plantio direto e rotações de culturas em agro-ecossistema subtropical  

Directory of Open Access Journals (Sweden)

Full Text Available Agricultural practices that reduce soil degradation and improve agricultural sustainability are needed particularly for tropical/subtropical soils. No-tillage planting causes minimal soil disturbance and combined with crop rotation may hold potential to meet these goals. Soil enzyme activities can provide information on how soil management is affecting the potential to perform the processes in soils such as decomposition and nutrient cycling. Soil enzyme activities were investigated in a split-plot experiment (3 replications where tillage (no till and conventional was the main plot and crop rotation (soybean/wheat, S/W; maize/wheat, M/W or cotton/wheat, C/W was the subplot. The experiment was established in 1976 in southern Brazil. Soil samples were taken at 0-5, 5-10 and 10-20 cm depths in 1997 and 1998. The 0-5 cm layer under NT system showed increases up 68% for amylase, 90% for cellulase, 219% for arylsulfatase, 46% for acid phosphatase, and 61% for alkaline phosphatase. There were significant correlations of soil enzyme activities with total organic C, and C and N microbial biomass. These results showed that NT increased microbial activity and that soil enzyme activity is a sensitive indicator of alteration soil quality by management.Práticas agrícolas que reduzam a degradação do solo e promovam sustentabilidade são importantes para os agrossistemas tropicais/subtropicais. O plantio direto (PD diminui as perdas de solo e, se combinado com rotação de culturas pode proteger o solo da degradação físico-química provocada pela agricultura intensiva. A atividade enzimática do solo pode fornecer importantes informações de como o manejo do solo está afetando a decomposição da material orgânica e a ciclagem dos nutrientes. Assim, avaliou-se a atividade das enzimas amilase, celulose, arilsulfatase, fosfatase ácida e fosfatase alcalina em um experimento a campo, instalado em 1976 em Londrina, PR, que tem como tratamentos o preparo do solo (plantio direto ou convencional nas parcelas e a rotação de culturas (soja/trigo, milho/trigo e algodão/trigo nas subparcelas. Amostras de solos foram coletadas a 0-5, 5-10 e 10-20 cm de profundidade em 1997 e 1998. Na profundidade de 0-5 cm sob PD, observaram-se aumentos de 68% na atividade da amilase, 90% na celulase, 219% na arilsulfatase, 46% na fosfatase ácida e 61% na fosfatase alcalina. Observaram-se correlações significativas entre a atividade enzimática e o C-orgânico total do solo e o C e N da biomassa microbiana. Esses resultados evidenciam que a atividade enzimática do solo é um indicador sensível de alterações na qualidade do solo, promovidas pelo manejo.

Elcio Liborio Balota

2004-12-01

93

Effects of crop rotation and soil tillage on weeds in organic farming  

Directory of Open Access Journals (Sweden)

Full Text Available An organic long-term field experiment with two factors has been carried out since 1998 at the experimental station Gladbacherhof, University of Giessen. Effects of 3 different farm types (with lifestock raising, stockless farming with rotational set-aside, stockless farming only cash crops combined with 4 tillage treatments (mouldboard plough, two-layer-plough, reduced tillage depth and tillage without plough on plants, soil and environment have been investigated. This article presents results on the coverage rate of arable wild plants (weed coverage, the range of weed species, the abundance of C. arvense (L. Scop. (Canada thistle and the weed phytomass during harvest time of the main crops dependent on farm type and soil tillage. It can be concluded that, compared to conventional economic weed thresholds, the weed coverage was generally relatively low and only limited ranges of species were found. Wild arable plants probably did not have any impact on yields of the cultivated plants due to intensive mechanical regulatory measures. In stockless organic farming without alfalfa-grass in the crop rotation Cirsium arvense (L. Scop. (Canada thistle might become a problem whereas this perennial root-weed does not seem to raise a long term problem in a soil tillage system without ploughing. In all treatments the abundance of weeds like Galium aparine L. (catchweed bedstraw and Stellaria media L. (chickweed was high. However, none of the farm types or soil tillage systems succeeded in providing evidence of promoting rare species or encouraging biodiversity. In order to achieve this special support measures should be implemented.

Schulz, Franz

2014-02-01

94

Energy balance of five fodder cropping systems in the irrigated lowlands of Northern Italy  

Directory of Open Access Journals (Sweden)

Full Text Available Extensification has recently become an important option in Western European agriculture, driven both by economic considerations (product surpluses together with the fact that developed countries cropping systems have been heavily relying on fossil energy and growing public concern on the possible adverse effects of intensive farming on the environment and human health. The adoption of rational fodder crop rotations, with the rediscovery of the beneficial effect of the meadow, is viewed as a possible mean to reduce the impact of farming systems in the lowlands of Northern Italy, characterised by highly intensive cropping and animal husbandry. For this reason our study examines the effects of crop rotation on the energy balance during 1985-2007 period in a long-term crop rotation trial in Northern Italy comparing five fodder crop systems, different in the degree of crop intensification and for the presence or absence of the meadow: a 1-year continuous cereal double cropping (R1; a 3-year rotation (R3; a 6-year rotation (R6; a permanent meadow (PM; and a continuous grain maize cropping (CM. Each rotation was subjected to two input treatments, defined as high (mostly used in lowlands of northern Italy and low (input reduction of ca. 30% respectively, in terms of nutrient levels, herbicide doses, and soil tillage methods. The crop rotations exerted a marked influence on the energy balance. The most efficient rotations in terms of net energy production energy efficiency have been characterized by reduced length and presence of maize and catch-crops.

Massimo Brambilla

2011-02-01

95

INFLUÊNCIA DO PREPARO DE SOLO E DA ROTAÇÃO DE CULTURAS NA SEVERIDADE DE PODRIDÕES RADICULARES NO FEIJOEIRO COMUM EFFECTS OF SOIL TILLAGE SYSTEM AND CROP ROTATION ON DRY BEAN ROOT ROT SEVERITY  

Directory of Open Access Journals (Sweden)

Full Text Available

As podridões radiculares do feijoeiro são causadas pelos fungos Rhizoctonia solani Kühn e Fusarium solani f. sp. phaseoli Snyd. & Hans. Neste trabalho testou-se a combinação dos fatores preparo de solo e rotação de culturas, além de se avaliarem seus efeitos sobre as podridões radiculares do feijoeiro. Os tipos de preparo de solo consistiram em: arado+grade (P1, arado (P2, grade (P3 e plantio direto (P4. As rotações de culturas foram: arroz-feijão (R1, milho-feijão (R2, arroz/calopogônio (Calopogonium muconoides-feijão (R3 e milho-feijão-milho-feijão-arroz-feijão (R4. A severidade de F. solani f. sp. phaseoli, avaliada aos 25 dias após o plantio, apresentou interação significativa, sendo a maior severidade encontrada na combinação da rotação R3 com o preparo de solo P1, e a menor severidade, na combinação da rotação R2 com o preparo de solo P3. Diferenças estatísticas ocorreram na severidade da doença provocada por R. solani. O preparo de solo P3 apresentou maior severidade que P4, e, entre as rotações, R3 apresentou a maior severidade da doença.

PALAVRAS-CHAVE: Rhizoctonia solani; Fusarium solani f. sp. phaseoli; práticas culturais; fungos.

Dry bean root rot is caused by the fungi Rhizoctonia solani Kühn and Fusarium solani f. sp. phaseoli Snyd. & Hans.The effects of the interaction between soil tillage systems andcrop rotation on the severity of root rot was tested. The soiltillage systems consisted of plough+harrow (P1, plough (P2,harrow (P3 and no tillage (P4 and the crop rotation treatmentswere rice-bean (R1, corn-bean (R2, rice/Calopogonium muconoides-bean (R3 and corn-bean-corn-bean-rice-bean (R4. The severity of F. solani f. sp. phaseoli was evaluated 25 days after planting. The interaction was significant for this variable. The higher severity was under R3 with soil tillage system treatment P1. The lowest severity was under interaction R2 with soil preparation P3. Significant differences were found in the severity of the disease caused by R. solani. Soil tillage system P3 presented significantly higher disease severity than P4, whereas rotation R3 presented significantly higher disease severity when compared to other treatments.

KEY-WORDS: Rhizoctonia solani, Fusarium solani f. sp. haseoli; cropping practices; fungi.

Pedro Marques da Silveira

2007-09-01

96

Rendimento de grãos de soja em função de diferentes sistemas de manejo de solo e de rotação de culturas / Soybean yield associated to different soil tillage methods and crop rotations systems  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo do presente trabalho foi avaliar sistemas de manejo de solo e de rotação de culturas sobre o rendimento de grãos e componentes do rendimento de soja durante seis anos. Foram comparados quatro sistemas de manejo de solo - 1) plantio direto, 2) cultivo mínimo, no inverno e semeadura direta, [...] no verão, 3) preparo convencional de solo com arado de discos, no inverno e semeadura direta, no verão e 4) preparo convencional de solo com arado de aivecas, no inverno e semeadura direta, no verão - e três sistemas de rotação de culturas: sistema I (trigo/soja), sistema II (trigo/soja e ervilhaca/milho ou sorgo) e sistema III (trigo/soja, ervilhaca/milho ou sorgo e aveia branca/soja). O delineamento experimental foi de blocos ao acaso, com parcelas subdivididas e três repetições. O rendimento de grãos e o peso de 1.000 grãos de soja cultivada sob plantio direto e sob cultivo mínimo foi superior ao de soja cultivada sob preparo convencional de solo com arado de discos e com arado de aivecas. A maior estatura de plantas de soja ocorreu no plantio direto. O rendimento de grãos de soja cultivada após trigo, no sistema II, foi superior ao de soja cultivada após aveia branca e após trigo, no sistema III, e após trigo, no sistema I. O menor rendimento de grãos, peso de grãos por planta de soja e peso de 1.000 grãos ocorreu quando em monocultura (trigo/soja). Abstract in english The objective of this six-year study was to assess the soil tillage systems and crop rotation systems on soybean grain and yield components were evaluated at Embrapa Trigo in Passo Fundo, RS, Brazil. Four soil tillage systems - 1) no-tillage, 2) minimum tillage in winter and no-tillage in summer, 3) [...] conventional tillage with disk plow in winter and no-tillage in summer, and 4) tillage using a moldboard plow in winter and no-tillage in summer - and three crop rotation systems [system I (wheat/soybean), system II (wheat/soybean and common vetch/corn or sorghum), and system III (wheat/soybean, common vetch/corn or sorghum and white oats/soybean)]. An experimental randomized blocks design, with split-plots and three replications, was used. The yield and weight of 1,000 kernels of soybean grown under no-tillage and minimum tillage was higher than soybean grown conventional soil tillage with disk plow and a moldboard plow. Plant height showed higher in the no-tillage. The yield of soybean grown after wheat, in system II, was higher than soybean grown after white oats and after wheat, in system III, and after wheat, in system I. The lowest soybean yield, grain weight/plant, and weight of 1,000 kernels was obtained in monoculture (wheat/soybean).

Henrique Pereira dos, Santos; Julio Cesar Barreneche, Lhamby; Silvio Tulio, Spera.

97

Effects of crop rotation on the incidence of soil-borne pathogens and the consequences for potato production.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis describes the effects of various rotations on the growth pattern, yield and quality of potato and on the incidence of soil-borne pathogens, other than potato cyst nematodes ( Globodera spp.), associated with potato. These rotations differed in the frequency of potato and in the crops with which the potato crop was rotated.The effects of the rotations depended greatly on the soil type. Lower yields of potato in short rotations were mainly caused by Streptomyces spp. (causing netted...

Scholte, K.

1989-01-01

98

Propriedades físicas do solo em sistemas de rotação de culturas conforme o uso de corretivos da acidez / Soil physical properties in crop rotation systems as affected by liming materials  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar o efeito de sistemas de rotação de culturas e de corretivos da acidez nas propriedades físicas do solo. O experimento foi realizado entre outubro de 2006 e julho de 2008, em Botucatu, SP, em blocos ao acaso, com parcelas subdivididas e oito repetições. As parcel [...] as foram constituídas por quatro sistemas de rotação: soja/pousio/milho/pousio, soja/aveia-branca/milho/feijão, soja/milheto/milho/guandu e soja/braquiária/milho/braquiária. As subparcelas consistiram do tratamento testemunha, sem correção, e da aplicação de 3,8 Mg ha-1 de calcário dolomítico (PRNT = 90%) ou de 4,1 Mg ha-1 de silicato de cálcio e magnésio (PRNT = 80%), na superfície de um Latossolo Vermelho argiloso. Foram determinadas: estabilidade de agregados, densidade do solo, porosidade total, macro e microporosidade, resistência do solo à penetração e umidade do solo. A aplicação dos corretivos de acidez em superfície não reduz a agregação do solo e aumenta a macroporosidade até 0,20 m de profundidade, após aplicação de silicato, e até 0,10 m, após aplicação de calcário. A manutenção do solo em pousio, na entressafra, prejudica a estruturação do solo, reduz a estabilidade de agregados e aumenta a resistência à penetração nas camadas superficiais. A semeadura de braquiária, entre as safras de verão, aumenta a estabilidade de agregados até 0,10 m de profundidade. Abstract in english The objective of this work was to evaluate the effects of crop rotation systems and liming materials on soil physical properties. The experiment was carried out from October 2006 to July 2008, in Botucatu, SP, Brazil, in a completely randomized block design in a split-plot arrangement with eight rep [...] licates. Main plots consisted of four crop rotation systems: soybean/fallow/maize/fallow, soybean/white-oat/maize/bean, soybean/millet/maize/pigeon pea and soybean/signal grass/maize/signal grass. Subplots consisted of the control treatment, without soil correction, and of the application of 3.8 Mg ha-1 of dolomitic lime (ECC = 90%) or 4.1 Mg ha-1 of calcium-magnesium silicate (ECC = 80%), on the surface of a clayed Rhodic Ferralsol. Aggregate stability, soil bulk density, total porosity, macro and microporosity, soil penetration resistance and moisture content were evaluated. Superficial application of the lime materials does not reduce soil aggregation and increases macroporosity down to 0.20 m, with calcium-magnesium silicate application, and to 0.10 m, when lime is applied. Soil under fallow in off-season decreases aggregate stability and increases soil penetration resistance in upper layers. The cultivation of Congo signal grass, between summer crops, increases aggregate stability down to 0.10-m depth.

Gustavo Spadotti Amaral, Castro; Juliano Carlos, Calonego; Carlos Alexandre Costa, Crusciol.

99

Effects of contrasting catch crops on nitrogen availability and nitrous oxide emissions in an organic cropping system  

DEFF Research Database (Denmark)

Legume-based catch crops (LBCCs) may act as an important source of nitrogen (N) in organic crop rotations because of biological N fixation. However, the potential risk of high nitrous oxide (N2O) emissions needs to be taken into account when including LBCCs in crop rotations. Here, we report the results from a one-year field experiment, which investigated N availability and N2O emissions as affected by three LBCCs, i.e., red clover (CL), red clover–ryegrass mixture (GC) and winter vetch (WV), two non-LBCCs, i.e., perennial ryegrass (GR) and fodder radish (FR), and a control (CO) without catch crops. The effect of two catch crop management strategies was also tested: autumn harvest of the catch crop versus incorporation of whole-crop residues by spring ploughing. LBCCs accumulated 59–67 kg N ha?1 in their tops, significantly more than those of the non-LBCC, 32–40 kg N ha?1. Macro-roots accounted for >33% of total N in the catch crops. In accordance with this, LBCCs enhanced the performance of the succeeding unfertilised spring barley, thus obtaining a grain yield of 3.3–4.5 Mg ha?1 compared to 2.6–3.3 Mg ha?1 grain yield from non-LBCC and the fallow control treatments. Autumn harvest of catch crops, especially LBCCs, tended to reduce crop yield. The annual N2O emissions were comparable across treatments except for fodder radish, which had the highest N2O emission, and also the highest average yield-scaled N2O emission, at 499 g N2O-N Mg?1 grain. Although the sampling strategy employed in this study introduces uncertainty about the spatial and temporal variability, differences in seasonal emission patterns among catch crops were captured and harvest of catch crops in late autumn induced significantly higher emissions during winter, but lower emissions after residue incorporation in spring. In comparison with non-LBCC, LBCCs have the potential to partly replace the effect of manure application in organic cropping systems with greater crop production and less environmental footprint with respect to N2O emissions. However, harvest of the catch crops may reduce crop yield unless the harvested N is recycled as fertiliser to the crops in the rotation.

Li, Xiaoxi; Petersen, SØren O

2014-01-01

100

Economic evaluation of a crop rotation portfolio for irrigated farms in central Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english The sustainable use of productive resources by agricultural producers in the central valley of Chile should be compatible with economic results so that producers can select an appropriate rotation or succession of annual crops and pasture. The objective of this work was to evaluate the economic beha [...] vior of four food crop and supplementary forage rotations using indicators of profitability and profit variability. Productive data were used from a long-term experiment (16 yr) in the central valley of Chile under conditions of irrigation. With productive data and information on historic input/output prices, the real net margin per rotation (RNMR) and its coefficient of variation (CV) were determined. The results indicated that the highest economic benefits and greatest economic stability were obtained with rotations that only included crops, namely sugar beet (Beta vulgaris L. subsp. vulgaris)-wheat (Triticum aestivum L.)-bean (Phaseolus vulgaris L.)-barley (Hordeum vulgare L.) (CR2) and corn (Zea mays L.)-wheat-bean-barley (CR4). These rotations included crops with low CV of the net margin, such as wheat, barley and beans, with values between 0.31 and 0.34. The rotations with crops and pasture, sugar beet-wheat-red clover (Trifolium pratense L.) (2) (CR1) and corn-wheat-red clover (2) (CR3) had lower net margins and more variability of this indicator. Red clover had the highest CV value (1.00). The selection of crops for rotations and their sequence were determining factors in the economic behavior of rotations, affecting the level of RNMR and the degree of inter-annual variability of this indicator. Thus, differences among rotations of 47% in net margin were determined (CR2 vs. CR1), which only differed in the replacement of pasture with red clover (2) by bean-barley. The economic analysis based on the net margin and its variability allow for discriminating among rotations, providing valuable information for producers in deciding which crops to use in rotations.

Jorge, González U; Pablo, Undurraga; Juan, Hirzel; Ingrid, Martínez G.

2013-09-01

 
 
 
 
101

Economic evaluation of a crop rotation portfolio for irrigated farms in central Chile  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english The sustainable use of productive resources by agricultural producers in the central valley of Chile should be compatible with economic results so that producers can select an appropriate rotation or succession of annual crops and pasture. The objective of this work was to evaluate the economic beha [...] vior of four food crop and supplementary forage rotations using indicators of profitability and profit variability. Productive data were used from a long-term experiment (16 yr) in the central valley of Chile under conditions of irrigation. With productive data and information on historic input/output prices, the real net margin per rotation (RNMR) and its coefficient of variation (CV) were determined. The results indicated that the highest economic benefits and greatest economic stability were obtained with rotations that only included crops, namely sugar beet (Beta vulgaris L. subsp. vulgaris)-wheat (Triticum aestivum L.)-bean (Phaseolus vulgaris L.)-barley (Hordeum vulgare L.) (CR2) and corn (Zea mays L.)-wheat-bean-barley (CR4). These rotations included crops with low CV of the net margin, such as wheat, barley and beans, with values between 0.31 and 0.34. The rotations with crops and pasture, sugar beet-wheat-red clover (Trifolium pratense L.) (2) (CR1) and corn-wheat-red clover (2) (CR3) had lower net margins and more variability of this indicator. Red clover had the highest CV value (1.00). The selection of crops for rotations and their sequence were determining factors in the economic behavior of rotations, affecting the level of RNMR and the degree of inter-annual variability of this indicator. Thus, differences among rotations of 47% in net margin were determined (CR2 vs. CR1), which only differed in the replacement of pasture with red clover (2) by bean-barley. The economic analysis based on the net margin and its variability allow for discriminating among rotations, providing valuable information for producers in deciding which crops to use in rotations.

Jorge, González U; Pablo, Undurraga; Juan, Hirzel; Ingrid, Martínez G.

102

Effectiveness of Growing the Sugar Buckwheat in Short Time Crop Rotation  

Directory of Open Access Journals (Sweden)

Full Text Available If you fertilize the sugar buckwheat by organ minerals on a one-time basic as a first harvest in 3-fiels short time crop rotation, it positively effects the productivity of 1st, 2nd an 3rd crops. Thus the highest rates of productivity have been observed by dung application 60 t/ha and NPK + dung 60 t/ha.

Asker U. Taychibekov

2012-09-01

103

Influence of Rotation Crops on the Strawberry Pathogens Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae.  

Science.gov (United States)

Field microplot, small plot, and greenhouse experiments were conducted to determine the effects of rotation crops on Pratylenchus penetrans, Meloidogyne hapla, and Rhizoctonia fragariae populations. Extraction of P. penetrans from roots and soil in microplots and field plots planted to rotation crops was highest for Garry oat, lowest for Triple S sorgho-sudangrass and Saia oat, and intermediate for strawberry, buckwheat, and canola. Isolation of R. fragariae from bait roots was highest for strawberry and canola after 2 years of rotation and lowest for Saia oat. Nematode extraction from roots of rotation crops in field soils was generally higher than from roots in microplots. Grasses were nonhosts of M. hapla. Strawberry, canola, and buckwheat supported root-knot populations over time, but there were no differences in nematode numbers regardless of crop after one season of strawberry growth. Garry oat, canola, and, to a lesser extent, buckwheat supported large populations of P. penetrans without visible root symptoms. Strawberry plants supported fewer nematodes due to root damage. Nematode numbers from soil were less than from roots for all crops. While there were similar trends for pathogen recovery after more than 1 year of strawberry growth following rotation, differences in pathogen density and fruit yield were not significant. In the greenhouse, P. penetrans populations in roots and soil in pots were much higher for Garry oat than for Saia oat. Total P. penetrans adult and juvenile numbers per pot ranged from 40 to 880 (mean = 365.6) for Garry oat and 0 to 40 (mean = 8.7) for Saia oat. Production of Saia oat as a rotation crop may be a means of managing strawberry nematodes and black root rot in Connecticut. PMID:19270931

Lamondia, J A

1999-12-01

104

Yield trends in the long-term crop rotation with organic and inorganic fertilisers on Alisols in Mata (Rwanda  

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Full Text Available A crop rotation system with various species was established on «Alisols» at Mata grassland site, oriental side of Zaire-Nile Watershed Divide (CZN, Rwanda. Inorganic and organic fertilisers were applied in various plots led in randomised complete blocs with three replicates. Crop yield data were each season recorded over a 9-year period. Results showed that there was very low or no harvest in plots without fertilisers. Where fertilisers were applied, the yield generally increased but remained relatively low: only few crops and varieties adapted to the Mata ecology such as potatoes and fi nger millet responded well to fertilisers. Liming was absolutely necessary to get any acceptable crop yield improvement with NPK. High rate of rich farmyard manure was effi cient alone and its effect was seen up to 4 seasons after its four regular seasonal applications. Mata compost (C/N>25, 0,3 g P.kg-1 had little benefi cial effect. One, four and half, and eight tons of lime per ha applied 3 times in 8 years increased soil pH (in water but not up to 6,5. It is then concluded that to succeed improving food production at the CZN area, selection of crops and varieties to fi t ecological conditions and amending soils to fi t crops be combined, but not opposed.

Neel H.

2006-01-01

105

Soil enzyme activities under long-term tillage and crop rotation systems in subtropical agro-ecosystems / Atividade enzimática em solo sob plantio direto e rotações de culturas em agro-ecossistema subtropical  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Práticas agrícolas que reduzam a degradação do solo e promovam sustentabilidade são importantes para os agrossistemas tropicais/subtropicais. O plantio direto (PD) diminui as perdas de solo e, se combinado com rotação de culturas pode proteger o solo da degradação físico-química provocada pela agric [...] ultura intensiva. A atividade enzimática do solo pode fornecer importantes informações de como o manejo do solo está afetando a decomposição da material orgânica e a ciclagem dos nutrientes. Assim, avaliou-se a atividade das enzimas amilase, celulose, arilsulfatase, fosfatase ácida e fosfatase alcalina em um experimento a campo, instalado em 1976 em Londrina, PR, que tem como tratamentos o preparo do solo (plantio direto ou convencional) nas parcelas e a rotação de culturas (soja/trigo, milho/trigo e algodão/trigo) nas subparcelas. Amostras de solos foram coletadas a 0-5, 5-10 e 10-20 cm de profundidade em 1997 e 1998. Na profundidade de 0-5 cm sob PD, observaram-se aumentos de 68% na atividade da amilase, 90% na celulase, 219% na arilsulfatase, 46% na fosfatase ácida e 61% na fosfatase alcalina. Observaram-se correlações significativas entre a atividade enzimática e o C-orgânico total do solo e o C e N da biomassa microbiana. Esses resultados evidenciam que a atividade enzimática do solo é um indicador sensível de alterações na qualidade do solo, promovidas pelo manejo. Abstract in english Agricultural practices that reduce soil degradation and improve agricultural sustainability are needed particularly for tropical/subtropical soils. No-tillage planting causes minimal soil disturbance and combined with crop rotation may hold potential to meet these goals. Soil enzyme activities can p [...] rovide information on how soil management is affecting the potential to perform the processes in soils such as decomposition and nutrient cycling. Soil enzyme activities were investigated in a split-plot experiment (3 replications) where tillage (no till and conventional) was the main plot and crop rotation (soybean/wheat, S/W; maize/wheat, M/W or cotton/wheat, C/W) was the subplot. The experiment was established in 1976 in southern Brazil. Soil samples were taken at 0-5, 5-10 and 10-20 cm depths in 1997 and 1998. The 0-5 cm layer under NT system showed increases up 68% for amylase, 90% for cellulase, 219% for arylsulfatase, 46% for acid phosphatase, and 61% for alkaline phosphatase. There were significant correlations of soil enzyme activities with total organic C, and C and N microbial biomass. These results showed that NT increased microbial activity and that soil enzyme activity is a sensitive indicator of alteration soil quality by management.

Elcio Liborio, Balota; Miriam, Kanashiro; Arnaldo, Colozzi Filho; Diva Souza, Andrade; Richard Peter, Dick.

106

[Characteristics of the microflora of soddy-podzol soil during single-crop cultivation of agricultural plants and during crop rotation].  

Science.gov (United States)

Structural organization of microbial populations in soddy-podzolic soil was studied during growth of agricultural plants in monoculture and in crop rotation. The content of bacteria and their biomass decreased when plants were grown in monoculture. The content of actinomycetes, bacilli and oligonitrophilic microorganisms increased in soil during crop rotation as compared with monocultures, suggesting a higher rate of mobilization processes. The content of microscopic fingi in soil increased when lupine was grown in monoculture. Growth of plants in monoculture affects the cenotic structure of soil microflora. The composition of active soil microflora was characterized by a wider spectrum of microbial forms during crop rotation of monocultures. PMID:135916

Berestetski?, O A; Torzhevski?, V I; Mochalov, Iu M

107

EFFECT OF CROP ROTATION AND LONG TERM FERTILIZATION ON THE CARBON AND GLOMALIN CONTENT IN THE SOIL  

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Full Text Available The research was performed on the basis of soil samples taken from a multi-year long fertilization experiment carried out in Skierniewice. The source of samples was soil under potato and rye cultivated in monoculture and in the 5-fields rotation system. The following combinations of fertilization were concerned: Ca, NPK and CaNPK (doses since 1976: 1.6 t·ha-1 CaO every 4 years in monoculture and 2 t·ha-1 CaO every 5 years in crop rotation, 90 kg·ha-1 N, 26 kg·ha-1 P, 91 kg·ha-1 K. Laboratory analyzes involved determination of total organic carbon (TOC and glomalin operationally described as a total glomalin related soil protein (TGRSP. It was found that regardless of cultivated plants and the method of fertilization, only cultivation system such as rotation and monoculture significantly influenced the content of TGRSP. TOC was significantly influenced by interaction between species of cultivated plant and the system of cultivation. The analyzed factors within the method of cultivation (monoculture and crop rotation did not influence significantly the TGRSP content while cultivated plant species, in monoculture, significantly influenced on TOC content. There was also noted positive correlation (r = 0.72 between TGRSP and TOC.

Piotr WOJEWÓDZKI

2012-12-01

108

Effects of grass-clover management and cover crops on nitrogen cycling and nitrous oxide emissions in a stockless organic crop rotation  

DEFF Research Database (Denmark)

Nitrogen (N) supply in stockless organic farming may be improved through use of grass-clover for anaerobic digestion, producing biogas and digested manure for use as fertilizer in the crop rotation. We studied the effects of grass-clover management on N cycling, nitrous oxide (N2O) emissions and cash-crop yields in an organic arable crop rotation on a sandy loam soil in a cool temperate climate. The four-course crop rotation included spring barley (with undersown grass-clover), grass-clover, potato and winter wheat (with undersown cover crop). Two fertilization treatments were compared: “?M” where plant material from grass-clover cuts was left in the field to decompose and no fertilizer or manure was applied to any crop in the rotation; and “+M” where plant material from grass-clover cuts was harvested and equivalent amounts of N in digested manure used for fertilization of cash crops in the rotation (spring barley, potato and winter wheat); actual digestion of grass-clover cuttings was not possible, instead digested pig manure was used as substitute for digested grass-clover. Nitrous oxide fluxes were monitored between April 2008 and May 2009. In general, application of digested manure had little or no effect on N2O emissions. Periods of high N2O emissions coincided with cover crop and grass-clover residue turnover, with little added effect of digested manure application. Annual N2O emissions did not vary between fertilization treatments, but the +M treatment had cash crop dry matter yields that were 14% higher than in the ?M treatment, and cash crop N yields were increased by 40%. The results show that reallocation of nutrients from grass-clover to cash crops following anaerobic digestion can help solve problems with low N availability. However, issues remain regarding N2O from cover crops and grass-clover in spring.

Brozyna, Michal Adam; Petersen, SØren O

2013-01-01

109

Effects of different 3-year cropping systems on soil microbial communities and rhizoctonia diseases of potato.  

Science.gov (United States)

ABSTRACT Eight different 3-year cropping systems, consisting of soybean-canola, soybean-barley, sweet corn-canola, sweet corn-soybean, green bean-sweet corn, canola-sweet corn, barley-clover, and continuous potato (non-rotation control) followed by potato as the third crop in all systems, were established in replicated field plots with two rotation entry points in Presque Isle, ME, in 1998. Cropping system effects on soil microbial community characteristics based on culturable soil microbial populations, single carbon source substrate utilization (SU) profiles, and whole-soil fatty acid methyl ester (FAME) profiles were evaluated in association with the development of soilborne diseases of potato in the 2000 and 2001 field seasons. Soil populations of culturable bacteria and overall microbial activity were highest following barley, canola, and sweet corn crops, and lowest following continuous potato. The SU profiles derived from BIOLOG ECO plates indicated higher substrate richness and diversity and greater utilization of certain carbohydrates, carboxylic acids, and amino acids associated with barley, canola, and some sweet corn rotations, indicating distinct differences in functional attributes of microbial communities among cropping systems. Soil FAME profiles also demonstrated distinct differences among cropping systems in their relative composition of fatty acid types and classes, representing structural attributes of microbial communities. Fatty acids most responsible for differentiation among cropping systems included 12:0, 16:1 omega5c, 16:1 omega7c, 18:1 omega9c, and 18:2omega6c. Based on FAME biomarkers, barley rotations resulted in higher fungi-to-bacteria ratios, sweet corn resulted in greater mycorrhizae populations, and continuous potato produced the lowest amounts of these and other biomarker traits. Incidence and severity of stem and stolon canker and black scurf of potato, caused by Rhizoctonia solani, were reduced for most rotations relative to the continuous potato control. Potato crops following canola, barley, or sweet corn provided the lowest levels of Rhizoctonia disease and best tuber quality, whereas potato crops following clover or soybean resulted in disease problems in some years. Both rotation crop and cropping sequence were important in shaping the microbial characteristics, soilborne disease, and tuber qualities. Several microbial parameters, including microbial populations and SU and FAME profile characteristics, were correlated with potato disease or yield measurements in one or both harvest years. In this study, we have demonstrated distinctive effects of specific rotation crops and cropping sequences on microbial communities and have begun to relate the implications of these changes to crop health and productivity. PMID:18944206

Larkin, Robert P; Honeycutt, C Wayne

2006-01-01

110

Rotatable electric cable connecting system  

Science.gov (United States)

A cable reel assembly is described which is particularly adapted for, but not limited to, a system for providing electrical connection of power and data signals between an orbiter vehicle, such as a space shuttle, and a recovered satellite. The assembly is comprised of two mutually opposing ring type structures having 180 deg relative rotation with one of the structures being held in fixed position while the other structure is rotatable. Motor controlled berthing latches and umbilical cable connectors for the satellite are located on the rim of the rotatable ring structure. The electrical cable assembly is fed in two sections from the orbiter vehicle into the outer rim portion of the fixed ring structure where they are directed inwardly and attached to two concentrically coiled metal bands whose respective ends are secured to inner and outer post members of circular sets of guide pins located on opposing circular plate members, one rotatable and one fixed. The cable sections are fed out as three output cable sections through openings in the central portion of the circular plate of the rotatable ring structure where they are directed to the latches and connectors located on its rim.

Manges, D. R. (inventor)

1985-01-01

111

Evaluation of Cuphea as a rotation crop for control of western corn rootworm (Coleoptera: Chrysomelidae).  

Science.gov (United States)

The ability to prevent significant root feeding damage to corn, Zea mays L., by the western corn rootworm, Diabrotica virgifera virgifera LeConte, by crop rotation with soybean, Glycine max (L.) Merr., has been lost in portions of the Corn Belt because this pest has adapted to laying eggs in soybean fields. Cuphea spp. has been proposed as a new broadleaf crop that may provide an undesirable habitat for rootworm adults because of its sticky surface and therefore may reduce or prevent oviposition in these fields. A 4-yr study (1 yr to establish seven rotation programs followed by 3 yr of evaluation) was conducted to determine whether crop rotation with Cuphea would provide cultural control of corn rootworm. In support of Cuphea as a rotation crop, fewer beetles were captured by sticky traps in plots of Cuphea over the 4 yr of this study compared with traps in corn and soybean, suggesting that fewer eggs may be laid in plots planted to Cuphea. Also, corn grown after Cuphea was significantly taller during vegetative growth, had significantly lower root damage ratings for 2 of 3 yr, and had significantly higher yields for 2 of 3 yr compared with continuous corn plots. In contrast to these benefits, growing Cuphea did not prevent economic damage to subsequent corn crops as indicated by root damage ratings > 3.0 recorded for corn plants in plots rotated from Cuphea, and sticky trap catches that exceeded the threshold of five beetles trap(-1) day(-1). Beetle emergence from corn plots rotated from Cuphea was significantly lower, not different and significantly higher compared with beetle emergence from continuous corn plots for 2002, 2003 and 2004 growing seasons, respectively. A high number of beetles were captured by emergence cages in plots planted to Cuphea, indicating that rootworm larvae may be capable of completing larval development by feeding on roots of Cuphea, although peak emergence lagged approximately 4 wk behind peak emergence from corn. Based on these data, it is unlikely that crop rotation with Cuphea will provide consistent, economical, cultural control of corn rootworm. PMID:16539123

Behle, Robert W; Isbell, Terry A

2005-12-01

112

Variabilidade espacial de atributos do solo em sistema de semeadura direta com rotação de culturas no cerrado brasileiro / Spatial variability of soil attributes in no a no-tillage system with crop rotation in the Brazilian savannah  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O presente estudo objetivou analisar a variabilidade espacial dos atributos químicos e da textura de um Latossolo Vermelho distroférrico. A propriedade onde o estudo foi realizado localiza-se no município de Sidrolândia (MS) e produz soja, milho e algodão, adotando rotação de culturas e o sistema de [...] plantio direto. Em uma área experimental de aproximadamente 90 hectares foi amostrado solo em 181 pontos georeferenciados. As amostras foram compostas por quatro amostras simples, representativas da profundidade de 0,00-0,20 m. Foram mensurados os atributos químicos e a textura do solo. Realizou-se, inicialmente, análise de discrepantes e, posteriormente, análise descritiva e geoestatística para caracterizar as amostras e identificar a dependência espacial dos atributos estudados. Não foi detectada dependência espacial para os atributos acidez ativa em água, alumínio, acidez potencial, saturação por bases e matéria orgânica. As melhores estimativas de valores para locais não amostrados foram observadas para os atributos físicos do solo, os quais apresentaram os melhores parâmetros de ajuste dos variogramas e da validação cruzada. As técnicas de geoestatística utilizadas possibilitaram o ajuste dos modelos teóricos que melhor representaram a semivariância experimental, possibilitando assim a construção de mapas temáticos da distribuição espacial dos valores dos atributos do solo estudado. Abstract in english This study aimed to analyze the spatial variability of the chemical attributes and texture of a red latosol. The study was carried out on a property in the town of Sidrolândia, Matto Grosso do Sul, which produces soybeans, corn and cotton, using crop rotation and a no-tillage system. In an experimen [...] tal area of approximately 90 hectares, samples were taken of the soil at 181 geo-referenced points. The samples were each composed of four single samples, representing depths of from 0 to 0.2 m. The chemical and texture of the soil were measured. Initially a discrepancy analysis was performed followed by descriptive and geostatistical analyses, to characterize the samples and identify the spatial dependence of the attributes studied. No spatial dependence was detected for the attributes: active water acidity, aluminum, potential acidity, base saturation and organic matter. The best estimates of values for non-sampled locations were observed for the physical properties of the soil, which presented parameters which best fit the variograms and cross-validation. The geostatistical techniques used allowed adjustment of the theoretical models that best represented the experimental semivariance, thus enabling the construction of thematic maps of spatial distribution for the values of the attributes of the studied soil.

Eduardo Leonel, Bottega; Daniel Marçal de, Queiroz; Francisco de Assis de Carvalho, Pinto; Cristiano Márcio Alves de, Souza.

113

Effect of Rotation Crops on Heterodera glycines Population Density in a Greenhouse Screening Study.  

Science.gov (United States)

Crop rotation is a common means of reducing pathogen populations in soil. Several rotation crops have been shown to reduce soybean cyst nematode (Heterodera glycines) populations, but a comprehensive study of the optimal crops is needed. A greenhouse study was conducted to determine the effect of growth and decomposition of 46 crops on population density of H. glycines. Crops were sown in soil infested with H. glycines. Plants were maintained until 75 days after planting, when the soil was mixed, a sample of the soil removed to determine egg density, and shoots and roots chopped and mixed into the soil. After 56 days, soil samples were again taken for egg counts, and a susceptible soybean ('Sturdy') was planted in the soil as a bioassay to determine egg viability. Sunn hemp (Crotalaria juncea), forage pea (Pisum sativum), lab-lab bean (Lablab purpureus), Illinois bundleflower (Desman-thus illinoensis), and alfalfa (Medicago sativa) generally resulted in smaller egg population density in soil or number of cysts formed on soybean in the bioassay than the fallow control. Sunn hemp most consistently showed the lowest numbers of eggs and cysts. As a group, legumes resulted in lower egg population densities than monocots, Brassica species, and other dicots. PMID:19259545

Warnke, S A; Chen, S Y; Wyse, D L; Johnson, G A; Porter, P M

2006-09-01

114

Dinâmica da agregação de um solo franco-arenoso em cinco sistemas de culturas em rotação e em sucessão Aggregation dynamics of a sandy soil under five cropping systems in rotation and in succession  

Directory of Open Access Journals (Sweden)

Full Text Available Espécies de cobertura, aliadas a práticas de manejo e conservação, recuperam ou mantêm características físicas do solo como a agregação. O objetivo deste trabalho foi determinar, ao longo do tempo, a influência de sistemas de culturas, de cobertura do solo e do teor de matéria orgânica sobre a agregação de um Argissolo Vermelho-Amarelo distrófico arênico em seu estado natural e sob rotação e sucessão de culturas. O estudo foi realizado na área experimental do Departamento de Solos da UFSM, em Santa Maria (RS. Amostras indeformadas, coletadas em intervalos de 60 dias, de outubro de 1997 a outubro de 1998, na profundidade de 0-0,05 m, foram analisadas quanto à estabilidade de agregados, teor de C orgânico e outros atributos físicos e químicos. A maior estabilidade estrutural ocorreu no solo sob campo natural e a menor em solo descoberto, em virtude do intenso preparo do solo e da redução do teor de matéria orgânica, aumentando os agregados de menor tamanho. Existe uma ação direta das culturas na formação e estabilização dos agregados, sendo a estabilidade e a distribuição do tamanho de agregados maiores em sistemas de cultivo que aportam material orgânico e cobrem o solo durante todo o ano. As seqüências de culturas influem diferenciadamente na agregação do solo, dependendo da época do ano e tempo de estabelecimento dos sistemas de culturas.Cover crops along with proper soil management recover or maintain soil physical properties such as aggregation. The objective of this study was to determine the effect of cropping systems, cover crops, and soil organic matter (SOM content on the temporal variation of soil aggregation in an Hapludalf in its natural state and under different cropping systems. The experiment was conducted at the experimental station of the Soil Department of the UFSM, Brazil. Undisturbed soil samples were collected in 60 day-intervals throughout an year (Ocotober/1997 to October/1998 from a depth of 0-0.05 m and analyzed for aggregate stability, SOM content, and selected physical and chemical properties. The greatest structural stability was observed under grassland and the smallest stability for bare soil due to the intense soil tillage and reduction in SOM, increasing the proportion of small aggregates. Cover crops formed and stabilized soil aggregates directly, and the stability and proportion of aggregates were greater under cultivation systems that increase SOM and cover the soil during the whole year. Different cropping sequences affect soil aggregation distinctly, depending on the time of the year and time of establishment of the crops.

E. V. Wohlenberg

2004-10-01

115

Biogas production from catch crops : Evaluation of biomass yield and methane potential of catch crops in organic crop rotations  

DEFF Research Database (Denmark)

Manure-based biogas plants in Denmark are dependent on high yielding biomass feedstock in order to secure economically feasible operation. The aim of this study was to investigate the potential of ten different catch crop species or mixtures as feedstock for biogas production in co-digestion with manure. The biomass yield per hectare and the specific methane yield of the catch crops in two different locations, namely Holstebro and Aabenraa, were investigated. The volatile solids (VS) yield per hectare was notably influenced by the differences in climate and soil conditions between the locations, being in the ranges of 1.4–3.0 t ha?1 and 0.3–1.7 t ha?1 for Holstebro and Aabenraa, respectively. Specific methane yields were in the range of 229–450 m3 t?1 of VS. Methane yields per hectare of up to 800 m3 ha?1 were obtained, making catch crops a promising source of feedstock for manure-based biogas plants in Denmark since this biomass is not competing with food/feed production.

Molinuevo-Salces, Beatriz; Larsen, SØren U.

2013-01-01

116

Görtler Vortices with System Rotation  

Science.gov (United States)

The steady primary instability of Görtler vortices developing along a curved Blasius boundary layer subject to spanwise system rotation is analysed through linear and nonlinear approaches, to clarify issues of vortex growth and wavelength selection, and to pave the way to further secondary instability studies. A linear marching stability analysis is carried out for a range of rotation numbers, to yield the (predictable) result that positive rotation, that is rotation in the sense of the basic flow, enhances the vortex development, while negative rotation dampens the vortices. Comparisons are also made with local, nonparallel linear stability results (Zebib and Bottaro, 1993) to demonstrate how the local theory overestimates vortex growth. The linear marching code is then used as a tool to predict wavelength selection of vortices, based on a criterion of maximum linear amplification. Nonlinear finite volume numerical simulations are performed for a series of spanwise wave numbers and rotation numbers. It is shown that energy growths of linear marching solutions coincide with those of nonlinear spatially developing flows up to fairly large disturbance amplitudes. The perturbation energy saturates at some downstream position at a level which seems to be independent of rotation, but that increases with the spanwise wavelength. Nonlinear simulations performed in a long (along the span) cross section, under conditions of random inflow disturbances, demonstrate that: (i) vortices are randomly spaced and at different stages of growth in each cross section; (ii) “upright” vortices are the exception in a universe of irregular structures; (iii) the average nonlinear wavelengths for different inlet random noises are close to those of maximum growth from the linear theory; (iv) perturbation energies decrease initially in a linear filtering phase (which does not depend on rotation, but is a function of the inlet noise distribution) until coherent patches of vorticity near the wall emerge and can be amplified by the instability mechanism; (v) the linear filter represents the receptivity of the flow: any random noise, no matter how strong, organizes itself linearly before subsequent growth can take place; (vi) the Görtler number, by itself, is not sufficient to define the state of development of a vortical flow, but should be coupled to a receptivity parameter; (vii) randomly excited Görtler vortices resemble and scale like coherent structures of turbulent boundary layers.

Bottaro, Alessandro; Klingmann, Barbro G. B.; Zebib, Abdelfattah

1996-09-01

117

Crop systems biology : an approach to connect functional genomics with crop modelling  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The response of the whole crop to environmental conditions is a critical factor in agriculture. It can only be understood if the organization of the crop system is taken into account. A popular view in modern science is that genomics (and other `omics¿) will provide knowledge and tools to allow the characteristics of the crop to be altered for improved actual and potential crop yields, increased resource use efficiency and enhanced crop system health. As a result of this view, (molecular) pl...

Yin, X.; Struik, P. C.

2007-01-01

118

Soil respiration in cucumber field under crop rotation in solar greenhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Crop residues are the primary source of carbon input in the soil carbon pool. Crop rotation can impact the plant biomass returned to the soil, and influence soil respiration. To study the effect of previous crops on soil respiration in cucumber (Cucumis statirus L.) fields in solar greenhouses, soil [...] respiration, plant height, leaf area and yield were measured during the growing season (from the end of Sept to the beginning of Jun the following year) from 2007 to 2010. The cucumber was grown following fallow (CK), kidney bean (KB), cowpea (CP), maize for green manure (MGM), black bean for green manure (BGM), tomato (TM), bok choy (BC). As compared with CK, KB, CP, MGM and BGM may increase soil respiration, while TM and BC may decrease soil respiration at full fruit stage in cucumber fields. Thus attention to the previous crop arrangement is a possible way of mitigating soil respiration in vegetable fields. Plant height, leaf area and yield had similar variation trends under seven previous crop treatments. The ratio of yield to soil respiration revealed that MGM is the crop of choice previous to cucumber when compared with CK, KB, CP, BGM, TM and BC.

Yinli, Liang; Caihong, Bai; Lan, Mu; Maojuan, Zhou.

119

Volatile organic compound emissions from Miscanthus and short rotation coppice willow bioenergy crops  

Science.gov (United States)

Miscanthus × giganteus and short rotation coppice (SRC) willow (Salix spp.) are increasingly important bioenergy crops. Above-canopy fluxes and mixing ratios of volatile organic compounds (VOCs) were measured in summer for the two crops at a site near Lincoln, UK, by proton transfer reaction mass spectrometry (PTR-MS) and virtual disjunct eddy covariance. The isoprene emission rate above willow peaked around midday at ?1 mg m-2 h-1, equivalent to 20 ?g gdw-1 h-1 normalised to 30 °C and 1000 ?mol m-2 s-1 PAR, much greater than for conventional arable crops. Average midday peak isoprene mixing ratio was ?1.4 ppbv. Acetone and acetic acid also showed small positive daytime fluxes. No measurable fluxes of VOCs were detected above the Miscanthus canopy. Differing isoprene emission rates between different bioenergy crops, and the crops or vegetation cover they may replace, means the impact on regional air quality should be taken into consideration in bioenergy crop selection.

Copeland, Nichola; Cape, J. Neil; Heal, Mathew R.

2012-12-01

120

Soil respiration in cucumber field under crop rotation in solar greenhouse  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Crop residues are the primary source of carbon input in the soil carbon pool. Crop rotation can impact the plant biomass returned to the soil, and influence soil respiration. To study the effect of previous crops on soil respiration in cucumber (Cucumis statirus L.) fields in solar greenhouses, soil [...] respiration, plant height, leaf area and yield were measured during the growing season (from the end of Sept to the beginning of Jun the following year) from 2007 to 2010. The cucumber was grown following fallow (CK), kidney bean (KB), cowpea (CP), maize for green manure (MGM), black bean for green manure (BGM), tomato (TM), bok choy (BC). As compared with CK, KB, CP, MGM and BGM may increase soil respiration, while TM and BC may decrease soil respiration at full fruit stage in cucumber fields. Thus attention to the previous crop arrangement is a possible way of mitigating soil respiration in vegetable fields. Plant height, leaf area and yield had similar variation trends under seven previous crop treatments. The ratio of yield to soil respiration revealed that MGM is the crop of choice previous to cucumber when compared with CK, KB, CP, BGM, TM and BC.

Yinli, Liang; Caihong, Bai; Lan, Mu; Maojuan, Zhou.

2014-08-01

 
 
 
 
121

Climate change impact on crop rotations of winter durum wheat and tomato in southern Italy: yield analysis and soil fertility  

Directory of Open Access Journals (Sweden)

Full Text Available Cropping systems are affected by climate change because of the strong relationship between crop development, growth, yield, CO2 atmospheric concentration and climate conditions. The increasing temperatures and the reduction of available water resources may result in negative impacts on the agricultural activity in Mediterranean environments than other areas. In this study the CERES-Wheat and CROPGRO-Tomato models were used to assess the effects of climate change on winter wheat (Triticum durum L. and processing tomato (Lycopersicon aesculentum Mill. in one of most productive areas of Italy, located in the northern part of the Puglia region. In particular we have compared three different General Circulation Models (HadCM3, CCSM3, ECHAM5 subjected to a statistical downscaling under two future IPCC scenarios (B1 and A2. The analysis was carried out at regional scale repeating the simulations for seven homogeneous area characterizing the spatial variability of the region. In the second part of the study, considering only HadCM3 data set, climate change impact on long-term sequences of the two crops combined in three crop rotations were evaluated in terms of yield performances and soil fertility as indicated by the soil organic content of carbon and nitrogen. The comparison between GCMs showed no significant differences for winter durum wheat yield, while noticeable differences were found for yield and irrigation requirements of tomato. Under future scenarios, the production levels were reduced for tomato, whereas positive yield effects were observed for winter durum wheat. For winter durum wheat the simulation indicated that two- and three-year rotations, including one year of tomato cultivation, improved the cereal yield and this positive effect maintained its validity also in future scenarios. For both crops higher requirements of water and nitrogen were predicted under future scenarios. This result coupled with the decrease of yield caused negative reduction of water use efficiency and nitrogen use efficiency for tomato cultivation.

Annamaria Castrignanò

2012-03-01

122

Effect of Crop Rotation on Meloidogyne spp. and Pratylenchus spp. Populations in Strawberry Fields in Taiwan.  

Science.gov (United States)

Changes in population levels of Meloidogyne hapla, M. incognita, Pratylenchus coffeae, and P. penetrans were studied in 12 strawberry fields in the Dahu region of Taiwan. Ten potential rotation crops and two cultural practices were evaluated for their effect on nematode populations and influence on strawberry yield. Rotation with rice or taro and the cultural practice of flooding and bare fallowing for four months were found to reduce nematode soil populations to two or fewer nematodes per 100 ml soil. Average strawberry yields increased between 2.4% to 6.3% following taro compared to the bare fallow treatment. Corn suppressed M. incognita and M. hapla populations and resulted in an increased in strawberry yield compared to bare fallow. Other phytopathogens also present in these fields limited taro as the rotation choice for nematode management. Results of this research and economic analysis of the input requirements for various rotation crops, corn and bare fallow were recommended as the most appropriate rotation strategies for nematode management in strawberry in this region. PMID:19259538

Chen, P; Tsay, T T

2006-09-01

123

Factors affecting soil organic matter conservation in Mediterranean hillside winter cereals-legumes cropping systems  

Directory of Open Access Journals (Sweden)

Full Text Available Soil conservation is an important issue for farming and environmental protection in Mediterranean areas. Hillside farming systems, based on winter cereals and legumes, are common in these areas and are the target of several environmental policies. Soil organic matter (SOM is widely used to assess the environmental performance of these cropping systems. Nevertheless, few studies have considered soil conservation practices in hillside systems in terms of implementing more effective agro-environmental policies for these areas. This paper compares the SOM conservation of different winter cereal based cropping systems within Mediterranean hillside crops/livestock farms. Seventeen cropping systems were characterised by on-farm surveys in the inland hilly area of Grosseto (Tuscany, Italy. For each cropping system, we performed a SOM balance, based on Hénin-Dupuis’ equation, using either local environmental databases or data from on-farm surveys. Differences between cropping systems were analysed by the Kruskal-Wallis test. On average, the cropping systems identified did not guarantee SOM conservation and varied considerably from farm to farm, however, some practices seemed to have a positive performance, e.g. cropping systems of cattle farms. According to the literature, annual SOM balance differs significantly depending on crop rotation length and longer crop rotations performed better than shorter ones. However, we found a local effect indicating that this better performance was influenced by local farmers' cooperatives, which to some extent counteracted the negative effect of crop rotation length. There were significant differences in the performance of dairy sheep and cattle farms (-1031 kg ha-1 yr-1 vs. +103 kg ha-1 yr-1, respectively. This suggests that the presence of livestock did not have the same favourable effect on soil conservation in Mediterranean systems and that this factor should be more investigated. Surprisingly, in our sample, for the same crop rotation length, livestock density did not affect the annual SOM balance. Due to the high variability in local cropping systems and soil characteristics, further surveys on a larger sample are needed to confirm these trends. However, our results shed light on the soil conservation effects of Mediterranean hillside cropping systems of winter cereals and legumes, and could support the local implementation of agro-environmental measures.

Hélène Rapey

2012-07-01

124

Soil properties, crop production and greenhouse gas emissions from organic and inorganic fertilizer-based arable cropping systems  

DEFF Research Database (Denmark)

Organic and conventional farming practices differ in the use of several management strategies, including use of catch crops, green manure, and fertilization, which may influence soil properties, greenhouse gas emissions and productivity of agroecosystems. An 11-yr-old field experiment on a sandy loam soil in Denmark was used to compare several crop rotations with respect to a range of physical, chemical and biological characteristics related to carbon (C) and nitrogen (N) flows. Four organic rotations and an inorganic fertilizer-based system were selected to evaluate effects of fertilizer type, catch crops, of grass-clover used as green manure, and of animal manure application. Soil was sampled from winter wheat and spring barley plots on 19 September 2007, 14 April 2008 and 22 September 2008, i.e. before, during, and after the growth season. The soils were analyzed for multiple attributes: total soil organic carbon (SOC), total N, microbial biomass N (MBN), potentially mineralizable N (PMN), and levels of potential ammonium oxidation (PAO) and denitrifying enzyme activity (DEA). In situ measurements of soil heterotrophic carbon dioxide (CO2) respiration and nitrous oxide emissions were conducted in plots with winter wheat. In April 2008, prior to field operations, intact soil cores were collected at two depths (0–5 and 5–10 cm) in plots under winter wheat. Water retention characteristics of each core were determined and used to calculate relative gas diffusivity (DP/Do). Finally, crop growth was monitored and grain yields measured at harvest maturity. The different management strategies between 1997 and 2007 led to soil carbon inputs that were on average 18–68% and 32–91% higher in the organic than inorganic fertilizer-based rotations for the sampled winter wheat and spring barley crops, respectively. Nevertheless, SOC levels in 2008 were similar across systems. The cumulative soil respiration for the period February to August 2008 ranged between 2 and 3 t CO2–C ha-1 and was correlated (r = 0.95) with average C inputs. In the organic cropping systems, pig slurry application and inclusion of catch crops generally increased soil respiration, PMN and PAO. At field capacity, relative gas diffusivity at 0–5 cm depth was >50% higher in the organic than the inorganic fertilizer-based system (P < 0.05). Crop yields in 2008 were generally lower in the low-input organic rotations than in the high-input inorganic fertilizer-based system; only spring barley in rotations with pig slurry application and incorporation of a catch crop prior to sowing obtained grain yields similar to levels achieved in the system where inorganic fertilizer was applied. These results suggest that within organic cropping systems, both microbial activity and crop yields could be enhanced through inclusion of catch crops. However, the timing of catch crop incorporation is critical.

Chirinda, Ngonidzashe; Olesen, JØrgen Eivind

2010-01-01

125

Tillage, crop rotation, and organic amendment effect on changes in soil organic matter.  

Science.gov (United States)

Carbon sequestration in agricultural soils is controlled by the balance of added organic residues and microbial oxidation of both residues and native organic matter (OM) as moderated by management and tillage. The PC-based model CQESTR predicts decomposition of residues, organic amendments and soil OM, based on cropping practices. CQESTR uses RUSLE (Revised Universal Soil Loss Equation) crop rotation and management practice, crop production, and operation databases. These data are supplemented with residue nitrogen and soil OM, bulk density, and layer thickness. CQESTR was calibrated with soil carbon data from 70-year-long experiments at the Research Center at Pendleton, OR. The calibrated model provides estimates with a 95% confidence interval of 0.33% OM. Validation at 11 independent sites resulted in a matching of observed with calculated OM with a 95% confidence interval of 0.55% OM. A 12th site, with a history of severe erosion, provided a poor match. PMID:11822719

Rickman, R; Douglas, C; Albrecht, S; Berc, J

2002-01-01

126

Short-rotation woody-crops program. Quarterly progress report for period ending May 31, 1981  

Energy Technology Data Exchange (ETDEWEB)

Progress of twenty projects in the Short Rotation Woody Crops Program is summarized for the period March 1 through May 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major project activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

Cushman, J.H.; Ranney, J.W.

1982-04-01

127

ESTIMATION OF RESOURCE-HEALING ROLE LUPINE AND STRAW IN THE GRAIN-ROW CROP ROTATION  

Directory of Open Access Journals (Sweden)

Full Text Available In field experiences on soddy-podzolic sandy soil of Meshchersky lowland high agroeconomic efficiency of an adaptive link of a crop rotation with, grown up on grain, a potato and barley is established, at entering winter wheat straw under lupine . Straw in a combination with lupine has proved to be a perspective reserve of reproduction of fertility of soils without participation of nitrogen of mineral fertilizers.

Tatyana ANISIMOVA

2014-03-01

128

Short-rotation woody-crops program. Quarterly progress report for period ending August 31, 1981  

Energy Technology Data Exchange (ETDEWEB)

Progress of twenty-one projects in the Short Rotation Woody Crops Program is summarized for the period June 1 through August 31, 1981. Individual quarterly reports included from each of the projects discuss accomplishments within specific project objectives and identify recent papers and publications resulting from the research. The major program activities are species screening and genetic selection, stand establishment and cultural treatment, and harvest, collection, transportation, and storage.

Cushman, J.H.; Ranney, J.W.

1982-04-01

129

Short-rotation woody crops for bioenergy and biofuels applications  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Purpose-grown trees will be part of the bioenergy solution in the United States, especially in the Southeast where plantation forestry is prevalent and economically important. Trees provide a “living biomass inventory” with existing end-use markets and associated infrastructure, unlike other biomass species such as perennial grasses. The economic feasibility of utilizing tree biomass is improved by increasing productivity through alternative silvicultural systems, improved breeding and bi...

Hinchee, Maud; Rottmann, William; Mullinax, Lauren; Zhang, Chunsheng; Chang, Shujun; Cunningham, Michael; Pearson, Leslie; Nehra, Narender

2009-01-01

130

Universal Entropy Bound for Rotating Systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

We conjecture a universal upper bound to the entropy of a rotating system. The entropy bound follows from application of the generalized second law of thermodynamics to an idealized gedanken experiment in which an entropy-bearing rotating system falls into a black hole. This bound is stronger than the Bekenstein entropy bound for non-rotating systems.

Hod, Shahar

1999-01-01

131

The consequent influence of crop rotation and six-year-long spring barley monoculture on yields and weed infestation of white mustard and oats  

Directory of Open Access Journals (Sweden)

Full Text Available The present study was conducted in the years 2007- 2008, after 6-year-long experiments in the cultivation of spring barley in a crop rotation system and in monoculture. The other experimental factor was the spring barley protection method. Intensive protection involved comprehensive treatment of barley (in-crop harrowing, seed dressing, application of herbicides, fungicides, a retardant and an insecticide. Extensive protection consisted only in in-crop harrowing, without the application of crop protection agents, except for seed dressing. The above mentioned factors formed the background for the study on the cultivation of white mustard and oats, as phytosanitary species, in successive years. In the test plants, no mineral fertilization and crop protection were applied. Such agricultural method enabled an objective assessment of the consequent effect of monoculture, crop rotation and crop treatments. A hypothesis was made that the cultivation of the phytosanitary plants in the stand after 6-year-long barley monoculture would allow obtaining the level of yields and weed infestation similar to those of the crop rotation treatments. It was also assumed that the cultivation of white mustard and oats would eliminate differences in plant productivity caused by the negative influence of extensive protection. It was proved that the cultivation of the phytosanitary plants eliminated the negative influence of monoculture on the level of their yields and weed infestation. However, the test plants did not compensate negative consequences of extensive protection. In spite of this, white mustard and oats effectively competed with weeds, and the number and weight of weeds in a crop canopy did not cause a dramatic decline in yields. In the test plant canopy, the following short-lived weeds were predominant: Chenopodium album, Galinsoga parviflora, Echinochloa crus-galli. The absence of herbicide application resulted in the compensation of perennial species: Elymus repens and Cirsium arvense.

Cezary Kwiatkowski

2009-12-01

132

Soil Microbial Substrate Properties and Microbial Community Responses under Irrigated Organic and Reduced-Tillage Crop and Forage Production Systems  

Science.gov (United States)

Changes in soil microbiotic properties such as microbial biomass and community structure in response to alternative management systems are driven by microbial substrate quality and substrate utilization. We evaluated irrigated crop and forage production in two separate four-year experiments for differences in microbial substrate quality, microbial biomass and community structure, and microbial substrate utilization under conventional, organic, and reduced-tillage management systems. The six different management systems were imposed on fields previously under long-term, intensively tilled maize production. Soils under crop and forage production responded to conversion from monocropping to crop rotation, as well as to the three different management systems, but in different ways. Under crop production, four years of organic management resulted in the highest soil organic C (SOC) and microbial biomass concentrations, while under forage production, reduced-tillage management most effectively increased SOC and microbial biomass. There were significant increases in relative abundance of bacteria, fungi, and protozoa, with two- to 36-fold increases in biomarker phospholipid fatty acids (PLFAs). Under crop production, dissolved organic C (DOC) content was higher under organic management than under reduced-tillage and conventional management. Perennial legume crops and organic soil amendments in the organic crop rotation system apparently favored greater soil microbial substrate availability, as well as more microbial biomass compared with other management systems that had fewer legume crops in rotation and synthetic fertilizer applications. Among the forage production management systems with equivalent crop rotations, reduced-tillage management had higher microbial substrate availability and greater microbial biomass than other management systems. Combined crop rotation, tillage management, soil amendments, and legume crops in rotations considerably influenced soil microbiotic properties. More research will expand our understanding of combined effects of these alternatives on feedbacks between soil microbiotic properties and SOC accrual. PMID:25090235

Ghimire, Rajan; Norton, Jay B.; Stahl, Peter D.; Norton, Urszula

2014-01-01

133

Biomass production of short-rotation bioenergy hardwood plantations affected by cover crops  

Energy Technology Data Exchange (ETDEWEB)

Effects of varying strip widths of four species of cover crops on the growth of sweetgum (Liquidambar styraciflua L.) seedlings planted as a short-rotation bioenergy woody crop were studied. Ryegrass (Lolium multiflorum L. a winter annual grass); tall fescue (Festuca arundinacea Schreb a cool season perennial grass); crimson clover (Trifloium incarnatum L. a winter annual legume); and Interstate sericea lespedeza (Lespedeza cuneata (Dumont) G. Don. a summer growing perennial legume), were planted using two different strip widths (1.22 and 2.44 m) between trees on a 1.5 x 3 m spacing. The control had no competition. Height, ground-line diameter and volume index of trees were determined on a monthly basis. Lespedeza and tall fescue significantly reduced ground line diameter compared to ryegrass and the control. Crimson clover significantly reduced ground line diameter compared to the control and volume index more than ryegrass and the control. During the first two growing seasons, there was no benefit from legumes as a cover crop over grasses. All cover crops except rye grass significantly reduced sweetgum biomass compared to control. The results indicate that cover crops lespedeza, tall fescue, crimson clover and ryegrass reduced biomass by approximately 41%, 37%, 27% and 15%, respectively, compared to the control. The 2.44 m strip width reduced sweetgum growth 40% relative to the control vs. 20% with the 1.22 m strip width. Strip width had a greater impact on diameter and volume index than height. (Author)

Malik, R.K.; Green, T.H.; Brown, G.F.; Beyl, C.A.; Sistani, K.R.; Mays, D.A. [Alabama A and M Univ., Normal, AL (United States). Center for Forestry and Ecology

2001-07-01

134

Predicting and mitigating the net greenhouse gas emissions of crop rotations in Western Europe  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nitrous oxide, carbon dioxide and methane are the main biogenic greenhouse gases (GHG) contributing to net greenhouse gas balance of agro-ecosystems. Evaluating the impact of agriculture on climate thus requires capacity to predict the net exchanges of these gases in a systemic approach, as related to environmental conditions and crop management. Here, we used experimental data sets from intensively-monitored cropping systems in France and Germany to calibrate and evaluate the ability of the ...

Lehuger, Simon; Gabrielle, Benoit; Laville, Patricia; Lamboni, Matieyendou; Loubet, Benjamin; Cellier, Pierre

2011-01-01

135

Nitrous oxide and carbon dioxide emissions from monoculture and rotational cropping of corn, soybean and winter wheat  

International Nuclear Information System (INIS)

Nitrous oxide (N2O) and carbon dioxide (CO2) emissions from agricultural soils are influenced by different types of crops, the amounts and types of nitrogen fertilizers used, and the soil and climatic conditions under which the crops are grown. Crop rotation also has an impact on N2O emissions, as the crop residues used to supply soluble carbon to soil biota often differ from the crops being grown. This study compared the influence of crops and residues from preceding crops on N2O and CO2 emissions from monoculture crops of soybeans, corn, and winter wheat at a site in Ontario. The phases of different rotations were compared with 2- and 3-year crop rotations. Results of the study showed that N2O emissions were approximately 3.1 to 5.1 times higher in monoculture corn than levels observed in winter wheat or soybean crops. When corn followed corn, average N2O emissions twice as high as when corn followed soybeans, and 65 per cent higher than when corn followed winter wheat. The higher levels of both N2O and CO2 were attributed to higher inorganic nitrogen (N) application rates in corn crops. In the corn phase, CO2 levels were higher when the preceding crop was winter wheat. It was concluded that N2O and CO2 emissions from agricultural fields are influenced by both current and preceding crops, a fact which should be considered and accounted which should be considered and accounted for in estimates and forecasts of agricultural greenhouse gas (GHG) emissions. 21 refs., 3 tabs., 10 figs

136

Fission of rapidly rotating fluid systems  

International Nuclear Information System (INIS)

Progress in understanding of the problem of fissional breakup of an equilibrium fluid system through the growth of dynamical distortional instabilities caused by rapid rotation is reviewed. Classic results on equilibrium states, stability, and routes to fission are reviewed, and the equilibrium states of uniformly rotating incompressible fluids, uniformly rotating polytropes, differentially rotating polytropes, rotating isothermal gas clouds, and nonisentropic fluids are discussed in detail. The Bardeen, Friedman, Schutz, and Sorkin (1977) criterion for linear stability in fission modes is considered along with the generic instability of rotating bodies and linear stability of fission modes in hydrodynamic simulations of fission are described in detail

137

Problems Associated with Crop Rotation for Management of Pratylenchus penetrans on Easter Lily.  

Science.gov (United States)

In Humboldt and Del Norte counties of California and Curry County, Oregon, Easter lilies (Lilium longiflotum) are grown commercially in a 3- to 6-year rotation with pasture for cattle and sheep. Bulbs are sold to greenhouse operations to produce flowering plants. The lesion nematode, Pratylenchus penetrans, is a serious detriment to Easter lily production. Both soil and planting stock are often infested; typically, a dual nematicide application is used consisting of a preplant soil fumigation followed by an at-planting application of an organophosphate or carbamate. Nematicide usage has resulted in ground-water contamination. Several factors that could lead to an improved crop rotation program were examined in five field trials in Oregon. Examining the relative nematode host status of crops for feeding cattle and sheep indicated differences in host suitability among clovers and fescues that could prove useful in development of pasture mixes. Populations of P. penetrans under continuous fallow and pasture were monitored for 4 years following harvest of Easter lilies. Populations fluctuated in both situations but generally increased on pasture plants and decreased under fallow. Nematodes were still detectable at the end of 4 years of weed-free fallow. Populations of P. penetrans on Easter lilies were followed over two successive crops. Numbers in soil peaked in July and then decreased while numbers within roots continued to increase until harvest in October. PMID:19274250

Westerdahl, B B; Giraud, D; Etter, S; Riddle, L J; Anderson, C A

1998-12-01

138

Sorbent-Bed Crop-Drying System  

Science.gov (United States)

Proposed aeration system helps reduce spoilage of stored grain or other crop stored in bulk. Air circulates through bin, sorbent bed, and heat exchanger. Outside air cools circulating air in heat exchanger. Sensors measure temperature and humidity, and adjust dampers to obtain requisite temperature and humidity. Suitable for grain bins and shipping barges.

Roberts, Barry C.

1992-01-01

139

Vibration Monitoring of Rotating Systems  

Directory of Open Access Journals (Sweden)

Full Text Available Most energy-conversion machines (e.g. vehicle engines and electric motors involve rotating components (e.g. roller bearings and gears, which generate vibrations. The behavior of a pump which includes a deliberate fault was chosen to illustrate this assertion. The test bearing at the driven end of the pump’s motor was deliberately damaged using a 1.5mm wire-cutting method and an adjustable coupling disk introduced to impose a shaft misalignment of 40. The resulting undesirable behavior of the pump was observed. Experimental data were measured at various speeds of the rotor. The sample period at various operating frequencies were 0.9, 0.6 and 0.45s respectively. The ball-passage frequency was observed at 4.4, 8.8, 13.2 and 17.6Hz. A computer-based analytical model was developed, in visual basic, for monitoring the machine failures: this led to an integrated system-process algorithm for diagnosis of faults in rotating components.

S. D. PROBERT

2010-02-01

140

Crop rotation in the Valle Calido del Alto Magdalena a sustainable focus of high yield  

International Nuclear Information System (INIS)

Experiments were carried out during five years at the Nataima Research Center, located at 431 m.a.s.l, with average temperature of 28 Celsius degrades and annual rainfall of 1274 Boyaca mm, on a soil classified as Arenic Haplustalf, to evaluate different crops rotation based on rice and sorghum; the combinations used were as follows; rice-rice (R-R), rice-- soybean (R-SY), rice-crotalaria-sorghum (R-C-S), sorghum-sorghum (S-S), sorghum-soybean (S-SY) and cotton-sorghum (Al-S). Simultaneously it was evaluated the response to four nitrogen levels, which allowed to find out yield functions and optimum economical. The rotations S-SY, R-SY and AI-S have been the best qualified from an environmental perspective. Sorghum-soybean rotation presents increases in yield compared with expected values, which allows thinking that it is a truly sustainable rotation. This rotation also had an excellent profitability and for that reason is considered the best option within the goals of this work

 
 
 
 
141

Weed infestation of a cereal-legume mixture depending on its concentration and position in a crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available A field study was carried out in the period 2000-2006 at the Experimental Station in Tomaszkowo belonging to the University of Warmia and Mazury in Olsztyn. Its aim was to compare weed infestation of a mixture of spring barley and field pea grown in a four crop rotation with different crop selection and sequence. Each year during tillering of spring barley and before the harvest of the mixture, weed species composition and density were evaluated, while additionally weed biomass was also estimated before the harvest. These results were used to determine species constancy, Simpson’s dominance index, the Shannon-Wiener diversity and evenness indices as well as the community similarity index based on floristic richness, numbers and biomass of particular weed species. The cropping frequency and the position of the mixture in the crop rotation did not differentiate the species composition and total biomass of weed communities in the cereal-legume mixture crops. The crop rotation in which the mixture constituted 50% and was grown after itself had a reducing effect on weed numbers. Growing field pea in the 4-year crop rotation promoted weed infestation of the mixture and the dominance of weed communities. Capsella bursa-pastoris, Chenopodium album, Echinochloa crus-galli, Elymus repens, Polygonum convolvulus, and Sonchus arvensis were constant components of the agrophytocenoses. The weed communities were more similar in terms of their floristic composition than in terms of weed density and air-dry weight of weeds.

Marta K. Kostrzewska

2012-10-01

142

Characterization of crop rotations in irrigation areas of the Ebro Valley from temporal series of Landsat TM images  

Science.gov (United States)

The present paper presents a method to characterize typical crop rotations from temporal series analysis of land use maps derived from supervised classifications of Landsat TM images. The analysis is based on spatial cross-tabulation of land use maps in raster format. As a case study, a temporal land use map series from 1993 to 2000 of the Flumen irrigation area (Huesca, Spain) was considered. The spatial cross-tabulation analysis between each pair of consecutive land use maps, performed in Idrisi 32, yielded a two dimensional matrix that allowed the identification of the typical crop rotations in the study area. Those are rice - fallow land - rice, sunflower - winter cereals - alfalfa - corn, and others as winter cereal or sunflower - fallow land - corn or alfalfa. Rice appears as a typical crop in this area, in which it is usually associated to salt- and/or sodium-affected soils. Those typical rotations have been also spatially located and represented in a map following the crop changes from one year to another year that are registered in the cross-tabulation images. The method can be useful to identify tendencies in the temporal variation of crop rotations in agricultural areas, and to locate typical areas with salt- and/or sodium-affected soils by mapping rotations in which rice is the main crop.

Martinez-Casasnovas, Jose A.; Martin-Montero, Almudena

2004-02-01

143

Non-synchronous rotating damping effects in gyroscopic rotating systems  

Science.gov (United States)

The effects of non-synchronous rotating damping, i.e., of energy dissipation in elements rotating at a speed different from that of the main rotor, on the dynamic behaviour of the latter have been already studied in a previous paper (J. Rotating Machinery 6 (6) (2000)) for the case of non-gyroscopic rotating systems. A planar model, namely the Jeffcott's rotor, was used. The present study is aimed at investigating, through analytical and numerical models, the behaviour of rotors having a non-negligible gyroscopic effect. The parameters of the system affecting the dynamic stability are identified and the threshold of instability is then computed. A sort of map of stability is provided to allow mechanical engineers predicting possibile range of instability for forward and backward whirling motions. An experimental validation on a simple test rig is presented in order to show the effectiveness of the proposed stability analysis. Non-synchronous rotating damping is implemented by using a non-synchronous electromagnetic damper based on eddy currents.

Brusa, Eugenio; Zolfini, Giacomo

2005-03-01

144

Effect of tillage, rotation and crop residues on wheat crop productivity, fertilizer nitrogen and water use efficiency and soil organic carbon status in dry area (rainfed) of north-west Pakistan  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Crop productivity, soil organic carbon (SOC), fertilizer nitrogen and water use efficiency (WUE) in rainfed dry area is influenced by tillage, rotation and crop residues management. Field experiments were conducted during 2004-09 to study the effect of tillage, rotation and crop residues on wheat yield, nitrogen fertilizer and water use efficiency and SOC under semi-arid condition in north-west Pakistan. The treatments consisted of three rotations: i) Wheat-fallow-wheat (farmers' practice) ii...

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

2012-01-01

145

Effect of changes in temperature and precipitation in Denmark on nitrate leaching in cereal cropping systems  

DEFF Research Database (Denmark)

The effect of variation in seasonal temperature and precipitation on soil water nitrate (NO3single bondN) concentration and leaching from winter and spring cereals cropping systems was investigated over three consecutive four-year crop rotation cycles from 1997 to 2008 in an organic farming crop rotation experiment in Denmark. Three experimental sites, varying in climate and soil type from coarse sand to sandy loam, were investigated. The experiment included experimental treatments with different rotations, manure rate and cover crop, and soil nitrate concentrations was monitored using suction cups. The effects of climate, soil and management were examined in a linear mixed model, and only parameters with significant effect (P < 0.05) were included in the final model. The model explained 61% and 47% of the variation in the square root transform of flow-weighted annual NO3single bondN concentration for winter and spring cereals, respectively, and 68% and 77% of the variation in the square root transform of annual NO3single bondN leaching for winter and spring cereals, respectively. Nitrate concentration and leaching were shown to be site specific and driven by climatic factors and crop management. There were significant effects on annual N concentration and NO3single bondN leaching of location, rotation, previous crop and crop cover during autumn and winter. The relative effects of temperature and precipitation differed between seasons and cropping systems. A sensitivity analysis revealed that the predicted N concentration and leaching increased with increases in temperature and precipitation.

Jabloun, Mohamed; Schelde, Kirsten

2015-01-01

146

Cooling system for rotating machine  

Science.gov (United States)

An electrical machine comprising a rotor is presented. The electrical machine includes the rotor disposed on a rotatable shaft and defining a plurality of radial protrusions extending from the shaft up to a periphery of the rotor. The radial protrusions having cavities define a fluid path. A stationary shaft is disposed concentrically within the rotatable shaft wherein an annular space is formed between the stationary and rotatable shaft. A plurality of magnetic segments is disposed on the radial protrusions and the fluid path from within the stationary shaft into the annular space and extending through the cavities within the radial protrusions.

Gerstler, William Dwight (Niskayuna, NY); El-Refaie, Ayman Mohamed Fawzi (Niskayuna, NY); Lokhandwalla, Murtuza (Clifton Park, NY); Alexander, James Pellegrino (Ballston Lake, NY); Quirion, Owen Scott (Clifton Park, NY); Palafox, Pepe (Schenectady, NY); Shen, Xiaochun (Schenectady, NY); Salasoo, Lembit (Schenectady, NY)

2011-08-09

147

Crop yield, root growth, and nutrient dynamics in a conventional and three organic cropping systems with different levels of external inputs and N re-cycling through fertility building crops  

DEFF Research Database (Denmark)

One of the core ideas behind organic production is that cropping systems should be less dependent on import of resources, and minimize negative effects on the surrounding environment compared to conventional production. However, even when clearly complying with regulations for organic production, it is not always obvious that these goals are reached. As an example, strong dependence on import of manure is often seen in current organic production, especially in systems producing high value crops such as vegetable crops. The aim of the present study was to test novel approaches to organic rotations, designed to reduce the reliance on import of external resources significantly. We compared a conventional system (C) and an organic system relying on manure import for soil fertility (O1) to two novel systems (O2 and O3) all based on the same crop rotation. The O2 and O3 systems represented new versions of the organic rotation, both relying on green manures and catch crops grown during the autumn after the maincrop as their main source of soil fertility, and the O3 system further leaving rows of the green manures to grow as intercrops between vegetable rows to improve the conditions for biodiversity and natural pest regulation in the crops. Reliance on resource import to the systems differed, with average annual import of nitrogen fertilizers of 149, 85, 25 and 25 kg N ha-1 in the C, O1, O2 and O3 systems, respectively. As expected, the crop yields were lower in the organic system. It differed strongly among crop species, but on average the organic crops yielded c. 82% of conventional yields in all three organic systems, when calculated based on the area actually grown with the main crops. In the O3 system some of the area of the vegetable fields was allocated to intercrops, so vegetable yields calculated based on total land area was only 63% of conventional yields. Differences in quality parameters of the harvested crops, i.e. nutrient content, dry matter content or damages by pests or diseases were fewand not systematic, whereas clear effects on nutrient balances and nitrogen leaching indicators were found. Root growth of all crops was studied in the C and O2 system, but only few effects of cropping system on root growth was observed. However, the addition of green manures to the systems almost doubled the average soil exploration by active root systems during the rotation from only 21% in C to 38% in O2 when measured to 2.4 m depth. This relates well to the observed differences in subsoil inorganic N content (Ninorg, 1–2 m depth) across the whole rotation (74 and 61 kg N ha-1 in C and O1 vs. only 22 and 21 kg N ha-1 in O2 and O3), indicating a strongly reduced N leaching loss in the two systems based on fertility building crops (green manures and catch crops). In short, the main distinctions were not observed between organic and conventional systems (i.e. C vs. O1, O2 and O3), but between systems based mainly on nutrient import vs. systems based mainly on fertility building crops (C and O1 vs. O2 and O3).

Thorup-Kristensen, Kristian; DresbØll, Dorte Bodin

2012-01-01

148

Short rotation forestry production systems  

Energy Technology Data Exchange (ETDEWEB)

The level of concern about non-technical barriers to short rotation forestry production systems differed greatly among the participant countries. In Canada and U.S.A. the greatest concern was the differential costs between fossil fuels and biomass fuels and the lack of energy policy equalizing the playing field. In Sweden, Denmark and U.K. the concerns related to technology transfer, incentives for getting long-term commitments from biomass fuel suppliers, financing mechanisms, and environmental issues. The reason for these differing concerns can be seen partly in a comparison of energy prices for gasoline and electricity for industry and households. The conclusion is that government intervention is required to facilitate the commercialization of biomass energy and that new policy tools may be needed. The Handbook on How to Grow Short Rotation Forests was in hard copy and electronic format, which can be downloaded from the World Wide Web and is available on CD-ROM. Full-scale plants for post-treatment of sewage water with the aim of improved nitrogen reduction have been built at several sites in southern Sweden. The ability of willow, when used as vegetation filters, to capture nutrients from the wastewater is being studied at some of these sites. This ability varies considerably with the development stage of the plantation and also with site conditions. The use of ash as a fertilizer is under investigation. Ash additions gave equal Salix stem mass as commercial fertilizers did. A lower uptake of P in ash treatments receiving P fertilizer indicated that the short term availability of P in ash could be 80% of that in P fertilizer. The liming effect of ash was similar to that of slaked lime. Due to increased pH in the lime and ash treatments, Mn and Cd mass in stems decreased. In the coppice research one study showed that the high-N plants had lower amounts of starch in the tissue than the low-N plants. The major storage locations for starch were in roots, stems and stool in this order. In these organs most of the starch was found in cortex cells in the bark followed by phloem cells and also to some extent in the xylem. The seasonal variation showed at what time the reserves were built up and when reserve products were utilised for the regrowth and resprouting. Also the effect of different harvesting techniques was studied. It was shown that significant damage to stools at harvesting remained throughout the three-year period of investigation. Even stools with extremely severe damage still showed a high ability to sprout, although at a lower level than less damaged stools. Studies have also indicated significant variation in sprouting ability between clones of S. viminalis, probably mainly due to genotypic differences

Ledin, S. [Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Soil Sciences; Sennerby-Forsse, L. [Swedish Forestry Research Inst., Uppsala (Sweden); Wright, Lynn [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.

1998-12-31

149

Boundary layer control of rotating convection systems.  

Science.gov (United States)

Turbulent rotating convection controls many observed features of stars and planets, such as magnetic fields, atmospheric jets and emitted heat flux patterns. It has long been argued that the influence of rotation on turbulent convection dynamics is governed by the ratio of the relevant global-scale forces: the Coriolis force and the buoyancy force. Here, however, we present results from laboratory and numerical experiments which exhibit transitions between rotationally dominated and non-rotating behaviour that are not determined by this global force balance. Instead, the transition is controlled by the relative thicknesses of the thermal (non-rotating) and Ekman (rotating) boundary layers. We formulate a predictive description of the transition between the two regimes on the basis of the competition between these two boundary layers. This transition scaling theory unifies the disparate results of an extensive array of previous experiments, and is broadly applicable to natural convection systems. PMID:19148097

King, Eric M; Stellmach, Stephan; Noir, Jerome; Hansen, Ulrich; Aurnou, Jonathan M

2009-01-15

150

Soil Quality Indicators as Affected by a Long Term Barley-Maize and Maize Cropping Systems  

Directory of Open Access Journals (Sweden)

Full Text Available Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L. and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L. with Italian ryegrass (R3 and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1 the high input level (H, done as a conventional tillage, 2 the low input level (L, where the tillage was replaced by harrowing and the manure was reduced by 30%. The effects of the two different cropping systems was assessed on soil nematofauna and soil physic parameters (structure or aggregate stability. Comparison was made of general composition, trophic structure and biodiversity of the nematofauna collected in both systems. Differences in nematode genera composition and distribution between the two systems were also recorded. The monoculture, compared to the three year rotation, had a negative influence on the nematofauna composition and its ecological succession. The Structural Stability Index (SSI values indicate that both the cropping systems had a negative effect on the aggregate stability. The results indicate that nematofauna can be used to assess the effects of cropping systems on soil ecosystem, and therefore be considered a good indicator of soil health to integrate information from different chemical or physical indicators.

Stefano Bocchi

2009-03-01

151

Soil Quality Indicators as Affected by a Long Term Barley-Maize and Maize Cropping Systems  

Directory of Open Access Journals (Sweden)

Full Text Available Most soil studies aim a better characterization of the system through indicators. In the present study nematofauna and soil structure were chosen as indicators to be assess soil health as related to agricultural practices. The field research was carried out on the two fodder cropping systems continuous maize (CM, Zea mays L. and a 3-year rotation of silage-maize – silage-barley (Hordeum vulgare L. with Italian ryegrass (R3 and grain-maize maintained in these conditions for 18 years. Each crop system was submitted to two management options: 1 the high input level (H, done as a conventional tillage, 2 the low input level (L, where the tillage was replaced by harrowing and the manure was reduced by 30%. The effects of the two different cropping systems was assessed on soil nematofauna and soil physic parameters (structure or aggregate stability. Comparison was made of general composition, trophic structure and biodiversity of the nematofauna collected in both systems. Differences in nematode genera composition and distribution between the two systems were also recorded. The monoculture, compared to the three year rotation, had a negative influence on the nematofauna composition and its ecological succession. The Structural Stability Index (SSI values indicate that both the cropping systems had a negative effect on the aggregate stability. The results indicate that nematofauna can be used to assess the effects of cropping systems on soil ecosystem, and therefore be considered a good indicator of soil health to integrate information from different chemical or physical indicators.

Anna Corsini

2011-02-01

152

Role of Nematodes, Nematicides, and Crop Rotation on the Productivity and Quality of Potato, Sweet Potato, Peanut, and Grain Sorghum  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The objective of this experiment was to determine the effects of fenamiphos 15G and short-cycle potato (PO)-sweet potato (SP) grown continuously and in rotation with peanut (PE)-grain sorghum (GS) on yield, crop quality, and mixed nematode population densities of Meloidogyne arenaria, M. hapla, M. incognita, and Mesocriconema ornatum. Greater root-gall indices and damage by M. hapla and M. incognita occurred on potato than other crops. Most crop yields were higher and root-gall indices lower ...

Johnson, A. W.; Dowler, C. C.; Glaze, N. C.; Handoo, Z. A.

1996-01-01

153

Nitrogen turnover and leaching in cropping systems with ryegrass catch crops  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This thesis deals with perennial ryegrass (Lolium perenne L.) catch crops and their short- and long-term effects on nitrogen leaching and nitrogen turnover in soils. Results are presented from three field experiments on a sandy soil in south-west Sweden, where undersown catch crops were used in cropping systems with and without applications of liquid manure. The effects of different tillage practices on soil mineral nitrogen and leaching were also studied. Two coupled simulation models, which...

Aronsson, Helena

2000-01-01

154

Rotating bodies and electrodynamics in the rotating reference system  

International Nuclear Information System (INIS)

Maxwell equations for a uniformly rotating non-inertial reference frame are derived. It is shown that electrodynamic field in a rotating reference frame may have negative energy to amplify electromagnetic waves reflected by a rotating absorber. Electromagnetic generator using this effect is considered. By analogy, a rotating conductor may spontaneously emit photons. Intensity of this spontaneous radiation is calculated

155

Efect of organic barley-based crop rotations on soil nutrient balance in a semiarid environment for a 16-year experiment  

Science.gov (United States)

In natural ecosystems with no percolating moisture regime, the biogeochemical cycle can be considered a closed system because the nutrients extracted by the roots will be returned to the soil after a certain time. In organic farming, a cycle model as close as possible is taken as a guideline, but we have to consider that unlike natural ecosystems, where most of the nutrients remain in the cycle, the agrosystems are open cycles. To achieve a sustainable fertility of the soil, the soil nutrient levels, the extractions according to the expected crop yields and the export refunds in the form of crop residues, biological nitrogen fixation, green manure or compost will have to be determined. Nutrient balance should be closed with external inputs, always avoiding to be a source of negative impacts on the environment. In organic farming without exogenous inputs, the effect of the crop rotations is much more noticeable in the nutrient balance than in the conventional farming fields which every year receive inputs of nutrients (nitrogen, phosphorus and potassium) in the form of chemical fertilizers. The most extractive crop rotations are those that produce a greater decrease in soil reserves, and in these cases exogenous inputs to maintain sustainability should be considered; however, in less extractive crop rotations, extractions can be restored by the edaphogenesis processes. In this work, soil organic matter, phosphorus and potassium balances were analyzed in different organic barley-based crop rotations (barley monoculture [b-b] and in rotation with vetch for hay production [B-Vh], vetch as green manure [B-Vm], sunflower [B-S], chickpea [B-C] and fallow [B-F]) in clay soils under a semiarid environment ("La Higueruela" Experimental Farm, Santa Olalla, Toledo, central Spain) over a 16 year period. Additionally, barley monoculture in conventional farming [B-B] was included. In the organic system, the fertilization involved the barley straw in all rotations, the sunflower straw in B-S, the symbiotic nitrogen from the vetch crops and the green manure in B-Vm. In the conventional system, fertilization consisted on barley straw and chemical fertilizers at a rate of 80-60-30 kg N-P-K ha-1. Before the organic management, the whole plot was subjected to conventional practices. The highest total yields (and therefore the nutrients extractions) were obtained in B-Vh, followed in this order by B-B, B-S, B-F, B-Vm, B-C and b-b. The crop rotations with the highest yields favoured the microbial activity and the organic residues mineralization, although this caused, eventually, a small decrease in the soil organic matter content. Since the eighth year, this parameter remained more stable until the end of the study period. The highest decrease of soil organic matter took place in B-F and B-S, while the lowest ones happened in B-B, where the great amounts of barley straw incorporated into the soil compensated the organic matter losses. The conversion from conventional to organic management with the incorporation of the straw to the soil implies a re-adaptation process with a decrease of the soil phosphorus level by the increasing soil microbial biomass. A decrease of phosphorus during the first six years of the experiment and a posterior recovery and stabilization of this ratio by the solubilisation of the fixed phosphorus was observed. B-F and B-S presented the lowest soluble phosphorus losses, while B-C the highest ones. In the same way, the potassium level decreased during the first eight years and after that remained constant. The highest decreases took place in the rotations with the biggest amounts of barley straw; this decrease could be explained by the nutrient immobilization caused by the microbial biomass.

Meco, Ramón; María Moreno, Marta; Lacasta, Carlos; Moreno, Carmen

2013-04-01

156

Nematode infestation and N-effect of legumes on soil and crop yelds in legume-sorghum rotations  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of cowpea (Vignaunguiculata and-groundnut (Arachis hypogea on succeeding sorghum yields, soil mineral N and nematode infestationwere studied during five cropping seasons (2000 to 2004 in a weakly acid Ultisol of the agronomy research station of Farakô-Ba lo-cated in the Guinean zone of Burkina Faso, West Africa. A factorial 5x5 design of five crop rotations with five fertilizer treatments in a split-plot arrangement with four replications was used.Sorghum yields were affected by the two factors (rotation with legumes and fertilizer ap-plications during the four years. But interactions were not observed between the two factors. Monocropping of sorghum produced the lowest yields and legume–sorghum rotations increased sorghum yields by50% to 300%. Ground-nut–sorghum and cowpea–sorghum rotations increased soil mineral N by36% and 52%, re-spectively. Crop rotation influenced nematode infestation but the effects on soil and sorghum root infestation differed according to the rotation. The cowpea–sorghum rotation increased soil and sorghum root infestationby nematodes while groundnut–sorghum decree-sed the nematode population. The soil of the cowpea-sorghum rotation contained 1.5 to 2 times more nematodes than the soil of the monocropping of sorghum. In contrast, the soil ofthe groundnut–sorghum rotation contained from 17 to 19 times fewernematodes than that of themonocropping of sorghum. However, nematode infestation did not affect any of the succeeding sorghum yields. It was concluded that the parasitic effect of nematodes was limited by the predominance of positive N-effects on the development of succeeding sorghum.

Abdoulsalam Sawadogo

2011-05-01

157

Avaliação do potencial de coberturas verdes e de sitemas de rotações de cultura na supressão do nematoide anelado (Mesocriconema xenoplax) em pré-plantio ao pessegueiro / Evaluation of green covering potential and crop rotation systems in the suppression of the ring nematode (Mesocriconema xenoplax) in peach pre-planting  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Em uma área naturalmente infestada com o nematoide anelado (Mesocriconema xenoplax), coberturas verdes foram testadas quanto a sua hospedabilidade, em cultivos de inverno e verão, comparativamente às parcelas mantidas sob pousio. Três sistemas de rotação de culturas, com as mesmas espécies vegetais [...] (aveia-preta/feijão-de-porco/milheto/nabo-forrageiro; nabo-forrageiro/milheto/aveia-branca/milho, e aveia-branca/mucuna-anã/trigo/sorgo), foram avaliados quanto ao potencial supressor do nematóide de M. xenoplax por dois anos, utilizando-se, como testemunhas, de parcelas mantidas sob pousio e alqueive. Os experimentos foram conduzidos a campo, em blocos ao acaso, com seis repetições. Antes e após o estabelecimento de cada cultivo, as populações do nematoide foram avaliadas quanto ao número de M. xenoplax/100cm³ de solo e fator de reprodução (FR= população final/população inicial) do nematoide anelado, onde FR1,00, favorecimento da reprodução. A maioria das culturas testadas foi hospedeira desfavorável (FR Abstract in english In a field naturally infested with ring nematode (Mesocriconema xenoplax), green covering were tested for their hostel in winter and summer crops comparing to plots kept in fallow lands. Tree crop rotation system with the same plant species (black oat/pig bean/ millet/forage radish; forage radish/ m [...] illet/white oat/corn; and white oat/mucuna deeringiana/wheat/sorghum) were evaluated for suppression potential to nematode M. xenoplax for two years, using as witness plots that were kept in fallow lands. The experiments were conducted in the field in a randomized block design with six repetitions. Before and after the establishment of each plot, the nematode populations were evaluated on the number of M. xenoplax/100cm³ of soil and the reproduction factor (RF= final population/initial population) of the ring nematode, where RF 1,00, favoring of the reproduction. Most of the crops analyzed were unfavorable host (RF

Cesar Bauer, Gomes; Flávio Luiz Carpena, Carvalho; João Guilherme, Casagrande Júnior; Elizete Beatriz, Radmann.

2010-03-01

158

Chapter 3.1. Dynamics of legume nitrogen fixation in intercrops and in crop rotations  

International Nuclear Information System (INIS)

Use of nitrogen-15 lends understanding of the dynamics and interactions between various pools in agricultural systems, including nitrogen fixation by legumes and utilization of soil and fertilizer nitrogen by crops in general. Biological nitrogen fixation in sole and intercropped legumes is discussed, as are intercrop design and methods of assessing possible yield benefits from intercropping. Advantages that accrue from inclusion of legumes, only some of which are linked with nitrogen transfer, are discussed with particular reference to two case studies

159

Divesting in crop diversity: trade-offs of modern cropping systems  

Science.gov (United States)

Since the advent of the Green Revolution in the 1960's, agriculture has experienced great advances in yield, seed genetics and management. This focus on increased yields and production came at the cost of many marginal, traditional crops because they could no longer compete with the bountiful harvests of massive mono-culture food systems. In the modern agricultural world, three staple crops are responsible for 46% of global agricultural production on 33% of global harvested area. Further, seventeen crops account for 73% of global crop production and use 58% of global harvested area. How has the distribution of individual crops today changed from before the Green Revolution began, and what are the broader implications of these changes for our food systems?

Engstrom, P.

2013-12-01

160

Enhancing productivity of salt affected soils through crops and cropping system  

International Nuclear Information System (INIS)

The reclamation of salt affected soils needs the addition of soil amendment and enough water to leach down the soluble salts. The operations may also include other simple agronomic techniques to reclaim soils and to know the crops and varieties that may be grown and other management practices which may be followed on such soils (Khan, 2001). The choice of crops to be grown during reclamation of salt affected soils is very important to obtain acceptable yields. This also decides cropping systems as well as favorable diversification for early reclamation, desirable yield and to meet the other requirements of farm families. In any salt affected soils, the following three measures are adopted for reclamation and sustaining the higher productivity of reclaimed soils. 1. Suitable choice of crops, forestry and tree species; 2. Suitable choice of cropping and agroforestry system; 3. Other measures to sustain the productivity of reclaimed soils. (author)

 
 
 
 
161

Long-term effects of cropping systems on N2O emission potential  

DEFF Research Database (Denmark)

The potential for N2O emissions outside the main growing season may be influenced by long-term effects of cropping system. This was investigated by collecting intact soil cores (100 cm3, 0–4 cm depth) under winter wheat in three organic cropping systems and a conventional reference within a long-term crop rotation experiment. Average annual inputs of C in crop residues and manure ranged from 1.7 to 3.3 Mg ha?1. A simulated freeze–thaw cycle resulted in a flush of CO2 during the first 48 h, which could be mainly from microbial sources. Other samples were adjusted to approximately ?10, ?30 or ?100 hPa and amended with excess 15NO3? prior to freezing and thawing. Denitrification was the main source of N2O during a 72-h incubation at 22 °C, as judged from N2O and total 15N evolution. Although the input of C in the conventionally managed cropping system was significantly less than in the organic cropping systems, it showed higher N2O evolution at all three matric potentials. Estimates of relative gas diffusivity (DP/D0) in soil from the four cropping systems indicated that C input affected soil aeration. Soil from the two cropping systems with highest C input showed N2O evolution at DP/D0 in excess of 0.02, which is normally considered a threshold for development of anaerobic sites in the soil, presumably because the oxygen demand was also high. The study shows that cropping system affects both soil gas diffusivity and C availability, and that both characteristics significantly influence the N2O emission potential.

Petersen, SØren O; Ambus, Per

2013-01-01

162

Microbial Community Composition as Affected by Dryland Cropping Systems and Tillage in a Semiarid Sandy Soil  

Directory of Open Access Journals (Sweden)

Full Text Available This study evaluated microbial communities of soil (0–10 cm as affected by dryland cropping systems under different tillage practices after 5 years. The soil type was an Olton sandy loam with an average of 16.4% clay, 67.6% sand and 0.65 g kg?1 of organic matter (OM. The cropping systems evaluated were grain sorghum (Sorghum bicolor L.—cotton (Gossypium hirsutum (Srg-Ct, cotton-winter rye (Secale cereale-grain sorghum (Ct-Rye-Srg, and a rotation of forage (f sorghum (Sorghum bicolor L. and Sorghum sudanense with winter rye (Srf-Rye, which were under no-tillage (nt and conventional tillage (ct practices. Soil microbial communities under cotton based cropping systems (Srg-Ct and Ct-Rye-Srg showed lower fungal:bacterial ratios compared to the soil under Srf-Rye. Soil under Srf-Rye showed higher population densities of Bacteroidetes and Proteobacteria while lower Actinobacteria compared to Srg-Ct and Ct-Rye-Srg. Chloroflexi, Gemmatimonadetes and Verrucomicrobiae were higher in tilled soil compared to the no-tilled plots. Regardless the limited irrigation available to sustain agricultural production within these dryland cropping systems, this study demonstrated that differences in microbial communities are more affected by crop rotation than tillage management history. Although soil fungal diversity was not analyzed in this study, pyrosequencing suggests that tillage practices can affect bacterial phyla distribution in this sandy soil.

Verónica Acosta-Martínez

2010-06-01

163

Soil Management Practices to Improve Nutrient-use Efficiencies and Reduce Risk in Millet-based Cropping Systems in the Sahel  

Directory of Open Access Journals (Sweden)

Full Text Available Low soil fertility and moisture deficit are among the main constraints to sustainable crop yields in the Sahel. A study therefore, was conducted at the ICRISAT Sahelian Center, Sadore in Niger to test the hypothesis that integrated soil husbandry practices consisting of manure, fertilizer and crop residues in rotational cropping systems use organic and mineral fertilizes efficiently, thereby resulting in higher yields and reduced risk. Results from an analysis of variance showed that choice of cropping systems explained more than 50% of overall variability in millet and cowpea grain yields. Among the cropping systems, rotation gave higher yields than sole crop and intercropping systems and increased millet yield by 46% without fertilizer. Rainfall-use efficiency and partial factor productivity of fertilizer were similarly higher in rotations than in millet monoculture system. Returns from cowpea grown in cowpea-millet rotation without fertilizer and the medium rates of fertilizers (4 kg P.ha-1 + 15 kg N.ha-1 were found to be most profitable in terms of high returns and low risk, principally because of a higher price of cowpea than millet. The study recommends crop diversification, either in the form of rotations or relay intercropping systems for the Sahel as an insurance against total crop failure.

Koala, S.

2003-01-01

164

Pyrosequencing reveals contrasting soil bacterial diversity and community structure of two main winter wheat cropping systems in China.  

Science.gov (United States)

Microbes are key components of the soil environment, playing an important role in maintaining soil health, sustainability, and productivity. The composition and structure of soil bacterial communities were examined in winter wheat-rice (WR) and winter wheat-maize (WM) cropping systems derived from five locations in the Low-Middle Yangtze River plain and the Huang-Huai-Hai plain by pyrosequencing of the 16S ribosomal RNA gene amplicons. A total of 102,367 high quality sequences were used for multivariate statistical analysis and to test for correlation between community structure and environmental variables such as crop rotations, soil properties, and locations. The most abundant phyla across all soil samples were Proteobacteria, Acidobacteria, and Bacteroidetes. Similar patterns of bacterial diversity and community structure were observed within the same cropping systems, and a higher relative abundance of anaerobic bacteria was found in WR compared to WM cropping systems. Variance partitioning analysis revealed complex relationships between bacterial community and environmental variables. The effect of crop rotations was low but significant, and interactions among soil properties, locations, and crop rotations accounted for most of the explained variation in the structure of bacterial communities. Soil properties such as pH, available P, and available K showed higher correlations (positive or negative) with the majority of the abundant taxa. Bacterial diversity (the Shannon index) and richness (Chao1 and ACE) were higher under WR than WM cropping systems. PMID:24276539

Zhao, Jun; Zhang, Ruifu; Xue, Chao; Xun, Weibing; Sun, Li; Xu, Yangchun; Shen, Qirong

2014-02-01

165

Effect of resource conserving techniques on crop productivity in rice-wheat cropping system  

International Nuclear Information System (INIS)

Rice-wheat cropping system is the most important one in Pakistan. The system provides food and livelihood for more than 15 million people in the country. The productivity of the system is much lower than the potential yields of both rice and wheat crops. With the traditional methods, rice-wheat system is not a profitable one to many farmers. Hence, Cost of cultivation must be reduced and at the same time, efficiency of resources like irrigation water, fuel, and fertilizers must be improved to make the crop production system more viable and eco- friendly. Resource conserving technology (RCT) must figure highly in this equation, since they play a major role in achieving the above goals. The RCT include laser land leveling, zero-tillage, bed furrow irrigation method and crop residue management. These technologies were evaluated in irrigated areas of Punjab where rice follows wheat. The results showed that paddy yield was not affected by the new methods. Direct seeding of rice crop saved irrigation water by 13% over the conventionally planted crop. Weeds were the major problem indirect seeded crop, which could be eliminated through cultural, mechanical and chemical means. Wheat crop on beds produced the highest yield but cost of production was minimum in the zero-till wheat crop. Planting of wheat on raised beds in making headway in low- lying and poorly drained areas. Thus, resource conserving tillage technology provides a tool for making progress towards improving and sor making progress towards improving and sustaining wheat production system, helping with food security and poverty alleviation in Pakistan in the next few decades. (author)

166

Conversão e balanço energético de sistemas de rotação de culturas para triticale, sob plantio direto Energy and balance conversion of crop rotation systems for triticale , under no-tillage  

Directory of Open Access Journals (Sweden)

Full Text Available Na agricultura moderna, interessam sistemas de produção eficientes no uso da energia. Objetivou-se avaliar a conversão e o balanço energético de cinco sistemas de rotação de culturas envolvendo o triticale. Os sistemas avaliados, no período de 1987 a 1991, foram: I (triticale/soja, II (triticale/soja e aveia preta/soja, III (triticale/soja e ervilhaca/milho, IV (triticale/ soja, ervilhaca/milho e aveia preta/soja e V (triticale/soja, triticale/soja, ervilhaca/milho e aveia preta/soja. Em 1990, nos sistemas II, IV e V, a aveia preta foi substituída por aveia branca. O experimento foi estabelecido em plantio direto, em delineamento de blocos ao acaso, com três repetições e parcelas com área útil de 24 m². Na média do período de 1987 a 1989, o sistema III apresentou conversão (9,30 e balanço energético (23.860 Mcal/ha maiores do que os demais sistemas estudados (I: 5,38, II: 5,02, IV: 8,12 e V: 7,37; I: 18.067 Mcal/ha, II: 13.790 Mcal/ha, IV: 19.875 Mcal/ha e V: 19.264 Mcal/ha, respectivamente. Nesse período, as condições climáticas transcorreram normalmente. Na média do período de 1990 a 1991, não houve diferenças significativas entre as médias para conversão e para balanço energético. Nesse período, as condições climáticas foram adversas às culturas em estudo.Efficient energy conversion production systems are important for modern agriculture. The objetive was to evaluate the energy conversion and balance of five rotation systems that included triticale. The evaluated systems, from 1987 to 1991, were: I (triticale/soybean, II (triticale/soybean and black oats/soybean, III (triticale/soybean and common vetch/corn, IV (triticale/soybean, common vetch/corn, and black oats/soybean, and V (triticale/soybean, triticale/soybean, common vetch/corn, and black oats/ soybean. In 1990, black oats was replaced by white oats in systems II, IV, and V. The experiment was set up under no-tillage, using a randomized block design with three replications and plots totalizing 24 m² . On average, for the period 1987 to 1989, system III showed higher energy conversou (9.30 and balance (23.860 Mcal/ha, as compared to the othen studied systems (I: 5.38, II: 5.02, IV: 8.12 e V: 7.37; I: 18.067 Mcal/ha, II: 13.790 Mcal/ha, IV: 19.875 Mcal/ha e V: 19.264 Mcal/ha, respectivily. In this period, the climatic conditions were normal. On average, the period 1990 to 1991, there were no significant differences between energy conversion and balance means. In this period, climatic conditions were adverse.

Henrique Pereira dos Santos

2000-03-01

167

Global crop production forecasting data system analysis  

Science.gov (United States)

The author has identified the following significant results. Findings led to the development of a theory of radiometric discrimination employing the mathematical framework of the theory of discrimination between scintillating radar targets. The theory indicated that the functions which drive accuracy of discrimination are the contrast ratio between targets, and the number of samples, or pixels, observed. Theoretical results led to three primary consequences, as regards the data system: (1) agricultural targets must be imaged at correctly chosen times, when the relative evolution of the crop's development is such as to maximize their contrast; (2) under these favorable conditions, the number of observed pixels can be significantly reduced with respect to wall-to-wall measurements; and (3) remotely sensed radiometric data must be suitably mixed with other auxiliary data, derived from external sources.

Castruccio, P. A. (principal investigator); Loats, H. L.; Lloyd, D. G.

1978-01-01

168

Linking N Cycling to Microbial Function Within Soil Microenvironments in Cover Crop Systems  

Science.gov (United States)

Cover crops have emerged as a crop management strategy to achieve agricultural sustainability and maintain environmental quality. Thus, fundamental knowledge of microbial-mediated C and N cycling is vital to understanding soil organic matter (SOM) dynamics in cover cropped agroecosystems. We investigated the effects of short-term cover crop-C input on N processing by microbial communities within SOM microenvironments and in bulk soil, across a gradient of organic to conventional crop management. We hypothesized that cover crop C and N inputs promote soil aggregation, which increases the abundance of ammonia oxidizing bacteria (AOB) and stimulates greater microbial cycling of N within soil microenvironments, thereby leading to potential increases in N stabilization coupled with decreases in N loss. Our hypothesis was tested on the long-term organic, low-input, and conventional maize-tomato rotations at the Center for Integrated Farming Systems experiment (Davis, CA). We collected soil samples (0-15cm) across the cover crop and subsequent maize growing seasons and then isolated three SOM fractions soil: coarse particulate organic matter (cPOM; >250um), microaggregates (53-250um), and silt-and-clay (nosZ, were employed to quantify AOB and denitrifier population sizes, respectively. We also measured gross ammonification and nitrification rates in short-term 15N-incubations of the bulk soil to link cover crop induced N cycling to N-transforming bacteria. Total soil C and N concentrations and soil aggregation were higher in the organic than conventional and low-input systems. The amoA and no Z copy numbers g-1 dry soil were highest in the microaggregate fraction and similar between the cPOM and silt-and-clay fractions, among all cropping treatments. Abundances of AOB and denitrifiers were lower in bulk soil from the conventional and low- input than organic system. Our study indicates that long-term, annual cover crop inputs to the organic system lead to greater aggregation and development of microaggregate structures. Consequently, the abundance of nitrifiers and denitrifiers as well as the rates of ammonification and nitrification are augmented in the organic system compared to the conventional, which does not receive a cover crop, and the low-input system, which receives cover crops only in alternate years. These results shed light on the specific mechanisms governing short-term N stabilization versus losses under long-term crop management.

Kong, A. Y.; Scow, K. M.; Hristova, K.; Six, J.

2007-12-01

169

Sustentabilidade de sistemas de rotação e sucessão de culturas em solos de várzea no Sul do Brasil / Crop rotations sustainability and successions systems in tilled plain areas in Southern Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A avaliação quantitativa com diferentes tipos de indicadores é fundamental na determinação da sustentabilidade dos sistemas de rotação e sucessão de culturas. Este estudo teve como objetivo avaliar a sustentabilidade de algumas sucessões de culturas em solo de várzea, nos sistemas de plantio direto [...] (PD) e convencional (SC). O trabalho foi conduzido em Pelotas, Rio Grande do Sul (RS), em área experimental da Embrapa Clima Temperado. Os tratamentos foram constituídos por cinco anos de implantação de sistemas de rotação e sucessão de culturas de inverno e de primavera-verão, seguidos de dois anos de pousio e três anos da cultura do arroz irrigado. As culturas de primavera-verão foram o milho e a soja, além do arroz; enquanto que as de inverno foram gramíneas, leguminosas, consórcios, nabo forrageiro e campo natural. O delineamento experimental foi o de blocos ao acaso com parcelas subdivididas, com três repetições. As culturas de verão ocuparam as parcelas, enquanto as espécies de inverno foram alocadas nas subparcelas. Os parâmetros observados foram transformados em índices para padronizar as diversas variáveis, cada uma em relação àquela de melhor comportamento mensurado, e dispostos em quatro categorias de análise: (a) indicadores agronômicos (matéria seca e rendimento de grãos); (b) indicadores ambientais (fertilidade do solo); (c) indicadores energéticos (produção e eficiência energética); d) indicadores econômicos (valor bruto da produção e rentabilidade). Pela média harmônica obtida entre os índices dos indicadores, foram comparados os diferentes sistemas de rotação e sucessão de culturas, inferindo-se daí sua sustentabilidade e suas diferenças (Teste t P?0,05). Concluiu-se que: (a) todos os sistemas de rotação e sucessão de culturas dos quais o milho faz parte apresentam maior índice de sustentabilidade; (b) os sistemas de rotação e sucessão de culturas S1 [gramínea x soja x arroz (PD)] e S4 [nabo x soja x arroz (PD)] apresentam, respectivamente, a maior e a menor sustentabilidade entre aqueles sistemas em que a cultura da soja participa; (c) o sistema S5 [campo nativo x soja x arroz (SC)] apresenta o menor índice de sustentabilidade; (d) o sistema S8 [Consórcio x milho x arroz (PD)] apresenta a melhor distribuição e o melhor equilíbrio entre as diversas perspectivas de sustentabilidade consideradas; (e) o sistema S10 [campo nativo x milho x arroz (SC)] tem pior desempenho, no que se refere à sustentabilidade entre os que incluem o milho; (f) o sistema de PD confere maior sustentabilidade às sucessões de cultura. Abstract in english The quantitative analysis with different types of indicators is crucial in determining the sustainability of crop succession. This study aimed to appraise that in tilled plain areas. The research was carried out in Pelotas, RS, Brazil at Embrapa Clima Temperado research area. The treatments consiste [...] d of successions of winter and spring-summer crops species for five years, followed by two years of fallow and three years of rice cropping. The spring-summer crops were corn and soybean, besides rice; the winter crops were cereals, leguminous pastures, mixtures species, turnip and native grass species. Seeding was performed either by no-till (NT) or conventional (CT). The experiment was planned in a split-plot randomized blocks design with three replications, where the summer crops occupied the plots, while the winter's species were allocated to the subplots. The parameters measured were transformed into index to standardize the variables, each one in relation to the better measurement behavior, and arranged in four categories of analysis: (a) Agronomics indices (dry weight and grain yield); (b) Environmental indicators (soil fertility); (c) Energy Indicators (gain and energy efficiency); d) Economic Indicators (profitability and gross value of production). Through harmonic average rates calculated for each indicator, comparisons

Francisco de Jesus, Vernetti Junior; Algenor da Silva, Gomes; Luis Osmar Braga, Schuch.

170

Sustentabilidade de sistemas de rotação e sucessão de culturas em solos de várzea no Sul do Brasil / Crop rotations sustainability and successions systems in tilled plain areas in Southern Brazil  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A avaliação quantitativa com diferentes tipos de indicadores é fundamental na determinação da sustentabilidade dos sistemas de rotação e sucessão de culturas. Este estudo teve como objetivo avaliar a sustentabilidade de algumas sucessões de culturas em solo de várzea, nos sistemas de plantio direto [...] (PD) e convencional (SC). O trabalho foi conduzido em Pelotas, Rio Grande do Sul (RS), em área experimental da Embrapa Clima Temperado. Os tratamentos foram constituídos por cinco anos de implantação de sistemas de rotação e sucessão de culturas de inverno e de primavera-verão, seguidos de dois anos de pousio e três anos da cultura do arroz irrigado. As culturas de primavera-verão foram o milho e a soja, além do arroz; enquanto que as de inverno foram gramíneas, leguminosas, consórcios, nabo forrageiro e campo natural. O delineamento experimental foi o de blocos ao acaso com parcelas subdivididas, com três repetições. As culturas de verão ocuparam as parcelas, enquanto as espécies de inverno foram alocadas nas subparcelas. Os parâmetros observados foram transformados em índices para padronizar as diversas variáveis, cada uma em relação àquela de melhor comportamento mensurado, e dispostos em quatro categorias de análise: (a) indicadores agronômicos (matéria seca e rendimento de grãos); (b) indicadores ambientais (fertilidade do solo); (c) indicadores energéticos (produção e eficiência energética); d) indicadores econômicos (valor bruto da produção e rentabilidade). Pela média harmônica obtida entre os índices dos indicadores, foram comparados os diferentes sistemas de rotação e sucessão de culturas, inferindo-se daí sua sustentabilidade e suas diferenças (Teste t P?0,05). Concluiu-se que: (a) todos os sistemas de rotação e sucessão de culturas dos quais o milho faz parte apresentam maior índice de sustentabilidade; (b) os sistemas de rotação e sucessão de culturas S1 [gramínea x soja x arroz (PD)] e S4 [nabo x soja x arroz (PD)] apresentam, respectivamente, a maior e a menor sustentabilidade entre aqueles sistemas em que a cultura da soja participa; (c) o sistema S5 [campo nativo x soja x arroz (SC)] apresenta o menor índice de sustentabilidade; (d) o sistema S8 [Consórcio x milho x arroz (PD)] apresenta a melhor distribuição e o melhor equilíbrio entre as diversas perspectivas de sustentabilidade consideradas; (e) o sistema S10 [campo nativo x milho x arroz (SC)] tem pior desempenho, no que se refere à sustentabilidade entre os que incluem o milho; (f) o sistema de PD confere maior sustentabilidade às sucessões de cultura. Abstract in english The quantitative analysis with different types of indicators is crucial in determining the sustainability of crop succession. This study aimed to appraise that in tilled plain areas. The research was carried out in Pelotas, RS, Brazil at Embrapa Clima Temperado research area. The treatments consiste [...] d of successions of winter and spring-summer crops species for five years, followed by two years of fallow and three years of rice cropping. The spring-summer crops were corn and soybean, besides rice; the winter crops were cereals, leguminous pastures, mixtures species, turnip and native grass species. Seeding was performed either by no-till (NT) or conventional (CT). The experiment was planned in a split-plot randomized blocks design with three replications, where the summer crops occupied the plots, while the winter's species were allocated to the subplots. The parameters measured were transformed into index to standardize the variables, each one in relation to the better measurement behavior, and arranged in four categories of analysis: (a) Agronomics indices (dry weight and grain yield); (b) Environmental indicators (soil fertility); (c) Energy Indicators (gain and energy efficiency); d) Economic Indicators (profitability and gross value of production). Through harmonic average rates calculated for each indicator, comparisons

Francisco de Jesus, Vernetti Junior; Algenor da Silva, Gomes; Luis Osmar Braga, Schuch.

1708-17-01

171

The rotating rake fan mode measurement system  

Science.gov (United States)

An experimental measurement system was developed and implemented by the NASA Glenn Research Center in the 1990s. The system is a continuously rotating radial rake immersed into the duct. This rotating rake provides a complete map of the acoustic duct modes present in a ducted fan and has been used on a variety of test articles: from a low-speed, concept test rig to a full-scale production turbofan engine. The rotating rake has been critical in developing and evaluating a number of noise reduction concepts as well as providing experimental databases for verification of several aero-acoustic codes. This paper will describe the physical theory (Sofrin) and the analytical techniques (Moore) upon which the rotating rake is based will be described. Data processing and analysis as well as implementation issues will be discussed. Several Rotating Rake systems have been custom built for 3 facilities. In order of complexity of the turbo machinery test article, these are (1) the Advanced Noise Control Fan, (2) various 22-inch fan rigs in the NASA Glenn 9×15 wind tunnel, and (3) a full scale turbofan, the Honeywell TFE-731-60. Descriptions and measurement achievements of these systems will be provided (Heidelberg, Sutliff).

Sutliff, Daniel

2003-10-01

172

Stem Weight Ratios of Siberian Elm (Ulmus Pumila L.) Grown as a Short Rotation Crop  

Energy Technology Data Exchange (ETDEWEB)

Siberian elm (Ulmus pumila L.) is a fast growing tree which has not been studied extensively for short rotation crop (SRC) purposes. Seedlings were planted in Madrid (Spain) in the year 2000 at a density of 1 plant/m{sup 2}. Trials were carried out in order to evaluate the biomass production in high-density plantations. The plantation was cut after the fourth growing season and evaluated for height, diameter, and dry weight. The same measurements were repeated for the sprouts of the 1st and 2nd year that followed. The mean biomass yield after 4 years was 101.6 g dw/m{sup 2} year-1; 269 g dw /m{sup 2} for 1-year-old sprouts and 480.4 g dw /m{sup 2} for 2-year-old sprouts. Correlations between height and basal diameter with dry weight were calculated for each year. There was a close correlation between the 4th year original plant weight and the 1-year-old sprouts but less than with the 2nd year. Water efficiency for biomass production was higher during the 2nd sprouting cycle.

Iriarte, Leyre; Fernandez, Jesus [Univ. Politecnica de Madrid (Spain). Dept. de Produccion Vegetal

2006-07-15

173

Eucalyptus and Populus short rotation woody crops for phosphate mined lands in Florida USA  

Energy Technology Data Exchange (ETDEWEB)

Our short-rotation woody crops (SRWC) research in central and southern Florida is (1) developing superior Eucalyptus grandis (EG), E. amplifolia (EA), and cottonwood (Populus deltoides, PD) genotypes, (2) determining appropriate management practices for and associated productivities of these genotypes, and (3) assessing their economics and markets. Reclaimed clay settling areas (CSA) and overburden sites in phosphate mined areas in central Florida are a potential land base of over 80,000ha for SRWC production. On CSAs, PD grows well in the absence of cogongrass (Imperata cylindrica) but is not as productive as the non-invasive EG and EA. SRWC establishment on CSAs requires strict implementation of the following cultural practices: thorough site preparation through herbiciding/disking and bedding, superior trees, watering/packing seedlings, fertilization with ammonium nitrate at planting and annually thereafter as feasible, high planting density possibly including double row planting, and winter harvesting so that coppice regeneration suppresses weeds. PD cultural requirements, that may require post-planting weed control to suppress herbaceous competition, exceed those of the eucalypts. EG SRWCs on CSAs are at risk of blowdown 3-4 years after planting or coppicing; younger PD, EG, and EA SRWCs appear much less susceptible to wind damage. Genetic improvement must continue if EG, EA, and PD are to increase in commercial feasibility. SRWC cost competitiveness will depend on establishment success, yield improvements, harvesting costs, and identifying/using incentives. Strong collaboration among public and private partners is necessary for commercializing SRWCs in Florida. (author)

Rockwood, D.L.; Carter, D.R.; Langholtz, M.H. [The School of Forest Resources and Conservation, University of Florida, Box 110410, Gainesville, FL 32611 0410 (United States); Stricker, J.A. [Polk County Extension Service, University of Florida, Gainesville, FL 32611 (United States)

2006-08-15

174

Performance and sustainability of short-rotation energy crops treated with municipal and industrial residues  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The sustainability of short-rotation willow coppice (SRWC) as a multifunctional system for phytoremediation—the use of plants for treatment of contaminated air, soil or water—and for producing energy biomass, was studied. SRWC is grown commercially in Sweden to produce energy biomass, nutrient-rich residues being applied as cost-efficient fertiliser to increase production. The principal residues used are municipal wastewater, landfill leachate, industrial wastewater (e.g. log-yard runoff)...

Dimitriou, Ioannis

2005-01-01

175

Efeito na produtividade da rotação de culturas de verão e crotalária no inverno / The efect of crotalaria cropped in the winter and of crop rotation on the yield of summer crops  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Em ensaio de rotação de culturas, conduzido em Pindorama, SP, num solo podzólico vermelho amarelo, fase arenosa, durante os anos agrícolas de 1991/92, 1992/93 e 1993/94, avaliou-se o efeito da rotação entre milho, soja e arroz, com e sem crotalária júncea de inverno, na produção das culturas, no fin [...] al do terceiro ano da experimentação. Não houve diferença entre tratamentos na produção da soja. A rotação aumentou a produção de arroz e milho, comparativamente ao monocultivo dessas culturas. A boa produtividade alcançada das culturas no terceiro ano pode ser atribuída, além da rotação, à ocorrência regular de chuvas e ao uso de cultivares tolerantes à acidez Abstract in english The effect of crop rotation among corn, soybean and rice as summer crops, and of crotalaria as a winter crop, was evaluated by the crop yield at the end of the third year.The experiment was established at Pindorama, SP, Brazil, on an acid soil(Red -Yellow Podzolic, sandy phase). After three years , [...] there was no yield difference among treatments for soybeam production. Crop rotation was beneficial for rice and corn prodution when compared to monocultures. The good productivity in the third year could also be atributed to regular rainfall and acidity tolerant cultivars.

H.A.A., MASCARENHAS; S.S.S., NOGUEIRA; R.T., TANAKA; A.L.M., MARTINS; Q.A.C., CARMELLO.

176

Energy efficiency in long-term Mediterranean cropping systems with different management intensities  

International Nuclear Information System (INIS)

Optimising the implementation of energy used in agriculture is an important objective in the 'Climate Action and Renewable Energy Package' adopted by the European Union. Therefore, studying the management of different cropping systems represents a good method to optimise input requirements, yield and net energy supply. The aim of this study is to compare the energy use of a 12-year rainfed cropping system, located in Tuscany, Italy. The system is cultivated under two different management intensities: a conventional system (CS) and a low input system (LIS) for a six-year crop rotation that included sugar beet, durum wheat, sorghum, sunflower, and durum wheat. In the sixth year, the soil was set-aside. The results showed that crop yield and energy yield were not significantly affected by management intensities, whereas energy efficiency of the low input system increased significantly, by about 30%. Future research should include more crops and locations to obtain further information about the range of energy parameters and their long-term trends. Furthermore, could be interesting to evaluate the overall reduction of environmental impacts and production costs that could occur limiting the use of chemicals and adopting conservative soil tillage strategies.

177

Residual effects of spraying imidazolinone-family herbicides on Clearfield® sunflower production from the point of view of crop rotation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This research was carried out to determine soil residual effects on stand establishment rate and yield in the rotation crops soft winter wheat (Triticum aestivum L.), barley (Hordeum vulgare L.), winter oil seed rape (WOSR) (Brassica napus L.), maize (Zea mays L.) and sugar beet (Beta vulgaris L.) following Intervix® (33g Imazamox + 15g Imazapyr) spraying in Clearfield® (CL) sunflower (Helianthus annuus L.) production. The experiments were conducted at the Trakya Agricultural Research Insti...

Süzer S.; Büyük H.

2010-01-01

178

Generalized linear dynamics of a plant-parasitic nematode population and the economic evaluation of crop rotations.  

Science.gov (United States)

In 1-year experiments, the final population density of nematodes is usually modeled as a function of initial density. Often, estimation of the parameters is precarious because nematode measurements, although laborious and expensive, are imprecise and the range in initial densities may be small. The estimation procedure can be improved by using orthogonal regression with a parameter for initial density on each experimental unit. In multi-year experiments parameters of a dynamic model can be estimated with optimization techniques like simulated annealing or Bayesian methods such as Markov chain Monte Carlo (MCMC). With these algorithms information from different experiments can be combined. In multi-year dynamic models, the stability of the steady states is an important issue. With chaotic dynamics, prediction of densities and associated economic loss will be possible only on a short timescale. In this study, a generic model was developed that describes population dynamics in crop rotations. Mathematical analysis showed stable steady states do exist for this dynamic model. Using the Metropolis algorithm, the model was fitted to data from a multi-year experiment on Pratylenchus penetrans dynamics with treatments that varied between years. For three crops, parameters for a yield loss assessment model were available and gross margin of the six possible rotations comprising these three crops and a fallow year were compared at the steady state of nematode density. Sensitivity of mean gross margin to changes in the parameter estimates was investigated. We discuss the general applicability of the dynamic rotation model and the opportunities arising from combination of the model with Bayesian calibration techniques for more efficient utilization and collection of data relevant for economic evaluation of crop rotations. PMID:19262843

Van Den Berg, W; Rossing, W A H

2005-03-01

179

Using dual-purpose crops in sheep-grazing systems.  

Science.gov (United States)

The utilisation of dual-purpose crops, especially wheat and canola grown for forage and grain production in sheep-grazing systems, is reviewed. When sown early and grazed in winter before stem elongation, later-maturing wheat and canola crops can be grazed with little impact on grain yield. Recent research has sought to develop crop- and grazing-management strategies for dual-purpose crops. Aspects examined have been grazing effects on crop growth, recovery and yield development along with an understanding of the grazing value of the crop fodder, its implications for animal nutrition and grazing management to maximise live-weight gain. By alleviating the winter 'feed gap', the increase in winter stocking rate afforded by grazing crops allows crop and livestock production to be increased simultaneously on the same farm. Integration of dual-purpose wheat with canola on mixed farms provides further systems advantages related to widened operational windows, weed and disease control and risk management. Dual-purpose crops are an innovation that has potential to assist in addressing the global food-security challenge. PMID:24323974

Dove, Hugh; Kirkegaard, John

2014-05-01

180

Life-cycle assessment of net greenhouse-gas flux for bioenergy cropping systems.  

Science.gov (United States)

Bioenergy cropping systems could help offset greenhouse gas emissions, but quantifying that offset is complex. Bioenergy crops offset carbon dioxide emissions by converting atmospheric CO2 to organic C in crop biomass and soil, but they also emit nitrous oxide and vary in their effects on soil oxidation of methane. Growing the crops requires energy (e.g., to operate farm machinery, produce inputs such as fertilizer) and so does converting the harvested product to usable fuels (feedstock conversion efficiency). The objective of this study was to quantify all these factors to determine the net effect of several bioenergy cropping systems on greenhouse-gas (GHG) emissions. We used the DAYCENT biogeochemistry model to assess soil GHG fluxes and biomass yields for corn, soybean, alfalfa, hybrid poplar, reed canarygrass, and switchgrass as bioenergy crops in Pennsylvania, USA. DAYCENT results were combined with estimates of fossil fuels used to provide farm inputs and operate agricultural machinery and fossil-fuel offsets from biomass yields to calculate net GHG fluxes for each cropping system considered. Displaced fossil fuel was the largest GHG sink, followed by soil carbon sequestration. N20 emissions were the largest GHG source. All cropping systems considered provided net GHG sinks, even when soil C was assumed to reach a new steady state and C sequestration in soil was not counted. Hybrid poplar and switchgrass provided the largest net GHG sinks, >200 g CO2e-C x m(-2) x yr(-1) for biomass conversion to ethanol, and >400 g CO2e-C x m(-2) x yr(-1) for biomass gasification for electricity generation. Compared with the life cycle of gasoline and diesel, ethanol and biodiesel from corn rotations reduced GHG emissions by approximately 40%, reed canarygrass by approximately 85%, and switchgrass and hybrid poplar by approximately 115%. PMID:17494388

Adler, Paul R; Del Grosso, Stephen J; Parton, William J

2007-04-01

 
 
 
 
181

Atributos físicos de um Latossolo Vermelho e produtividade de culturas cultivadas em sucessão e rotação / Physical properties of an Oxisol and crops yield under succession and rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Este estudo objetivou avaliar os efeitos da sucessão e rotação de culturas nos atributos físicos e na produtividade dos cultivos agrícolas de um Latossolo Vermelho sob plantio direto, localizado no Estado do Rio Grande do Sul. Os tratamentos contaram de quatro seqüências de culturas cultivadas de 19 [...] 98 a 2001: 1) sucessão trigo / soja; 2) rotação milho / aveia / milho+guandu anão / trigo / soja / trigo; 3) rotação guandu anão / trigo / soja / trigo / soja / aveia; e 4) rotação Crotalária / trigo / soja / aveia / milho / trigo. Em outubro de 2000 e de 2001, foram coletadas amostras de solo para determinar os atributos físicos do solo. Em todas as safras foi medida a produtividade das culturas. O Latossolo Vermelho cultivado com plantio direto apresenta um grau de compactação elevado, com densidade do solo acima e volume de macroporos abaixo do limite crítico para a classe textural muito argiloso. As maiores limitações ocorrem abaixo da camada de 0 a 0,03m, pois na camada mais superficial, apesar das pressões exercidas, a mobilização do solo nas operações de semeadura e adubação em linha aumenta a porosidade e reduz a densidade do solo. Nessa camada, houve maior volume de poros entre a saturação e a capacidade de campo, responsáveis pela aeração do solo, e entre a capacidade de campo e o ponto de murcha permanente, responsáveis pelo armazenamento da água disponível para as plantas. A introdução de plantas de cobertura a cada três anos não foi eficiente para reduzir a compactação. A produtividade das culturas foi influenciada positivamente na rotação com Crotalária, enquanto os demais sistemas não diferiram da sucessão de culturas. Abstract in english This study had as objective to evaluate the effects of crops succession and rotation on physical properties and crops yield on an Oxisol (clayey Haplortox) under no tillage system, in Rio Grande do Sul State, Brazil. The treatments included four cropping sequences, used from 1998 to 2001: 1) success [...] ion wheat / soybean, 2) rotation corn / oat / corn+ Cajanus cajan L. Millsp / wheat / soybean / wheat, 3) rotation Cajanus cajan L. Millsp / wheat / soybean / wheat / soybean / oat, and 4) rotation Crotalaria juncea L. / wheat / soybean / oat / corn / wheat. In October of 2000 and 2001, soil samples were collected to determine physical properties. In all years, the crops yield was measured. The Oxisol cultivated under no-tillage had a high compaction degree, with soil bulk density greater and macroporosity smaller than the critical limit for clay texture. The largest limitations were observed below the layer of 0 to 0,03m, because in the uppermost layer soil mobilization by successive operations of fertilization and sowing increases soil porosity and reduces soil density. Thus, greater volume of pores is observed between soil saturation and field capacity, responsible for soil aeration, and between field capacity and wilting point, responsible for storage of plant available water. The use of cover crops once every three years was not efficient to reduce soil compaction. The yield of the subsequent crops was influenced positively in the rotation with Crotalaria juncea, while the other cropping systems did not differ from crop succession.

Silvio Aymone, Genro Junior; Dalvan José, Reinert; José Miguel, Reichert; Jackson Adriano, Albuquerque.

182

Modelling of nitrogen leaching under a complex winter wheat and red clover crop rotation in a drained agricultural field  

Science.gov (United States)

The European Water Framework Directive requires conformity of water management structures all over Europe to pursue a good water quality for all water bodies. The highest nitrate concentrations in the water were measured in regions with well-drained soils, ploughed pastures and high nitrogen inputs. The objective of this study was to calculate the nitrate nitrogen leaching out of a subsurface drainage system under organic farming conditions, especially for the seepage period in winter. Water and nitrogen fluxes between soil and vegetation were simulated with the soil-vegetation-atmosphere-transfer model CoupModel using data from an 8 years lasting monitoring programme on a field in Northern Germany. Modelling was focused on a crop rotation sequence consisting of winter wheat with undersown red clover followed by two years of red clover used as temporary grassland. Measured soil temperature in a depth of 15 cm was reproduced very well (Nash-Sutcliffe-efficiency NSE = 0.95; R2 = 0.98). Results also indicated that CoupModel accurately simulated drainage discharge and nitrate N loss under winter wheat from 2001 to 2002 with a NSE of 0.73 for the drainage discharge and a NSE of 0.49 for the nitrate N leaching. For the following red clover period the accordance between simulated and measured drainage discharge (NSE = 0.01) and nitrate N loads in the drainage (NSE = 0.31) was much lower. The inaccuracy in the modelling results in November 2002 seems to origin from an inadequate description of soil covering and thus the interception of the hibernating red clover. Secondly, the high nitrogen leaching in February 2004 could not be matched due to poorly adapted nitrogen dynamics in the model. The reason could be that common single parameter values in the mineralization part of the model were not suitable to reproduce an abrupt, short-term N leaching. In general, the results demonstrate the potential of CoupModel to predict water and nitrate N fluxes under complex crop rotations including bicropping and legumes.

Conrad, Y.; Fohrer, N.

183

Biomass production in new sustainable multipurpose cropping systems  

Energy Technology Data Exchange (ETDEWEB)

Conventional crops such as wheat, rye, triticale and sweet sorghum have been used as energy crops with the advantage that farmers already know how to grow them. However, current thinking is that growing grains as dedicated energy crops is not such a good idea, since grains require high input and annual ploughing, which leaches nitrates and other nutrients from the soil. Instead, recent European research has looked at perennial energy crops such as willow, poplar, alder, giant reed, Miscanthus and cardoon and a research project in the USA combining physiology, plant breeding and crop management has shown that switchgrass has a promising future as an energy crop. Compared to traditional crops, the perennials need lower input and pose less risk of nutrient leaching. Biomass from perennial crops contains lower levels of nutrient input and better combustion characteristics. Promising as the perennial energy crops are, they are still relatively new and do not benefit from the centuries of selection and breeding associated with conventional crops. Much progress in improving yield and quality remains to be made through better breeding and crop management. There is still very limited information on the long-term effects of energy crops on soil carbon levels and on nitrous oxide emissions. However, studies indicate that growing perennial energy crops may be a real win-win solution, delivering not only renewable energy but also clean water, better recycling and carbon sequestration in soils. Using energy crops to produce electricity is an effective way to mitigate the greenhouse effect, mainly through the replacement of fossil fuels. In order to plan long-term investments in crops, machinery and power stations farmers and the energy industry need clear signals from governments on the future of bioenergy. The energy crop chain should be analysed for administrative and legislative bottlenecks that may hamper commercial development. Finally there is a need for further breeding of specific energy crops with higher energy contents, lower energy inputs and optimised quality for downstream processing; for net intercropping systems with high resistance to pests and diseases; and for further R and D on cost reduction and environmental optimisation of the complete production chain. (BA)

Joergensen, U. [Danish Inst. of Agricultural Sciences, Tjele (Denmark); Oestergaard, H. [ Risoe National Lab., Plant Res. Dept., Roskilde (Denmark)

2003-11-01

184

Spatial distribution and controlling factors of heavy metals contents in paddy soil and crop grains of rice-wheat cropping system along highway in East China.  

Science.gov (United States)

There is consensus concerning the heavy metal pollution from traffic emission on roadside agricultural land. However, few efforts have been paid on examining the contamination characteristics of heavy metals in roadside paddy-upland rotation field, and especially in combination with detailed quantitative analysis. In this study, we investigated the concentrations of heavy metals (Pb, Cd, Cr and Zn) in soil and crop grains of the rice-wheat cropping system along a major highway in East China in 2008 and analyzed the spatial distribution characteristics of heavy metals and their influencing factors with GIS and Classification and Regression Trees (CART). Significantly elevated levels of heavy metals in soil, rice and wheat grains indicated the heavy metals contamination of traffic emission in roadside rice-wheat rotation field. The contamination levels of Cd, Cr and Zn in wheat grain were higher than rice grain, while that of Pb showed an opposite trend. Obvious dissimilarities in the spatial distributions of heavy metals contents were found between in the soil, rice and wheat grains, indicating that the heavy metals contents in the roadside crop grains were not only determined by the concentrations of heavy metals in the paddy soil. Results of CART analysis showed that the spatial variation of the heavy metals contents in crop grains was mainly affected by the soil organic matter or soil pH, followed by the distance from highway and wind direction. Our findings have important implications for the environmental assessment and crop planning for food security along the highway. PMID:22527116

Feng, Jinfei; Zhao, Jian; Bian, Xinmin; Zhang, Weijian

2012-10-01

185

Input-output cost of agronomic production of crops under rotate growing condition for applying to Mediterranean Italian buffaloes  

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Full Text Available Forage availability with low cost of production is the main farmer requisite for obtaining a competitive husbandry dairy product in the market. Cropping system for silage consumption differently impact the cost of Milk Feeding Unit (MFU and sustainable agronomic cultivation of herbage production. The experiment aimed to assess the analytical cost of MFU per hectare in four forage cropping system models based on two crops per year bred under irrigated and rainfed condition in a Mediterranean site with intensive buffaloes breeding pressure.

N. Berardo

2010-02-01

186

EUE (energy use efficiency) of cropping systems for a sustainable agriculture  

International Nuclear Information System (INIS)

Energy efficiency of agriculture needs improvement to reduce the dependency on non-renewable energy sources. We estimated the energy flows of a wheat-maize-soybean-maize rotation of three different cropping systems: (i) low-input integrated farming (LI), (ii) integrated farming following European Regulations (IFS), and (iii) conventional farming (CONV). Balancing N fertilization with actual crop requirements and adopting minimum tillage proved the most efficient techniques to reduce energy inputs, contributing 64.7% and 11.2% respectively to the total reduction. Large differences among crops in energy efficiency (maize: 2.2 MJ kg-1 grain; wheat: 2.6 MJ kg-1 grain; soybean: 4.1 MJ kg-1 grain) suggest that crop rotation and crop management can be equally important in determining cropping system energy efficiency. Integrated farming techniques improved energy efficiency by reducing energy inputs without affecting energy outputs. Compared with CONV, energy use efficiency increased 31.4% and 32.7% in IFS and LI, respectively, while obtaining similar net energy values. Including SOM evolution in the energy analysis greatly enhanced the energy performance of IFS and, even more dramatically, LI compared to CONV. Improved energy efficiency suggests the adoption of alternative farming systems to reduce greenhouse gas emissions from agriculture. However, a thorough evaluation should include net global warming potential assessment. -- Highlights: ? We evaluated the energy flows of integrated as alternative to conventional Farming. ? Energy flows, soil organic matter evolution included, were analyzed following process analysis. ? Energy flows were compared using indicators. ? Integrated farming improved energy efficiency without affecting net energy. ? Inclusion of soil organic matter in energy analysis accrue environmental evaluation.

187

Soil Management Practices to Improve Nutrient-use Efficiencies and Reduce Risk in Millet-based Cropping Systems in the Sahel  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Low soil fertility and moisture deficit are among the main constraints to sustainable crop yields in the Sahel. A study therefore, was conducted at the ICRISAT Sahelian Center, Sadore in Niger to test the hypothesis that integrated soil husbandry practices consisting of manure, fertilizer and crop residues in rotational cropping systems use organic and mineral fertilizes efficiently, thereby resulting in higher yields and reduced risk. Results from an analysis of variance showed that choice o...

Koala, S.; Shapiro, B; Bationo, A.; Yamoah, Cf

2003-01-01

188

Password Based Rotational Multistory Car Parking System  

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Full Text Available Parking is a big issue in thickly populated areas and in larger cities due to heavy traffic. This intended application of rotational multistory parking system effectively minimizes this issue. It results in less space and more secure parking. ATMEL microcontroller is used as main processor while LCD and motors are as complimentary components for display and rotation The model is based on circular mechanism giving low cost, less space and optimum performance. Password locking system is used to verify the object and detects number of free spaces available in the parking lot. The world has become a global market and numbers of vehicles are also increased to an uncontrollable situation. Keeping this problem the intended model is designed. Password locking system embedded in the work has made the parking of vehicles very much secure.

Nayab Suhail Hamirani

2011-12-01

189

Infiltração de água no solo sob escarificação e rotação de culturas Water infiltration in soil as influenced by chiseling and crop rotations  

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Full Text Available Nos solos com restrições físicas e, ou, físico-hídricas ao crescimento de raízes, aumentar o potencial de armazenagem de água por meio de melhorias na infiltração pode ser uma estratégia viável para aumento da produtividade das culturas. Nesse sentido, este trabalho teve como objetivo avaliar a infiltração de água em um Nitossolo Vermelho distrófico, com três sistemas de rotação de culturas sob semeadura direta com e sem escarificação inicial. O sistema de rotação de culturas constou de: (1 milheto/soja/sorgo/milho/sorgo (M/S/So/Mi/So, (2 milheto/soja/Brachiaria ruziziensis/milho/Brachiaria ruziziensis (M/S/B/Mi/B e (3 milheto/soja/Brachiaria ruziziensis + mamona/milho/Brachiaria ruziziensis + mamona (M/S/B+Ma/Mi/B+Ma. A infiltração de água no solo foi avaliada em campo com anéis concêntricos instalados na superfície, a 0,10 e 0,20 m de profundidade, em 2006 e 2007. Após o primeiro ano, o manejo com escarificação inicial do solo apresentou a maior infiltração de água. A rotação Brachiaria ruziziensis + mamona proporcionou maior infiltração da água no solo. A atividade do sistema radicular das espécies nas parcelas sem escarificação inicial aumentou a velocidade de infiltração da água no solo.In soils with physical and/or physical hydric restrictions for root growth, it may be a viable strategy to increase crop productivity by increasing water storage potential through improvements in water infiltration. Accordingly, the objective of this study was to determine water infiltration in a Hapludult in three crop rotations under no-tillage, with and without initial chiseling. Crop rotations consisted of: millet/soybean/sorghum/maize/sorghum; millet/soybean/Brachiaria ruziziensis/corn/Brachiaria ruziziensis; and millet/soybean/Brachiaria ruziziensis + castor bean/corn/Brachiaria ruziziensis + castor bean. Water infiltration in soil was evaluated in the field, using concentric discs at the soil surface and at depths of 0.10 and 0.20 m, in 2006 and 2007. After the first year, chiseling led to increased infiltration of water into the soil. Water infiltration was greatest in the crop rotation system with Brachiaria ruziziensis + castor bean. The activity of root systems of crops in the plots without chiseling increased the rate of water infiltration into the soil.

Maryara Buriola Prando

2010-06-01

190

Infiltração de água no solo sob escarificação e rotação de culturas / Water infiltration in soil as influenced by chiseling and crop rotations  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Nos solos com restrições físicas e, ou, físico-hídricas ao crescimento de raízes, aumentar o potencial de armazenagem de água por meio de melhorias na infiltração pode ser uma estratégia viável para aumento da produtividade das culturas. Nesse sentido, este trabalho teve como objetivo avaliar a infi [...] ltração de água em um Nitossolo Vermelho distrófico, com três sistemas de rotação de culturas sob semeadura direta com e sem escarificação inicial. O sistema de rotação de culturas constou de: (1) milheto/soja/sorgo/milho/sorgo (M/S/So/Mi/So), (2) milheto/soja/Brachiaria ruziziensis/milho/Brachiaria ruziziensis (M/S/B/Mi/B) e (3) milheto/soja/Brachiaria ruziziensis + mamona/milho/Brachiaria ruziziensis + mamona (M/S/B+Ma/Mi/B+Ma). A infiltração de água no solo foi avaliada em campo com anéis concêntricos instalados na superfície, a 0,10 e 0,20 m de profundidade, em 2006 e 2007. Após o primeiro ano, o manejo com escarificação inicial do solo apresentou a maior infiltração de água. A rotação Brachiaria ruziziensis + mamona proporcionou maior infiltração da água no solo. A atividade do sistema radicular das espécies nas parcelas sem escarificação inicial aumentou a velocidade de infiltração da água no solo. Abstract in english In soils with physical and/or physical hydric restrictions for root growth, it may be a viable strategy to increase crop productivity by increasing water storage potential through improvements in water infiltration. Accordingly, the objective of this study was to determine water infiltration in a Ha [...] pludult in three crop rotations under no-tillage, with and without initial chiseling. Crop rotations consisted of: millet/soybean/sorghum/maize/sorghum; millet/soybean/Brachiaria ruziziensis/corn/Brachiaria ruziziensis; and millet/soybean/Brachiaria ruziziensis + castor bean/corn/Brachiaria ruziziensis + castor bean. Water infiltration in soil was evaluated in the field, using concentric discs at the soil surface and at depths of 0.10 and 0.20 m, in 2006 and 2007. After the first year, chiseling led to increased infiltration of water into the soil. Water infiltration was greatest in the crop rotation system with Brachiaria ruziziensis + castor bean. The activity of root systems of crops in the plots without chiseling increased the rate of water infiltration into the soil.

Maryara Buriola, Prando; Dácio, Olibone; Ana Paula Encide, Olibone; Ciro Antonio, Rosolem.

191

Economics of short-rotation woody crops plantation at Amana, Iowa  

International Nuclear Information System (INIS)

This paper reports on a 21 ha energy plantation of silver maple (Acer saccharinum) established on an old-field bottomland site near Amana, IA. The project started in 1988 and sponsored by the Oak Ridge National Laboratory, (US Dept. of Energy), is a 6 year cooperative effort of the Amana Society, Department of Forestry, ISU, and the Iowa Dept. of Natural Resources. The objective is to accurately estimate biomass yields and costs of growing wood for energy in a short-rotation, close spacing system under operational conditions. Research is being conducted on spacing rotation, fertilization, groundwater quality, and improved seedlings. A detailed cost accounting system was established to accurately record time and cost data by activity. Establishment costs (rent, site preparation, tree planting) and initial (2 year) cultural management costs (herbicide and mowing) total $1,304/ha. Cost proportions for rent, site preparation, and planting are 11%, 18.2%, and 59.4%, respectively. Cultural management costs incurred through 1990 total $148/ha

192

Meteorological risks and impacts on crop production systems in Belgium  

Science.gov (United States)

Extreme weather events such as droughts, heat stress, rain storms and floods can have devastating effects on cropping systems. The perspective of rising risk-exposure is exacerbated further by projected increases of extreme events with climate change. More limits to aid received for agricultural damage and an overall reduction of direct income support to farmers further impacts farmers' resilience. Based on insurance claims, potatoes and rapeseed are the most vulnerable crops, followed by cereals and sugar beets. Damages due to adverse meteorological events are strongly dependent on crop type, crop stage and soil type. Current knowledge gaps exist in the response of arable crops to the occurrence of extreme events. The degree of temporal overlap between extreme weather events and the sensitive periods of the farming calendar requires a modelling approach to capture the mixture of non-linear interactions between the crop and its environment. The regional crop model REGCROP (Gobin, 2010) enabled to examine the likely frequency and magnitude of drought, heat stress and waterlogging in relation to the cropping season and crop sensitive stages of six arable crops: winter wheat, winter barley, winter rapeseed, potato, sugar beet and maize. Since crop development is driven by thermal time, crops matured earlier during the warmer 1988-2008 period than during the 1947-1987 period. Drought and heat stress, in particular during the sensitive crop stages, occur at different times in the cropping season and significantly differ between two climatic periods, 1947-1987 and 1988-2008. Soil moisture deficit increases towards harvesting, such that earlier maturing winter crops may avoid drought stress that occurs in late spring and summer. This is reflected in a decrease both in magnitude and frequency of soil moisture deficit around the sensitive stages during the 1988-2008 period when atmospheric drought may be compensated for with soil moisture. The risk of drought spells during the sensitive stages of summer crops increases and may be further aggravated by atmospheric moisture deficits and heat stress. Summer crops may therefore benefit from earlier planting dates and beneficial moisture conditions during early canopy development, but will suffer from increased drought and heat stress during crop maturity. During the harvesting stages, the number of waterlogged days increases in particular for tuber crops. Physically based crop models assist in understanding the links between different factors causing crop damage. The approach allows for assessing the meteorological impacts on crop growth due to the sensitive stages occurring earlier during the growing season and due to extreme weather events. Though average yields have risen continuously between 1947 and 2008 mainly due to technological advances, there is no evidence that relative tolerance to adverse weather conditions such as atmospheric moisture deficit and temperature extremes has changed.

Gobin, Anne

2013-04-01

193

Increasing Cropping System Diversity Balances Productivity, Profitability and Environmental Health  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Balancing productivity, profitability, and environmental health is a key challenge for agricultural sustainability. Most crop production systems in the United States are characterized by low species and management diversity, high use of fossil energy and agrichemicals, and large negative impacts on the environment. We hypothesized that cropping system diversification would promote ecosystem services that would supplement, and eventually displace, synthetic external inputs used to maintain cro...

Davis, Adam S.; Hill, Jason D.; Chase, Craig A.; Johanns, Ann M.; Liebman, Matt

2012-01-01

194

Influence of crop rotation and meteorological conditons on density and biomass of weeds in spring barley (Hordeum vulgare L.  

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Full Text Available The paper presents the analysis of changes in weed infestation in spring barley cultivated in the years 1990-2004 in crop rotation with a 25% proportion of this cereal (potato - spring barley - sowing peas - winter triticale, when it was grown after potato, and in crop rotation with its 75% proportion (potato - spring barley - spring barley - spring barley, when it was grown once or twice after spring barley. In the experiment, no weed control was applied. Every year in the spring (at full emergence of the cereal and before the harvest, the composition of weed species and weed density of particular weed species were determined, and before the harvest also their biomass. Weed density increased linearly on all plots during the 15-year period. The average values confirm the increase in weed biomass in the case when spring barley was grown once or twice after this crop; however, those differences were influenced by the previous situation only during some seasons. Weed density and biomass showed high year-to-year variability and a positive correlation with the amount of precipitation and a negative correlation with temperature during the period of the study. A negative correlation between the yield of barley and weed biomass was shown.

Maria Wanic

2010-06-01

195

Telescopic system with a rotating objective element  

Science.gov (United States)

The angular resolution is the ability of a telescope to render detail: the higher the resolution the finer is the detail. It is, together with the aperture, the most important characteristic of telescopes. We propose a new construction of telescopes with improved ratio of angular resolution and area of the primary optical element (mirror or lense). For this purpose we use the rotation of the primary optical element with one dominating dimension. The length of the dominating dimension of the primary optical element determines the angular resolution. During the rotation a sequence of images is stored in a computer and the images of observed objects can be reconstructed using a relatively simple software. The angular resolution is determined by the maximal length of the primary optical element of the system. This construction of telescopic systems allows to construct telescopes of high resolution with lower weight and fraction of usual costs.

Chadzitaskos, Goce; Tolar, J.

2004-10-01

196

Telescopic system with a rotating objective element  

CERN Document Server

The angular resolution is tha ability of a telescope to render detail: the higher the resolution the finer is the detail. it is, together with the aperture, the most important characteristic of telescopes. We propose a new construction of telescopes with improved ratio of angular resolution and area of the primary optical element (mirror or lense). For this purpose we use the rotation of the primary optical element with one dominating dimension. The length of the dominating dimension of the primary optical element determines the angular resolution. During the rotation a sequence of images is stored in a computer and the images of observed objects can be reconstructed using a relatively simple software. The angular resolution is determined by the maximal length of the primary optical element of the system. This construction of telescopic systems allows to construct telescopes of high resolution with lower weight and fraction of usual costs.

Chadzitaskos, G

2003-01-01

197

Using the DNDC model to compare soil organic carbon dynamics under different crop rotation and fertilizer strategies  

Energy Technology Data Exchange (ETDEWEB)

Soil organic carbon (SOC) plays a vital role in determining soil fertility, water holding capacity and susceptibility to land degradation. On the Chinese Loess Plateau, a large amount of crop residues is regularly removed; therefore, this agricultural area mainly depends on fertilizer inputs to maintain crop yields. This paper aims to use a computer simulation model (DeNitrification and DeComposition, or DNDC) to estimate the changes of SOC content and crop yield from 1998 to 2047 under different cropping systems, providing some strategies to maintain the SOC in balance and to increase crop yields. The results demonstrated that: (i) single manure application or combined with nitrogen fertilizer could significantly enhance the SOC content and crop yield on the sloped land, terraced field and flat land; and (ii) in contrast to sloped land and terraced field, the SOC content and crop yield both continuously increased in flat fields, indicating that the flat field in this region is a good soil surface for carbon sequestration. These results emphasize that application of manure combined with nitrogen fertilizer would be a better management practice to achieve a goal of increasing soil carbon sequestration and food security. (Author)

Mu, L.; Liang, Y.; Xue, Q.; Chen, C.; Lin, X.

2014-06-01

198

Effect of tillage, rotation and crop residues on wheat crop productivity, fertilizer nitrogen and water use efficiency and soil organic carbon status in dry area (rainfed) of north-west Pakistan  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Crop productivity, soil organic carbon (SOC), fertilizer nitrogen and water use efficiency (WUE) in rainfed dry area is influenced by tillage, rotation and crop residues management. Field experiments were conducted during 2004-09 to study the effect of tillage, rotation and crop residues on wheat yi [...] eld, nitrogen fertilizer and water use efficiency and SOC under semi-arid condition in north-west Pakistan. The treatments consisted of three rotations: i) Wheat-fallow-wheat (farmers' practice) ii) Wheat- summer legume-wheat and iii) Wheat-summer cereal-wheat with two tillage and crop residues management treatments: i) Tillage (crop residues removed) and Tillage (crop residues retained) and ii) No-tillage (crop residues removed) and No-tillage (crop residues retained). Basal doses of N60: P60 (kg ha-1) to wheat, N90: P60 and N20: P60 (kg ha-1) to summer cereals and legumes rotation crops were applied respectively. Labeled urea having 1% 15N atom excess at 60 kg N ha-1 was applied to wheat as an aqueous solution in micro plot within each treatment plot. Changes in soil water storage were monitored with neutron moisture probe for calculation of WUE. The results revealed that the wheat grain and straw yield was not increased by the tillage treatment. Crop residues retention significantly enhanced the wheat grain and straw yield. Crop residues with no-tillage resulted in 520 kg ha-1 greater wheat grain yield than residues removed treatment. Similarly WUE, N yield and fertilizer N utilization by wheat was increased significantly by crop residues under no-tillage compared to the tillage treatment. Maximum N fertilizer utilization 24.1 %, 62.7 % and 38.0 % in wheat were obtained under no-tillage + residues treatment during 2006, 2007 and 2008 respectively. The SOC in surface soil (0-15 cm) was higher in wheat-fallow-wheat and wheat-legume-wheat rotation under no-tillage + residues treatment. The results showed that no-tillage + crop residues and legume based rotation treatment were beneficial under the rainfed (dry) conditions.

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

2012-12-01

199

Effect of tillage, rotation and crop residues on wheat crop productivity, fertilizer nitrogen and water use efficiency and soil organic carbon status in dry area (rainfed) of north-west Pakistan  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in english Crop productivity, soil organic carbon (SOC), fertilizer nitrogen and water use efficiency (WUE) in rainfed dry area is influenced by tillage, rotation and crop residues management. Field experiments were conducted during 2004-09 to study the effect of tillage, rotation and crop residues on wheat yi [...] eld, nitrogen fertilizer and water use efficiency and SOC under semi-arid condition in north-west Pakistan. The treatments consisted of three rotations: i) Wheat-fallow-wheat (farmers' practice) ii) Wheat- summer legume-wheat and iii) Wheat-summer cereal-wheat with two tillage and crop residues management treatments: i) Tillage (crop residues removed) and Tillage (crop residues retained) and ii) No-tillage (crop residues removed) and No-tillage (crop residues retained). Basal doses of N60: P60 (kg ha-1) to wheat, N90: P60 and N20: P60 (kg ha-1) to summer cereals and legumes rotation crops were applied respectively. Labeled urea having 1% 15N atom excess at 60 kg N ha-1 was applied to wheat as an aqueous solution in micro plot within each treatment plot. Changes in soil water storage were monitored with neutron moisture probe for calculation of WUE. The results revealed that the wheat grain and straw yield was not increased by the tillage treatment. Crop residues retention significantly enhanced the wheat grain and straw yield. Crop residues with no-tillage resulted in 520 kg ha-1 greater wheat grain yield than residues removed treatment. Similarly WUE, N yield and fertilizer N utilization by wheat was increased significantly by crop residues under no-tillage compared to the tillage treatment. Maximum N fertilizer utilization 24.1 %, 62.7 % and 38.0 % in wheat were obtained under no-tillage + residues treatment during 2006, 2007 and 2008 respectively. The SOC in surface soil (0-15 cm) was higher in wheat-fallow-wheat and wheat-legume-wheat rotation under no-tillage + residues treatment. The results showed that no-tillage + crop residues and legume based rotation treatment were beneficial under the rainfed (dry) conditions.

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

200

MODELIMG CROP PATTEN SYSTEM USING LINEAR PROGRAMMING  

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Full Text Available In agricultural situations, farmers usually faced with the problem of how to allocate their limited production resources among cropping and livestock activities. Farmer's planners can offer effective techniques, such as linear programming (lp to address the problem and produce optimal solution. In this paper we have demonstrated that how a farmer who has limited resources such as farmers availability ,storage capacity and availability of land can be formulated as a linear programming having linear objective function with three constraints. The objective is to develop an understanding of utility of farmer's availability resources and then maximization of total profit. In our case we have selected two crops rice and corn, formulate the (lp problem and after solving through LINGO, the results showed that farmer obtained maximum profit using his resources.

Mushtaq A. Lone

2014-06-01

 
 
 
 
201

Sustainable Production of Japanese Eggplants in a Piedmont Soil in Rotation with Winter Cover Crops  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Eggplant is a popular vegetable consumed all over the world. Cover cropping is an efficient way of recycling nutrients and reducing inorganic fertilizer requirements to maintain the sustainability of the soil without affecting productivity and profitability. Eggplants (Solanum melongena) (Japanese varieties Hansel and Kamo) were grown in a Piedmont soil with two main treatments, cover crop (CC) and no cover crop (NC), and four sub-fertilizer treatments (T1: 0-0-0, T2: 56-28-112, T3: 84-56-168...

Ahmed Elobeid; Kurt Taylor; Muchha Reddy; Ramesh Ravella

2013-01-01

202

Perturbation theory approach to rotational tunneling systems  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Diagrammatic perturbation theory is used to consider the problem of the coupling of a molecular group libration to the lattice vibrations in solids exhibiting rotational tunneling detected by inelastic neutron scattering. The technique is applied to a molecular group of symmetry C3 in presence of th [...] e hindering potential of the solid. The spectral density for transitions between rotational tunneling states in the ground librational level is obtained as a function of temperature. Low temperature results are presented for di erent phonon spectrum parameters. They are used to check the assumption that this coupling is the origin of the peculiar behaviour of the line shifting and broadening as a function of temperature in the INS spectra of such systems.

Luciano T., Peixoto.

2000-03-01

203

Perturbation theory approach to rotational tunneling systems  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in english Diagrammatic perturbation theory is used to consider the problem of the coupling of a molecular group libration to the lattice vibrations in solids exhibiting rotational tunneling detected by inelastic neutron scattering. The technique is applied to a molecular group of symmetry C3 in presence of th [...] e hindering potential of the solid. The spectral density for transitions between rotational tunneling states in the ground librational level is obtained as a function of temperature. Low temperature results are presented for di erent phonon spectrum parameters. They are used to check the assumption that this coupling is the origin of the peculiar behaviour of the line shifting and broadening as a function of temperature in the INS spectra of such systems.

Luciano T., Peixoto.

204

Thermodynamic equilibrium in relativistic rotating systems  

International Nuclear Information System (INIS)

The thermodynamic equilibrium configurations of relativistic rotating stars are studied using the maximum entropy principle. It is shown that the heuristic arguments for the equilibrium conditions can be developed into a maximum entropy principle in which the variations are carried out in a fixed background spacetime. This maximum principle with the fixed background assumption is technically simpler than, but has to be justified by, a maximum entropy principle without the assumption. Such a maximum entropy principle is formulated in this paper, showing that the general relativistic system can be treated on the same footing as other long-range force systems. (author)

205

Effects of different potato cropping system approaches and water management on soilborne diseases and soil microbial communities.  

Science.gov (United States)

Four different potato cropping systems, designed to address specific management goals of soil conservation, soil improvement, disease suppression, and a status quo standard rotation control, were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics. The status quo system (SQ) consisted of barley underseeded with red clover followed by potato (2-year). The soil-conserving system (SC) featured an additional year of forage grass and reduced tillage (3-year, barley/timothy-timothy-potato). The soil-improving system (SI) added yearly compost amendments to the SC rotation, and the disease-suppressive system (DS) featured diverse crops with known disease-suppressive capability (3-year, mustard/rapeseed-sudangrass/rye-potato). Each system was also compared with a continuous potato control (PP) and evaluated under both irrigated and nonirrigated conditions. Data collected over three potato seasons following full rotation cycles demonstrated that all rotations reduced stem canker (10 to 50%) relative to PP. The SQ, SC, and DS systems reduced black scurf (18 to 58%) relative to PP; SI reduced scurf under nonirrigated but not irrigated conditions; and scurf was lower in DS than all other systems. The SQ, SC, and DS systems also reduced common scab (15 to 45%), and scab was lower in DS than all other systems. Irrigation increased black scurf and common scab but also resulted in higher yields for most rotations. SI produced the highest yields under nonirrigated conditions, and DS produced high yields and low disease under both irrigation regimes. Each cropping system resulted in distinctive changes in soil microbial community characteristics as represented by microbial populations, substrate utilization, and fatty acid methyl-ester (FAME) profiles. SI tended to increase soil moisture, microbial populations, and activity, as well result in higher proportions of monounsaturated FAMEs and the FAME biomarker for mycorrhizae (16:1 ?6c) relative to most other rotations. DS resulted in moderate microbial populations and activity but higher substrate richness and diversity in substrate utilization profiles. DS also resulted in relatively higher proportions of FAME biomarkers for fungi (18:2 ?6c), actinomycetes, and gram-positive bacteria than most other systems, whereas PP resulted in the lowest microbial populations and activity; substrate richness and diversity; proportions of monounsaturated and polyunsaturated FAME classes; and fungal, mycorrhizae, and actinomycete FAME biomarkers of all cropping systems. Overall, soil water, soil quality, and soilborne diseases were all important factors affecting productivity, and cropping systems addressing these constraints improved production. Cropping system approaches will need to balance these factors to achieve sustainable production and disease management. PMID:20839965

Larkin, Robert P; Honeycutt, C Wayne; Griffin, Timothy S; Olanya, O Modesto; Halloran, John M; He, Zhongqi

2011-01-01

206

Predicting the net carbon exchanges of crop rotations in Europe with an agro-ecosystem model  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Carbon fluxes between croplands and atmosphere are highly conditioned by farmer practices that involved intense atmospheric CO2 uptake during crop growing season compared to other terrestrial ecosystems. Modelling and measuring land-atmosphere carbon exchanges from arable lands are important tasks to predict the influence of vegetation dynamics on climate change and its retroactive effects on crop productivity. We tested the agro-ecosystem model CERES-EGC against gap-filled daily net CO2 exch...

Lehuger, Simon; Gabrielle, Benoi?t; Cellier, Pierre; Loubet, Benjamin; Roche, Romain; Be?ziat, Pierre; E?ric, Ceschia; Wattenbach, Martin

2009-01-01

207

Agregados em um Latossolo sob sistema plantio direto e rotação de culturas / Aggregates in a Rhodic Ferralsol under no-tillage and crop rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo deste trabalho foi avaliar a influência dos cultivos de outono-inverno e primavera, em sistema de plantio direto, nos agregados e matéria orgânica de um Latossolo. O experimento foi conduzido durante as safras 2006/2007, 2007/2008 e 2008/2009. No outono-inverno foram estabelecidas parcela [...] s principais com braquiária (Urochloa ruziziensis), sorgo granífero (Sorghum bicolor) e sorgo consorciado com braquiária. Na primavera, foram cultivados, em subparcelas, milheto (Pennisetum glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense), crotalária (Crotalaria juncea) ou pousio. A soja foi cultivada como safra de verão, o que totalizou 12 tratamentos. A massa de matéria seca e o crescimento radicular das plantas de cobertura da primavera foram determinados em 2006 e 2008. Foram coletadas amostras de solo nas camadas de 0-5 e 5-10 cm, após o manejo das plantas de cobertura de primavera, no primeiro e terceiro anos agrícolas. Foram determinados o diâmetro médio ponderado, o diâmetro médio geométrico, o índice de estabilidade de agregados, os agregados maiores que 2 mm, a matéria orgânica e os teores de carbono orgânico total nas amostras coletadas no terceiro ano. O milheto e 'Cober Crop' produziram maior quantidade de massa de matéria seca e maior crescimento radicular. A estruturação do solo melhorou com a rotação dos cultivos das plantas de cobertura antecedentes à safra de verão. O cultivo de 'Cober Crop' e milheto influenciou a formação de macroagregados nas camadas superficiais Abstract in english The objective of this work was to evaluate the influence of fall-winter and spring crops, cultivated under no-tillage system, on the aggregates and organic matter of a Rhodic Ferralsol. The experiment was performed in the 2006/2007, 2007/2008 and 2008/2009 growing seasons. Congo signal grass (Urochl [...] oa ruziziensis), grain sorghum (Sorghum bicolor) and sorghum mixed with brachiaria were cropped in the fall-winter to consist the main plots. In the spring, millet (Pennisetum glaucum), 'Cober Crop' (Sorghum bicolor x Sorghum sudanense) and Indian hemp (Crotalaria juncea) were cultivated as subplots as well as a fallow treatment. Soybean was cropped in the summer, totaling 12 treatments. Cover crop dry matter and root growth were evaluated in 2006 and 2008. Soil samples were taken from 0-5 and 5-10 cm depths, after spring cover crops managing, in the first and third years. The mean weight diameter, geometric mean diameter, aggregate stability index, aggregates larger than 2 mm, organic matter and total organic carbon levels were evaluated in the samples of the third year. Millet and 'Cober Crop' showed higher dry matter production and root growth. The soil aggregation was improved by cover crop rotations before the summer growing season. The cultivation of 'Cober Crop' and millet influenced the macroaggregate formation in the superficial layers

Rodrigo Arroyo, Garcia; Ciro Antonio, Rosolem.

1489-14-01

208

Agregados em um Latossolo sob sistema plantio direto e rotação de culturas Aggregates in a Rhodic Ferralsol under no-tillage and crop rotation  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi avaliar a influência dos cultivos de outono-inverno e primavera, em sistema de plantio direto, nos agregados e matéria orgânica de um Latossolo. O experimento foi conduzido durante as safras 2006/2007, 2007/2008 e 2008/2009. No outono-inverno foram estabelecidas parcelas principais com braquiária (Urochloa ruziziensis, sorgo granífero (Sorghum bicolor e sorgo consorciado com braquiária. Na primavera, foram cultivados, em subparcelas, milheto (Pennisetum glaucum, 'Cober Crop' (Sorghum bicolor x Sorghum sudanense, crotalária (Crotalaria juncea ou pousio. A soja foi cultivada como safra de verão, o que totalizou 12 tratamentos. A massa de matéria seca e o crescimento radicular das plantas de cobertura da primavera foram determinados em 2006 e 2008. Foram coletadas amostras de solo nas camadas de 0-5 e 5-10 cm, após o manejo das plantas de cobertura de primavera, no primeiro e terceiro anos agrícolas. Foram determinados o diâmetro médio ponderado, o diâmetro médio geométrico, o índice de estabilidade de agregados, os agregados maiores que 2 mm, a matéria orgânica e os teores de carbono orgânico total nas amostras coletadas no terceiro ano. O milheto e 'Cober Crop' produziram maior quantidade de massa de matéria seca e maior crescimento radicular. A estruturação do solo melhorou com a rotação dos cultivos das plantas de cobertura antecedentes à safra de verão. O cultivo de 'Cober Crop' e milheto influenciou a formação de macroagregados nas camadas superficiaisThe objective of this work was to evaluate the influence of fall-winter and spring crops, cultivated under no-tillage system, on the aggregates and organic matter of a Rhodic Ferralsol. The experiment was performed in the 2006/2007, 2007/2008 and 2008/2009 growing seasons. Congo signal grass (Urochloa ruziziensis, grain sorghum (Sorghum bicolor and sorghum mixed with brachiaria were cropped in the fall-winter to consist the main plots. In the spring, millet (Pennisetum glaucum, 'Cober Crop' (Sorghum bicolor x Sorghum sudanense and Indian hemp (Crotalaria juncea were cultivated as subplots as well as a fallow treatment. Soybean was cropped in the summer, totaling 12 treatments. Cover crop dry matter and root growth were evaluated in 2006 and 2008. Soil samples were taken from 0-5 and 5-10 cm depths, after spring cover crops managing, in the first and third years. The mean weight diameter, geometric mean diameter, aggregate stability index, aggregates larger than 2 mm, organic matter and total organic carbon levels were evaluated in the samples of the third year. Millet and 'Cober Crop' showed higher dry matter production and root growth. The soil aggregation was improved by cover crop rotations before the summer growing season. The cultivation of 'Cober Crop' and millet influenced the macroaggregate formation in the superficial layers

Rodrigo Arroyo Garcia

2010-12-01

209

Effects of different cropping systems and weed management methods on free energy and content of pigments in maize  

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Full Text Available Rotation is a cropping system that has many advantages and ensures better crop growth and yielding. Its combinination with other cropping measures can ensure optimal crop density for maximal growth and photosynthesis efficiency. The aim of this study was to investigate the influence of different cropping systems: monoculture and two rotations, including maize, wheat and soybean (MSW and MWS, and different weed management methods (weed removal by hoeing, application of a full recommended herbicide dose (RD and half that dose (0.5 RD, and weedy check on weed biomass and maize growth parameters - leaf area index (LAI, free energy, contents of chlorophyll and carotenoids, grain yield, and their possible relationships in two fields of the maize hybrids ZP 677 (H1 and ZP 606 (H2. The lowest LAI and grain yield were found in monoculture, particularly in weedy check, which had relatively high weed infestation. Higher weed biomass was also observed in herbicide treated plots in monoculture. Such high competition pressure indicates a stress reflected on reduced LAI and chlorophyll content, and increased free energy and content of carotenoids. On the other hand, rotation, particularly if it is combined with the application of herbicides or hoeing, had a positive impact on yielding potential by increasing LAI and the contents of chlorophyll and carotenoids, and decreasing free energy.

Igor Spasojevi?

2014-03-01

210

Microbial soil quality indicators under different crop rotations and tillage management / Indicadores microbianos da qualidade do solo sob diferentes rotações de culturas e manejo do solo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Foi conduzido um experimento sob condições de campo para avaliar o efeito da forma de manejo do solo (Plantio direto - PD e plantio convencional - PC) e dos sistemas de rotação de culturas sobre o carbono da biomassa microbiana (Cmic), respiração basal do solo (RBS), quociente metabólico (qCO2), car [...] bono orgânico total (Corg) e relação carbono da biomassa microbiana: carbono orgânico total (Cmic/Corg). As amostras de solo foram coletadas em uma área cultivada com trigo como cultura de inverno e soja como cultura de verão, ambas em rotação com ervilhaca, milho e aveia preta. Amostras de solo também foram coletadas em uma floresta secundária usada com referência. Os dados de cada sistema de manejo do solo (PD e PC) foram comparados com a floresta secundária pelo teste "t" (p Abstract in english An experiment was carried out under field conditions to assess the effects of soil management (no-tillage- NT and conventional tillage- CT) and crop rotation systems on microbial biomass-C (Cmic), basal soil respiration (BSR), metabolic quotient (qCO2), soil organic carbon content (Corg) and microbi [...] al carbon to organic carbon ratio (Cmic/Corg). Soil samples were collected on an area cultivated with wheat as winter crop and soybean as summer crop, both in rotation with vetch, maize and oats. Samples were also collected in a secondary forest used as reference. Data of each management system (NT and CT) were compared to forest area by "t" test (p

Enderson Petrônio de Brito, Ferreira; Henrique Pereira dos, Santos; Janaina Ribeiro, Costa; Helvécio, De-Polli; Norma Gouvêa, Rumjanek.

2010-06-01

211

Microbial soil quality indicators under different crop rotations and tillage management / Indicadores microbianos da qualidade do solo sob diferentes rotações de culturas e manejo do solo  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Foi conduzido um experimento sob condições de campo para avaliar o efeito da forma de manejo do solo (Plantio direto - PD e plantio convencional - PC) e dos sistemas de rotação de culturas sobre o carbono da biomassa microbiana (Cmic), respiração basal do solo (RBS), quociente metabólico (qCO2), car [...] bono orgânico total (Corg) e relação carbono da biomassa microbiana: carbono orgânico total (Cmic/Corg). As amostras de solo foram coletadas em uma área cultivada com trigo como cultura de inverno e soja como cultura de verão, ambas em rotação com ervilhaca, milho e aveia preta. Amostras de solo também foram coletadas em uma floresta secundária usada com referência. Os dados de cada sistema de manejo do solo (PD e PC) foram comparados com a floresta secundária pelo teste "t" (p Abstract in english An experiment was carried out under field conditions to assess the effects of soil management (no-tillage- NT and conventional tillage- CT) and crop rotation systems on microbial biomass-C (Cmic), basal soil respiration (BSR), metabolic quotient (qCO2), soil organic carbon content (Corg) and microbi [...] al carbon to organic carbon ratio (Cmic/Corg). Soil samples were collected on an area cultivated with wheat as winter crop and soybean as summer crop, both in rotation with vetch, maize and oats. Samples were also collected in a secondary forest used as reference. Data of each management system (NT and CT) were compared to forest area by "t" test (p

Enderson Petrônio de Brito, Ferreira; Henrique Pereira dos, Santos; Janaina Ribeiro, Costa; Helvécio, De-Polli; Norma Gouvêa, Rumjanek.

212

Implementation of dynamic crop growth processes into a land surface model: evaluation of energy, water and carbon fluxes under corn and soybean rotation  

Directory of Open Access Journals (Sweden)

Full Text Available Worldwide expansion of agriculture is impacting Earth's climate by altering the carbon, water and energy fluxes, but climate in turn is impacting crop production. To study this two-way interaction and its impact on seasonal dynamics of carbon, water and energy fluxes, we implemented dynamic crop growth processes into a land surface model, the Integrated Science Assessment Model (ISAM. In particular, we implement crop specific phenology schemes, which account for light, water, and nutrient stresses while allocating the assimilated carbon to leaf, root, stem and grain pools; dynamic vegetation structure growth, which better simulate the LAI and canopy height; dynamic root distribution processes in the soil layers, which better simulate the root response of soil water uptake and transpiration; and litter fall due to fresh and old dead leaves to better represent the water and energy interception by both stem and brown leaves of the canopy during leaf senescence. Observational data for LAI, above and below ground biomass, and carbon, water and energy fluxes were compiled from two Ameri-Flux sites, Mead, NE and Bondville, IL, to calibrate and evaluate the model performance under corn (C4-soybean (C3 rotation system over the period 2001–2004. The calibrated model was able to capture the diurnal and seasonal patterns of carbon assimilation, water and energy fluxes under the corn-soybean rotation system at these two sites. Specifically, the calculated GPP, net radiation fluxes at the top of canopy and latent heat fluxes compared well with observations. The largest bias in model results is in sensible heat flux (H for corn and soybean at both sites. With dynamic carbon allocation and root distribution processes, model simulated GPP and latent heat flux (LH were in much better agreement with observation data than for the without dynamic case. Modeled latent heat improved by 12–27% during the growing season at both sites, leading to the improvement in modeled GPP by 13–61% compared to the without dynamic case.

Y. Song

2013-06-01

213

Estabilidade de agregados do solo após manejo com rotações de culturas e escarificação / Soil aggregate stability after management with crop rotation and chiseling  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O objetivo desse trabalho foi avaliar, em solo compactado, a estabilidade dos agregados influenciada pelo cultivo de espécies de cobertura em esquema de rotações de culturas, em sistema de semeadura direta, mediante o efeito da escarificação mecânica. As rotações de culturas repetidas por três anos [...] consecutivos envolveram o cultivo de triticale e girassol, no outono-inverno, associados ao cultivo de milheto, de sorgo forrageiro e de Crotalária júncea como plantas de cobertura, antecedendo o da soja (cultura de verão). No tratamento envolvendo a escarificação mecânica, a área permaneceu em pousio entre os cultivos de outono-inverno e de verão. O experimento foi realizado na Fazenda Experimental Lageado (Botucatu-SP), nos anos agrícolas de 2003/2004, 2004/2005 e 2005/2006. O delineamento experimental foi o de blocos ao acaso, com quatro repetições, em esquema de parcelas subdivididas. As amostras para a análise da estabilidade de agregados foram coletadas nas profundidades de 0 a 0,05 m e de 0,05 a 0,10 m após o manejo das plantas de cobertura em dezembro de 2003 e de 2005. Logo no primeiro ano de instalação do experimento, o cultivo de triticale resultou em maior porcentagem de agregados com mais de 2 mm, maior DMG e maior DMP na camada de 0 a 5 cm, além de maior DMP na camada de 0,05 a 0,10 m. Já a escarificação do solo e a ausência do cultivo de plantas de cobertura proporcionaram menor porcentagem de agregados maiores que 2 mm e menor DMP na camada de 0,05 a 0,10 m. A estabilidade dos agregados foi influenciada pela rotação de culturas, sendo maior na camada de 0 a 0,05 m e de 0,05 a 0,10 m quando o triticale foi introduzido como espécie de outono-inverno. Abstract in english The objective of this study was to compare, in compacted soil condition, the aggregate stability after different crops rotations under no-tillage system and chiseling. The following crop rotations were repeated for three consecutive years under no-tillage: triticale (X Triticosecale Wittmack) and su [...] nflower (Helianthus annus) as autumn-winter crops, together with pearl millet (Pennisetum glaucum), forage sorghum (Sorghum bicolor) and sunn hemp (Crotalaria juncea) in spring, preceeding soybean (summer crop). In the chiseling treatment the area was kept bare between the autumn-winter and the summer crops. The study was carried out in three growing seasons (2003/2004, 2004/2005 and 2005/2006), in Botucatu, state of São Paulo, Brazil. The experiment had a complete randomized block design with split-plot and four replications. The samples for aggregate stability analysis were collected in the layers 0-5 and 5-10 cm after cover crop desiccation, in the first and third year of the experiment. In the first year of the experiment, triticale resulted in a higher percentage of aggregates larger than 2 mm, higher Mean Geometric Diameter and Mean Weight Diameter (MWD) of aggregates at the depth of 0-5 cm, and higher MWD at 5-10 cm. Chiseling and absence of cover crops reduced the percentage of aggregates larger than 2 mm and MWD values at 5-10 cm. Aggregate stability is influenced by crop rotation, and was highest in the layers 0-5 and 5-10 cm when triticale was used as autumn-winter species.

Juliano Carlos, Calonego; Ciro Antonio, Rosolem.

1399-14-01

214

Estabilidade de agregados do solo após manejo com rotações de culturas e escarificação Soil aggregate stability after management with crop rotation and chiseling  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo desse trabalho foi avaliar, em solo compactado, a estabilidade dos agregados influenciada pelo cultivo de espécies de cobertura em esquema de rotações de culturas, em sistema de semeadura direta, mediante o efeito da escarificação mecânica. As rotações de culturas repetidas por três anos consecutivos envolveram o cultivo de triticale e girassol, no outono-inverno, associados ao cultivo de milheto, de sorgo forrageiro e de Crotalária júncea como plantas de cobertura, antecedendo o da soja (cultura de verão. No tratamento envolvendo a escarificação mecânica, a área permaneceu em pousio entre os cultivos de outono-inverno e de verão. O experimento foi realizado na Fazenda Experimental Lageado (Botucatu-SP, nos anos agrícolas de 2003/2004, 2004/2005 e 2005/2006. O delineamento experimental foi o de blocos ao acaso, com quatro repetições, em esquema de parcelas subdivididas. As amostras para a análise da estabilidade de agregados foram coletadas nas profundidades de 0 a 0,05 m e de 0,05 a 0,10 m após o manejo das plantas de cobertura em dezembro de 2003 e de 2005. Logo no primeiro ano de instalação do experimento, o cultivo de triticale resultou em maior porcentagem de agregados com mais de 2 mm, maior DMG e maior DMP na camada de 0 a 5 cm, além de maior DMP na camada de 0,05 a 0,10 m. Já a escarificação do solo e a ausência do cultivo de plantas de cobertura proporcionaram menor porcentagem de agregados maiores que 2 mm e menor DMP na camada de 0,05 a 0,10 m. A estabilidade dos agregados foi influenciada pela rotação de culturas, sendo maior na camada de 0 a 0,05 m e de 0,05 a 0,10 m quando o triticale foi introduzido como espécie de outono-inverno.The objective of this study was to compare, in compacted soil condition, the aggregate stability after different crops rotations under no-tillage system and chiseling. The following crop rotations were repeated for three consecutive years under no-tillage: triticale (X Triticosecale Wittmack and sunflower (Helianthus annus as autumn-winter crops, together with pearl millet (Pennisetum glaucum, forage sorghum (Sorghum bicolor and sunn hemp (Crotalaria juncea in spring, preceeding soybean (summer crop. In the chiseling treatment the area was kept bare between the autumn-winter and the summer crops. The study was carried out in three growing seasons (2003/2004, 2004/2005 and 2005/2006, in Botucatu, state of São Paulo, Brazil. The experiment had a complete randomized block design with split-plot and four replications. The samples for aggregate stability analysis were collected in the layers 0-5 and 5-10 cm after cover crop desiccation, in the first and third year of the experiment. In the first year of the experiment, triticale resulted in a higher percentage of aggregates larger than 2 mm, higher Mean Geometric Diameter and Mean Weight Diameter (MWD of aggregates at the depth of 0-5 cm, and higher MWD at 5-10 cm. Chiseling and absence of cover crops reduced the percentage of aggregates larger than 2 mm and MWD values at 5-10 cm. Aggregate stability is influenced by crop rotation, and was highest in the layers 0-5 and 5-10 cm when triticale was used as autumn-winter species.

Juliano Carlos Calonego

2008-08-01

215

Assessment of factors influencing groundwater-level change using groundwater flow simulation, considering vertical infiltration from rice-planted and crop-rotated paddy fields in Japan  

Science.gov (United States)

Assessing factors that influence groundwater levels such as land use and pumping strategy, is essential to adequately manage groundwater resources. A transient numerical model for groundwater flow with infiltration was developed for the Tedori River alluvial fan (140 km2), Japan. The main water input into the groundwater body in this area is irrigation water, which is significantly influenced by land use, namely paddy and upland fields. The proposed model consists of two models, a one-dimensional (1-D) unsaturated-zone water flow model (HYDRUS-1D) for estimating groundwater recharge and a 3-D groundwater flow model (MODFLOW). Numerical simulation of groundwater flow from October 1975 to November 2009 was performed to validate the model. Simulation revealed seasonal groundwater level fluctuations, affected by paddy irrigation management. However, computational accuracy was limited by the spatiotemporal data resolution of the groundwater use. Both annual groundwater levels and recharge during the irrigation periods from 1975 to 2009 showed long-term decreasing trends. With the decline in rice-planted paddy field area, groundwater recharge cumulatively decreased to 61 % of the peak in 1977. A paddy-upland crop-rotation system could decrease groundwater recharge to 73-98 % relative to no crop rotation.

Iwasaki, Yumi; Nakamura, Kimihito; Horino, Haruhiko; Kawashima, Shigeto

2014-07-01

216

Efecto de la rotación de cultivos y prácticas de labranza sobre las fracciones de la materia orgánica del suelo / TILLAGE SYSTEM AND CROP ROTATION EFFECTS ON SOIL ORGANIC MATTER FRACTIONS / EFEITO DA ROTAÇÃO DE CULTIVOS E PRÁTICAS DE LAVRAGEM SOBRE AS FRAÇÕES DA MATÉRIA ORGÂNICA DO SOLO  

Scientific Electronic Library Online (English)

Full Text Available SciELO Venezuela | Language: Spanish Abstract in portuguese As práticas de lavragem e rotação de cultivos podem modificar a matéria orgânica do solo (MOS). Um estudo conduzido por sete anos, onde se incluíram lavragem e rotação de cultivos, foi utilizado para avaliar o efeito do manejo do solo sobre as diferentes frações do C e N. O experimento foi localizad [...] o em Turén, estado Portuguesa, Venezuela, e incluiu dois sistemas de lavragem, lavragem convencional (LC) e semeadura direta (SD), e duas rotações de cultivos, milho-algodão (MA) e milho-feijão (MF). Amostras de solo foram coletadas a três profundidades e se analisou o C (COT) e N orgânico total (NOT), C (MMC) e N (MMN) da massa microbiana, C e N mineralizável (Cmin e Nmin), N lábil potencialmente mineralizável (N1) e sua taxa de decomposição (kl). As mudanças observadas em COS e NOS em resposta à lavragem e à rotação de cultivos foram relacionadas com a quantidade e qualidade de resíduos de plantas que retornam ao solo, mas não com a sua distribuição no perfil do solo, com exceção da MO mineralizável. Este estudo demonstra a importância da MMC, MMN e da mineralização do C e N como índices para conhecer a dinâmica da MOS em uma zona tropical. Por outra parte, o N1 pode ser usado como indicador da capacidade do solo de liberar N da MOS. Abstract in spanish Las prácticas de labranza y rotación de cultivos pueden modificar la materia orgánica del suelo (MOS). Un estudio conducido por siete años, donde se incluyeron labranza y rotación de cultivos, fue utilizado para evaluar el efecto del manejo de suelo sobre las diferentes fracciones de C y N. El exper [...] imento fue localizado en Turén, estado Portuguesa, Venezuela, e incluyó dos sistemas de labranza, labranza convencional (LC) y siembra directa (SD), y dos rotaciones de cultivos, maíz-algodón (MA) y maíz-fríjol (MF). Muestras de suelo fueron colectadas a tres profundidades y se analizó el C (COT) y N orgánico total (NOT), C (MMC) y N (MMN) de la masa microbiana, C y N mineralizable (Cmin y Nmin), N lábil potencialmente mineralizable (N1) y su tasa de descomposición (k l). Los cambios observados en COT y NOT en respuesta a la labranza y a la rotación de cultivos fueron relacionados con la cantidad y calidad de residuos de planta que regresan al suelo, pero no con su distribución en el perfil del suelo, con excepción de la MO mineralizable. Este estudio demuestra la importancia de la MMC, MMN y de la mineralización de C y N como índices para conocer la dinámica de la MOS en una zona tropical. Por otra parte, el N1 puede ser usado como indicador de la capacidad del suelo de liberar N de la MOS. Abstract in english Cultivation practices such as tillage and crop rotation can modify soil organic matter (MOS). A crop rotation-tillage study was conducted for seven years in order to evaluate the effects on the different pools of C and N. The experiment was located in Turén, Portuguesa State, Venezuela, with two til [...] lage systems: conventional tillage (CT), and no tillage (NT) and two crop rotations, corn-cotton (CC), and corn-bean (CB). Soil samples were collected at three depths and analyzed for total organic C (COT) and N (TON), microbial biomass C (MMC) and N (MMN), mineralized C and N (Cmin and Nmin), and potentially mineralized labile N (N1) and its decay rate (k l). The changes observed in COT and NOT in response to tillage and rotation were related to the quantity and quality of plant residues returned to the soil, but not to their distribution in the soil profile, with exception of MO mineralization. This study shows the importance of the MMC, MMN, C and N mineralization as indexes of MOS dynamics in a tropical region. On the other hand, N1 can be used as an indicator of the relative soil capacity to release N from MOS.

Yusmary, Espinoza; Zenaida, Lozano; Lorenzo, Velásquez.

217

From the Academy: Colloquium perspective. Toward cropping systems that enhance productivity and sustainability.  

Science.gov (United States)

The defining features of any cropping system are (i) the crop rotation and (ii) the kind or intensity of tillage. The trend worldwide starting in the late 20th century has been (i) to specialize competitively in the production of two, three, a single, or closely related crops such as different market classes of wheat and barley, and (ii) to use direct seeding, also known as no-till, to cut costs and save soil, time, and fuel. The availability of glyphosate- and insect-resistant varieties of soybeans, corn, cotton, and canola has helped greatly to address weed and insect pest pressures favored by direct seeding these crops. However, little has been done through genetics and breeding to address diseases caused by residue- and soil-inhabiting pathogens that remain major obstacles to wider adoption of these potentially more productive and sustainable systems. Instead, the gains have been due largely to innovations in management, including enhancement of root defense by antibiotic-producing rhizosphere-inhabiting bacteria inhibitory to root pathogens. Historically, new varieties have facilitated wider adoption of new management, and changes in management have facilitated wider adoption of new varieties. Although actual yields may be lower in direct-seed compared with conventional cropping systems, largely due to diseases, the yield potential is higher because of more available water and increases in soil organic matter. Achieving the full production potential of these more-sustainable cropping systems must now await the development of varieties adapted to or resistant to the hazards shown to account for the yield depressions associated with direct seeding. PMID:17130454

Cook, R James

2006-12-01

218

Productivity of winter rye in organic vs. Conventional cropping system  

Directory of Open Access Journals (Sweden)

Full Text Available Rye is a cereal which is very much demanded at the market, for making a special kind of bread, but it is little grown in Serbia. The aim of this paper is to investigate possibilities of organic growing of winter rye, comparing with the conventional one, in agroecological conditions of Valjevo hilly region during 2008/2009 and 2009/2010 cropping seasons. The trial was set up in a village of Kotešica, on soil which had not been used for agriculture for 7 years. In organic cropping system three combinations of microbiological fertiliser baktofil with zeolite and hydrogel were used prior to sowing. Half of each plot was treated with foliar microbiological fertiliser Slavol during crop growing period. In conventional cropping system three variants with mineral fertilisers were included: NPK, NPK+zeolite, NPK+hydrogel. Results of the yield obtained in the experiment showed a significant difference between two seasons, 2008/2009 and 2009/2010. In comparison with the control, the treatments in an organic cropping system resulted with statistically insignificant differences for mean values in both years, while the mean in conventional cropping system has significantly higher yield of winter rye. Organic cropping system under conditions of Valjevo hilly region did not give significantly lower rye yield compared with the conventional one in a moderate growing season such was 2008/2009. The combination of soil microbiological fertiliser (Baktofil with foliar fertiliser (Slavol and zeolite gave the highest winter rye grain yield in all other treatments in the second year of investigation. In a very wet season (2009/2010 mineral fertiliser NPK showed an advantage, especially in combinations with zeolite, and this treatment can be recommended.

Olja?a Jasmina M.

2010-01-01

219

Crop rotation as a factor differentiating the intensity of the diseases of field pea (Pisum sativum L.  

Directory of Open Access Journals (Sweden)

Full Text Available The research was conducted in the years 1998-2001. The aim of the research was to determine the health of the field pea cv. Kormoran grown in four various crop rotations and to determine the patogens causing the root-rot. On the pea plants the following diseases were found: root rot (complex of fungi, ascochyta blight (Ascochyta pisi, Phoma pinodella, Mycospaerella pinodes and fusarium foot rot (Fusarium spp.. All the diseases occurred in the highest intensity on the pea cultivated in three-field crop rotation without manure. The weather conditions affected the intensity of the diseases. From the roots of seedlings with the symptoms of root rot 44,7% of fungi with pathogenic potential in relation to pea were obtained. The most commonly isolated were Fusarium oxysporum (26,7% of all isolates, Rhizoctonia solani (10,7%, F.solani (3,3%, F.avenaceum (2,7% and F.equiseti (1,3%. From the infected root necks, 55,3% of potential pathogens of field pea were obtained. Among the isolates the most commonly found was F.oxysporum (31,1% of all isolates. Other fungi of the Fusarium genus constituted 15,4% of isolates, R.solani 7,0%, and Sclerotinia sclerotiorum 1,8%.

Tomasz P. Kurowski

2002-06-01

220

Influence of crop rotation and meteorological conditons on biodiversity of weed communities in spring barley (Hordeum vulgare L.  

Directory of Open Access Journals (Sweden)

Full Text Available The paper presents the analysis of changes in weed biodiversity in spring barley cultivated in the years 1990-2004 in crop rotation with a 25% proportion of this cereal (potato - spring barley - sowing peas - winter triticale, when it was grown after potato, and in crop rotation with its 75% proportion (potato - spring barley - spring barley - spring barley, when it was grown once or twice after spring barley. In the experiment, no weed control was applied. Every year in the spring (at full emergence of the cereal and before the harvest, the composition of weed species and numbers of particular weed species were determined, and before the harvest also their biomass. On this basis, the constancy of species in particular years, Shannon-Wiener species diversity indices and diversity profiles according to Rényi were determined. Weed species richness increased linearly at all plots during the 15-year period. Chenopodium album was a constant and dominant species in terms of weed species density and biomass year after year. The quality of the plot had no clear influence on the diversity of weeds in barley. Weed density and biomass showed high year-to-year variability and a positive correlation with the amount of precipitation and a negative correlation with temperature during the period of the study. The significance of the correlation between the productivity of barley and weed diversity was not confirmed.

Marta K. Kostrzewska

2010-06-01

 
 
 
 
221

Evaluation of Carabid Beetle Diversity in Different Bioenergy Cropping Systems  

Directory of Open Access Journals (Sweden)

Full Text Available Normal 0 7.8 ? 0 2 false false false EN-US ZH-CN X-NONE MicrosoftInternetExplorer4 Changes in agricultural land use as a consequence of an increased demand of energy crops have resulted in an increase of maize cropped area in many regions of Germany. The focus on maize as main biogas substrate, has led in some cases to negative ecological and environmental impacts, such as a loss of agro biodiversity reflected in a loss of field flora and fauna biodiversity. The present paper deals with the evaluation of the fauna in different bioenergy cropping systems on two sites in South-West Germany, with a special focus on the species richness of carabid beetle (Coleoptera: Carabidae assemblages as an indicator for the general status of diversity. A maize field, an agroforestry system with maize and different tree species as well as different alternative biogas crops (amaranth, sunflower was investigated for their carabid beetle activity, density, and species richness using pitfall traps. Moreover, for an adequate evaluation of the carabid assemblages different common diversity indices (Shannon-Wiener diversity (H’, Simpson diversity (D and Evenness (J’ were used. In the case of the maize field on both field edges 8 and 6 carabid beetle species, respectively were trapped, while in the field centre 2 carabid beetle species were trapped. The agroforestry system indicated slightly higher crabid beetle species richness close to the tree strips. The investigation of alternative biogas crops showed no significant differences in carabid beetle diversity. Overall, the results of the different studies showed, that biodiversity of bioenergy cropping systems could be enhanced by the creation of refuge areas for carabid beetles or other animals. Refuges could be either field margins with grass and hedgerows or strips of more extensively used perennial energy crops across the field.

Benjamin Mast

2012-06-01

222

Long-term effects of cropping system on N2O emission potential  

DEFF Research Database (Denmark)

The potential for N2O emissions outside the main growing season may be influenced by long-term effects of cropping system. This was investigated by collecting intact soil cores (100 cm3, 0-4 cm depth) under winter wheat in three organic cropping systems and a conventional reference within a long-term crop rotation experiment. Average annual inputs of C in crop residues and manure ranged from 1.7 to 3.3 Mg ha-1. A simulated freeze-thaw cycle resulted in a flush of CO2 during the first 48 h, which could be mainly from microbial sources. Other samples were adjusted to approximately –10, -30 or –100 hPa and amended with excess 15NO3- prior to freezing and thawing. Denitrification was the main source of N2O during a 72-h incubation at 22 °C, as judged from N2O and total 15N evolution. Although the input of C in the conventionally managed cropping system was significantly less than in the organic cropping systems, it showed higher N2O evolution at all three matric potentials. Estimates of relative gas diffusivity (DP/D0) in soil from the four cropping systems indicated that C input affected soil aeration. Soil from the two cropping systems with highest C input showed N2O evolution at DP/D0 in excess of 0.02, which is normally considered a threshold for development of anaerobic sites in the soil, presumably because the oxygen demand was also high. The study shows that cropping system affects both soil gas diffusivity and C availability, and that both characteristics significantly influence the N2O emission potential.

Ambus, Per

2013-01-01

223

Soil water retention and s index after crop rotation and chiseling / Retenção de água no solo e índice s influenciados por rotação de culturas e escarificação  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A compactação do solo pode ser corrigida mecanicamente ou usando espécies vegetais com sistema radicular vigoroso. Um experimento foi conduzido com soja (Glycine max) em rotação com triticale (X Triticosecale) e girassol (Helianthus annuus) cultivados no outono/inverno, associados com milheto (Penni [...] setum glaucum), sorgo (Sorghum bicolor) ou crotalária (Crotalaria juncea) cultivados na primavera. Rotações sob semeadura direta foram comparadas com um tratamento com escarificação no início do experimento. A qualidade do solo foi estimada usando-se o índice S e as curvas de retenção de água do solo nas profundidades de 0-0,05, 0,075-0,15, 0,15-0,20, 0,275-0,325 e 0,475-0,525 m. As rotações de culturas e a escarificação melhoraram a qualidade do solo, aumentando o índice S acima de 0,035 até 0,20 m no perfil do solo. Entretanto, a melhoria na qualidade do solo, conforme determinada por meio do índice S, não justifica o uso de escarificação mecânica, uma vez que as parcelas sob rotação de culturas em semeadura direta mostraram qualidade física do solo semelhante após três anos. Abstract in english Soil compaction can be minimized either mechanically or biologically, using plant species with vigorous root systems. An experiment was carried out with soybean (Glycine max) in rotation with triticale (X Triticosecale) and sunflower (Helianthus annuus) in fall-winter associated with pearl millet (P [...] ennisetum glaucum), grain sorghum (Sorghum bicolor) or sunn hemp (Crotalaria juncea) in spring. Crop rotation under no-till was compared with mechanical chiseling. The experiment was carried out in Botucatu, São Paulo State, Brazil. Soil quality was estimated using the S index and soil water retention curves (in the layers of 0-0.05, 0.075-0.125, 0.15-0.20, 0.275-0.325, and 0.475-0.525 m deep). Crop rotation and chiseling improved soil quality, increasing the S index to over 0.035 to a depth of 20 cm in the soil profile. The improved soil quality, as shown by the S index, makes the use of mechanical chiseling unnecessary, since after 3 years the soil physical quality under no-tilled crop rotation and chiseling was similar.

Juliano Carlos, Calonego; Ciro Antonio, Rosolem.

1927-19-01

224

Soil water retention and s index after crop rotation and chiseling / Retenção de água no solo e índice s influenciados por rotação de culturas e escarificação  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese A compactação do solo pode ser corrigida mecanicamente ou usando espécies vegetais com sistema radicular vigoroso. Um experimento foi conduzido com soja (Glycine max) em rotação com triticale (X Triticosecale) e girassol (Helianthus annuus) cultivados no outono/inverno, associados com milheto (Penni [...] setum glaucum), sorgo (Sorghum bicolor) ou crotalária (Crotalaria juncea) cultivados na primavera. Rotações sob semeadura direta foram comparadas com um tratamento com escarificação no início do experimento. A qualidade do solo foi estimada usando-se o índice S e as curvas de retenção de água do solo nas profundidades de 0-0,05, 0,075-0,15, 0,15-0,20, 0,275-0,325 e 0,475-0,525 m. As rotações de culturas e a escarificação melhoraram a qualidade do solo, aumentando o índice S acima de 0,035 até 0,20 m no perfil do solo. Entretanto, a melhoria na qualidade do solo, conforme determinada por meio do índice S, não justifica o uso de escarificação mecânica, uma vez que as parcelas sob rotação de culturas em semeadura direta mostraram qualidade física do solo semelhante após três anos. Abstract in english Soil compaction can be minimized either mechanically or biologically, using plant species with vigorous root systems. An experiment was carried out with soybean (Glycine max) in rotation with triticale (X Triticosecale) and sunflower (Helianthus annuus) in fall-winter associated with pearl millet (P [...] ennisetum glaucum), grain sorghum (Sorghum bicolor) or sunn hemp (Crotalaria juncea) in spring. Crop rotation under no-till was compared with mechanical chiseling. The experiment was carried out in Botucatu, São Paulo State, Brazil. Soil quality was estimated using the S index and soil water retention curves (in the layers of 0-0.05, 0.075-0.125, 0.15-0.20, 0.275-0.325, and 0.475-0.525 m deep). Crop rotation and chiseling improved soil quality, increasing the S index to over 0.035 to a depth of 20 cm in the soil profile. The improved soil quality, as shown by the S index, makes the use of mechanical chiseling unnecessary, since after 3 years the soil physical quality under no-tilled crop rotation and chiseling was similar.

Juliano Carlos, Calonego; Ciro Antonio, Rosolem.

225

Soil water retention and s index after crop rotation and chiseling Retenção de água no solo e índice s influenciados por rotação de culturas e escarificação  

Directory of Open Access Journals (Sweden)

Full Text Available Soil compaction can be minimized either mechanically or biologically, using plant species with vigorous root systems. An experiment was carried out with soybean (Glycine max in rotation with triticale (X Triticosecale and sunflower (Helianthus annuus in fall-winter associated with pearl millet (Pennisetum glaucum, grain sorghum (Sorghum bicolor or sunn hemp (Crotalaria juncea in spring. Crop rotation under no-till was compared with mechanical chiseling. The experiment was carried out in Botucatu, São Paulo State, Brazil. Soil quality was estimated using the S index and soil water retention curves (in the layers of 0-0.05, 0.075-0.125, 0.15-0.20, 0.275-0.325, and 0.475-0.525 m deep. Crop rotation and chiseling improved soil quality, increasing the S index to over 0.035 to a depth of 20 cm in the soil profile. The improved soil quality, as shown by the S index, makes the use of mechanical chiseling unnecessary, since after 3 years the soil physical quality under no-tilled crop rotation and chiseling was similar.A compactação do solo pode ser corrigida mecanicamente ou usando espécies vegetais com sistema radicular vigoroso. Um experimento foi conduzido com soja (Glycine max em rotação com triticale (X Triticosecale e girassol (Helianthus annuus cultivados no outono/inverno, associados com milheto (Pennisetum glaucum, sorgo (Sorghum bicolor ou crotalária (Crotalaria juncea cultivados na primavera. Rotações sob semeadura direta foram comparadas com um tratamento com escarificação no início do experimento. A qualidade do solo foi estimada usando-se o índice S e as curvas de retenção de água do solo nas profundidades de 0-0,05, 0,075-0,15, 0,15-0,20, 0,275-0,325 e 0,475-0,525 m. As rotações de culturas e a escarificação melhoraram a qualidade do solo, aumentando o índice S acima de 0,035 até 0,20 m no perfil do solo. Entretanto, a melhoria na qualidade do solo, conforme determinada por meio do índice S, não justifica o uso de escarificação mecânica, uma vez que as parcelas sob rotação de culturas em semeadura direta mostraram qualidade física do solo semelhante após três anos.

Juliano Carlos Calonego

2011-12-01

226

Residual Influence of Early Season Crop Fertilization and Cropping System on Growth and Yield of Cassava  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Problem statement: In assessing fertilizer effects to sustain an intensive cropping system, the residual effects of fertilizer applied to preceding maize on the growth and yield of cassava and the effects of intercropping with soybean were studied in field experiments at Ibadan, Nigeria. Approach: Maize, established in April was fertilized using either organic manure or inorganic fertilizer or a mixture of organic manure and inor...

Makinde, E. A.; Ayoola, O. T.

2008-01-01

227

Counter-Rotating Tandem Motor Drilling System  

Energy Technology Data Exchange (ETDEWEB)

Gas Technology Institute (GTI), in partnership with Dennis Tool Company (DTC), has worked to develop an advanced drill bit system to be used with microhole drilling assemblies. One of the main objectives of this project was to utilize new and existing coiled tubing and slimhole drilling technologies to develop Microhole Technology (MHT) so as to make significant reductions in the cost of E&P down to 5000 feet in wellbores as small as 3.5 inches in diameter. This new technology was developed to work toward the DOE's goal of enabling domestic shallow oil and gas wells to be drilled inexpensively compared to wells drilled utilizing conventional drilling practices. Overall drilling costs can be lowered by drilling a well as quickly as possible. For this reason, a high drilling rate of penetration is always desired. In general, high drilling rates of penetration (ROP) can be achieved by increasing the weight on bit and increasing the rotary speed of the bit. As the weight on bit is increased, the cutting inserts penetrate deeper into the rock, resulting in a deeper depth of cut. As the depth of cut increases, the amount of torque required to turn the bit also increases. The Counter-Rotating Tandem Motor Drilling System (CRTMDS) was planned to achieve high rate of penetration (ROP) resulting in the reduction of the drilling cost. The system includes two counter-rotating cutter systems to reduce or eliminate the reactive torque the drillpipe or coiled tubing must resist. This would allow the application of maximum weight-on-bit and rotational velocities that a coiled tubing drilling unit is capable of delivering. Several variations of the CRTDMS were designed, manufactured and tested. The original tests failed leading to design modifications. Two versions of the modified system were tested and showed that the concept is both positive and practical; however, the tests showed that for the system to be robust and durable, borehole diameter should be substantially larger than that of slim holes. As a result, the research team decided to complete the project, document the tested designs and seek further support for the concept outside of the DOE.

Kent Perry

2009-04-30

228

A Comparative Analysis of Global Cropping Systems Models and Maps  

Science.gov (United States)

Agricultural practices have dramatically altered the land cover of the Earth, but the spatial extent and intensity of these practices is often difficult to catalogue. Cropland accounts for nearly 15 million km2 of the Earth's land cover - amounting to 12% of the Earth's ice-free land surface - yet information on the distribution and performance of specific crops is often available only through national or sub-national statistics. While remote sensing products offer spatially disaggregated information, those currently available on a global scale are ill-suited for many applications due to the limited separation of crop types within the area classified as cropland. Recently, however, there have been multiple independent efforts to incorporate the detailed information available from statistical surveys with supplemental spatial information to produce a spatially explicit global dataset specific to individual cropss for the year 2000. While these datasets provide analysts and decision makers with improved information on global cropping systems, the final global cropping maps differ from one another substantially. This study aims to explore and quantify systematic similarities and differences between four major global cropping systems products: the monthly irrigated and rainfed crop areas around the year 2000 (MIRAC2000) dataset, the spatial production allocation model (SPAM), the global agro-ecological zone (GAEZ) dataset, and the dataset developed by Monfreda et al., 2008. The analysis explores not only the final cropping systems maps but also the interdependencies of each product, methodological differences and modeling assumptions, which will provide users with information vital for discerning between datasets in selecting a product appropriate for each intended application.

Anderson, W. B.; You, L.; Wood, S.; Wood-Sichra, U.; Wu, W.

2013-12-01

229

The impacts of land-use change from grassland to bioenergy Short Rotation Coppice (SRC) Willow on the crop and ecosystem greenhouse gas balance  

Science.gov (United States)

The aim of this research is to better understand the greenhouse gas balance of land-use transition to bioenergy cropping systems in a UK context. Given limited land availability, addressing the food-energy-water nexus remains a challenge, and it is imperative that bioenergy crops are sited appropriately and that competition with food crops is minimized. Here we present the results of a years' worth of soil and GHG data for a conversion from ex-set aside grassland to short rotation coppice (SRC) willow for bioenergy on a commercial scale. Initial results indicate that willow was a net sink for CO2 in comparison to grassland which was a net source of CO2. This provides evidence that the GHG balance of transitions to SRC bioenergy crops will potentially result in increased soil carbon. The empirical findings from this study have been combined with modelled estimates for the site to both test and validate the ECOSSE model. Initial comparisons show that the model is able to accurately predict the respiration occurring at the field site, suggesting that it is a valuable approach for up-scaling from point sites such as this to wider geographical areas and for considering future climate scenarios. The modelling output will also provide a user-friendly tool for land owners which will determine the GHG and soil carbon effects of changing land to bioenergy for UK. This work is based on the Ecosystem Land Use Modelling & Soil Carbon GHG Flux Trial (ELUM) project, which was commissioned and funded by the Energy Technologies Institute (ETI). This work was also jointly funded by the Carbo Biocrop Project.

Harris, Zoe M.; Alberti, Giorgio; Dondini, Marta; Smith, Pete; Taylor, Gail

2014-05-01

230

Use of the crown competition factor concept to select clones and spacings for short-rotation woody crops.  

Science.gov (United States)

Plantation spacing and rotation age are interrelated critical factors in optimizing production of short-rotation woody crops (SRWC). Different genotypes have different spacing and rotation-age optima. I have developed a method for estimating the optimum for new Populus clones based on a modification of the crown competition factor (CCF) concept, which was originally developed for conventional forestry practices with older trees. Measurements of as few as 100 trees of a new clone over a relatively short time period could be used to predict the optimum spacing and rotation age combinations for that clone. The technique could also be used to quantify basic differences in crown architecture and yield physiology among genotypes. One set of at least 20 trees is planted at an open-grown spacing and measured annually for crown and basal stem diameters. The regression of crown diameter on stem diameter is used to calculate the land area that would be occupied per open-grown tree at various stem diameters. This allows prediction of the spacing needed to reach the minimum density for maximum stand growth at a given age or stem size. A second set of 80 measurement trees is planted in a closely spaced set of Nelder arcs to force overstocking within the first few years of growth. Productivity measurements on these trees establish the upper limit on CCF for maximum stand growth. The data are then used to calculate the best spacing and rotation age combination for a new clone. Application of this model may lead to a better understanding of the productive advantages of the sylleptic branch habit, different branch angles and seasonal growth rates, different carbon allocation strategies, and responses to competition. PMID:14967657

Hall, R. B.

1994-01-01

231

Residual Influence of Early Season Crop Fertilization and Cropping System on Growth and Yield of Cassava  

Directory of Open Access Journals (Sweden)

Full Text Available Problem statement: In assessing fertilizer effects to sustain an intensive cropping system, the residual effects of fertilizer applied to preceding maize on the growth and yield of cassava and the effects of intercropping with soybean were studied in field experiments at Ibadan, Nigeria. Approach: Maize, established in April was fertilized using either organic manure or inorganic fertilizer or a mixture of organic manure and inorganic fertilizers. Organic manure was an equal mixture of domestic waste collected from a composted refuse dumping site applied at l0 t ha-1. Inorganic fertilizer was 150kg N supplied as urea and 50 kg P ha-1 as Single Super phosphate fertilizer. The mixture of organic and inorganic fertilizer treatment was 5 tonnes organic manure and 75kg N+25 kg P ha-1. Cassava was established in June and soybean planted in July, after harvesting maize. Results: Organic fertilizer treatment gave the tallest plants of 53 cm. Plants from sole inorganic fertilizer and from a mixture of organic and inorganic fertilizers had comparable heights but were significantly lower than plants from sole organic fertilizer application. Organic fertilizer application gave the highest seed yield of 481 kg ha-1 that was significantly higher than 380 kg ha-1 observed from a mixture of organic and inorganic fertilizers. Stover yield followed the same trend as seed yield. Cassava plant height was increased with fertilization but was reduced with intercropping. Sole organic fertilization had the tallest plants. Plant leaf area was neither significantly affected by fertilizer type nor cropping system. Fresh root yield was significantly reduced by 16% with soybean intercropping. Sole organic fertilizer application gave the highest yields of 22 tons ha-1 in sole crop and 18 tons ha-1 in intercrop with soybean. Conclusion: Cultivating an early season maize crop, followed by a cassava-soybean intercrop is more favored with application of 10 tons ha-1 organic fertilizer.

E. A. Makinde

2008-01-01

232

The perspective crops for the bioregenerative human life support systems  

Science.gov (United States)

The perspective crops for the bioregenerative human life support systems V.I. Polonskiy, J.E. Polonskaya aKrasnoyarsk State Agrarian University, 660049, Krasnoyarsk, Russia In the nearest future the space missions will be too long. In this case it is necessary to provide the crew by vitamins, antioxidants, and water-soluble dietary fibers. These compounds will be produced by higher plants. There was not enough attention at present to increasing content of micronutrients in edible parts of crops candidates for CELSS. We suggested to add the new crops to this list. 1. Barley -is the best crop for including to food crops (wheat, rice, soybean). Many of the health effects of barley are connected to dietary fibers beta-glucan of barley grains. Bar-ley is the only seed from cereals including wheat with content of all eight tocopherols (vitamin E, important antioxidant). Barley grains contain much greater amounts of phenolic compounds (potential antioxidant activities) than other cereal grains. Considerable focus is on supplement-ing wheat-based breads with barley to introduce the inherent nutritional advantages of barley flour, currently only 20We have selected and tested during 5 generations two high productive barley lines -1-K-O and 25-K-O. Our investigations (special breeding program for improving grain quality of barley) are in progress. 2. Volatile crops. Young leaves and shoots of these crops are edible and have a piquant taste. A lot of organic volatile compounds, oils, vitamins, antioxidants are in their biomass. These micronutrients are useful for good appetite and health of the crew. We have investigated 11 species: basil (Ocimum basilicum), hyssop (Hyssopus officinalis), marjoram (Origanum majorana), sweet-Mary (Melissa officinalis), common thyme (Thymus vulgaris), creeping thyme (Thymus serpyllum), summer savory (Satureja hortensis), catnip (Nepeta cataria), rue (Ruta graveolens), coriander (Coriandrum Ativum), sulfurwort (Levisticum officinale). These plants were grown under artificial light conditions from 5 to 7 months. All crops were cut periodically in every month. On the base of our investigations it is possible to recommend for using in CELSS the next crops: marjoram, sweet-Mary and common thyme. The micronutrients containing in barley and above mentioned volatile crops will be useful for good appetite and health of the crew.

Polonskiy, Vadim; Polonskaya, Janna

233

A quantum mechanical treatment of rotating fermion systems  

International Nuclear Information System (INIS)

A system of rotating fermions has been quantized taking into account the constraints implied by the conservation of angular momentum and the existence of the conjugate angle. This solution is here applied to the simple but non trivial case of pairing rotations. Both intrinsic and rotational excitations reporduce the exact eigenvalues. (Auth.)

234

A rotação de cultura reduz a matocompetição e aumenta o teor de clorofila e a produtividade do arroz Crop rotation reduces weed competition and increases chlorophyll concentration and yield of rice  

Directory of Open Access Journals (Sweden)

Full Text Available A rotação de culturas é uma prática importante em sistemas agrícolas sustentáveis pelos efeitos benéficos tanto na fertilidade do solo como na redução da matocompetição, entre outros. Este trabalho foi conduzido no campo experimental da UEMA, em São Luís, MA. Avaliou-se o efeito da rotação de culturas na incidência de plantas invasoras, nos teores de clorofila e na produtividade do arroz (Oryza sativa L. cv. Guarani. Cultivou-se o arroz com e sem adubação nitrogenada, bem como em rotação com caupi (Vigna unguiculata (L. Walp., crotalária (Crotalaria paulina Schrank e mucuna (Mucuna aterrima Piper & Tracy. No primeiro ciclo a cobertura morta das leguminosas, deixada sobre o solo para a safra seguinte, foi máxima na crotalária, intermediária na mucuna e mínima no caupi. No segundo ciclo, cultivado em plantio direto sem uso de herbicidas, a rotação com mucuna e crotalária reduziu a biomassa, a cobertura e a densidade das invasoras. O teor de clorofila foi maior na rotação com crotalária do que na testemunha. A produtividade do arroz foi maior na rotação com crotalária e mucuna do que no arroz em cultivo sucessivo com ou sem N. Concluiu-se que a rotação do arroz com leguminosas aumenta a produtividade do arroz e reduz a matocompetição.Crop rotation is an essential practice in sustainable agricultural systems, because its effects on soil fertility and other benefits including reduction on weed competition. A field experiment was carried out at the UEMA experimental station, São Luís, Maranhão State, Brazil, to evaluate the effect of crop rotation on weed population, leaf chlorophyll concentration and yield of rice (Oryza sativa L. cv. Guarani. The rice was cultivated with and without N application, and in rotation with cowpea (Vigna unguiculata (L. Walp., hyacinthbean (Crotalaria paulina Schrank and velvetbean (Mucuna aterrima Piper & Tracy. First crop legume residues were highest in hyacinthbean, less in velvetbean and least in cowpea. They were left at soil surface as mulch for the second crop, which was cultivated in a minimum tillage system without using herbicides. At the second crop, weed biomass, weed cover, and weed density were lower in the hyacinthbean and velvetbean rotation than in continuous rice. Leaf chlorophyll concentration was greater in the hyacinthbean-rice sequence than in control plots. Rice yield was greater when rotated with hyacinthbean or velvetbean than in continuous crop with or without N application. It was concluded that legume in rice rotation reduces weed competition and improves the yield of rice.

Ricardo Antonio Marenco

1999-10-01

235

A rotação de cultura reduz a matocompetição e aumenta o teor de clorofila e a produtividade do arroz / Crop rotation reduces weed competition and increases chlorophyll concentration and yield of rice  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese A rotação de culturas é uma prática importante em sistemas agrícolas sustentáveis pelos efeitos benéficos tanto na fertilidade do solo como na redução da matocompetição, entre outros. Este trabalho foi conduzido no campo experimental da UEMA, em São Luís, MA. Avaliou-se o efeito da rotação de cultur [...] as na incidência de plantas invasoras, nos teores de clorofila e na produtividade do arroz (Oryza sativa L. cv. Guarani). Cultivou-se o arroz com e sem adubação nitrogenada, bem como em rotação com caupi (Vigna unguiculata (L.) Walp.), crotalária (Crotalaria paulina Schrank) e mucuna (Mucuna aterrima Piper & Tracy). No primeiro ciclo a cobertura morta das leguminosas, deixada sobre o solo para a safra seguinte, foi máxima na crotalária, intermediária na mucuna e mínima no caupi. No segundo ciclo, cultivado em plantio direto sem uso de herbicidas, a rotação com mucuna e crotalária reduziu a biomassa, a cobertura e a densidade das invasoras. O teor de clorofila foi maior na rotação com crotalária do que na testemunha. A produtividade do arroz foi maior na rotação com crotalária e mucuna do que no arroz em cultivo sucessivo com ou sem N. Concluiu-se que a rotação do arroz com leguminosas aumenta a produtividade do arroz e reduz a matocompetição. Abstract in english Crop rotation is an essential practice in sustainable agricultural systems, because its effects on soil fertility and other benefits including reduction on weed competition. A field experiment was carried out at the UEMA experimental station, São Luís, Maranhão State, Brazil, to evaluate the effect [...] of crop rotation on weed population, leaf chlorophyll concentration and yield of rice (Oryza sativa L. cv. Guarani). The rice was cultivated with and without N application, and in rotation with cowpea (Vigna unguiculata (L.) Walp.), hyacinthbean (Crotalaria paulina Schrank) and velvetbean (Mucuna aterrima Piper & Tracy). First crop legume residues were highest in hyacinthbean, less in velvetbean and least in cowpea. They were left at soil surface as mulch for the second crop, which was cultivated in a minimum tillage system without using herbicides. At the second crop, weed biomass, weed cover, and weed density were lower in the hyacinthbean and velvetbean rotation than in continuous rice. Leaf chlorophyll concentration was greater in the hyacinthbean-rice sequence than in control plots. Rice yield was greater when rotated with hyacinthbean or velvetbean than in continuous crop with or without N application. It was concluded that legume in rice rotation reduces weed competition and improves the yield of rice.

Ricardo Antonio, Marenco; Ávila Maria Bastos, Santos.

236

Rotating coil system for multipole magnets  

International Nuclear Information System (INIS)

We are preparing a rotating coil system for precise magnetic harmonic field measurement. A flexible print circuit sheet, where a pair of one turn coils are printed on, is glued on a quartz rod. The coil location can be well defined because of the one turn coil scheme and the small thermal expansion coefficient of quartz eliminates the ambient temperature effect. The two coils located on the quarts rod with the angle difference of 180 degree can separate the odd and even harmonics components by recording both the signals simultaneously to get their sum and difference. 24-bit ADC's are used for higher resolution and the signal are integrated digitally. The coil wire positions (radius and azimuthal angle) are evaluated by a small magnet that has a sharp magnetic field distribution. (author)

237

Performance testing rotating gamma camera SPECT systems  

International Nuclear Information System (INIS)

A reasonably simple protocol for testing the performance of rotating gamma camera SPECT systems has been established, which could be performed in about 10 hours. This protocol has been used to test almost all currently available systems, including GE, Siemens, Technicare, Elscint, Phillips, CGR, etc. In general, several models of a given system were tested in order to give an indication of the range of results that might be obtained. Reconstructions were performed in a standard manner (Uniformity correction, Ramp filter, no attenuation correction) in order to try to eliminate the effect of differences in software. In addition to using the Jaszczak phantom as an overall test pattern, measurements were made of spatial resolution, energy resolution, contrast, variations of sensitivity and uniformity with angle, etc. Results indicated that some systems, with a high resolution collimator and after very careful setting up, could achieve a spatial resolution of the order of 11mm, with good image quality. Not all commercially available systems performed as well. Strong indication was given of the need to improve spatial resolution, even at the expense of sensitivity, confirming the results from simulated tomographic data for various design compromises. Tests were also performed varying the energy window used. It was found that only very few system were capable of producing artefact free images with other than a symmetric photopeak window. However, very significant improvement of image quality of current systems with respect to older systems were noted. This protocol has been used, in addition, to establish a routine quality assurance program for such SPECT systems

238

Rotational multiphoton endoscopy with a 1 ?m fiber laser system  

Science.gov (United States)

We present multiphoton microendoscopy with a rotational probe and a 1 ?m fiber-based femtosecond laser. The rotational probe is based on a double-clad photonic crystal fiber, a gradient index lens, a microprism, and a rotational microelectronicmechanical system (MEMS) motor. The MEMS motor has a diameter of 2.2 mm and can provide 360° full-view rotation. The fiber laser provides ultrashort pulses with a central wavelength at 1.034 ?m and a repetition rate of 50 MHz. Second-harmonic-generation images of rat-tail tendon and fish scale are demonstrated with the rotational probe-based multiphoton system. PMID:19649060

Liu, Gangjun; Xie, Tuqiang; Tomov, Ivan V.; Su, Jianping; Yu, Lingfeng; Zhang, Jun; Tromberg, Bruce J.; Chen, Zhongping

2009-01-01

239

Diagnostic system based on vibration measurement for rotating machines  

International Nuclear Information System (INIS)

Large-scale electric power plants have a number of rotating machines which occupy important positions in the plant system. Therefore, respective users assign several countermeasures to improve their reliability and availability. Especially, the maintenance of rotating machines for efficient operation as well as the promotion and strengthening of precautions for safety have now become system requirements. In the above context, we have developed a machinery diagnostic system for rotating machinery, fully utilizing the experience and technology that we have so for developed. This paper introduces the various diagnostic systems for rotating machines. (author)

240

Availability and residual effect of rock phosphate on crop rotation rice mungbean using isotope techniques  

International Nuclear Information System (INIS)

The experiment was conducted to study the availability and the residual effect of rock phosphate on crop performance under the rice-mungbean crop sequence. Ratchaburi (RRP) and Lamphun (LRP) rock phosphates were used to compare with triple superphosphate (TSP) at rate of 500 mg P/pot for TSP and 5000 mg P/pot for for two rock phosphates (R P). Upland rice (Sew Majun) was planted in three soils; Pakchong, Yasothorn and Lamnarai with the application of TSP and R P. 32 P - labelled TSP at 50 mg P was used as the standard in each treatment with factorial in RCB plot design. Mungbean was the succeeding crop after rice harvesting. Results showed that maximum dry weight yield was obtained from TSP application for all soil series, following by RRP and LRP respectively. The dry matter yields for all sources of phosphate application were the highest in Pakchong soil and lower in Yasothorn and Lamnarai soils respectively. The percent phosphorus derived form fertilizer (% Pdff) which obtained from 32 P dilution method was 13% average in TSP treatment for all three soils while R P treatment gave 7%. The utilization of P was the highest in TSP treatment average 2-4% (11.21 mg P) of applied P. Percent utilization obtained from RRP treatments average 0.02-0.38% (1-19 mg P) of applied P for all three soils, while LRP gave lowest % P utilization average 0.04-0.36% (2-18 mg P) of applied P. The residual P effect to mungbean succeeding crop showed that R P were superior than TSP. Dry matter yield from RRP was maximum for all soils. The % Pdff in mungbean was average 23% in TSP treatment and 35-37% from RRP and LRP from all soils. Pakchong soil gave lowest % Pdff. The % Pdff of Yasothorn and Lamnarai soils were nearly the same. The utilization from residual of TSP treatment was average 3-5% (14-25 mg P) of applied P. The residual of LRP to mungbean were average 0.4-1% (19-41 mg P) of applied P

 
 
 
 
241

SELF BALANCING SYSTEM FOR ROTATING MECHANISMS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Se presenta el análisis de un sistema de autobalance el cual utiliza bolas libres de movimiento rotando con el rotor que será balanceado. Se usa la ecuación de Lagrange para derivar un sistema de ecuaciones no lineales para un sistema autónomo con respecto a un sistema de coordenadas polares. De las [...] ecuaciones de movimiento, se obtienen ecuaciones linealizadas variacionalmente y posiciones de equilibrio por el método de perturbación. A causa de la resistencia al movimiento, la excentricidad y el movimiento de los cuerpos libres que son provocados por la influencia de vibraciones externas, hace imposible obtener un balanceo completo. Basado en el método variacional, se investiga el comportamiento dinámico del sistema en la frontera de la posición de equilibrio. Los resultados del análisis de estabilidad proveen los requerimientos de diseño para el sistema de autobalance. Abstract in english A self balancing system analysis is presented which utilizes freely moving balancing bodies (balls) rotating in unison with a rotor to be balanced. Using Lagrange´s Equation, we derive the non-linear equations of motion for an autonomous system with respect to the polar coordinate system. From the e [...] quations of motion for the autonomous system, the equilibrium positions and the linear variational equations are obtained by the perturbation method. Because of resistance to motion, eccentricity of race over which the balancing bodies are moving and the influence of external vibrations, it is impossible to attain a complete balance. Based on the variational equations, the dynamic stability of the system in the neighborhood of the equilibrium positions is investigated. The results of the stability analysis provide the design requirements for the self balancing system.

Marco Antonio, Meraz; Andrés, Yánez; Carlos, Jiménez; Raúl, Pichardo.

242

SELF BALANCING SYSTEM FOR ROTATING MECHANISMS  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: English Abstract in spanish Se presenta el análisis de un sistema de autobalance el cual utiliza bolas libres de movimiento rotando con el rotor que será balanceado. Se usa la ecuación de Lagrange para derivar un sistema de ecuaciones no lineales para un sistema autónomo con respecto a un sistema de coordenadas polares. De las [...] ecuaciones de movimiento, se obtienen ecuaciones linealizadas variacionalmente y posiciones de equilibrio por el método de perturbación. A causa de la resistencia al movimiento, la excentricidad y el movimiento de los cuerpos libres que son provocados por la influencia de vibraciones externas, hace imposible obtener un balanceo completo. Basado en el método variacional, se investiga el comportamiento dinámico del sistema en la frontera de la posición de equilibrio. Los resultados del análisis de estabilidad proveen los requerimientos de diseño para el sistema de autobalance. Abstract in english A self balancing system analysis is presented which utilizes freely moving balancing bodies (balls) rotating in unison with a rotor to be balanced. Using Lagrange´s Equation, we derive the non-linear equations of motion for an autonomous system with respect to the polar coordinate system. From the e [...] quations of motion for the autonomous system, the equilibrium positions and the linear variational equations are obtained by the perturbation method. Because of resistance to motion, eccentricity of race over which the balancing bodies are moving and the influence of external vibrations, it is impossible to attain a complete balance. Based on the variational equations, the dynamic stability of the system in the neighborhood of the equilibrium positions is investigated. The results of the stability analysis provide the design requirements for the self balancing system.

Marco Antonio, Meraz; Andrés, Yánez; Carlos, Jiménez; Raúl, Pichardo.

2005-08-01

243

Stress field rotation or block rotation: An example from the Lake Mead fault system  

Science.gov (United States)

The Coulomb criterion, as applied by Anderson (1951), has been widely used as the basis for inferring paleostresses from in situ fault slip data, assuming that faults are optimally oriented relative to the tectonic stress direction. Consequently if stress direction is fixed during deformation so must be the faults. Freund (1974) has shown that faults, when arranged in sets, must generally rotate as they slip. Nur et al., (1986) showed how sufficiently large rotations require the development of new sets of faults which are more favorably oriented to the principal direction of stress. This leads to the appearance of multiple fault sets in which older faults are offset by younger ones, both having the same sense of slip. Consequently correct paleostress analysis must include the possible effect of fault and material rotation, in addition to stress field rotation. The combined effects of stress field rotation and material rotation were investigated in the Lake Meade Fault System (LMFS) especially in the Hoover Dam area. Fault inversion results imply an apparent 60 degrees clockwise (CW) rotation of the stress field since mid-Miocene time. In contrast structural data from the rest of the Great Basin suggest only a 30 degrees CW stress field rotation. By incorporating paleomagnetic and seismic evidence, the 30 degrees discrepancy can be neatly resolved. Based on paleomagnetic declination anomalies, it is inferred that slip on NW trending right lateral faults caused a local 30 degrees counter-clockwise (CCW) rotation of blocks and faults in the Lake Mead area. Consequently the inferred 60 degrees CW rotation of the stress field in the LMFS consists of an actual 30 degrees CW rotation of the stress field (as for the entire Great Basin) plus a local 30 degrees CCW material rotation of the LMFS fault blocks.

Ron, Hagai; Nur, Amos; Aydin, Atilla

1990-01-01

244

Velvetbean and Bahiagrass as Rotation Crops for Management of Meloidogyne spp. and Heterodera glycines in Soybean  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Soybean (Glycine max) yield often is limited by the phytoparasitic nematodes Meloidogyne spp. and Heterodera glycines in the southeastern United States. We studied the effects of rotation with bahiagrass (Paspalum notatum), velvetbean (Mucuna pruiens), or continuous soybean, aldicarb, and soybean cultivar on yield and population densities in two fields infested with a mixture of Meloidogyne spp. and H. glycines. Velvetbean and bahiagrass reduced population levels of both nematode species to n...

Weaver, D. B.; Rodri?guez-ka?bana, R.; Carden, E. L.

1998-01-01

245

Problems Associated with Crop Rotation for Management of Pratylenchus penetrans on Easter Lily  

Digital Repository Infrastructure Vision for European Research (DRIVER)

In Humboldt and Del Norte counties of California and Curry County, Oregon, Easter lilies (Lilium longiflotum) are grown commercially in a 3- to 6-year rotation with pasture for cattle and sheep. Bulbs are sold to greenhouse operations to produce flowering plants. The lesion nematode, Pratylenchus penetrans, is a serious detriment to Easter lily production. Both soil and planting stock are often infested; typically, a dual nematicide application is used consisting of a preplant soil fumigation...

Westerdahl, B. B.; Giraud, D.; Etter, S.; Riddle, L. J.; Anderson, C. A.

1998-01-01

246

Evaluación de la macrofauna del suelo en rotaciones cultivos-pasturas con laboreo convencional / Evaluation of soil macrofauna in crop-pasture rotations with conventional tillage  

Scientific Electronic Library Online (English)

Full Text Available SciELO Mexico | Language: Spanish Abstract in spanish Los invertebrados que habitan el suelo son actores importantes en los procesos edáficos. La fauna edáfica comprende a organismos con tamaños y estrategias adaptativas diferentes. Los de mayor tamaño, constituyen la macrofauna (ancho del cuerpo mayor a 2 mm), que se destaca porque directa o indirecta [...] mente afectan las propiedades del suelo. Las comunidades presentes son la consecuencia de las prácticas de manejo de suelo que se realizan, por lo que tienen gran potencial de uso como indicadores. Este trabajo tuvo como objetivo evaluar el efecto de diferentes sistemas de rotación cultivos-pasturas sobre las comunidades de la macrofauna del suelo. Los tratamientos evaluados fueron: agricultura continua sin (S1) y con fertilización (S2), rotación agricultura 33% - pradera 66% (S4), rotación agricultura 50% - pradera 50% (S5), y rotación agricultura 66% - pradera 33% (S7). El número de individuos varió de acuerdo a la intensidad de los usos del suelo evaluados. Los tratamientos S1 y S4 tuvieron respectivamente, las menores y mayores densidades poblacionales de la mayoría de los taxones. El análisis de Co-Inercia entre las propiedades edáficas y la densidad fue significativo. El primer eje ordenó los usos del suelo de acuerdo a su intensidad. Los taxones Oligochaeta y Coleoptera adultos estuvieron asociados a S4, sistema con mayor cantidad de carbono orgánico y nitrógeno total. La evaluación de la macrofauna del suelo conjuntamente con las propiedades del mismo, es una herramienta útil para evaluar la sustentabilidad ambiental de los distintos usos del suelo. Abstract in english Soil-inhabiting invertebrates play an important role in soil processes. Soil fauna include organisms of diverse sizes and adaptive strategies. Macrofauna, large organisms with body width greater than 2 mm, influence soil properties, both directly and indirectly. Their communities are influenced by s [...] oil management and thus, have a great potential as bioindicators. The objective of this study was to evaluate the effect of different crop-pasture rotations on soil macrofauna. Treatments included continuous agriculture without (S1) and with (S2) fertilization, 33% crop - 66% pasture rotation (S4), 50% crop-pasture rotation (S5), and 66% crop - 33% pasture rotation (S7). The number of organisms collected varied with land use intensity; treatments S1 and S4 had the lowest and highest population densities for most taxa, respectively. The Co-Inertia analysis between soil properties and population density was significant. The first axis ordered land uses in relation to its intensity. Oligochaeta and Coleoptera adults were associated with S4, the system with highest organic carbon and total nitrogen contents. The evaluation of soil macrofauna together with soil properties is a useful tool to assess land use sustainability.

María Stella, ZERBINO.

247

Yield of cotton/cowpea and sunflower/cowpea crop rotation systems during the reclamation process of a saline-sodic soil / Produtividade de sistemas de rotação algodão/ feijão-de-corda e girassol/ feijão-de-corda durante o processo de recuperação de um solo salino-sódico  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese O objetivo deste trabalho foi avaliar o uso de subsolagem, gesso agrícola e matéria orgânica, associados ao cultivo de algodão, girassol e feijão-de-corda em sistemas de rotação, visando à recuperação e o aproveitamento de um solo salino-sódico. Os tratamentos foram dispostos em um delineamento em b [...] locos casualizados, em parcelas subdivididas, com quatro repetições, durante dois ciclos. As parcelas foram formadas pelos tratamentos: T1. Subsolagem (S); T2. S + 20 Mg ha-1 de gesso (G); T3. S + 40 Mg ha-1 de matéria orgânica (MO); T4. S + 10 Mg ha-1 de G + 20 Mg ha-1 de MO; T5. S + 20 Mg ha-1 de G + 40 Mg ha-1 de MO, e as subparcelas corresponderam às rotações culturais algodão feijão-de-corda (AL/FC) e girassol feijão-de-corda (GI/FC). O emprego dos corretivos contribuiu para a diminuição dos níveis de salinidade e sodicidade do solo. O algodão não apresentou nenhuma resposta à aplicação dos tratamentos, enquanto a cultura do girassol foi favorecida pela aplicação de corretivos apenas no segundo ciclo. As maiores produtividades do feijão-de-corda no tratamento T5, no ciclo de 2009/2010, são indicativos de que as maiores doses de gesso e de matéria orgânica aplicadas neste tratamento aceleraram o processo de recuperação. Para os demais tratamentos com corretivos, verificou-se efeito benéfico para essa cultura apenas no segundo ciclo de produção, quando os valores se igualaram ao T5. Abstract in english The objective of this study was to evaluate the use of subsoiling, gypsum and organic matter associated with the cultivation of cotton, sunflower and cowpea in crop rotation, seeking the reclamation and use of a saline-sodic soil. The treatments were arranged in a randomized block design in split pl [...] ots with four replications, during two crop cycles (2009/2010 and 2010/2011). The plots were formed by the treatments: T1. Subsoiling (S); T2. S + 20 Mg ha-1 of gypsum; T3. S + 40 Mg ha-1 of organic matter; T4. S + 10 Mg ha-1 of gypsum + 20 Mg ha-1 of organic matter; T5. S + 20 Mg ha-1 of gypsum + 40 Mg ha-1 of organic matter and the sub-plots consisted of the cotton-cowpea (C/CP) and sunflower-cowpea (S/CP) crop rotation. The use of gypsum and organic matter contributed to decrease the soil salinity and sodicity. Cotton was not affected by the treatments, while the sunflower crop was favored by the application of amendments only in the second production cycle. Higher yields of cowpea in T5 treatment, during the 2009/2010 cycle, are indicative that higher doses of gypsum and organic matter applied in this treatment accelerate the reclamation process. For other treatments with amendment application there was a beneficial effect for this crop only in the second cycle, when the values of productivity were similar to T5.

Carlos H. C. de, Sousa; Claudivan F. de, Lacerda; Francisco L. B. da, Silva; Antonia L. R., Neves; Raimundo N. T., Costa; Hans R., Gheyi.

2014-10-01

248

Shear flow instabilities in a rotating system  

Science.gov (United States)

Instabilities of viscous shear flows in a fluid layer rotating about a vertical axis were investigated. Two basic states were considered: (1) a baroclinic linear shear flow, which is associated with an imposed horizontal temperature gradient, and (2) double Ekman layers, which are produced by the relative motion of the two horizontal boundaries. Two instability mechanisms are present in this system, the inflection point mode and the symmetric mode. The linear theory of these instabilities is considered in the case baroclinic flow and Ekman layer flow. A Runge-Kutta shooting method was used in the numerical analysis. In special cases the nonlinear properties of the instabilites were studied. Finite amplitude disturbances in the form of rolls were investigated using the Galerkin technique. It was found that the existence of multiple solutions is a common feature. Moreover, finite amplitude disturbances can exist at Reynolds numbers lower than that predicted by the linear analysis. To test whether the finite amplitude rolls are realized, a stability analysis of the combined circulation was also performed.

Chen, W. L.

249

Wing shape and size of the western corn rootworm (Coleoptera: Chrysomelidae) is related to sex and resistance to soybean-maize crop rotation.  

Science.gov (United States)

The western corn rootworm, Diabrotica virgifera virgifera LeConte, is a major pest of maize in the United States and more recently, Europe. Understanding the dispersal dynamics of this species will provide crucial information for its management. This study used geometric morphometric analysis of hind wing venation based on 13 landmarks in 223 specimens from nine locations in Illinois, Nebraska, Iowa, and Missouri, to assess whether wing shape and size differed between rotated and continuously grown maize where crop rotation-resistant and susceptible individuals are found, respectively. Before assessing differences between rotation-resistant and susceptible individuals, sexual dimorphism was investigated. No significant difference in wing (centroid) size was found between males and females; however, females had significantly different shaped (more elongated) wings compared with males. Wing shape and (centroid) size were significantly larger among individuals from rotated maize where crop-rotation resistance was reported; however, cross-validation of these results revealed that collection site resistance status was an only better than average predictor of shape in males and females. This study provides preliminary evidence of wing shape and size differences in D. v. virgifera from rotated versus continuous maize. Further study is needed to confirm whether wing shape and size can be used to track the movement of rotation-resistant individuals and populations as a means to better inform management strategies. PMID:24020261

Mikac, K M; Douglas, J; Spencer, J L

2013-08-01

250

Gut bacteria facilitate adaptation to crop rotation in the western corn rootworm.  

Science.gov (United States)

Insects are constantly adapting to human-driven landscape changes; however, the roles of their gut microbiota in these processes remain largely unknown. The western corn rootworm (WCR, Diabrotica virgifera virgifera LeConte) (Coleoptera: Chrysomelidae) is a major corn pest that has been controlled via annual rotation between corn (Zea mays) and nonhost soybean (Glycine max) in the United States. This practice selected for a "rotation-resistant" variant (RR-WCR) with reduced ovipositional fidelity to cornfields. When in soybean fields, RR-WCRs also exhibit an elevated tolerance of antiherbivory defenses (i.e., cysteine protease inhibitors) expressed in soybean foliage. Here we show that gut bacterial microbiota is an important factor facilitating this corn specialist's (WCR's) physiological adaptation to brief soybean herbivory. Comparisons of gut microbiota between RR- and wild-type WCR (WT-WCR) revealed concomitant shifts in bacterial community structure with host adaptation to soybean diets. Antibiotic suppression of gut bacteria significantly reduced RR-WCR tolerance of soybean herbivory to the level of WT-WCR, whereas WT-WCR were unaffected. Our findings demonstrate that gut bacteria help to facilitate rapid adaptation of insects in managed ecosystems. PMID:23798396

Chu, Chia-Ching; Spencer, Joseph L; Curzi, Matías J; Zavala, Jorge A; Seufferheld, Manfredo J

2013-07-16

251

Convective Heat and Mass Transfer in Rotating Disk Systems  

CERN Document Server

The book describes results of investigations of a series of convective heat and mass transfer problems in rotating-disk systems, namely, over free rotating disks, under conditions of transient heat transfer, solid- body rotation of fluid, orthogonal flow impingement onto a disk, swirl radial flow between parallel co-rotating disks, in cone-disk systems and for Prandtl and Schmidt numbers larger than unity. Methodology used included integral methods, self-similar and approximate analytical solutions, as well as CFD. The book is aimed at the professional audience of academic researchers, industr

Shevchuk, Igor V

2009-01-01

252

Efeitos da rotação de culturas na incidência de podridões radiciais e na produtividade da soja / Effects of crop rotation on root rot incidence and on soybean grain yield  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Em experimentos conduzidos no campo, no sistema plantio direto, nas safras de verão de 2003/04, 2004/05 e 2005/06 foram avaliados os efeitos de culturas de inverno, da rotação e da monocultura sobre a emergência de plântulas, na incidência de podridões radiciais e no rendimento de grãos da soja. Dem [...] onstrou-se não haver efeitos das culturas de inverno sobre a emergência de plântulas da soja. Quanto à incidência de podridões radiciais em monocultura foi registrada uma intensidade de até 99,2%. O maior rendimento de grãos foi obtido na soja cultivada em rotação com uma safra com milho. Os fungos isolados do sistema radicial de plantas infectadas foram, Macrophomina phaseolina, Phomopsis sp., Fusarium spp. e Colletotrichum truncata. O solo da área experimental pode ser considerado supressivo aos fatores que reduzem a germinação, a emergência de plântulas e de morte de plântulas/plantas de soja. Quanto ao seu efeito em reduzir as podridões radiciais, ainda não se detectou efeito supressivo, porém a rotação da soja com o milho reduziu a incidência de podridões radiciais e aumentou o rendimento de grãos da soja. Abstract in english In experiments carried out in the field, under no-till planting system, in 2003/04, 2004/05 and 2005/06 summer growing seasons, the effects of winter crops, rotation and monoculture on seedling emergence, root rot incidence and soybean grain yield were assessed. There were no effects of winter crops [...] on soybean seedling emergence. As to root rot incidence on monoculture, an intensity of up to 99.2% was recorded. Grain yield was highest when soybean was cultivated in one season of rotation with corn. The fungi isolated from the root system of infected plants were Macrophomina phaseolina, Phomopsis sp., Fusarium spp. and Colletotrichum truncata. The soil at the experimental area can be considered suppressive to factors that reduce soybean germination, seedling emergence, and seedling/plant death. Considering its effect in reducing root rot, a suppressive action has not been detected yet; however, soybean rotation with corn reduced root rot incidence and increased soybean grain yield.

Erlei Melo, Reis; Marivane, Segalin; Nara Lucia, Moraes; Valeria Cecília, Ghissi.

2014-03-01

253

Prototype Geographic Information Systems Mapping of Crop Products Featured Local  

Directory of Open Access Journals (Sweden)

Full Text Available Local featured program in Indonesia cannot be separated entirely from commodity strategic bases. Until in 2006, agricultural development formulation showed indicative targets for featured crops commodity production. The problem of food security is forming of farmer’s independence to protect local resources in efficiently and optimally, so these resources can be more utilized. It can be achieved by assist of information technologies and communication in forming of Geographic Information System (GIS to support consistency of food security in Indonesia. This research designs prototype geographic information system in order to conduct the accurate mapping and to know the local featured crops production in Indonesia. This level is conducted for documentation and mapping of agricultural products which is the local featured production. This documentation requires the usage of potential physical, economic, social and cultural environment by the utilization of information technology and communication, which have the ability of relevancy and accessibility of reliable information.

Teddy Oswari

2013-06-01

254

How short rotation forest crops can be used for sustainable remediation of contaminated areas  

Energy Technology Data Exchange (ETDEWEB)

In large territories of the CIS, it becomes obvious from the factual consequences of the Chernobyl environmental contamination that no successful remediation actions can be achieved without considering realistic technical and economical issues. In these conditions, the Short Rotation Forestry concept for energy purposes is proposed as an alternative and integrated approach for the recovery of agricultural practices on waste farm land. This corrective option will be examined with respect to this ecological, economical, and social relevancy. Different aspects of the culture in contaminated areas and of energy production from biomass remain to be investigated, developed and validated in the light of radiation protection criteria. In particular, attention will be drawn on the opportunity of this new concept to be integrated in the development of the site remediation research activities at SCK.CEN.

Thiry, I.

1996-09-18

255

Functional biodiversity to improve pest control in organic cropping systems  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A sustainable use of functional agrobiodiversity (FAB) providing habitats with suitable floral resources is needed to conserve and improve pest control by natural enemies in organic cropping and other low-input systems. We present an overview on our activities identifying appropriate flowering plants in relation to the antagonists-pest complex and quantifying benefits and limits in lab- and field tests. We have focussed on the control of apple-aphids and cabbage lepidopterean pests in two org...

Pfiffner, Lukas; Scha?rer, Hans-jakob; Luka, Henryk

2013-01-01

256

Evapotranspiration and crop coefficient of poplar and willow short-rotation coppice used as vegetation filter.  

Science.gov (United States)

Ten-day evapotranspiration (ETc) and crop coefficient (k(c)) of willow and poplar SRC used as vegetation filter and grown under fertilised (F) and unfertilised (NF) conditions, were determined for two successive growing seasons using volumetric lysimeters. During the first growing season, total ETc observed was, respectively, 620 (NF)-1190 (F)mm in willow and 590 (NF)-725 (F) in poplar. During the second growing season, ETc showed a general increase, mainly in fertilised lysimeters where it ranged between 890 (NF)-1790 mm (F) in willow and 710 (NF)-1100 mm (NF) in poplar. kc reached in both years its maximum between the end of August and the beginning of September. In 2004 maximum kc ranged from 1.25-2.84 in willow and 1.06-1.90 in poplar, whereas in 2005 it ranged from 1.97-5.30 in willow and 1.71-4.28 in poplar. ETc seemed to be strongly correlated to plant development and mainly dependent on its nutritional status rather than on the differences between the species. PMID:17977718

Guidi, Werther; Piccioni, Emiliano; Bonari, Enrico

2008-07-01

257

The Controlled Ecological Life Support System Antarctic Analog Project: Prototype Crop Production and Water Treatment System Performance  

Science.gov (United States)

The Controlled Ecological Life Support System (CELSS) Antarctic Analog Project (CAAP), is a joint endeavor between the National Science Foundation, Office of Polar Programs (NSF-OPP) and the NASA. The fundamental objective is to develop, deploy, and operate a testbed of advanced life support technologies at the Amundsen-Scott South Pole Station that enable the objectives of both the NSF and NASA. The functions of food production, water purification, and waste treatment, recycle and reduction provided by CAAP will improve the quality of life for the South Pole inhabitants, reduce logistics dependence, enhance safety and minimize environmental impacts associated with human presence on the polar plateau. Because of the analogous technical, scientific, and mission features with Planetary missions such as a mission to Mars, CAAP provides NASA with a method for validating technologies and overall approaches to supporting humans. Prototype systems for sewage treatment, water recycle and crop production are being evaluated at Ames Research Center. The product water from sewage treatment using a Wiped-Film Rotating Disk is suitable for input to the crop production system. The crop production system has provided an enhanced level of performance compared with projected performance for plant-based life support: an approximate 50% increase in productivity per unit area, more than a 65% decrease in power for plant lighting, and more than a 75% decrease in the total power requirement to produce an equivalent mass of edible biomass.

Bubenheim, David L.; Flynn, Michael T.; Bates, Maynard; Schlick, Greg; Kliss, Mark (Technical Monitor)

1997-01-01

258

Nematode Numbers and Crop Yield in a Fenamiphos-Treated Sweet Corn-Sweet Potato-Vetch Cropping System  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Nematode population densities and yield of sweet corn and sweet potato as affected by the nematicide fenamiphos, in a sweet corn-sweet potato-vetch cropping system, were determined in a 5-year test (1981-85). Sweet potato was the best host of Meloidogyne incognita of these three crops. Fenamiphos 15G (6.7 kg a.i./ha) incorporated broadcast in the top 15 cm of the soil layer before planting of each crop increased (P ? 0.05) yields of sweet corn in 1981 and 1982 and sweet potato number 1 grad...

Johnson, A. W.; Dowler, C. C.; Glaze, N. C.; Chalfant, R. B.; Golden, A. M.

1992-01-01

259

PREVIOUS CROP AND NITROGEN FERTILIZATION ON CORN YIELD IN IRRIGATED NO TILLAGE SYSTEM  

Directory of Open Access Journals (Sweden)

Full Text Available Nitrogen is a nutrient that contributes positevely to corn productivity and is important, when planted in crop rotation associated with espécies vegetais que sejam capazes de contribuir para adição desse nutriente ao solo, que poderá ser disponibilizado para a cultura sucessora. This research was carried out at Experimental Nucleus of Agrarian Science of the Federal University of Mato Grosso do Sul, in 1998/99 crop season, in Dourados – MS. Experimental design used was randomized blocks in split plots with three replications. In plots the effect of black oat (Avena strigosa Schieb and Raphanus sativus L., var. oleiferus a Metzg and in subplots nitrogen doses (0; 60; 90 and 120 kg ha-1 as covering was applied in C-855 triple hybrid corn in irrigated no tillage system were evaluated. Previous crop and nitrogen doses did not influence stem diameter, plant height, ear index, ear length and diameter. Independent of nitrogen doses, corn sew after Raphanus sativus showed the greatest grain yield.

LUIZ CARLOS FERREIRA DE SOUZA

2003-12-01

260

Cropping Systems to Improve Carbon Sequestration for Mitigation of Climate Change  

Directory of Open Access Journals (Sweden)

Full Text Available The recent trend of an increase in the concentration of greenhouse gases (GHGs in the atmosphere has led to an ele-vated concern and urgency to adopt measures for carbon (C sequestration to mitigate the climate change. Among all GHGs, carbon dioxide (CO2 is the most important one which occurs in the greatest concentration and has the strong-est radiative forcing among all. Reducing the release of CO2 to the atmosphere through “green energy” technologies or fossil fuel energy alternatives, such as wind, solar and hydraulic energies, is a major challenge. However, removal of atmospheric CO2 by terrestrial ecosystems via C sequestration and converting the sequestered C into the soil organic C has provided a great opportunity for shifting GHG emission to mitigate the climate change. Soil is an ideal reservoir for storage of organic C since soil organic C has been depleted due to land misuse and inappropriate management through the long history. To optimize the efficiency of C sequestration in agriculture, cropping systems, such as crop rotation, intercropping, cover cropping, etc., play a critical role by influencing optimal yield, total increased C sequestered with biomass, and that remained in the soil. As matter of fact, soil C sequestration is a multiple purpose strategy. It restores degraded soils, enhances the land productivity, improves the diversity, protects the environment and reduces the enrichment of atmospheric CO2, hence shifts emission of GHGs and mitigates climate change.

Qingren Wang

2010-09-01

 
 
 
 
261

Phase considerations in a rotating system  

International Nuclear Information System (INIS)

A neutron interferometer in constant absolute rotation will exhibit a certain phase-shift between its two beams, a phenomenon shared with the classic Sagnac or Michelson-Gale-Pearson experiments or with the modern laser-gyrocompass composed of lasers in a ring. To first order in the rotational frequency, it is possible to understand by employing only rudimentary theory, the essence of this phenomenon to any degree of relativistiness of the participating particle. This paper is mainly paedagogical, noting the similarity due to permanent rotation between photon-, electron and neutron-interferometers. Future experimentation, aside from corroborating well believed tenets, may hope with improving precision to bring new approaches to measurement of fundamental effects

262

Thermodynamics in rotating systems -- analysis of selected examples  

CERN Document Server

We solve a set of selected exercises on rotational motion requiring a mechanical and thermodynamical analysis. When non-conservative forces or thermal effects are present, a complete study must use the first law of thermodynamics together with the Newton's second law. The latter is here better expressed in terms of an `angular' impulse-momentum equation (Poinsot-Euler equation), or, equivalently, in terms of a `rotational' pseudo-work-energy equation. Thermodynamical aspects in rotational systems, when e.g. frictional forces are present or when there is a variation of the rotational kinetic energy due to internal sources of energy, are discussed.

Güémez, Julio

2014-01-01

263

Demanda de tração em haste sulcadora na integração lavoura-pecuária com diferentes pressões de pastejo e sua relação com o estado de compactação do solo / Draft requirement in direct drilling in crop and cattle rotation systems using different grazing pressures and its relation to soil compactness status  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese Conduziu-se um experimento com integração lavoura-pecuária em Latossolo Vermelho distroférrico para avaliar o esforço de tração em hastes sulcadoras de adubo utilizadas em semeadura direta, atuando em diferentes profundidades e intensidades de pastejo, bem como o efeito desse último fator sobre o es [...] tado de compactação do solo. Os tratamentos principais foram constituídos pelas alturas da pastagem de inverno (aveia + azevém): 0,10; 0,20; 0,30 e 0,40 m e sem pastejo, obtidas variando-se a carga animal, e os tratamentos secundários foram duas profundidades de atuação da haste sulcadora de adubo: 0,12 e 0,15 m. A massa seca de raízes da pastagem, na camada de 0 a 0,12 m, aumentou com o incremento na intensidade de pastejo. Analisando os valores de resistência mecânica do solo à penetração, o efeito do pastejo foi detectado até 0,12 m, sendo crescentes com a intensidade de pastejo. A força de tração demandada pelas hastes aumentou de 1.900 para 4.300 N (120%), quando a profundidade de trabalho passou de 0,12 para 0,15 m. O esforço de tração nas hastes sulcadoras também foi maior quanto maior a carga de animais sobre a pastagem, embora as diferenças tenham sido significativas apenas entre os tratamentos sem pastejo e os mantidos a alturas de 0,10 e 0,20 m. Os valores de resistência do solo à penetração e de esforço de tração demandado pelas hastes sulcadoras apresentaram correlação significativa. Abstract in english An experiment was carried out with crop and cattle rotation in an Oxisoil, in Tupanciretã - RS, which aimed to evaluate the draft effort in fertilizer direct drillings used in direct seeding, working at different depths and intensities of fields under different grazing pressures. Grazing pressure ef [...] fects on soil compactness were also assessed. The main treatments were grazing maintaining 0.10, 0.20, 0.30, 0.40 m pasture (Lolium multiflorum + Avena strigosa) without grazing, height (adjusting the number of cows on the plots) and two working depths of fertilizer shanks: 0.12 m and 0.15 m. Root dry matter in the superficial layer (0.0 - 0.12 m) was increased when higher grazing pressures were used. Soil resistance to a penetrometer showed increased values at higher grazing pressures; it was detected until 0.12 m depth. Draft requirement of fertilizer shanks increased from 1,900 to 4,300 N (120%) when the working depth changed from 0.12 m to 0.15 m condition. Draft demand by fertilizer shanks was higher on soils under higher pressures as well, but the absolute values showed that only treatments with remaining heights of 0.10 and 0.20 m were different from those found without grazing systems. Soil resistance to penetrometer and power demand by fertilizer shanks was closely related.

Osmar, Conte; Renato, Levien; Carlos R., Trein; Carla T. C., Cepik; Henrique, Debiasi.

264

Demanda de tração em haste sulcadora na integração lavoura-pecuária com diferentes pressões de pastejo e sua relação com o estado de compactação do solo Draft requirement in direct drilling in crop and cattle rotation systems using different grazing pressures and its relation to soil compactness status  

Directory of Open Access Journals (Sweden)

Full Text Available Conduziu-se um experimento com integração lavoura-pecuária em Latossolo Vermelho distroférrico para avaliar o esforço de tração em hastes sulcadoras de adubo utilizadas em semeadura direta, atuando em diferentes profundidades e intensidades de pastejo, bem como o efeito desse último fator sobre o estado de compactação do solo. Os tratamentos principais foram constituídos pelas alturas da pastagem de inverno (aveia + azevém: 0,10; 0,20; 0,30 e 0,40 m e sem pastejo, obtidas variando-se a carga animal, e os tratamentos secundários foram duas profundidades de atuação da haste sulcadora de adubo: 0,12 e 0,15 m. A massa seca de raízes da pastagem, na camada de 0 a 0,12 m, aumentou com o incremento na intensidade de pastejo. Analisando os valores de resistência mecânica do solo à penetração, o efeito do pastejo foi detectado até 0,12 m, sendo crescentes com a intensidade de pastejo. A força de tração demandada pelas hastes aumentou de 1.900 para 4.300 N (120%, quando a profundidade de trabalho passou de 0,12 para 0,15 m. O esforço de tração nas hastes sulcadoras também foi maior quanto maior a carga de animais sobre a pastagem, embora as diferenças tenham sido significativas apenas entre os tratamentos sem pastejo e os mantidos a alturas de 0,10 e 0,20 m. Os valores de resistência do solo à penetração e de esforço de tração demandado pelas hastes sulcadoras apresentaram correlação significativa.An experiment was carried out with crop and cattle rotation in an Oxisoil, in Tupanciretã - RS, which aimed to evaluate the draft effort in fertilizer direct drillings used in direct seeding, working at different depths and intensities of fields under different grazing pressures. Grazing pressure effects on soil compactness were also assessed. The main treatments were grazing maintaining 0.10, 0.20, 0.30, 0.40 m pasture (Lolium multiflorum + Avena strigosa without grazing, height (adjusting the number of cows on the plots and two working depths of fertilizer shanks: 0.12 m and 0.15 m. Root dry matter in the superficial layer (0.0 - 0.12 m was increased when higher grazing pressures were used. Soil resistance to a penetrometer showed increased values at higher grazing pressures; it was detected until 0.12 m depth. Draft requirement of fertilizer shanks increased from 1,900 to 4,300 N (120% when the working depth changed from 0.12 m to 0.15 m condition. Draft demand by fertilizer shanks was higher on soils under higher pressures as well, but the absolute values showed that only treatments with remaining heights of 0.10 and 0.20 m were different from those found without grazing systems. Soil resistance to penetrometer and power demand by fertilizer shanks was closely related.

Osmar Conte

2007-04-01

265

Influence of Soil Tillage Systems on Soil Respiration and Production on Wheat, Maize and Soybean Crop  

Science.gov (United States)

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-UEFISCSU, project number PN II-RU 273/2010.

Moraru, P. I.; Rusu, T.

2012-04-01

266

Short rotation coppice culture of willows and poplars as energy crops on metal contaminated agricultural soils.  

Science.gov (United States)

Phytoremediation, more precisely phytoextraction, has been placed forward as an environmental friendly remediation technique, that can gradually reduce increased soil metal concentrations, in particular the bioavailable fractions. The aim of this study was to investigate the possibilities of growing willows and poplars under short rotation coppice (SRC) on an acid, poor, sandy metal contaminated soil, to combine in this way soil remediation by phytoextraction on one hand, and production of biomass for energy purposes on the other. Above ground biomass productivities were low for poplars to moderate for willows, which was not surprising, taking into account the soil conditions that are not very favorable for growth of these trees. Calculated phytoextraction efficiency was much longer for poplars than these for willows. We calculated that for phytoextraction in this particular case it would take at least 36 years to reach the legal threshold values for cadmium, but in combination with production of feedstock for bioenergy processes, this type of land use can offer an alternative income for local farmers. Based on the data of the first growing cycle, for this particular case, SRC of willows should be recommended. PMID:22046760

Ruttens, Ann; Boulet, Jana; Weyens, Nele; Smeets, Karen; Adriaensen, Kristin; Meers, Erik; Van Slycken, Stijn; Tack, Filip; Meiresonne, Linda; Thewys, Theo; Witters, Nele; Carleer, Robert; Dupae, Joke; Vangronsveld, Jaco

2011-01-01

267

Effects of Residue Management and Cropping Systems on Wheat Yield Stability in a Semiarid Mediterranean Clay Soil  

Directory of Open Access Journals (Sweden)

Full Text Available Agriculture is the single biggest user of land and water in Morocco; however its performances are still low due to high rainfall variation and rates of soil productivity depletion. Increasing concerns about soil and environment quality degradation have raised the need to review existing tillage management systems and develop new systems for seed-bed preparation. Consequently, No-tillage is found a promising practice of soil management to improve simultaneously soil quality and wheat production in semiarid Morocco. However, residue management under No-tillage was Not yet studied in conjunction with wheat rotation. Therefore, a field study was conducted in the semiarid Chaouia Plain of Morocco during the period from 1994 to 2003, in order to evaluate the impacts of different tillage practices (conventional tillage (CT, No-tillage (NT; No-tillage wheat residue management scenarios (total NTr, partial NTp and No-removal of residues NTm and crop rotations (continuous wheat (CW, Wheat-Fallow (WF, Wheat-Maize-Fallow (WMF, Wheat-Lentil-Fallow (WLF and Wheat-Barley-Fallow (WBF on wheat production. Over-years, conventional tillage system permitted lower yield of wheat while NT maintenance of crop residue at the surface is needed to increase it. Basically, NTp could be adopted in mixed crop-livestock systems of semiarid areas for the purpose of guarantying grain and feed. Wheat yields were the lowest under continuous wheat for all years. Wheat-fallow rotation is an important option in dry years or areas, while wheat-fallow-lentil or barley rotations are recommended in better environments. Stability analysis indicated that yields in the No-tillage system were less influenced by adverse growing conditions than conventional tillage system, particularly under low rainfall. These results indicate that improved soil quality under No-tillage enhanced wheat yield stability by reducing the impact of adverse growing conditions.

Rachid Mrabet

2011-06-01

268

Carbon sequestration in maize and grass dominant cropping systems in Flanders  

Science.gov (United States)

Sources of soil organic matter (SOM) input to the soil in agro-ecosystems are typically crop residues. The question arises how removing crop residues from a field influences soil carbon sequestration. We investigated four long-term maize and grass dominant cropping systems each with a different residue management. Under silage maize (SM) all stover is removed from the field and only a stubble remains, whereas under grain maize (GM) only the grains are harvested and all stover is returned to the soil. Fields with a history of at least 15 consecutive years of either SM (with or without a second annual crop of Italian ryegrass) or GM, and fields under permanent grass were selected from a geodatabase that covers 15 years of crop rotation for all of the ca. 500,000 agricultural fields in Flanders. For each cropping system 10 fields were sampled (40 in total) following the area-frame randomized soil sampling (AFRSS) protocol (Stolbovoy et al., 2007). For 6 out of 10 fields only the topsoil was sampled (0-30 cm), whereas for the 4 other fields both topsoil and subsoil (30-60 cm and 60-90 cm) were sampled. The total soil organic carbon (SOC) and nitrogen content and the stable carbon isotope ratio (13C/12C) were determined for each soil sample. From each field 1 topsoil sample was fractionated by the Zimmermann fractionation procedure (Zimmermann et al., 2007) which distinguishes between 5 different SOC fractions (POM, DOC, silt and clay associated SOC, chemically resistant SOC, SOC associated with sand fraction). Besides analysis of the SOC and nitrogen content of each fraction, the origin of the carbon was determined through isotope-ratio mass spectrometry. Although there was no significant difference between SM and GM regarding the total SOC stock for the upper 30 cm (ca. 75 à 80 Mg C.ha-1), fields under continuous GM contained in the 0-30 cm layer 60% more maize-derived C4-SOC as compared to fields under continuous SM (ca. 14 and 9 Mg C.ha-1 respectively). Significant differences could also be demonstrated for the carbon fractions of soils with different cropping histories. Each fraction of a GM-topsoil contained significantly more C4-SOC as compared to a SM-topsoil (with or without a second annual crop) with the sizes of the fractions being equal. The more labile POM- en DOC-fractions accounted for the biggest part of the maize C4-SOC detected in the bulk sample, whereas the silt and clay associated SOC and chemically resistant SOC consisted mainly out of old grass C3-SOC. For the deeper soil layers no significant differences could be demonstrated between GM and SM, neither for the total SOC stock nor for the C4-SOC stock. Our results suggest that the soils with maize cropping systems in Flanders are near carbon saturation, such that crop residue management does not influence the total amount, but rather the quality of the carbon sequestered. Stolbovoy, V., Montanarella, L., Filippi, N., Jones, A., Gallego, J., and Grassi, G. (2007). Soil sampling protocol to certify the changes of organic carbon stock in mineral soil of the European Union. Version 2. EUR 21576 EN/2. Office for Official Publications of the European Communities, Luxembourg. 56p. Zimmermann, M., Leifeld, J., Schmidt, M.W.I., Smith, P., and Fuhrer, J. (2007). Measured soil organic matter fractions can be related to pools in the RothC model. European Journal of Soil Science, 58: 658-667.

Van De Vreken, Philippe; Gobin, Anne; Merckx, Roel

2014-05-01

269

The impact of the long-term application of superphosphate as sulphur containing fertilizer on the yield of crops in the rotation  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Long-term field trials were carried out at the Lithuanian Institute of Agriculture in Dotnuva (Central Lithuania) during 1971-2004 on an Endocalcari - Endohypogleic Cambisol (CMg-n-w-can). The agrochemical characteristics demonstrated moderate contents of potassium and phosphorus, poor contents of available sulphur, the content of carbon ranged from 1.33 to 1.49 %. The aim of the study was to estimate the effects of sulphur containing fertilizer on the yield of crops in the Norfolk crop rotat...

Mas?auskas, Vytas; Mas?auskiene?, Audrone?

2005-01-01

270

ROMADIS - A rotating machinery diagnosis system  

International Nuclear Information System (INIS)

This paper describes the PC-based software package ROMADIS developed for the rotating machinery diagnosis. It contains advanced signal processing techniques for extracting multi-features from the time records and uses a modified decision tree technique for the knowledge acquisition, the knowledge representation and the failure diagnosis process. It is user-friendly programmed and the diagnostic results are very easy to be verified. (author). 5 refs, 3 figs

271

Effect of Cropping System and Contouring or Download Sowing on Soil Water Erosion under no Tillage  

Science.gov (United States)

Water erosion is the main responsible factor of soil and water losses, thus also causing soil degradation, especially on agricultural land, and it is also one factor of degradation outside the place of the origin of erosion. No tillage agriculture has been practiced in the last few decades for the purposes of water erosion control in various regions of Brazil. However, it has been shown that no tillage does not adequately control water erosion unless other complementary conservationist practices such as contour tillage or terracement. Although the erosion problem is widely recognized, there are still difficulties in estimating their magnitude, the environmental impact and the economic consequences, especially when it occurs in a conservation system like no tillage. The aim of this study was to quantify runoff and soil losses by water erosion under five different soil tillage treatments at Santa Catarina State, Southern Brazil. A field study was carried out using a rotating-boom rainfall simulator with 64 mmh-1 rainfall intensity for 90 minutes. Four rainfall tests were applied over the experimental period, one in each of the successive soybean and maize crop stages. Both soil cover by surface crop residue and soil cover by soybean and maize plant canopy were measured immediately before each rainfall test. Soil and water losses were smaller when sowing in contour than when sowing downslope. Contouring has promoted an average reduction of 42% in soil losses and 20% in water losses. Maize crop has promoted an average reduction of 19% in soil losses and 12% in water losses, in relation to the soybean crop. Therefore runoff rates and soil losses were higher in the downslope plots and in the soybean crop. Soil cover by previous crop residue was an important factor for reducing soil losses. Runoff rates were influenced by the soil water content before each rainfall test (R2= 0.78). The highest runoff occurred during the third simulated rainfall test, with the 83% of the total rain applied; immediately before the test the soil moisture was 36%. The smallest losses occurred in the fourth test, with 55% of the total rain applied where the soil moisture immediately before the rainfall test was 25%.

Marioti, J.; Padilha, J.; Bertol, I.; Barbosa, F. T.; Ramos, J. C.; Werner, R. S.; Vidal Vázquez, E.; Tanaka, M. S.

2012-04-01

272

IERS: International Earth Rotation and Reference Systems Service  

Science.gov (United States)

The International Earth Rotation and Reference Systems Service (IERS) was created to provide the astronomical, geodetic, and geophysical communities with standards, geophysical data, earth orientation parameters, and celestial and terrestrial reference systems. After discovering the structure and history of the Service, users can discover the many Product, Technique, and Combination Centres located throughout the world. The website provides a series of bulletins, technical notes, and annual reports. Visitors can learn about the measurement of irregularities in the earth's rotation and observation techniques.

273

An expert system for vibration based diagnostics of rotating machines  

International Nuclear Information System (INIS)

Very often changes in the mechanical condition of the rotating machinery can be observed as changes in its vibration. This paper presents an expert system for vibration-based diagnosis of rotating machines by describing the architecture of the developed prototype system. The importance of modelling the problem solving knowledge as well as the domain knowledge is emphasized by presenting the knowledge in several levels

274

New weed control strategies in maize considering narrow crop rotations with maize, greater ALSresistance in common weeds and application restrictions with regard to active substance  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Many herbicides with different HRAC-groups are available for weed control in maize. Because of narrow maize crop rotation summer weeds and warmth loving weeds are encouraged. On the other hand the new confirmed cases of an ALS target site resistance in the weed species Echinochloa crus-galli and Amaranthus retroflexus in Brandenburg, Stellaria media in Saxony and Matricaria recutita and Tripleurospermum perforatum in Brandenburg and Thuringia, warn that in the future the sulfonylureas must be...

Ewert, Katrin; Schro?der, Gerhard; Meinlschmidt, Ewa; Bergmann, Elke

2014-01-01

275

Efeitos do preparo do solo, plantio direto e de rotações de culturas sobre o rendimento e a economicidade do feijoeiro irrigado Agronomic effect of soil tillage, no-tillage and crop rotation on yield of irrigated common bean  

Directory of Open Access Journals (Sweden)

Full Text Available O objetivo deste trabalho foi identificar os efeitos de sistemas de preparo do solo e de rotações de culturas sobre o rendimento de grãos e economicidade da cultura do feijoeiro (Phaseolus vulgaris L. irrigado pelo sistema pivô central. O trabalho foi conduzido durante seis anos consecutivos, na Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, localizado no Município de Santo Antônio de Goiás, GO, em Latossolo Vermelho-Escuro, de textura argilosa. O experimento consistiu de um fatorial 4 x 6, em delineamento inteiramente casualizado, com parcelas subdivididas. Os sistemas de preparo do solo foram: P1 arado de aiveca (novembro-dezembro alternado com grade aradora (maio-junho; P2 arado de aiveca contínuo; P3 grade aradora contínua; P4 plantio direto; e as rotações de culturas: R1 arroz-feijão; R2 milho-feijão; R3 soja-trigo, R4 soja-trigo-soja-feijão-arroz-feijão; R5 arroz consorciado com calopogônio-feijão; e R6 milho-feijão-milho-feijão-arroz -feijão. As rotações R1, R2, R3 e R5 foram anuais, e as R4 e R6, trienais. Neste trabalho analisaram-se somente as rotações que continham feijão. O arroz, o milho e a soja foram semeados em novembro-dezembro (verão, e o feijão e o trigo, em maio-junho (inverno. Houve efeito do preparo do solo e das rotações de cultura sobre o rendimento de grãos do feijoeiro. A cultura produziu mais quando se utilizou no preparo do solo a combinação de arado de aiveca, nos cultivos de verão, e grade aradora nos de inverno. Os rendimentos do feijoeiro foram maiores quando a cultura foi implantada bienalmente na mesma área, nas rotações com arroz/calopogônio e arroz, e menores, nas rotações com milho. O feijoeiro irrigado, com relação ao preparo do solo e rotações de culturas, foi economicamente viável, propiciando taxas de retorno que variaram de 67% a 97%.The objective of this study was to evaluate the agronomic effect of soil tillage and crop rotation on grain yield of common bean (Phaseolus vulgaris L. irrigated by central pivot. The study was conducted at the Embrapa-Centro Nacional de Pesquisa de Arroz e Feijão, in a Dark-Red Latosol with clay texture, during six consecutive years. Basic experiment was a 4 x 6 factorial, having a completely randomized block design with subdivided plots. Soil tillage systems were: P1 moldboard plough (November-December, alternated with harrow disc (May-June; P2 moldboard plough; P3 harrow disc, and P4 no-tillage. The crop rotations used were: R1 rice-common bean; R2 corn-common bean; R3 soybean-wheat; R4 soybean-wheat-soybean-common bean-rice-common bean; R5 rice associated with Calopogonium mucunoides-common bean; and R6 corn-common bean-corn-common bean-rice-common bean. The crop rotations R1, R2, R3, and R5 were annual and R4 and R6 were triennial; in this study, only rotations with common bean were evaluated. Rice, corn and soybean were sown in November/December (summer and common bean and wheat in May/June (winter. Grain yield of common bean was influenced by soil tillage and crop rotation. Yield was higher under soil prepared with moldboard plough in combination with summer sowing and prepared with harrow disc in winter sowing. Common bean grain yield was higher when biannual sowing was done in the same area in rotation with rice/C. mucunoides and rice, and lower in rotation with corn. Irrigated common bean crop was economically viable as a function of soil tillage and crop rotation and economic return varied from 67% to 97%.

Pedro Marques da Silveira

2001-02-01

276

Magnetic nanofluids and magnetic composite fluids in rotating seal systems  

Energy Technology Data Exchange (ETDEWEB)

Recent results are presented concerning the development of magnetofluidic leakage-free rotating seals for vacuum and high pressure gases, evidencing significant advantages compared to mechanical seals. The micro-pilot scale production of various types of magnetizable sealing fluids is shortly reviewed, in particular the main steps of the chemical synthesis of magnetic nanofluids and magnetic composite fluids with light hydrocarbon, mineral oil and synthetic oil carrier liquids. The behavior of different types of magnetizable fluids in the rotating sealing systems is analyzed. Design concepts, some constructive details and testing procedures of magnetofluidic rotating seals are presented such as the testing equipment. The main characteristics of several magnetofluidic sealing systems and their applications will be presented: vacuum deposition systems and liquefied gas pumps applications, mechanical and magnetic nanofluid combined seals, gas valves up to 40 bar equipped by rotating seal with magnetic nanofluids and magnetic composite fluids.

Borbath, T; Borbath, I; Boros, T [Roseal Corporation, Nicolae Balcescu street, no. 5/A, Odorheiu Secuiesc, 535600 (Romania); Bica, D; Vekas, L [Lab. Magnetic Fluids, Center for Fundamental and Advanced Technical Research, Romanian Academy, Timisoara Division (LMF-CFATR-RATD) Mihai Viteazul Bvd., no. 24, Timisoara, 300223 (Romania); Potencz, I, E-mail: office@roseal.topnet.r [National Center for Engineering of Systems with Complex Fluids, University Politehnica Timisoara, Mihai Viteazul Bvd., no. 1, Timisoara, 300222 (Romania)

2010-08-15

277

Atributos químicos de um Cambissolo Húmico após 12 anos sob preparo convencional e semeadura direta em rotação e sucessão de culturas / Chemical properties of a Humic Dystrudept after 12 years under conventional and no tillage with crop succession and rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: Portuguese Abstract in portuguese O manejo adequado do solo é uma das bases para a sustentabilidade do sistema agrícola. O objetivo do estudo foi avaliar atributos químicos de um Cambissolo Húmico Alumínico após 12 anos em dois sistemas de preparo do solo, com rotação e sucessão de culturas. O experimento foi conduzido em Lages, SC, [...] utilizando preparo convencional (PC) e semeadura direta (SD), sob rotação (r) e sucessão (s) de culturas. O delineamento experimental foi inteiramente casualizado com quatro repetições. As sequências de cultivo foram: feijão-pousio-milho-pousio-soja-pousio no PCr; milho-pousio no PCs; feijão-aveia-milho-nabo-soja-ervilhaca na SDr; e milho-ervilhaca na SDs. As amostras de solo foram coletadas nas camadas 0-2,5; 2,5-5; 5-10; e 10-20cm. Avaliou-se carbono orgânico total (COT), cálcio, magnésio, alumínio trocável, fósforo, potássio, nitrogênio total (NT) e pH em água. A SD aumentou os teores de COT e nutrientes em comparação ao PC, especialmente na camada superficial do solo. O cultivo de milho e ervilhaca em sucessão aumentou os teores de COT e NT na camada superficial do solo em comparação com a rotação sob semeadura direta. Abstract in english Suitable soil management is one of the bases for sustainability in agricultural systems. The study aimed to evaluate chemical properties of a Humic Dystrudept for 12 years under two tillage systems, with crops rotation and succession. The experiment was carried out in Lages, SC, under conventional t [...] illage (CT) and no-till (NT), with rotation (r) and succession (s) cropping systems, using crop sequences of beans-fallow-maize-fallow-soybean in CTr; maize-fallow in CTs; beans-oats-maize-fodder radish-soybean-vetch in NTr; and maize-vetch in NTs. The experimental design was completely randomized with four replicates. The soil samples were collected in the layers 0-2.5, 2.5-5, 5-10 and 10-20cm. The variables assessed were total organic carbon (TOC), calcium, magnesium, exchangeable aluminum, phosphorus, potassium, total nitrogen (TN) and water pH. The no-tillage system increased TOC and nutrient levels in comparison with conventional tillage, especially in the surface soil layer. Maize and vetch crop succession had higher TOC and TN contents in the surface soil layer compared to crop rotation under no-tillage.

Andréia Patrícia, Andrade; Álvaro Luiz, Mafra; Cristiano Della, Picolla; Jackson Adriano, Albuquerque; Ildegardis, Bertol.

2012-05-01

278

Interacting galaxies: co-rotating and counter-rotating systems with tidal tails  

CERN Document Server

We analyse interacting galaxy pairs with evidence of tidal features in the Sloan Digital Sky Survey Data Release 7 (SDSS-DR7). The pairs were selected within $z<0.1$ by requiring a projected separation $r_p < 50 \\kpc$ and relative radial velocity $\\Delta V < 500 \\kms$. We complete spectroscopic pairs using galaxies with photometric redshifts considering $\\Delta V_{phot} < 6800 \\kms$, taking into account the mean photometric redshift uncertainty. We classify by visual inspection pairs of spirals into co-rotating and counter-rotating systems. For a subsample of non-AGN galaxies, counter-rotating pairs have larger star formation rates, and a higher fraction of young, star-forming galaxies. These effects are enhanced by restricting to $r_p < 12 \\kpc$. The distributions of $C$, $D_n(4000)$ and $(M_u-M_r)$ for AGN galaxies show that counter-rotating hosts have bluer colours and younger stellar population than the co-rotating galaxies although the relative fractions of Seyfert, Liner, Composite and Am...

Mesa, Valeria; Alonso, Sol; Coldwell, Georgina; Lambas, Diego G

2013-01-01

279

An ultrasonic system for weed detection in cereal crops.  

Science.gov (United States)

Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index) computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were assessed by discriminant analysis. The ultrasonic readings permitted the separation between weed infested zones and non-infested areas with up to 92.8% of success. This system will potentially reduce the cost of weed detection and offers an opportunity to its use in non-selective methods for weed control. PMID:23443401

Andújar, Dionisio; Weis, Martin; Gerhards, Roland

2012-01-01

280

An Ultrasonic System for Weed Detection in Cereal Crops  

Directory of Open Access Journals (Sweden)

Full Text Available Site-specific weed management requires sensing of the actual weed infestation levels in agricultural fields to adapt the management accordingly. However, sophisticated sensor systems are not yet in wider practical use, since they are not easily available for the farmers and their handling as well as the management practice requires additional efforts. A new sensor-based weed detection method is presented in this paper and its applicability to cereal crops is evaluated. An ultrasonic distance sensor for the determination of plant heights was used for weed detection. It was hypothesised that the weed infested zones have a higher amount of biomass than non-infested areas and that this can be determined by plant height measurements. Ultrasonic distance measurements were taken in a winter wheat field infested by grass weeds and broad-leaved weeds. A total of 80 and 40 circular-shaped samples of different weed densities and compositions were assessed at two different dates. The sensor was pointed directly to the ground for height determination. In the following, weeds were counted and then removed from the sample locations. Grass weeds and broad-leaved weeds were separately removed. Differences between weed infested and weed-free measurements were determined. Dry-matter of weeds and crop was assessed and evaluated together with the sensor measurements. RGB images were taken prior and after weed removal to determine the coverage percentages of weeds and crop per sampling point. Image processing steps included EGI (excess green index computation and thresholding to separate plants and background. The relationship between ultrasonic readings and the corresponding coverage of the crop and weeds were assessed using multiple regression analysis. Results revealed a height difference between infested and non-infested sample locations. Density and biomass of weeds present in the sample influenced the ultrasonic readings. The possibilities of weed group discrimination were assessed by discriminant analysis. The ultrasonic readings permitted the separation between weed infested zones and non-infested areas with up to 92.8% of success. This system will potentially reduce the cost of weed detection and offers an opportunity to its use in non-selective methods for weed control.

Dionisio Andújar

2012-12-01

 
 
 
 
281

Energy crops for biogas plants. Mecklenburg-Western Pomerania; Energiepflanzen fuer Biogasanlagen. Mecklenburg-Vorpommern  

Energy Technology Data Exchange (ETDEWEB)

For agriculturists in Mecklenburg-Western Pomerania (Federal Republic of Germany), the brochure under consideration provides recommendations on alternative crop rotation systems. With the help of these alternative cultivation systems, crop rotation with high yields in combination with high diversity, diversification and sustainability can be realized. Subsequently to the presentation of energy crops for the production of biogas, recommendations for the design of crop rotation are given. Other chapters of this booklet deal with ensilage and gas yields as well as the economics of energy crop cultivation.

Aurbacher, J.; Bull, I.; Formowitz, B. (and others)

2012-06-15

282

Effect of nitrogen fertilization and cover cropping systems on sorghum grain characteristics.  

Science.gov (United States)

Cover crop treatments and nitrogen (N) fertilization rates were investigated for their impact on sorghum grain quality attributes. Sorghum was planted in field plots treated with differing cover cropping systems and fertilization rates. The size (weight and diameter) and hardness of the kernels were influenced by both the cover crop and N rates. The protein content increased as the N rate increased and also with the addition of cover crops to the system. The protein digestibility values and starch granule size distributions were not affected by N rate or the cover cropping treatments. Soil properties were tested to determine relationships with grain quality attributes. The utilization of cover crops appears to increase the protein content without causing a deleterious effect on protein digestibility. The end-product quality is not hampered by the use of beneficial cropping systems necessary for sustainable agriculture. PMID:23705643

Kaufman, R C; Wilson, J D; Bean, S R; Presley, D R; Blanco-Canqui, H; Mikha, M

2013-06-19

283

Adaptive control of a rotating system  

Science.gov (United States)

In the present paper, an adaptive control of structural vibrations is presented. Based on earlier research, we claim that the periodical switching on of magneto-rheological controlled dampers results in the reduction of the amplitudes of vibrations more than does their permanent actuation. This statement, when applied to a moving load problem, was mathematically proved in earlier papers. In the present paper we determine the efficiency of such a control applied to a rotating shaft. The earlier mathematical analysis allows us to propose a control strategy. A finite element simulation together with the solution of the control problem shows that the dampers should act only during a short period of the highest displacements of the structure. The same conclusion is found in experimental tests. Although high frequency control with MR dampers is less efficient than in the theoretical investigations, we have found an amplitude reduction in the range of 10-20%.

Dyniewicz, Bart?omiej; Pr?gowska, Agnieszka; Bajer, Czes?aw I.

2014-02-01

284

Characteristics of Soil in Environment Friendly Rice-wheat Cropping System in Southern Korea  

Directory of Open Access Journals (Sweden)

Full Text Available A field experiment was conducted to compare soil microbial populations, microbial-N status and soil physical and chemical characteristics in a no-till, unfertilized, direct-sown, wheat-rice, relay-cropping system (NTWR and also in a conventional transplanted rice single cropping system (CTR. The wheat-rice system was imposed for 2, 4 and 7 years to identify the time course responses in the soil and crop. Recycling of crop residues in the wheat-rice cropping system generally increased the soil organic matter (OM contents but reduced the level of available P2O5 compared with the conventional system. Generally the soil was fertile with a high initial organic matter contents. Organic matter was increased by 30% during the 7 years of wheat-rice cropping. Other soil physical features, bulk density and permeability to air and water indicated that soil structure could be improved in response to wheat-rice cropping. Seasonal variability of soil microorganisms suggested that 7-year cropping could improve soil physicochemical characteristics but mineral contents in relation to cation exchange capacity (CEC would decrease after 4-years cropping. Soil tillage may adversely affect soil microbial dynamics. In conclusion, a no-till, unfertilized, direct-sown, wheat-rice cropping system, is likely to sustain grain yield by improving soil bio-physicochemical factors and is one of the most ecologically stable, economically sound and socially supportive wheat-rice production systems.

Y.S. Cho

2002-01-01

285

Diagnostic system based on vibration measurement for rotating machines  

International Nuclear Information System (INIS)

Large scale electric power plants are equipped with a number of the rotating machines which occupy important positions in the plant system. Therefore, respective users assign several countermeasure to improve their reliability and availability as well, among which the maintenance of such equipment for efficient operation as well as the promotion and strengthening of precautions for safety have now become system requirements. In the above context, we have developed a machinery diagnostic system for rotating machinery, fully utilizing the experience and technology that we have so far developed. This paper indroduces this machinery diagnostic system which was installed at the Tsuruga Nuclear Power Plant of Japan Atomic Power Company. (author)

286

Crop rotation biomass and arbuscular mycorrhizal fungi effects on sugarcane yield / Produção de biomassa e presença de fungos micorrízicos arbusculares em culturas utilizadas em rotação com a cana-de-açúcar  

Scientific Electronic Library Online (English)

Full Text Available SciELO Brazil | Language: English Abstract in portuguese Sugarcane (Saccharum spp.) is an important crop for sugar production and agro-energy purposes in Brazil. In the sugarcane production system after a 4- to 8-year cycle crop rotation may be used before replanting sugarcane to improve soil conditions and give an extra income. This study had the objecti [...] ve of characterizing the biomass and the natural colonization of arbuscular mycorrhizal fungi (AMF) of leguminous green manure and sunflower (Helianthus annuus L.) in rotation with sugarcane. Their effect on stalk and sugar yield of sugarcane cv. IAC 87-3396 grown subsequently was also studied. Cane yield was harvested in three subsequent cuttings. Peanut cv. IAC-Caiapó, sunflower cv. IAC-Uruguai and velvet bean (Mucuna aterrimum Piper and Tracy) were the rotational crops that resulted in the greater percentage of AMF. Sunflower was the specie that most extracted nutrients from the soil, followed by peanut cv. IAC-Tatu and mung bean (Vigna radiata L. Wilczek). The colonization with AMF had a positive correlation with sugarcane plant height, at the first cut (p = 0.01 and R = 0.52) but not with the stalk or cane yields. Sunflower was the rotational crop that brought about the greatest yield increase of the subsequent sugarcane crop: 46% increase in stalk yield and 50% in sugar yield compared with the control. Except for both peanut varieties, all rotational crops caused an increase in net income of the cropping system in the average of three sugarcane harvests. Abstract in english A cana-de-açúcar (Saccharum spp.) vem sendo cultivada no Brasil para produção de açúcar e agroenergia. Em seu sistema de produção, após um ciclo de 4 a 8 anos, é possível a rotação com plantas de cobertura, antes do seu replantio, para melhoria do solo e geração de renda. Estudou-se a caracterização [...] e produtividade de biomassa de leguminosas (como adubos-verdes) e girassol (Helianthus annuus L.), a ocorrência natural de micorrizas, o teor de açúcar e a produtividade em colmos da cana-de-açúcar IAC 87-3396 e a viabilidade econômica desse sistema com cultivo após as opções de rotação, com quantificação da produtividade durante três cortes consecutivos. O amendoim (Arachis hypogaea L.) cv. IAC-Caiapó, girassol cv. IAC-Uruguai e mucuna-preta (Mucuna aterrimum Piper and Tracy) foram as culturas que apresentaram maior percentagem de colonização por fungos micorrízicos. O girassol foi a planta de cobertura que mais extraiu nutrientes do solo, seguido por amendoim (Arachis hipogaea L.) cv. IAC-Tatu e feijão-mungo (Vigna radiata L. Wilczek). A colonização por fungos micorrízicos mostrou correlação positiva com a altura de plantas de cana no primeiro corte (p = 0,01 e R = 0,52), mas não se correlacionou com a produtividade de colmos ou açúcar. No primeiro corte, o girassol foi a cultura de rotação que ocasionou o maior aumento de produtividade, da ordem de 46% em colmos e de 50% na quantidade de açúcar, em comparação com a testemunha. Com exceção dos amendoins, todas as culturas em rotação aumentaram a renda líquida do sistema na média de três cortes de cana-de-açúcar.

Edmilson José, Ambrosano; Rozario, Azcón; Heitor, Cantarella; Gláucia Maria Bovi, Ambrosano; Eliana Aparecida, Schammass; Takashi, Muraoka; Paulo César Ocheuze, Trivelin; Fabrício, Rossi; Nivaldo, Guirado; Maria Regina Gonçalves, Ungaro; Juliana Rolim Salomé, Teramoto.

2010-12-01

287

Analysis and modelling of rotational systems with the Modyfit application  

Directory of Open Access Journals (Sweden)

Full Text Available Purpose: of this article is to present an application to analysis and modelling of rotational systems. Independent modules of application enables controlling and regulation of characteristics of systems in transportation. The base problem of analyzing systems in transportation is expressing the interaction between the main motion and local vibrations of subsystems.Design/methodology/approach: Mathematical models derived in previous articles were used to implement the mathematical models in numerical calculations. The objectives of creating the Modyfit application were connected with analyzing and modelling rotating systems with taking into account relations between major and local motions. Considerations were done by the Galerkin’s method.Findings: There are many effects of analyzing systems with rotation consideration. Main of them are connected with analyzing systems in function of increasing the value of angular velocity. In such way of analyzing we can observe creating additional poles in the dynamical characteristics and we can also observe that instead of modes there are created zeros.Research limitations/implications: Analyzed systems are simple linear homogeneous beams and rods. Working motion is limited to plane motion. Future research would consider complex systems, damping and nonlinearity.Practical implications: of the application are numerical analysis of beams and rods in rotational transportation and designing such systems. Thank to the Modyfit we can derived the stability zones of analyzed beams and rods and we can observe eigenfrequencies and zeros in function of angular velocity.Originality/value: The Modyfit is a forerunner implementation of derived models in a numerical environment of dynamical flexibility. Analyzing models are rotating flexible systems with consideration the rotational transportation effect.

S. ?ó?kiewski

2008-09-01

288

Soil Fungal Resources in Annual Cropping Systems and Their Potential for Management  

Science.gov (United States)

Soil fungi are a critical component of agroecosystems and provide ecological services that impact the production of food and bioproducts. Effective management of fungal resources is essential to optimize the productivity and sustainability of agricultural ecosystems. In this review, we (i) highlight the functional groups of fungi that play key roles in agricultural ecosystems, (ii) examine the influence of agronomic practices on these fungi, and (iii) propose ways to improve the management and contribution of soil fungi to annual cropping systems. Many of these key soil fungal organisms (i.e., arbuscular mycorrhizal fungi and fungal root endophytes) interact directly with plants and are determinants of the efficiency of agroecosystems. In turn, plants largely control rhizosphere fungi through the production of carbon and energy rich compounds and of bioactive phytochemicals, making them a powerful tool for the management of soil fungal diversity in agriculture. The use of crop rotations and selection of optimal plant genotypes can be used to improve soil biodiversity and promote beneficial soil fungi. In addition, other agronomic practices (e.g., no-till, microbial inoculants, and biochemical amendments) can be used to enhance the effect of beneficial fungi and increase the health and productivity of cultivated soils.

Esmaeili Taheri, Ahmad; Bainard, Luke D.; Yang, Chao; Navarro-Borrell, Adriana; Hamel, Chantal

2014-01-01

289

Soil fungal resources in annual cropping systems and their potential for management.  

Science.gov (United States)

Soil fungi are a critical component of agroecosystems and provide ecological services that impact the production of food and bioproducts. Effective management of fungal resources is essential to optimize the productivity and sustainability of agricultural ecosystems. In this review, we (i) highlight the functional groups of fungi that play key roles in agricultural ecosystems, (ii) examine the influence of agronomic practices on these fungi, and (iii) propose ways to improve the management and contribution of soil fungi to annual cropping systems. Many of these key soil fungal organisms (i.e., arbuscular mycorrhizal fungi and fungal root endophytes) interact directly with plants and are determinants of the efficiency of agroecosystems. In turn, plants largely control rhizosphere fungi through the production of carbon and energy rich compounds and of bioactive phytochemicals, making them a powerful tool for the management of soil fungal diversity in agriculture. The use of crop rotations and selection of optimal plant genotypes can be used to improve soil biodiversity and promote beneficial soil fungi. In addition, other agronomic practices (e.g., no-till, microbial inoculants, and biochemical amendments) can be used to enhance the effect of beneficial fungi and increase the health and productivity of cultivated soils. PMID:25247177

Ellouze, Walid; Esmaeili Taheri, Ahmad; Bainard, Luke D; Yang, Chao; Bazghaleh, Navid; Navarro-Borrell, Adriana; Hanson, Keith; Hamel, Chantal

2014-01-01

290

Exact treatment of interacting bosons in rotating systems and lattices  

DEFF Research Database (Denmark)

Quantum systems of ultra-cold particles constitute a unique tool for studying the fundamental phenomena of physics in their purest and most isolated forms. Complicated dynamics are found even for few particles and to comprehend the features of systems with many particles, we must first understand these basic building blocks. In this dissertation we investigate few-particle behavior in rotating traps and optical lattices. These systems are both experimentally realizable and are used on a daily basis in quantum gas laboratories all over the world. At temperatures near absolute zero the quantum mechanical nature of particles dominate, resulting in a behavior fundamentally different from that of classical particles. In rotating systems this causes quantization of angular momentum which can lead to macroscopic vortices in rotating Bose-Einstein condensates. In optical lattices the atom becomes extended over several lattice points causing complicated many-body dynamics and phase transitions.

SØrensen, Ole SØe

2012-01-01

291

Control system for several rotating mirror camera synchronization operation  

Science.gov (United States)

This paper introduces a single chip microcomputer control system for synchronization operation of several rotating mirror high-speed cameras. The system consists of four parts: the microcomputer control unit (including the synchronization part and precise measurement part and the time delay part), the shutter control unit, the motor driving unit and the high voltage pulse generator unit. The control system has been used to control the synchronization working process of the GSI cameras (driven by a motor) and FJZ-250 rotating mirror cameras (driven by a gas driven turbine). We have obtained the films of the same objective from different directions in different speed or in same speed.

Liu, Ningwen; Wu, Yunfeng; Tan, Xianxiang; Lai, Guoji

1997-05-01

292

Incorporation of Green Manure Plants into Bean Cropping Systems Contribute to Root-Knot Nematode Suppression  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Green manure plants were evaluated to determine their suitability as rotation crops with common bean to suppress root-knot (Meloidogyne spp.) nematodes. They were also evaluated as soil amendments in nematode control. The plants were Calliandra calothyrsus, Canavalia ensiformis, Chenopodium quinoa, Crotalaria juncea, Desmodium uncinatum, Gliricidia sepium, Leucaena leucocephala, Mucuna pruriens, Tephrosia purpurea,...

Kimenju, J. W.; Kagundu, A. M.; Nderitu, J. H.; Mambala, F.; Mutua, G. K.; Kariuki, G. M.

2008-01-01

293

Mycotoxin occurrence and Aspergillus flavus soil propagules in a corn and cotton glyphosate-resistant cropping systems.  

Science.gov (United States)

The effects of cotton-corn rotation and glyphosate use on levels of soil-borne Aspergillus flavus, aflatoxin and fumonisin contamination in corn and cotton seed were determined during 2002-2005 in Stoneville, Mississippi (USA). There were four rotation systems (continuous cotton, continuous corn, cotton-corn and corn-cotton) for both glyphosate-resistant (GR) and non-GR cultivars-herbicide system arranged in a randomized complete block design with four replications. Aspergillus flavus populations in surface (5-cm depth) soil, sampled before planting (March/April), mid-season June) and after harvest (September), ranged from 1.47 to 2.99 log (10) cfu g(-1) soil in the four rotation systems. Propagules of A. flavus were higher in the continuous corn system compared to the continuous cotton system on three sample dates, and cotton rotated with corn decreased A. flavus propagules in three of nine sample dates. Propagules of A. flavus were significantly greater in plots with GR cultivars compared to non-GR cultivars in three samples. In cotton seed, aflatoxin and fumonisin levels were similar ( or = 20 microg kg(-1)) only in GR cultivar in 2004 and 2005. Fumonisin was higher in non-GR cultivar (4 mg kg(-1)) regardless of rotation in 2004; however, in 2002, 2003 and 2005, aflatoxin and fumonisin levels were similar regardless of rotation and glyphosate. These results indicate the potential for increased aflatoxin and fumonisin levels (1 of 4 years) in corn; however, climatic conditions encountered during this study did not allow for mycotoxin production. In laboratory incubation studies, fairly high concentrations of glyphosate were required to inhibit A. flavus growth; however no short-term effect of soil treatment with glyphosate on A. flavus populations were observed. These data suggest that altered populations of A. flavus or higher aflatoxin concentrations in corn grain were due to indirect effects of the GR cropping system. PMID:17917911

Reddy, K N; Abbas, H K; Zablotowicz, R M; Abel, C A; Koger, C H

2007-12-01

294

Influence of Rice Rotation Systems on Soil Nematode Trophic Groups in Arkansas  

Directory of Open Access Journals (Sweden)

Full Text Available The effects of crop rotation sequences and combinations on soil nematode populations were investigated. Tillage versus non-tillage treatments were applied to crop rotation sequences dominated by flooded rice in a split plot design. The rotated crops were rice, soybean, and corn, including a fallow for a total of eight rotation treatments. All nematode feeding groups were recovered i.e bacterial feeding-, fungal feeding-, plant feeding-, carnivorous-, and omnivorous- nematodes. A total of 24 nematode genera in 20 families were identified and categorized into their respective trophic groups and colonizer persister (cp values. All rotations that included soybean significantly (P<0.05 or numerically increased soil nematode populations, irrespective of trophic groups, while all rotations that included rice and corn, had a nematode reductive effect. No-tillage plots recorded significantly higher populations of the predatory nematodes. The effectiveness of a rotation sequence depends primarily on the crop species and secondarily on soil conditions e.g anaerobic.

Martin Moluwa Matute

2012-02-01

295

Crop heat stress in the context of Earth System modeling  

Science.gov (United States)

Siebert et al (2014 Environ. Res. Lett. 9 044012) suggest that crop models do not represent the effect of heat stress on crop yield adequately unless they apply such effect to sensitive phases in a crop’s growth cycle. Siebert et al focus particularly on the phase considered most sensitive for wheat yield in Germany, the time of anthesis. Siebert et al find that observed canopy rather than 2 m or ground temperature better quantifies the effect of heat stress during anthesis on wheat yield in Germany when evaluated against data from pot experiments under controlled conditions.

Levis, Samuel

2014-05-01

296

New portable sensor system for rotational seismic motion measurements  

International Nuclear Information System (INIS)

A new mechanical sensor system for recording the rotation of ground velocity has been constructed. It is based on measurements of differential motions between paired sensors mounted along the perimeter of a rigid (undeformable) disk. The elementary sensors creating the pairs are sensitive low-frequency geophones currently used in seismic exploration to record translational motions. The main features of the new rotational seismic sensor system are flat characteristics in the wide frequency range from 1 to 200 Hz and sensitivity limit of the order of 10-8 rad/s. Notable advantages are small dimensions, portability, easy installation and operation in the field, and the possibility of calibrating the geophones in situ simultaneously with the measurement. An important feature of the instrument is that it provides records of translational seismic motions together with rotations, which allows many important seismological applications. We have used the new sensor system to record the vertical rotation velocity due to a small earthquake of ML=2.2, which occurred within the earthquake swarm in Western Bohemia in autumn 2008. We found good agreement of the rotation record with the transverse acceleration as predicted by theory. This measurement demonstrates that this device has a much wider application than just to prospecting measurements, for which it was originally designed.

297

A rotating liquid helium transfer system  

International Nuclear Information System (INIS)

This chapter demonstrates the successful operation of a stable transfer system suitable for fault worthy superconducting generators. A turbine type flowmeter for liquid helium has been developed and successfully operated. The transfer system was cooled to helium temperature and the transfer of liquid was initiated without any detectable pressure oscillations or surges. Transfer system losses were computed for subcooled, two-phase and superheated helium transfer and various mass flow rates up to 70 L/h. Transfer losses are shown to be a strong function of angular velocity, void fraction and mass flow rate. It is suggested that to minimize losses and oscillation a vapor separator should be used at the transfer system inlet to control void fraction in the transfer stream

298

[N2O emission from rice-rapeseed rotation system in Chengdu Plain of Sichun Basin].  

Science.gov (United States)

By using static chamber/gas chromatograph techniques, the N2O emission from rice-rapeseed rotation system in Chengdu Plain of Sichuan Basin was measured from June 2005 to June 2006, with its characteristics and affecting factors investigated. The results showed that the total emission of N2O in a rotation cycle was (8.3 +/- 2.8) kg x hm(-2) x a(-1), and the emission in rice season, rapeseed season and fallow season accounted for 30%, 65%, and 5% of the total, respectively. In rice season, the mean N2O flux was higher during alternative drainage and irrigation than during continuous flooding and drainage, and was roughly the same during continuous flooding and drainage. N application was the main driving factor for the appearance of N2O emission peak, and the lower moisture content in surface soil layer in rapeseed season and fallow season was the main cause inducing soil N2O absorption. Soil moisture, soil temperature, N application, and crop involvement affected the N2O emission to various extents, and soil moisture was the key factor affecting the N2O emission. To avoid the high frequency of dry and wet alternation in rice season or to regulate soil moisture content to a level of 50%-70% WFPS (percentage of water-filled pore space) in rapeseed season and fallow season could effectively decrease the N2O emission from the rice-rapeseed rotation system. PMID:18808020

Yu, Ya-Jun; Zhu, Bo; Wang, Xiao-Guo; Xiang, Hong-Yan; Zheng, Xun-Hua

2008-06-01

299

Effects of uniform rotational flow on predator-prey system  

Science.gov (United States)

Rotational flow is often observed in lotic ecosystems, such as streams and rivers. For example, when an obstacle interrupts water flowing in a stream, energy dissipation and momentum transfer can result in the formation of rotational flow, or a vortex. In this study, I examined how rotational flow affects a predator-prey system by constructing a spatially explicit lattice model consisting of predators, prey, and plants. A predation relationship existed between the species. The species densities in the model were given as S (for predator), P (for prey), and G (for plant). A predator (prey) had a probability of giving birth to an offspring when it ate prey (plant). When a predator or prey was first introduced, or born, its health state was assigned an initial value of 20 that subsequently decreased by one with every time step. The predator (prey) was removed from the system when the health state decreased to less than zero. The degree of flow rotation was characterized by the variable, R. A higher R indicates a higher tendency that predators and prey move along circular paths. Plants were not affected by the flow because they were assumed to be attached to the streambed. Results showed that R positively affected both predator and prey survival, while its effect on plants was negligible. Flow rotation facilitated disturbances in individuals’ movements, which consequently strengthens the predator and prey relationship and prevents death from starvation. An increase in S accelerated the extinction of predators and prey.

Lee, Sang-Hee

2012-12-01

300

Rotating solid radiative coolant system for space nuclear reactors  

Energy Technology Data Exchange (ETDEWEB)

The RING power system described in this paper is proposed as a primary or emergency heat rejection system for advanced space reactor power applications. The system employs a set of four (4) counter-rotating, 90 degree offset, coolant-carrying rings. The rings (segmented, corrugated, finned, thin-walled pipes, filled with liquid lithium) pass through a cavity heat exchanger and reradiate the absorbed heat to the space environment. 25 refs., 6 figs., 3 tabs.

Apley, W.J.; Babb, A.L.

1988-05-01

 
 
 
 
301

Emergy Assessment of a Wheat-Maize Rotation System with Different Water Assignments in the North China Plain  

Science.gov (United States)

Sustainable water use is seriously compromised in the North China Plain (NCP) due to the huge water requirements of agriculture, the largest use of water resources. An integrated approach which combines the ecosystem model with emergy analysis is presented to determine the optimum quantity of irrigation for sustainable development in irrigated cropping systems. Since the traditional emergy method pays little attention to the dynamic interaction among components of the ecological system and dynamic emergy accounting is in its infancy, it is hard to evaluate the cropping system in hypothetical situations or in response to specific changes. In order to solve this problem, an ecosystem model (Vegetation Interface Processes (VIP) model) is introduced for emergy analysis to describe the production processes. Some raw data, collected by investigating or observing in conventional emergy analysis, may be calculated by the VIP model in the new approach. To demonstrate the advantage of this new approach, we use it to assess the wheat-maize rotation cropping system at different irrigation levels and derive the optimum quantity of irrigation according to the index of ecosystem sustainable development in NCP. The results show, the optimum quantity of irrigation in this region should be 240-330 mm per year in the wheat system and no irrigation in the maize system, because with this quantity of irrigation the rotation crop system reveals: best efficiency in energy transformation (transformity = 6.05E + 4 sej/J); highest sustainability (renewability = 25%); lowest environmental impact (environmental loading ratio = 3.5) and the greatest sustainability index (Emergy Sustainability Index = 0.47) compared with the system in other irrigation amounts. This study demonstrates that application of the new approach is broader than the conventional emergy analysis and the new approach is helpful in optimizing resources allocation, resource-savings and maintaining agricultural sustainability.

Hu, Shi; Mo, Xingguo; Lin, Zhonghui; Qiu, Jianxiu

2010-10-01

302

Emergy assessment of a wheat-maize rotation system with different water assignments in the north China plain.  

Science.gov (United States)

Sustainable water use is seriously compromised in the North China Plain (NCP) due to the huge water requirements of agriculture, the largest use of water resources. An integrated approach which combines the ecosystem model with emergy analysis is presented to determine the optimum quantity of irrigation for sustainable development in irrigated cropping systems. Since the traditional emergy method pays little attention to the dynamic interaction among components of the ecological system and dynamic emergy accounting is in its infancy, it is hard to evaluate the cropping system in hypothetical situations or in response to specific changes. In order to solve this problem, an ecosystem model (Vegetation Interface Processes (VIP) model) is introduced for emergy analysis to describe the production processes. Some raw data, collected by investigating or observing in conventional emergy analysis, may be calculated by the VIP model in the new approach. To demonstrate the advantage of this new approach, we use it to assess the wheat-maize rotation cropping system at different irrigation levels and derive the optimum quantity of irrigation according to the index of ecosystem sustainable development in NCP. The results show, the optimum quantity of irrigation in this region should be 240-330 mm per year in the wheat system and no irrigation in the maize system, because with this quantity of irrigation the rotation crop system reveals: best efficiency in energy transformation (transformity = 6.05E + 4 sej/J); highest sustainability (renewability = 25%); lowest environmental impact (environmental loading ratio = 3.5) and the greatest sustainability index (Emergy Sustainability Index = 0.47) compared with the system in other irrigation amounts. This study demonstrates that application of the new approach is broader than the conventional emergy analysis and the new approach is helpful in optimizing resources allocation, resource-savings and maintaining agricultural sustainability. PMID:20812011

Hu, Shi; Mo, Xingguo; Lin, Zhonghui; Qiu, Jianxiu

2010-10-01

303

A WEB BASED TOMATO CROP EXPERT INFORMATION SYSTEM BASED ON ARTIFICIAL INTELLIGENCE AND MACHINE LEARNING ALGORITHMS  

Directory of Open Access Journals (Sweden)

Full Text Available Tomato is now the most widely grown vegetable crop in World. It is grown throughout the world in farm gardens, small home-gardens, and by market gardeners for fresh consumption as well as for processingpurposes. This Tomato crop expert advisory system is aimed at a collaborative venture with eminent Agriculture Scientist and Experts in the area of Tomato Plantation with an excellent team of computer Engineers, programmers and designers. This Expert System contains two main parts one is Tomato Information System and the other is Tomato Crop Expert System where in Information system, the user can get all the static information about different species, Diseases,Symptoms, chemical controls, Preventions, Pests, Virus of Tomato fruits and plants. In Advisory System, the user is having aninteraction with the expert system online; the user has to answer the questions asked by the Expert System. Depends on the response by the user the expert system decides the disease and displays its control measure of disease. This Tomato Crop Information Expert System deals with different varieties of Tomato Crop, Identification of various diseases generally occurs to tomato crop based on the symptoms.This Rule based Expert System validates the symptoms of the tomato crop using the techniques of ID3 Algorithm and some optimization algorithms. This is a Web based Expert System with java as the front end and SQL as the backend.

Prasad Babu M.S

2010-03-01

304

On the simplest binary system of rotating black holes  

International Nuclear Information System (INIS)

Exact axisymmetric stationary solution of the Einstein equations describing a system of two counter-rotating identical Kerr black holes is worked out in a physical parametrization within the framework of the Ernst formalism and analytically extended double-Kerr solution. The derivation of the limiting case of extreme constituents is also discussed.

305

Rotating Motion Control of Tethered Satellite Cluster Systems  

Science.gov (United States)

We propose the concept of Tethered Satellite Cluster Systems. The system consists of the satellites connected by tethers, and keeps and changes the formation with active tension/length control of the tether. The purpose of the system is the saving of the thruster fuel required for the coordinated mission and the improvement of the control precision, using tether tension. The system is applied to tethered service satellites, which perform the missions, for example an autonomic inspection, casting, capture, moorage and deorbit of an uncontrolled satellite. In this paper, we treat the rotating motion; satellites rotate on the center of the mass of the system with the formation in same plane. We establish the coordinated control method using tension and thrust. This control method can decrease the fuel consumption of the thruster, for utilizing the tether tension/torque equilibriums. It can also improve the control precision. Moreover, we establish the formation control method without thrust for the transition to the objective formation.

Mori, Osamu; Matunaga, Saburo

306

Influence of Soil Management on Water Retention from Saturation to Oven Dryness and Dominant Soil Water States in a Vertisol under Crop Rotation  

Science.gov (United States)

Unique water transfer and retention properties of Vertisols strongly affect their use in rainfed agriculture in water-limited environments. Despite the agricultural importance of the hydraulic properties of those soils, water retention data dryer than the wilting point are generally scarce, mainly as a result of practical constraints of traditional water retention measurement methods. In this work we provide a detailed description of regionalized water retention data from saturation to oven dryness, obtained from 54 minimally disturbed topsoil (0-0.05m) samples collected at a 3.5-ha experimental field in SW Spain where conventional tillage (CT) and direct drilling (DD) is compared in a wheat-sunflower-legume crop rotation on a Vertisol. Water retention was measured from saturation to oven dryness using sand and sand-kaolin boxes, a pressure plate apparatus and a dew point psychrometer, respectively. A common shape of the water retention curve (WRC) was observed in both tillage systems, with a strong discontinuity in its slope near -0.4 MPa and a decreasing spread from the wet to the dry end. A continuous function, consisting of the sum of a double exponential model (Dexter et al, 2008) and the Groenevelt and Grant (2004) model could be fitted successfully to the data. Two inflection points in the WRC were interpreted as boundaries between the structural and the textural pore spaces and between the textural and the intra-clay aggregate pore spaces. Water retention was significantly higher in DD (ptransitions between persistent wet and dry water content states. References Dexter, A.R., E.A. Czy?, G. Richard, A. Reszkowska, 2008. A user-friendly water retention function that takes account of the textural and structural pore spaces in soil. Geoderma, 143:243-253. Groenevelt, P.A., C.D. Grant, 2004. A new model for the soil-water retention curve that solves the problem of residual water contents. Eur. J. Soil Sci. 55:479-485.

Vanderlinden, Karl; Pachepsky, Yakov; Pederera, Aura; Martinez, Gonzalo; Espejo, Antonio Jesus; Giraldez, Juan Vicente

2014-05-01

307

The earth dynamic system: the earth rotation vs mantle convection  

Directory of Open Access Journals (Sweden)

Full Text Available The earth dynamic system is one of the key scientific questions on the earth science. The thermodynamic behavior and gravity force of the earth and the rheology nature of the mantle prove that mantle convection is the main power source leading the lithosphere to break and move. Yet the directivity of both the structures in the crust and plate movement reminds of the earth rotation. Here we demonstrate that the mantle convection and inertia force of the earth rotation affect each other, the former being the power source of lithosphere plate break and motion, and the latter determining the direction of the mantle convection and plate motion. The sense of plate motion depends on the mantle upwells, whose trends are controlled by the earth rotation. The geometric shapes of the plate boundaries can adjust the direction of plate movement.

Shuping Chen

2010-12-01

308

Experiences with a rotating gamma camera tomographic system  

International Nuclear Information System (INIS)

From a physical point of view all on emission CT system does is improve the angular sampling of an object at the expense of degrading the signal to noise ratio, since the counting time is reduced at all sample points. The constraints on ECAT systems are discussed in terms of a system such as the GE rotating gamma camera tomography system. The author considers the optimum number of angles sampled for present ECAT systems, the resolution which can be obtained, the sensitivity of an ECAT device and the contrast obtained with tomographic systems

309

Estrategias de fertilización fosforada en una rotación de cultivos en el sudeste bonaerense / Phosphorus fertilization strategies in a Buenos Aires southeast crop rotation  

Scientific Electronic Library Online (English)

Full Text Available SciELO Argentina | Language: Spanish Abstract in spanish En suelos del sudeste Bonaerense el fósforo (P) del fertilizante forma productos de mediana a alta solubilidad, lo cual le confiere un alto valor residual. A partir de esto, surge la posibilidad de definir estrategias de fertilización basadas en la frecuencia con que se efectúa su aplicación. Para r [...] otaciones de cuatro cultivos en tres años se desconoce el efecto de alternativas de fertilización fosfatada. Los objetivos fueron: 1) evaluar el rendimiento de cultivos fertilizados con P anualmente y cada tres años, a la rotación de cultivos, y 2) determinar la eficiencia de uso y de recuperación del P (EUP y ERP, respectivamente) aplicado para dichas estrategias de fertilización. El experimento se realizó sobre un complejo de Paleudol Petrocálcico y Argiudol Típico en la EEA I.N.T.A. Balcarce, con un alto nivel inicial de P-Bray (28,7 mg kg-1) y bajo siembra directa. A lo largo de dos ciclos de rotación, integrados por maíz, soja y trigo/soja de segunda, se evaluaron tres tratamientos: aplicación de P con frecuencia anual, por única vez a la rotación y un testigo sin P, en bloques completos aleatorizados con cuatro repeticiones. No se observaron diferencias en el rendimiento de los cultivos fertilizados en forma anual y a la rotación, durante los dos ciclos. El testigo difirió de los tratamientos fertilizados solo durante el segundo ciclo de rotación. La EUP de la rotación (EUProt) no difirió entre estrategias de aplicación (19,4 y 32,4 kg kg-1 durante el primer ciclo y 32,9 y 37,4 kg kg-1 durante el segundo, para tratamientos fertilizados anualmente y a la rotación, respectivamente). Tampoco existieron diferencias entre estrategias de fertilización en la EUP de cada cultivo. En cambio, durante el primer ciclo, la ERP resultó mayor para el tratamiento fertilizado a la rotación respecto de la aplicación anual (0,13 y 0,03 kg kg-1), mientras que en el segundo ciclo no se detectaron diferencias entre ambos (0,16 y 0,17 kg kg-1 para la aplicación anual y a la rotación, respectivamente). Se encontró una débil asociación entre la variación anual en el nivel de P-Bray y el balance de P correspondiente al cultivo implantado dicho año. Para el tratamiento testigo, se elaboró un modelo para predecir la disminución en el P disponible considerando el nivel inicial de P-Bray y la exportación de P de los cultivos como variables. Abstract in english In the soils of southeast Buenos Aires, fertilizer phosphorus (P) forms medium to high solubility products, making it possible to define different fertilization strategies based on application frequency. The effect of P application rates capable of fulfilling all crop requirements in intensive rotat [...] ions in the region is unknown. The objectives of this work were to: (1) assess yields in crops fertilized with P annually and once during the crop rotation and (2) determine P use efficiency and P recovery for each fertilization strategy. The experiment was conducted at the E.E.A. I.N.T.A. Balcarce on a Typic Argiudoll and Petrocalcic Paleudoll complex, under no-tillage and with high P-Bray (Bray & Kurts, 1945) content (28.7 mg kg-1). During the two rotation cycles for maize, soybean, and double wheat/soybean crop, three treatments were assessed: application of P annually, application once during the rotation cycle, and a control without P application. The experimental design was in randomized blocks with four repetitions. No crop yield differences were found between annual and rotation fertilization strategies across the two cycles evaluated. The control crop yield did not differ from the fertilized crop during the first rotation cycle but did during the second. The crop rotation P use efficiency (EUProt) did not differ between nutrient applications strategies (19.4 and 32.4 kg kg-1 during the first cycle and 32.9 and 37.4 kg kg-1 during the second for annually and rotation fertilized treatments respectively). There were no differences between strategies in the crop P use

Guillermo Adrián, Divito; Hernán, Sainz Rozas; Hernán Eduardo, Echeverría.

2010-07-01

310

In situ denitrification rates in shallow groundwater beneath a spring barley - mustard cover crop system  

Science.gov (United States)

Mustard catch crop has been reported to increase dissolved organic carbon (DOC) concentrations in groundwater, which can be used as an energy source for denitrifiers. This study investigates the impact of a mustard catch crop on in situ denitrification and nitrous oxide (N2O) emissions from an aquifer overlain by arable land. Denitrification rates and N2O-N/(N2O-N+N2-N) mole fractions were measured in situ with a push-pull method in shallow groundwater under a spring barley system in experimental plots with an without a mustard cover crop. The results suggest that a mustard cover crop could substantially enhance reduction of groundwater nitrate (NO3--N) via denitrification without significantly increasing N2O emissions. Mean total denitrification (TDN) rates below mustard cover crop and no cover crop were 7.61 and 0.002 µg kg-1 d-1, respectively. Estimated N2O-N/(N2O-N+N2-N) ratios, being 0.001 and 1.0 below mustard cover crop and no cover crop respectively, indicate that denitrification below mustard cover crop reduces N2O to N2, unlike the plot with no cover crop. The observed enhanced denitrification under the mustard cover crop may result from the higher groundwater DOC under mustard cover crop (1.53 mg L-1) than no cover crop (0.90 mg L-1) being added by the root exudates and root masses of mustard. This study gives insights into the missing piece in agricultural nitrogen (N) balance and groundwater derived N2O emissions under arable land.

Mofizur Rahman Jahangir, Mohammad; Minet, Eddy; Johnston, Paul; Coxon, Catherine; Richards, Karl

2014-05-01

311

Integrating livestock manure with a corn-soybean bioenergy cropping system improves short-term carbon sequestration rates and net global warming potential  

International Nuclear Information System (INIS)

Carbon cycling and the global warming potential (GWP) of bioenergy cropping systems with complete biomass removal are of agronomic and environmental concern. Corn growers who plan to remove corn stover as a feedstock for the emerging cellulosic ethanol industry will benefit from carbon amendments such as manure and compost, to replace carbon removed with the corn stover. The objective of this research was to determine the effect of beef cattle feedlot manure and composted dairy manure on short-term carbon sequestration rates and net global warming potential (GWP) in a corn-soybean rotation with complete corn-stover removal. Field experiments consisting of a corn-soybean rotation with whole-plant corn harvest, were conducted near East Lansing, MI over a three-year period beginning in 2002. Compost and manure amendments raised soil carbon (C) at a level sufficient to overcome the C debt associated with manure production, manure collection and storage, land application, and post-application field emissions. The net GWP in carbon dioxide equivalents for the manure and compost amended cropping systems was -934 and -784 g m-2 y-1, respectively, compared to 52 g m-2 y-1 for the non-manure amended synthetic fertilizer check. This work further substantiates the environmental benefits associated with renewable fuels and demonstrates that with proper management, the integration of livestock manures in biofuel cropping systems can enhanures in biofuel cropping systems can enhance greenhouse gas (GHG) remediation. (author)

312

PARÁMETROS HIDRÁULICOS DETERMINADOS EN UN ANDISOL BAJO DIFERENTES ROTACIONES CULTURALES DESPUÉS DE DIEZ AÑOS / Hydraulic parameters determinated in Andisol under different crop rotations after ten years  

Scientific Electronic Library Online (English)

Full Text Available SciELO Chile | Language: Spanish Abstract in spanish Los parámetros Hidráulicos fueron medidos en un suelo de origen volcánico del Valle Central (Humic Haploxerands) bajo diferentes rotaciones culturales con distinto manejo agronómico e intensidad de uso del suelo y fueron agrupadas en cuatro rotaciones que incluyeron pradera y dos rotaciones intensiv [...] as, sin pradera. Las mediciones de conductividad Hidráulica saturada (Kfs) fueron realizadas in-situ. Se determinaron, además, dos parámetros Hidráulicos del suelo: El parámetro á y el potencial de flujo mátrico (?m). Todas las parcelas con pradera, dentro de la rotación tuvieron valores similares de Kfs. Las parcelas con rotaciones intensivas presentaron valores extremos el mayor y menor valor de Kfs, donde la rotación: remolacha-trigo-frejol-cebada, presentó el mayor Kfs (P?0,05) de todos los tratamientos. Nuestros r