WorldWideScience

Sample records for ground cover crops

  1. Crop Ground Cover Fraction and Canopy Chlorophyll Content Mapping using RapidEye imagery

    Science.gov (United States)

    Zillmann, E.; Schonert, M.; Lilienthal, H.; Siegmann, B.; Jarmer, T.; Rosso, P.; Weichelt, T.

    2015-04-01

    Remote sensing is a suitable tool for estimating the spatial variability of crop canopy characteristics, such as canopy chlorophyll content (CCC) and green ground cover (GGC%), which are often used for crop productivity analysis and site-specific crop management. Empirical relationships exist between different vegetation indices (VI) and CCC and GGC% that allow spatial estimation of canopy characteristics from remote sensing imagery. However, the use of VIs is not suitable for an operational production of CCC and GGC% maps due to the limited transferability of derived empirical relationships to other regions. Thus, the operational value of crop status maps derived from remotely sensed data would be much higher if there was no need for reparametrization of the approach for different situations. This paper reports on the suitability of high-resolution RapidEye data for estimating crop development status of winter wheat over the growing season, and demonstrates two different approaches for mapping CCC and GGC%, which do not rely on empirical relationships. The final CCC map represents relative differences in CCC, which can be quickly calibrated to field specific conditions using SPAD chlorophyll meter readings at a few points. The prediction model is capable of predicting SPAD readings with an average accuracy of 77%. The GGC% map provides absolute values at any point in the field. A high R2 value of 80% was obtained for the relationship between estimated and observed GGC%. The mean absolute error for each of the two acquisition dates was 5.3% and 8.7%, respectively.

  2. Crop cover the principal influence on non-crop ground beetle (Coleoptera, Carabidae) activity and assemblages at the farm scale in a long-term assessment.

    Science.gov (United States)

    Eyre, M D; Sanderson, R A; McMillan, S D; Critchley, C N R

    2016-04-01

    Ground beetle data were generated using pitfall traps in the 17-year period from 1993 to 2009 and used to investigate the effects of changes in surrounding crop cover on beetle activity and assemblages, together with the effects of weather variability. Beetles were recorded from non-crop field margins (overgrown hedges). Crop cover changes explained far more variation in the beetle assemblages recorded than did temperature and rainfall variation. A reduction in management intensity and disturbance in the crops surrounding the traps, especially the introduction and development of willow coppice, was concomitant with changes in individual species activity and assemblage composition of beetles trapped in non-crop habitat. There were no consistent patterns in either overall beetle activity or in the number of species recorded over the 17-year period, but there was a clear change from assemblages dominated by smaller species with higher dispersal capability to ones with larger beetles with less dispersal potential and a preference for less disturbed agroecosystems. The influence of surrounding crops on ground beetle activity in non-crop habitat has implications for ecosystem service provision by ground beetles as pest predators. These results are contrary to conventional assumptions and interpretations, which suggest activity of pest predators in crops is influenced primarily by adjacent non-crop habitat. The long-term nature of the assessment was important in elucidation of patterns and trends, and indicated that policies such as agri-environment schemes should take cropping patterns into account when promoting management options that are intended to enhance natural pest control.

  3. Cover crops and N credits

    Science.gov (United States)

    Cover crops often provide many short- and long-term benefits to cropping systems. Legume cover crops can significantly reduce the N fertilizer requirement of non-legume cash crops that follow. The objectives of this presentation were to: I) educate stakeholders about the potential benefits of cover ...

  4. Intensity of Ground Cover Crop Arachis pintoi, Rhizobium Inoculation and Phosphorus Application and Their Effects on Field Growth and Nutrient Status of Cocoa Plants

    Directory of Open Access Journals (Sweden)

    John Bako Baon

    2006-08-01

    Full Text Available Arachis pintoiis potentially as a cover crop for cocoa (Theobroma cacaoL. farm, however information regarding its effect on the growth of cocoa plants in the field is very limited. The objective of this experiment is to investigate the combined influence of ground cover crop A. pintoi, rhizobial bacterial inoculation and phosphorus (P fertilizer on the growth of cocoa in the field and nutrient status. This experiment laid out in split-split plot design consisted of three levels of cover crop (without, A. pintoiand Calopogonium caeruleum, two levels of rhizobium inoculation (not inoculated and inoculated and two levels of phosphorus application (no P added and P added. The results showed that in field condition the presence of A. pintoias cover crop did not affect the growth of cocoa. On the other hand, C. caeruleumas cover crop tended to restrict cocoa growth compared to A. pintoi. Application of P increased leaf number of cocoa plant. Biomass production of A. pintoiwas 40% higher than C. caeruleum. Soil organic carbon and nitrogen contents were not affected by ground cover crops, though higher value (0.235% N and 1.63% organic C was obtained from combined treatments of inoculation and P addition or neither inoculation nor P addition. In the case of no rhizobium inoculation, soil N content in cocoa farm with A. pintoicover crop was lower than that of without cover crop or with C. caeruleum. Cover crop increased plant N content when there was no inoculation, on the other hand rhizobium inoculation decreased N content of cocoa tissue. Tissue P content of cocoa plant was not influenced by A. Pintoicover crop or by rhizobium inoculation, except that the P tissue content of cocoa was 28% higher when the cover crop was C. caeruleumand inoculated. Key words : Arachis pintoi, Theobroma cacao, Calopogonium caeruleum, rhizobium, nitrogen, phosphorus.

  5. High plains cover crop research

    Science.gov (United States)

    Some recent statements have been made about the benefits of growing cover crops in mixtures as compared with single-species plantings of cover crops. Those stated benefits have included greatly reduced water use, enhanced soil microbiological activity, increased biomass productivity, and enhanced wa...

  6. Midwest Cover Crops Field Guide

    Science.gov (United States)

    Producers who want to prevent soil erosion, improve nutrient cycling, sustain their soils, and protect/maintain the environment have been returning to a very old practice: planting cover crops. Cover crops are effective tools for reducing soil erosion and increasing nutrient recycling on farmlands, ...

  7. Cover crop biomass harvest for bioenergy: implications for crop productivity

    Science.gov (United States)

    Winter cover crops, such as rye (Secale cereale), are usually used in conservation agriculture systems in the Southeast. Typically, the cover crop is terminated two to three weeks before planting the summer crop, with the cover biomass left on the soil surface as a mulch. However, these cover crops ...

  8. Replacing fallow by cover crops: economic sustainability

    Science.gov (United States)

    Gabriel, José Luis; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Replacing fallow by cover crops in intensive fertilized systems has been demonstrated as an efficient tool for reducing nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of this new technology is still limited because they are either unwilling or unable, although adoption reluctance is frequently rooted in low economic profitability, low water se efficiency or poor knowledge. Economic analyses permit a comparison between the profit that farmers obtain from agricultural products and the cost of adopting specific agricultural techniques. The goal of this study was to evaluate the economic impact of replacing the usual winter fallow with cover crops (barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo)) in irrigated maize systems and variable Mediterranean weather conditions using stochastic Monte-Carlo simulations of key farms' financial performance indicators. The three scenarios studied for each cover crop were: i) just leaving the cover crop residue in the ground, ii) leaving the cover crop residue but reduce following maize fertilization according to the N available from the previous cover crop and iii) selling the cover crop residue for animal feeding. All the scenarios were compared with respect to a typical maize-fallow rotation. With observed data from six different years and in various field trials, looking for different weather conditions, probability distribution functions of maize yield, cover crop biomass production and N fertilizer saving was fitted. Based in statistical sources maize grain price, different forage prices and the cost of fertilizer were fitted to probability distribution functions too. As result, introducing a cover crop involved extra costs with respect to fallow as the initial investment, because new seed, herbicide or extra field operations. Additional

  9. Cover crops to improve soil health and pollinator habitat in nut orchards

    Science.gov (United States)

    Jerry. Van Sambeek

    2017-01-01

    Recently several national programs have been initiated calling for improving soil health and creating pollinator habitat using cover crops. Opportunities exist for nut growers to do both with the use of cover crops in our nut orchards. Because we can include perennial ground covers as cover crops, we have even more choices than landowners managing cover crops during...

  10. Managing cover crops: an economic perspective

    Science.gov (United States)

    Common reasons given by producers as to why they do not adopt cover crops are related to economics: time, labor, and cost required for planting and managing cover crops. While many of the agronomic benefits of cover crops directly relate to economics, there are costs associated with adopting the pra...

  11. The short term influence of aboveground biomass cover crops on C sequestration and β–glucosidase in a vineyard ground under semiarid conditions

    Directory of Open Access Journals (Sweden)

    Fernando Peregrina

    2014-10-01

    Full Text Available Tillage and semiarid Mediterranean climatic conditions accelerate soil organic matter losses in Spanish vineyards. Previous studies showed that cover crops can increase soil organic carbon (SOC in Mediterranean vineyards. The objectives of this study were to evaluate the influence of two different cover crops in the short term on soil C sequestration in a semiarid vineyard and to study the potential use of both β–glucosidase enzimatic activity (GLU and the GLU/SOC ratio in order to assess the SOC increase. The experiment was carried out in a cv. Tempranillo (Vitis vinifera L. vineyard on a Oxyaquic Xerorthent soil in Rioja winegrowing region (NE, Spain. The experimental design was established in 2009 with three treatments: conventional tillage; sown barley cover crop (Hordeum vulgare, L.; sown Persian clover cover crop (Trifolium resupinatum L.. Carbon in the aboveground biomass with each cover crop was monitored. Soil was sampled in June 2011 and June 2012, and SOC, GLU and the GLU/SOC ratio were determined. After 3 years both cover crops increased SOC at soil surface with C sequestration rates of 0.47 and 1.19 t C ha-1 yr-1 for BV and CV respectively. GLU and GLU/SOC ratio increased in both cover crops at 0-5 cm soil depth. The C sequestration rates and GLU were related to the cover crops aboveground biomass. In consequence, in semiarid vineyards under cover crops GLU could be an appropriate indicator to asses the increase of SOC and the soil quality improvement in the short-term (2-3 years.

  12. Use of Cover Crops in Hardwood Production

    Science.gov (United States)

    Randy Rentz

    2005-01-01

    Cover crops are as essential a practice in hardwood production as in pine production or any other nursery operation. Without proper cover crop rotation in a nursery plan, we open ourselves up to an array of problems: more diseases, wrong pH, more weeds, reduced fertility, and less downward percolation of soil moisture due, in part, to compaction....

  13. Winter cover crops influence Amaranthus palmeri establishment

    Science.gov (United States)

    Winter cover crops were evaluated for their effect on Palmer amaranth (PA) suppression in cotton production. Cover crops examined included rye and four winter legumes: narrow-leaf lupine, crimson clover, Austrian winter pea, and cahaba vetch. Each legume was evaluated alone and in a mixture with rye...

  14. Impact of no-till cover cropping of Italian ryegrass on above and below ground faunal communities inhabiting a soybean field with special emphasis on soybean cyst nematodes

    Science.gov (United States)

    Two field trials were conducted in Maryland to evaluate the ability of an Italian ryegrass (IR) (Lolium multiflorum) cover crop in a no-till soybean (Glycine max) planting to 1) reduce populations of plant-parasitic nematodes (i.e., the soybean cyst nematode, Heterodera glycines and lesion nematodes...

  15. Managing cover crops on strawberry furrow bottoms

    Science.gov (United States)

    Bare furrows in strawberry fields with plastic mulch covered beds can lead to lots of soil erosion and runoff during winter rainy periods. This article describes how growers can plant and manage cover crops in these furrows to minimize runoff and soil erosion. This is based on on-going research at...

  16. Water-saving ground cover rice production system reduces net greenhouse gas fluxes in an annual rice-based cropping system

    Directory of Open Access Journals (Sweden)

    Z. Yao

    2014-06-01

    Full Text Available To safeguard food security and preserve precious water resources, the technology of water-saving ground cover rice production system (GCRPS is being increasingly adopted for the rice cultivation. However, changes in soil water status and temperature under GCRPS may affect soil biogeochemical processes that control the biosphere–atmosphere exchanges of methane (CH4, nitrous oxide (N2O and carbon dioxide (CO2. The overall goal of this study is to better understand how net ecosystem greenhouse gas exchanges (NEGE and grain yields are affected by GCRPS in an annual rice-based cropping system. Our evaluation was based on measurements of the CH4 and N2O fluxes and soil heterotrophic respiration (CO2 emission over a complete year, as well as the estimated soil carbon sequestration intensity for six different fertilizer treatments for conventional paddy and GCRPS. The fertilizer treatments included urea application and no N fertilization for both conventional paddy (CUN and CNN and GCRPS (GUN and GNN, solely chicken manure (GCM and combined urea and chicken manure applications (GUM for GCRPS. Averaging across all the fertilizer treatments, GCRPS increased annual N2O emission and grain yield by 40% and 9%, respectively, and decreased annual CH4 emission by 69%, while GCRPS did not affect soil CO2 emissions relative to the conventional paddy. The annual direct emission factors of N2O were 4.01, 0.087 and 0.50% for GUN, GCM and GUM, respectively, and 1.52% for the conventional paddy (CUN. The annual soil carbon sequestration intensity under GCRPS was estimated to be an average of −1.33 Mg C ha−1 yr−1, which is approximately 44% higher than the conventional paddy. The annual NEGE were 10.80–11.02 Mg CO2-eq ha−1 yr−1 for the conventional paddy and 3.05–9.37 Mg CO2-eq ha−1 yr−1 for the GCRPS, suggesting the potential feasibility of GCRPS in reducing net greenhouse effect from rice cultivation. Using organic fertilizers for GCRPS

  17. Do cover crop mixtures have the same ability to suppress weeds as competitive monoculture cover crops?

    Directory of Open Access Journals (Sweden)

    Brust, Jochen

    2014-02-01

    Full Text Available An increasing number of farmers use cover crop mixtures instead of monoculture cover crops to improve soil and crop quality. However, only little information is available about the weed suppression ability of cover crop mixtures. Therefore, two field experiments were conducted in Baden-Württemberg between 2010 and 2012, to compare growth and weed suppression of monoculture cover crops and cover crop mixtures. In the first experiment, heterogeneous results between yellow mustard and the cover crop mixture occurred. For further research, a field experiment was conducted in 2012 to compare monocultures of yellow mustard and hemp with three cover crop mixtures. The evaluated mixtures were: “MELO”: for soil melioration; “BETA”: includes only plant species with no close relation to main cash crops in Central Europe and “GPS”: for usage as energy substrate in spring. Yellow mustard, MELO, BETA and GPS covered 90% of the soil in less than 42 days and were able to reduce photosynthetically active radiation (PAR on soil surface by more than 96% after 52 days. Hemp covered 90% of the soil after 47 days and reduced PAR by 91% after 52 days. Eight weeks after planting, only BETA showed similar growth to yellow mustard which produced the highest dry matter. The GPS mixture had comparatively poor growth, while MELO produced similar dry matter to hemp. Yellow mustard, MELO and BETA reduced weed growth by 96% compared with a no cover crop control, while hemp and GPS reduced weeds by 85% and 79%. In spring, weed dry matter was reduced by more than 94% in plots with yellow mustard and all mixtures, while in hemp plots weeds were only reduced by 71%. The results suggest that the tested cover crop mixtures offer similar weed suppression ability until spring as the monoculture of the competitive yellow mustard.

  18. feasibility of winter cover crop production under rainfed conditions in ...

    African Journals Online (AJOL)

    ACSS

    Low winter rainfall poses a challenge to production of high biomass from cover ... February planted cover crops had the lowest residues remaining at maize ..... Interaction effects of planting date and cover crop species on cover crop dry weight at termination in Eastern Cape ... to weed species density (per m2) at cover crop.

  19. Using cash cover crops to provide pollinator provisions

    Science.gov (United States)

    To date, the use of winter cover crops in MN and SD has been slow to be adopted. The short growing season and potential for late wet springs make cover crops risky to farmers with little economic return. The use of cash cover crops in this area offers the standard advantages of other cover crops, wi...

  20. Soybean growth and yield under cover crops

    Directory of Open Access Journals (Sweden)

    Priscila de Oliveira

    2013-04-01

    Full Text Available The use of cover crops in no-tillage systems can provide better conditions for the development of soybean plants with positive effects on grain yield and growth analysis techniques allow researchers to characterize and understand the behavior of soybean plants under different straw covers. Thus, the aim of this study was to characterize, using growth analysis, yield components and agronomic performance of soybean under common bean, Brachiaria brizantha and pearl millet straws. The experiment was performed on a soil under cerrado in the municipality of Santo Antônio de Goiás, GO. The experiment was arranged in a randomized complete block design with three treatments (cover crops and five replications. Soybean grain yield was lower in the B. brizantha straw treatment (3,708 kg ha-1 than both in the pearl millet (4.772 kg ha-1 and common bean straw treatments (5,200 kg ha-1. The soybean growth analysis in B. brizantha, pearl millet and common bean allowed characterizing the variation in the production of dry matter of leaves, stems, pods and total and leaf area index that provided different grain yields. The cover crop directly affects the soybean grain yield.

  1. Cover crops in cereals – better companions than weeds?

    OpenAIRE

    Salonen, Jukka; Zarina, Livija; Melander, Bo

    2016-01-01

    Cover crops have gained popularity in cereal cropping now that they are one of the subsidized options in agri-environmental schemes of the EU. Several studies on cover/catch crops affecting nutrient leaching have been published but less information is available concerning their applicability for weed management. In our opinion, combinations of crop and cover crop types as well as crop sequencing conform IPM principles and optimize weed management. The PRODIVA project (ERA-Net Core Organic Plu...

  2. Cover Crops Effects on Soil Chemical Properties and Onion Yield

    Directory of Open Access Journals (Sweden)

    Rodolfo Assis de Oliveira

    2016-01-01

    Full Text Available ABSTRACT Cover crops contribute to nutrient cycling and may improve soil chemical properties and, consequently, increase crop yield. The aim of this study was to evaluate cover crop residue decomposition and nutrient release, and the effects of these plants on soil chemical properties and on onion (Allium cepa L. yield in a no-tillage system. The experiment was carried out in an Inceptisol in southern Brazil, where cover crops were sown in April 2012 and 2013. In July 2013, shoots of weeds (WD, black oats (BO, rye (RY, oilseed radish (RD, oilseed radish + black oats (RD + BO, and oilseed radish + rye (RD + RY were cut at ground level and part of these material from each treatment was placed in litter bags. The litter bags were distributed on the soil surface and were collected at 0, 30, 45, 60, 75, and 90 days after distribution (DAD. The residues in the litter bags were dried, weighed, and ground, and then analyzed to quantify lignin, cellulose, non-structural biomass, total organic carbon (TOC, N, P, K, Ca, and Mg. In November 2012 and 2013, onion crops were harvested to quantify yield, and bulbs were classified according to diameter, and the number of rotted and flowering bulbs was determined. Soil in the 0.00-0.10 m layer was collected for chemical analysis before transplanting and after harvesting onion in December 2012 and 2013. The rye plant residues presented the highest half-life and they released less nutrients until 90 DAD. The great permanence of rye residue was considered a protection to soil surface, the opposite was observed with spontaneous vegetation. The cultivation and addition of dry residue of cover crops increased the onion yield at 2.5 Mg ha-1.

  3. Cover crops to improve soil health and pollinator habitat in nut orchards: Part II

    Science.gov (United States)

    Jerry. Van Sambeek

    2017-01-01

    Integrating cover crops into a nut orchard can have some unique benefits and problems not found when used cover crops during the fallow period between cash crops. Studies show ground covers can reduce hardwood tree growth anywhere from a few percent to more than 70 percent in the case of tall fescue. This means if it takes 3 years to put on one inch of diameter growth...

  4. Modeled conterminous United States Crop Cover datasets for 2000 - 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  5. Modeled conterminous United States Crop Cover datasets for 2001

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  6. Modeled conterminous United States Crop Cover datasets for 2002

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  7. Modeled conterminous United States Crop Cover datasets for 2004

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  8. Modeled conterminous United States Crop Cover datasets for 2013

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  9. Modeled conterminous United States Crop Cover datasets for 2012

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  10. Modeled conterminous United States Crop Cover datasets for 2011

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  11. Modeled conterminous United States Crop Cover datasets for 2006

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  12. Modeled conterminous United States Crop Cover datasets for 2009

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Crop cover maps have become widely used in a range of research applications. Multiple crop cover maps have been developed to suite particular research interests. The...

  13. The potential of cover crops for improving soil function

    Science.gov (United States)

    Stoate, Chris; Crotty, Felicity

    2017-04-01

    Cover crops can be grown over the autumn and winter ensuring green cover throughout the year. They have been described as improving soil structure, reducing soil erosion and potentially even a form of grass weed control. These crops retain nutrients within the plant, potentially making them available for future crops, as well as increasing soil organic matter. Over the last three years, we have investigated how different cover crop regimes affect soil quality. Three separate experiments over each autumn/winter period have investigated how different cover crops affect soil biology, physics and chemistry, with each experiment building on the previous one. There have been significant effects of cover crops on soil structure, as well as significantly lower weed biomass and increased yields in the following crop - in comparison to bare stubble. For example, the effect of drilling the cover crops on soil structure in comparison to a bare stubble control that had not been driven on by machinery was quantified, and over the winter period the soil structure of the cover crop treatments changed, with compaction reduced in the cover crop treatments, whilst the bare stubble control remained unchanged. Weeds were found in significantly lower biomass in the cover crop mixes in comparison to the bare stubble control, and significantly lower weed biomass continued to be found in the following spring oat crop where the cover crops had been, indicating a weed suppressive effect that has a continued legacy in the following crop. The following spring oats have shown similar results in the last two years, with higher yields in the previous cover crop areas compared to the bare stubble controls. Overall, these results are indicating that cover crops have the potential to provide improvements to soil quality, reduce weeds and improve yields. We discuss the economic implications.

  14. Cover Crop Chart: An Intuitive Educational Resource for Extension Professionals

    Science.gov (United States)

    Liebig, Mark A.; Johnson, Holly; Archer, David; Hendrickson, John; Nichols, Kristine; Schmer, Marty; Tanaka, Don

    2013-01-01

    Interest in cover crops by agricultural producers has increased the need for information regarding the suitability of crops for addressing different production and natural resource goals. To help address this need, staff at the USDA-ARS Northern Great Plains Research Laboratory developed a decision aid called the Cover Crop Chart (CCC). Visually…

  15. Cover crop effects on soil carbon and nitrogen under bioenergy sorghum crops

    Science.gov (United States)

    Cover crops can increase soil C and N storage and reduce the potential for N leaching under agronomic crops, but information on their benefits under bioenergy crops is scanty due to the removal of aboveground biomass. The objective of the study was to evaluate the effect of cover crops on soil organ...

  16. Winter Cover Crops and Nitrous Oxide Emissions in Early Spring

    Science.gov (United States)

    Morris, C. K.; Walter, M. T.; Reiss, E. R.

    2015-12-01

    Winter cover crops mixtures can be used to manage greenhouse gas (GHG) emissions during critical periods such as spring thaw. Legumes are added to cover crops mixtures to increase crop productivity, but it is unknown if this effect decreases N2O emissions. In this project we investigate the relationship between biodiversity, productivity and GHG fluxes in cover crops varieties typically grown for soil heath in agricultural systems. Surface GHG emissions were measured with closed chambers beginning during snowmelt events and continuing until crops were tilled into the soil in early summer. We found that nitrous oxide emissions were reduced in cover cropped plots during the early spring thaw period when compared to bare soil. GHG emission reductions in agriculture can be achieved with proper selection of winter hardy cover crops.

  17. Limited Impact of a Fall-Seeded, Spring-Terminated Rye Cover Crop on Beneficial Arthropods.

    Science.gov (United States)

    Dunbar, Mike W; Gassmann, Aaron J; O'Neal, Matthew E

    2017-04-01

    Cover crops are beneficial to agroecosystems because they decrease soil erosion and nutrient loss while increasing within-field plant diversity. Greater plant diversity within cropping systems can positively affect beneficial arthropod communities. We hypothesized that increasing plant diversity within annually rotated corn and soybean with the addition of a rye cover crop would positively affect the beneficial ground and canopy-dwelling communities compared with rotated corn and soybean grown without a cover crop. From 2011 through 2013, arthropod communities were measured at two locations in Iowa four times throughout each growing season. Pitfall traps were used to sample ground-dwelling arthropods within the corn and soybean plots and sweep nets were used to measure the beneficial arthropods in soybean canopies. Beneficial arthropods captured were identified to either class, order, or family. In both corn and soybean, community composition and total community activity density and abundance did not differ between plots that included the rye cover crop and plots without the rye cover crop. Most taxa did not significantly respond to the presence of the rye cover crop when analyzed individually, with the exceptions of Carabidae and Gryllidae sampled from soybean pitfall traps. Activity density of Carabidae was significantly greater in soybean plots that included a rye cover crop, while activity density of Gryllidae was significantly reduced in plots with the rye cover crop. Although a rye cover crop may be agronomically beneficial, there may be only limited effects on beneficial arthropods when added within an annual rotation of corn and soybean. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  18. Winter cover crops impact on corn production in semiarid regions

    Science.gov (United States)

    Cover crops have been proposed as a technique to increase soil health. This study examined the impact of winter brassica cover crop cocktails grown after wheat (Triticum aestivum) on corn yields; corn yield losses due to water and N stress; soil bacteria to fungi ratios; mycorrhizal markers; and ge...

  19. Cover crop-based ecological weed management: exploration and optimization

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one of the mai

  20. Cover crops use in agrosystems: Innovations and applications. Chapter 3

    NARCIS (Netherlands)

    Scholberg, J.M.S.; Dogliotti, S.; Zotarelli, L.; Cherr, C.M.; Leoni, C.; Rossing, W.A.H.

    2010-01-01

    Cover crops can reduce the dependence of farmers on agrochemicals while enhancing overall agrosystem’s performance. However, the inherent complexity of cover-crop-based systems hampers their adoption by conventional farmers. Therefore, special management skills and alternative research and technolog

  1. Fertilizer effects on a winter cereal cover crop

    Science.gov (United States)

    Benefits associated with conservation tillage in the Southeast are improved by using a winter cereal cover crop. In general, cover crop benefits increase as biomass production is increased, but the infertile soils typically require additional N (inorganic or organic). Currently, limited informatio...

  2. Herbicide and cover crop residue integration in conservation tillage tomato

    Science.gov (United States)

    The increased adoption of conservation tillage in vegetable production requires more information on the role of various cover crops in weed control, tomato quality, and yield. Three conservation-tillage systems utilizing crimson clover, turnip, and cereal rye as winter cover crops were compared to a...

  3. Cover crop-based ecological weed management: exploration and optimization

    NARCIS (Netherlands)

    Kruidhof, H.M.

    2008-01-01

    Keywords: organic farming, ecologically-based weed management, cover crops, green manure, allelopathy, Secale cereale, Brassica napus, Medicago sativa Cover crop-based ecological weed management: exploration and optimization. In organic farming systems, weed control is recognized as one of the

  4. Remote sensing to monitor cover crop adoption in southeastern Pennsylvania

    Science.gov (United States)

    Hively, Wells; Sjoerd Duiker,; Greg McCarty,; Prabhakara, Kusuma

    2015-01-01

    In the Chesapeake Bay Watershed, winter cereal cover crops are often planted in rotation with summer crops to reduce the loss of nutrients and sediment from agricultural systems. Cover crops can also improve soil health, control weeds and pests, supplement forage needs, and support resilient cropping systems. In southeastern Pennsylvania, cover crops can be successfully established following corn (Zea mays L.) silage harvest and are strongly promoted for use in this niche. They are also planted following corn grain, soybean (Glycine max L.), and vegetable harvest. In Pennsylvania, the use of winter cover crops for agricultural conservation has been supported through a combination of outreach, regulation, and incentives. On-farm implementation is thought to be increasing, but the actual extent of cover crops is not well quantified. Satellite imagery can be used to map green winter cover crop vegetation on agricultural fields and, when integrated with additional remote sensing data products, can be used to evaluate wintertime vegetative groundcover following specific summer crops. This study used Landsat and SPOT (System Probatoire d’ Observation de la Terre) satellite imagery, in combination with the USDA National Agricultural Statistics Service Cropland Data Layer, to evaluate the extent and amount of green wintertime vegetation on agricultural fields in four Pennsylvania counties (Berks, Lebanon, Lancaster, and York) from 2010 to 2013. In December of 2010, a windshield survey was conducted to collect baseline data on winter cover crop implementation, with particular focus on identifying corn harvested for silage (expected earlier harvest date and lower levels of crop residue), versus for grain (expected later harvest date and higher levels of crop residue). Satellite spectral indices were successfully used to detect both the amount of green vegetative groundcover and the amount of crop residue on the surveyed fields. Analysis of wintertime satellite imagery

  5. Cover Crop Biomass and Corn Yield Following 13 Rye, Wheat, and Triticale Cultivars Used as Winter Cover Crops

    Science.gov (United States)

    Winter cover crops have the potential to reduce nitrate leaching and erosion in corn-soybean rotations in the upper Midwest. The cover crop growing season between harvest and planting of corn and soybean, however, is short and cold. Additionally, previous studies in Iowa have indicated that winter r...

  6. Comparison of different cover crop mulches and extracts on inhibition of crop and weed growth

    Directory of Open Access Journals (Sweden)

    Sturm, Domonic Johannes

    2016-02-01

    Full Text Available Weed suppression of cover crops is a result of competition for light, space, water and nutrients and the release of allelochemicals in the soil. Two laboratory and greenhouse experiments were conducted to analyse biochemical effects of extracts and mulches of Fagopyrum tataricum (L. Gaertn., Raphanus sativus var. oleiformis Pers. and a cover crop mixture on germination and plant growth of the crop plants maize (Zea mays L. and sugar beet (Beta vulgaris ssp. vulgaris var. altissima Döll. and the weeds Chenopodium album L., Matricaria chamomilla L. and Stellaria media (L. Vill.. In the first experiment, aqueous cover crop extracts were applied on crop and weed seeds in germination assays. Germination rate, mean germination time and root length of crops and weeds were measured. In experiment 2, the influence of cover crop mulch on germination rate and dry weight of the test plants was determined after a period of 21 days. Significant reductions of the root length for all test plants were observed in experiment 1. Additionally, mean germination time was extended for crops and weeds by all cover crops. Germination rate and dry matter of crops and weeds were decreased significantly in experiment 2 compared to the untreated control. Root length, germination rate and mean germination time in germination tests in experiment 1 were found to be correlated with biomass of crops and weeds in experiment 2. This work reveals the important role of biochemical effects on weed suppression by cover crops.

  7. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    Science.gov (United States)

    Ladoni, Moslem; Kravchenko, Alexandra N; Robertson, G Phillip

    2015-01-01

    Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover) and non-leguminous (winter rye) cover crops on potentially mineralizable N (PMN) and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management in row-crop

  8. Topography Mediates the Influence of Cover Crops on Soil Nitrate Levels in Row Crop Agricultural Systems.

    Directory of Open Access Journals (Sweden)

    Moslem Ladoni

    Full Text Available Supplying adequate amounts of soil N for plant growth during the growing season and across large agricultural fields is a challenge for conservational agricultural systems with cover crops. Knowledge about cover crop effects on N comes mostly from small, flat research plots and performance of cover crops across topographically diverse agricultural land is poorly understood. Our objective was to assess effects of both leguminous (red clover and non-leguminous (winter rye cover crops on potentially mineralizable N (PMN and [Formula: see text] levels across a topographically diverse landscape. We studied conventional, low-input, and organic managements in corn-soybean-wheat rotation. The rotations of low-input and organic managements included rye and red clover cover crops. The managements were implemented in twenty large undulating fields in Southwest Michigan starting from 2006. The data collection and analysis were conducted during three growing seasons of 2011, 2012 and 2013. Observational micro-plots with and without cover crops were laid within each field on three contrasting topographical positions of depression, slope and summit. Soil samples were collected 4-5 times during each growing season and analyzed for [Formula: see text] and PMN. The results showed that all three managements were similar in their temporal and spatial distributions of NO3-N. Red clover cover crop increased [Formula: see text] by 35% on depression, 20% on slope and 32% on summit positions. Rye cover crop had a significant 15% negative effect on [Formula: see text] in topographical depressions but not in slope and summit positions. The magnitude of the cover crop effects on soil mineral nitrogen across topographically diverse fields was associated with the amount of cover crop growth and residue production. The results emphasize the potential environmental and economic benefits that can be generated by implementing site-specific topography-driven cover crop management

  9. The Use of Cover Crops as Climate-Smart Management in Midwest Cropping Systems

    Science.gov (United States)

    Basche, A.; Miguez, F.; Archontoulis, S.; Kaspar, T.

    2014-12-01

    The observed trends in the Midwestern United States of increasing rainfall variability will likely continue into the future. Events such as individual days of heavy rain as well as seasons of floods and droughts have large impacts on agricultural productivity and the natural resource base that underpins it. Such events lead to increased soil erosion, decreased water quality and reduced corn and soybean yields. Winter cover crops offer the potential to buffer many of these impacts because they essentially double the time for a living plant to protect and improve the soil. However, at present, cover crops are infrequently utilized in the Midwest (representing 1-2% of row cropped land cover) in particular due to producer concerns over higher costs and management, limited time and winter growing conditions as well as the potential harm to corn yields. In order to expand their use, there is a need to quantify how cover crops impact Midwest cropping systems in the long term and namely to understand how to optimize the benefits of cover crops while minimizing their impacts on cash crops. We are working with APSIM, a cropping systems platform, to specifically quantify the long term future impacts of cover crop incorporation in corn-based cropping systems. In general, our regional analysis showed only minor changes to corn and soybean yields (cover crop was or was not included in the simulation. Further, a "bad spring" scenario (where every third year had an abnormally wet/cold spring and cover crop termination and planting cash crop were within one day) did not result in any major changes to cash crop yields. Through simulations we estimate an average increase of 4-9% organic matter improvement in the topsoil and an average decrease in soil erosion of 14-32% depending on cover crop planting date and growth. Our work is part of the Climate and Corn-based Cropping Systems Coordinated Agriculture Project (CSCAP), a collaboration of eleven Midwestern institutions established

  10. Cover crops and crop residue management under no-till systems improve soils and environmental quality

    Science.gov (United States)

    Kumar, Sandeep; Wegner, Brianna; Vahyala, Ibrahim; Osborne, Shannon; Schumacher, Thomas; Lehman, Michael

    2015-04-01

    Crop residue harvest is a common practice in the Midwestern USA for the ethanol production. However, excessive removal of crop residues from the soil surface contributes to the degradation of important soil quality indicators such as soil organic carbon (SOC). Addition of a cover crop may help to mitigate these negative effects. The present study was set up to assess the impacts of corn (Zea mays L.) residue removal and cover crops on various soil quality indicators and surface greenhouse gas (GHG) fluxes. The study was being conducted on plots located at the North Central Agricultural Research Laboratory (NCARL) in Brookings, South Dakota, USA. Three plots of a corn and soybean (Glycine max (L.) Merr.) rotation under a no-till (NT) system are being monitored for soils and surface gas fluxes. Each plot has three residue removal (high residue removal, HRR; medium residue removal, MRR; and low residue removal, LRR) treatments and two cover crops (cover crops and no cover crops) treatments. Both corn and soybean are represented every year. Gas flux measurements were taken weekly using a closed static chamber method. Data show that residue removal significantly impacted soil quality indicators while more time was needed for an affect from cover crop treatments to be noticed. The LRR treatment resulted in higher SOC concentrations, increased aggregate stability, and increased microbial activity. The LRR treatment also increased soil organic matter (SOM) and particulate organic matter (POM) concentrations. Cover crops used in HRR (high corn residue removal) improved SOC (27 g kg-1) by 6% compared to that without cover crops (25.4 g kg-1). Cover crops significantly impacted POM concentration directly after the residue removal treatments were applied in 2012. CO2 fluxes were observed to increase as temperature increased, while N2O fluxes increased as soil moisture increased. CH4 fluxes were responsive to both increases in temperature and moisture. On average, soils under

  11. Doses and application seasons of potassium on soybean crop in succession the cover crops

    Directory of Open Access Journals (Sweden)

    Amilton Ferreira Silva

    2014-02-01

    Full Text Available Potassium (K is the second nutrient that is required in larger amounts by soybean crop. With the use of high doses of that nutrient and increase of no-tillage areas in last years, some changes occurred in ways of this nutrient application, as well as the introduction of cover crops in the system for straw formation. Due those facts, the aim with this work was to study doses and times of potassium application for soybean sowed as succession for cover crops in no-tillage system, in a clayey Distrofic Red Latosol, in cerrado region. The experimental design was a randomized block with treatments arranged in 3x3x5 factorial scheme, with the following factors, cover crops: Pearl millet (Pennisetum glaucum and Proso millet (Panicum miliaceum and a control (fallow area, rates of K2O (0, 50 e 100 kg ha-1 and K2O application forms (100% in the cover crops; 100% at sowing of soybean; 100% in topdressing in soybean; 50% at sowing cover crops + 50% at soybean sowing; 50% at soybean sowing + 50% in topdressing in the soybean with four replicates. The Pennisetum glaucum as soybean predecessor crop yields higher dry matter content than the Panicum miliaceum in a short period of time. In clay soil with high content of potassium there was no response to the applied potassium levels. Full doses of potassium maintenance fertilization can be applied in the predecessor cover crop, at sowing or topdressing in soybean crop.

  12. Root characteristics of cover crops and their erosion-reducing potential during concentrated runoff

    Science.gov (United States)

    de Baets, S.; Poesen, J.

    2009-04-01

    In the loam region in central Belgium, a lot of research has been conducted on the effects of cover crops for preventing splash and interrill erosion and on their nutrient pumping effectiveness. As this is a very effective erosion and environment conservation technique, planting cover crops during the winter season is widely applied in the loess belt. Most of these cover crops freeze at the beginning of the winter period. Consequently, the above-ground biomass becomes less effective in protecting the soil from water erosion. Apart from the effects of the above-ground biomass in protecting the soil against raindrop impacts and reducing flow velocities by the retarding effects of their stems, plant roots also play an important role in improving soil strength. Previous research showed that roots contribute to a large extent to the resistance of topsoils against concentrated flow erosion. Unfortunately, information on root properties of common cover crops (e.g. Sinapis alba, Phacelia tanacetifoli, Lolium perenne, Avena sativa, Secale cereale, Raphanus sativus subsp. oleiferus) is very scarce. Therefore, root density distribution with depth and their erosion-reducing effects during concentrated flow erosion were assessed by conducting root auger measurements and concentrated flow experiments at the end of the growth period (December). The preliminary results indicate that the studied cover crops are not equally effective in preventing soil loss by concentrated flow erosion at the end of the growing season. Cover crops with thick roots, such as Sinapis alba and Raphanus sativus subsp. oleiferus are less effective than cover crops with fine-branched roots such as Phacelia tanacetifoli, Lolium perenne (Ryegrass), Avena sativa (Oats) and Secale cereale (Rye) in preventing soil losses by concentrated flow erosion. These results enable soil managers to select the most suitable crops and maximize soil protection.

  13. Tillage and cover cropping effects on soil properties and crop production in Illinois

    Science.gov (United States)

    Cover crops (CCs) have been heralded for their potential to improve soil properties, retain nutrients in the field, and increase subsequent crop yields yet support for these claims within the state of Illinois remains limited. We assessed the effects of integrating five sets of CCs into a corn-soybe...

  14. Production and economic viability of banana managed with cover crops

    Directory of Open Access Journals (Sweden)

    Francisca E. L. Barbosa

    Full Text Available ABSTRACT This research aimed to evaluate the yield and economic viability of three crop cycles of the banana cv. ‘Prata Anã’ in association with perennial herbaceous legumes, natural vegetation, or compared with the conventional management. The research was conducted using a complete randomized block design with split-split plots and four replicates. The plots were formed by four irrigation depths: 50, 75, 100 and 125% of crop evapotranspiration, and the subplots by cover crops (Calopogonium muconoides, Pueraria phaseoloides, and natural cover without N addition or no cover crops with addition of N fertilization (conventional management. The subsubplots were formed by the second, third and fourth banana production cycles. Yield and economic viability of the cultivation were estimated for a period of seven years. The conventional management promoted greater yield and economic viability in the cultivation of ‘Prata Anã’ banana, due to the N fertilization. Managements with leguminous cover crops were also economically viable, but they should be investigated in combination with N fertilization and compared with the conventional method.

  15. Using cash cover crops to provide pollinator provisions in the Upper Midwest

    Science.gov (United States)

    To date, the use of winter cover crops in MN and SD has been slow to be adopted. The short growing season and potential for late, wet springs make cover crops risky to farmers with little economic return. The use of cash cover crops in this area offers the standard advantages of other cover crops, w...

  16. Biomass and nutrient cycling by winter cover crops

    Directory of Open Access Journals (Sweden)

    Jana Koefender

    Full Text Available ABSTRACT Cover crops are of fundamental importance for the sustainability of the no-tillage system, to ensure soil coverage and to provide benefits for the subsequent crop. The objective of this study was to evaluate the production of biomass and the content and accumulation of nutrients by winter cover crops. The experimental design used in the experiment was a randomized complete block with four replications and six treatments: oilseed radish, vetch, black oats, vetch + black oats, vetch + oilseed radish and fallow. Black oat, oilseed radish in single cultivation and black oat + vetch and vetch + oilseed radish intercroppings showed higher dry matter production. Vetch + oilseed radish intercropping demonstrates higher performance regarding cycling of nutrients, with higher accumulations of N, P, K, Ca, Mg, S, Cu, Zn, Fe, Na and B.

  17. 7 CFR 1437.503 - Covered losses and recordkeeping requirements for covered tropical crops.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Covered losses and recordkeeping requirements for covered tropical crops. 1437.503 Section 1437.503 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS...

  18. Tillage System and Cover Crop Effects on Soil Quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    2014-01-01

    Information about the quantitative effect of conservation tillage combined with a cover crop on soil structure is still limited. This study examined the effect of these management practices on soil pore characteristics of a sandy loam soil in a long-term field trial. The tillage treatments (main...

  19. Evaluation of organic cover crop termination methods: flame or fiction?

    Science.gov (United States)

    Use of winter cover crops is an integral component of organic vegetable systems. However, timely spring termination currently relies on tillage in most instances due to time constraints. Thus, the use of conservation practices in organic systems is usually disjointed with some tillage required betw...

  20. Humic substances and its distribution in coffee crop under cover crops and weed control methods

    Directory of Open Access Journals (Sweden)

    Bruno Henrique Martins

    2016-08-01

    Full Text Available ABSTRACT Humic substances (HS comprise the passive element in soil organic matter (SOM, and represent one of the soil carbon pools which may be altered by different cover crops and weed control methods. This study aimed to assess HS distribution and characteristics in an experimental coffee crop area subjected to cover crops and cultural, mechanical, and chemical weed control. The study was carried out at Londrina, in the state of Paraná, southern Brazil (23°21’30” S; 51°10’17” W. In 2008, seven weed control/cover crops were established in a randomized block design between two coffee rows as the main-plot factor per plot and soil sampling depths (0-10 cm, 10-20 cm, 20-30 cm and 30-40 cm as a split-plot. HS were extracted through alkaline and acid solutions and analyzed by chromic acid wet oxidation and UV-Vis spectroscopy. Chemical attributes presented variations in the topsoil between the field conditions analyzed. Cover crop cutting and coffee tree pruning residues left on the soil surface may have interfered in nutrient cycling and the humification process. Data showed that humic substances comprised about 50 % of SOM. Although different cover crops and weed control methods did not alter humic and fulvic acid carbon content, a possible incidence of condensed aromatic structures at depth increments in fulvic acids was observed, leading to an average decrease of 53 % in the E4/E6 ratio. Humin carbon content increased 25 % in the topsoil, particularly under crop weed-control methods, probably due to high incorporation of recalcitrant structures from coffee tree pruning residues and cover crops.

  1. Cover crop frequency and compost effects on a legume-rye cover crop during 8 years of organic vegetables

    Science.gov (United States)

    Organic matter inputs from compost or cover crops (CC) are important to maintain or improve soil quality, but their impact in high-value vegetable production systems are not well understood. Therefore, we evaluated the effects of CC frequency (every winter versus every 4th winter) and yard-waste co...

  2. Biological and microbiological attributes in Oxisol managed with cover crops

    Directory of Open Access Journals (Sweden)

    Rodrigo Ferreira da Silva

    2017-05-01

    Full Text Available The inclusion of winter cover crops and fertilization with nitrogen to the soil can have an effect on their biological and microbiological attributes. The aim of this study was to evaluate biological and microbiological attributes in soil under different winter cover crops and nitrogen doses. The experiment was conducted at the Frederico Westphalen-RS campus of the Federal University of Santa Maria (UFSM in a Rhodic Hapludox soil. The experimental design was a randomized block in factorial arrangement (2 x 10: 10 winter cover crops systems (Fallow [control], black oats, white oats, ryegrass, forage turnip, vetch, white lupine; black oat + forage turnip; black oat + vetch and black oat + vetch + fodder turnip, and two nitrogen rates in the form of urea applied in successive crops of beans common and maize, with four replications. We assessed the biological attributes (Margalef’s richness, Simpson’s dominance, Shannon’s diversity and abundance of organisms and microbiological (carbon and nitrogen microbial biomass, basal respiration, metabolic quotient and microbial quotient of the soil. The fallow with wild species and white lupine showed greater Simpson’s dominance and abundance of organisms due to the increase in the number of individuals of the order Collembola. Vetch improved the biological attributes of the soil with increase in Collembola abundance and diversity of organisms of soil fauna. The application of nitrogen favored the microbial biomass carbon and reduced the metabolic quotient.

  3. Aggregate distribution and associated organic carbon influenced by cover crops

    Science.gov (United States)

    Barquero, Irene; García-González, Irene; Benito, Marta; Gabriel, Jose Luis; Quemada, Miguel; Hontoria, Chiquinquirá

    2013-04-01

    Replacing fallow with cover crops during the non-cropping period seems to be a good alternative to diminish soil degradation by enhancing soil aggregation and increasing organic carbon. The aim of this study was to analyze the effect of replacing fallow by different winter cover crops (CC) on the aggregate distribution and C associated of an Haplic Calcisol. The study area was located in Central Spain, under semi-arid Mediterranean climate. A 4-year field trial was conducted using Barley (Hordeum vulgare L.) and Vetch (Vicia sativa L.) as CC during the intercropping period of maize (Zea mays L.) under irrigation. All treatments were equally irrigated and fertilized. Maize was directly sown over CC residues previously killed in early spring. Composite samples were collected at 0-5 and 5-20 cm depths in each treatment on autumn of 2010. Soil samples were separated by wet sieving into four aggregate-size classes: large macroaggregates ( >2000 µm); small macroaggregates (250-2000 µm); microaggregates (53-250 µm); and Organic carbon associated to each aggregate-size class was measured by Walkley-Black Method. Our preliminary results showed that the aggregate-size distribution was dominated by microaggregates (48-53%) and the cover crops increased aggregate size resulting in a higher MWD (0.28 mm) in comparison with fallow (0.20 mm) in the 0-5 cm layer. Barley showed a higher MWD than fallow also in 5-20 cm layer. Organic carbon concentrations in aggregate-size classes at top layer followed the order: large macroaggregates > small macroaggregates > microaggregates > silt + clay size. Treatments did not influence C concentration in aggregate-size classes. In conclusion, cover crops improved soil structure increasing the proportion of macroaggregates and MWD being Barley more effective than Vetch at subsurface layer.

  4. Cover crops knowledge and implementation willingness by producers of several crops

    Directory of Open Access Journals (Sweden)

    Robin Gómez Gómez

    2017-04-01

    Full Text Available The objective of this study was to assess the knowledge on cover crops and native vegetation mulches and the willingness to implement them by papaya, oil palm, and banana producers in Costa Rica. An evaluation instrument with twenty eight questions to be answered as true or false was developed, and it was used to yield a knowledge indicator. Seven additional questions with responses on a scale from 0 to 5 were included to explore producers’ willingness to implement cover crops or native vegetation mulches on their farms. The evaluation was completed in 2014, and was filled out by 36 papaya producers, 30 oil palm producers, and 57 banana producers. Item analyses to determine reliability produced Cronbach’s alpha values above 90%. For this study a factors analysis was performed in order to determine the measurement of one single variable, knowledge on cover crops and native vegetation mulches. Global knowledge scores varied signi cantly between producer groups. Banana producers assessments yielded the highest mean with the lowest variability, whereas papaya producers had the lower mean and the highest variability. Likewise, answers to each of the questions differed importantly between producer groups. It was also determined that producers of these crops are willing to implement and get training on cover crops and native vegetation mulches.

  5. Tillage System and Cover Crop Effects on Soil Quality

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    2014-01-01

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

  6. Cover Crop Biomass Harvest Influences Cotton Nitrogen Utilization and Productivity

    Directory of Open Access Journals (Sweden)

    F. Ducamp

    2012-01-01

    Full Text Available There is a potential in the southeastern US to harvest winter cover crops from cotton (Gossypium hirsutum L. fields for biofuels or animal feed use, but this could impact yields and nitrogen (N fertilizer response. An experiment was established to examine rye (Secale cereale L. residue management (RM and N rates on cotton productivity. Three RM treatments (no winter cover crop (NC, residue removed (REM and residue retained (RET and four N rates for cotton were studied. Cotton population, leaf and plant N concentration, cotton biomass and N uptake at first square, and cotton biomass production between first square and cutout were higher for RET, followed by REM and NC. However, leaf N concentration at early bloom and N concentration in the cotton biomass between first square and cutout were higher for NC, followed by REM and RET. Seed cotton yield response to N interacted with year and RM, but yields were greater with RET followed by REM both years. These results indicate that a rye cover crop can be beneficial for cotton, especially during hot and dry years. Long-term studies would be required to completely understand the effect of rye residue harvest on cotton production under conservation tillage.

  7. Alfalfa interseeded into silage corn can serve as a cover crop and subsequent forage crop

    Science.gov (United States)

    Alfalfa (Medicago sativa) and corn (Zea mays) silage are commonly grown in rotation in dairy forage production systems throughout the northern regions of the USA. Alfalfa interseeded into silage corn could potentially serve two purposes: as a cover crop during the silage corn production year, and as...

  8. Cover crops effect on farm benefits and nitrate leaching: linking economic and environmental analysis

    Science.gov (United States)

    Gabriel, José Luis; Vanclooster, Marnik; Garrido, Alberto; Quemada, Miguel

    2013-04-01

    Introducing cover crops interspersed with intensively fertilized crops in rotation has the potential to reduce nitrate leaching. However, despite the evident environmental services provided and the range of agronomic benefits documented in the literature, farmers' adoption of the technique is still limited because growing CC could lead to extra costs for the farm in three different forms: direct, indirect, and opportunity costs. Environmental studies are complex, and evaluating the indicators that are representative of the environmental impact of an agricultural system is a complicated task that is conducted by specialized groups and methodologies. Multidisciplinary studies may help to develop reliable approaches that would contribute to choosing the best agricultural strategies based on linking economic and environmental benefits. This study evaluates barley (Hordeum vulgare L., cv. Vanessa), vetch (Vicia villosa L., cv. Vereda) and rapeseed (Brassica napus L., cv. Licapo) as cover crops between maize, leaving the residue in the ground or selling it for animal feeding, and compares the economic and environmental results with respect to a typical maize-fallow rotation. Nitrate leaching for different weather conditions was calculated using the mechanistic-deterministic WAVE model, using the Richards equation parameterised with a conceptual model for the soil hydraulic properties for describing the water flow in the vadose zone, combined with field observed data. The economic impact was evaluated through stochastic (Monte-Carlo) simulation models of farms' profits using probability distribution functions of maize yield and cover crop biomass developed fitted with data collected from various field trials (during more than 5 years) and probability distribution functions of maize and different cover crop forage prices fitted from statistical sources. Stochastic dominance relationships are obtained to rank the most profitable strategies from a farm financial perspective

  9. Effect of water content and organic carbon on remote sensing of crop residue cover

    Science.gov (United States)

    Serbin, G.; Hunt, E. R., Jr.; Daughtry, C. S. T.; McCarty, G. W.; Brown, D. J.; Doraiswamy, P. C.

    2009-04-01

    Crop residue cover is an important indicator of tillage method. Remote sensing of crop residue cover is an attractive and efficient method when compared with traditional ground-based methods, e.g., the line-point transect or windshield survey. A number of spectral indices have been devised for residue cover estimation. Of these, the most effective are those in the shortwave infrared portion of the spectrum, situated between 1950 and 2500 nm. These indices include the hyperspectral Cellulose Absorption Index (CAI), and advanced multispectral indices, i.e., the Lignin-Cellulose Absorption (LCA) index and the Shortwave Infrared Normalized Difference Residue Index (SINDRI), which were devised for the NASA Terra Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) sensor. Spectra of numerous soils from U.S. Corn Belt (Indiana and Iowa) were acquired under wetness conditions varying from saturation to oven-dry conditions. The behavior of soil reflectance with water content was also dependent on the soil organic carbon content (SOC) of the soils, and the location of the spectral bands relative to significant water absorptions. High-SOC soils showed the least change in spectral index values with increase in soil water content. Low-SOC soils, on the other hand, showed measurable difference. For CAI, low-SOC soils show an initial decrease in index value followed by an increase, due to the way that water content affects CAI spectral bands. Crop residue CAI values decrease with water content. For LCA, water content increases decrease crop residue index values and increase them for soils, resulting in decreased contrast. SINDRI is also affected by SOC and water content. As such, spatial information on the distribution of surface soil water content and SOC, when used in a geographic information system (GIS), will improve the accuracy of remotely-sensed crop residue cover estimates.

  10. Soil Water Improvements with the Long Term Use of a Winter Rye Cover Crop

    Science.gov (United States)

    Basche, A.; Kaspar, T.; Archontoulis, S.; Jaynes, D. B.; Sauer, T. J.; Parkin, T.; Miguez, F.

    2015-12-01

    The Midwestern United States, a region that produces one-third of maize and one-quarter of soybeans globally, is projected to experience increasing rainfall variability with future climate change. One approach to mitigate climate impacts is to utilize crop and soil management practices that enhance soil water storage, reducing the risks of flooding and runoff as well as drought-induced crop water stress. While some research indicates that a winter cover crop in a maize-soybean rotation increases soil water, producers continue to be concerned that water use by cover crops will reduce water for a following cash crop. We analyzed continuous in-field soil moisture measurements over from 2008-2014 at a Central Iowa research site that has included a winter rye cover crop in a maize-soybean rotation for thirteen years. This period of study included years in the top third of wettest years on record (2008, 2010, 2014) as well as years in the bottom third of driest years (2012, 2013). We found the cover crop treatment to have significantly higher soil water storage from 2012-2014 when compared to the no cover crop treatment and in most years greater soil water content later in the growing season when a cover crop was present. We further found that the winter rye cover crop significantly increased the field capacity water content and plant available water compared to the no cover crop treatment. Finally, in 2012 and 2013, we measured maize and soybean biomass every 2-3 weeks and did not see treatment differences in crop growth, leaf area or nitrogen uptake. Final crop yields were not statistically different between the cover and no cover crop treatment in any of the years of this analysis. This research indicates that the long-term use of a winter rye cover crop can improve soil water dynamics without sacrificing cash crop growth.

  11. Impacts of Cover Crops on Water and Nutrient Dynamics in Agroecosystems

    Science.gov (United States)

    Williard, K.; Swanberg, S.; Schoonover, J.

    2013-05-01

    Intensive cropping systems of corn (Zea Mays L.) and soybeans (Glycine max) are commonly leaky systems with respect to nitrogen (N). Reactive N outputs from agroecosystems can contribute to eutrophication and hypoxic zones in downstream water bodies and greenhouse gas (N2O) emissions. Incorporating cover crops into temperate agroecosystem rotations has been promoted as a tool to increase nitrogen use efficiency and thus limit reactive N outputs to the environment. Our objective was determine how cereal rye (Secale cereal L.) and annual ryegrass (Lolium multiflorum) cover crops impact nutrient and soil water dynamics in an intensive corn and soybean cropping rotation in central Illinois. Cover crops were planted in mid to late October and terminated in early April prior to corn or soybean planting. In the spring just prior to cover crop termination, soil moisture levels were lower in the cover crop plots compared to no cover plots. This can be a concern for the subsequent crop in relatively dry years, which the Midwestern United States experienced in 2012. No cover plots had greater nutrient leaching below the rooting zone compared to cover crop areas, as expected. The cover crops were likely scavenging nutrients during the fall and early spring and should provide nutrients to the subsequent crop via decomposition and mineralization of the cover crop residue. Over the long term, cover crop systems should produce greater inputs and cycling of carbon and N, increasing the productivity of crops due to the long-term accumulation of soil organic matter. This study demonstrates that there may be short term trade-offs in reduced soil moisture levels that should be considered alongside the long term nutrient scavenging and recycling benefits of cover crops.

  12. Timing of Glyphosate Applications to Wheat Cover Crops to Reduce Onion Stunting Caused by Rhizoctonia solana

    Science.gov (United States)

    Stunting caused by Rhizoctonia spp. is economically important in irrigated onion bulb crops in the semi-arid Columbia Basin of Oregon and Washington, where cereal winter cover crops commonly are planted the previous fall to prevent wind erosion of soil. The cover crop is killed with herbicide applic...

  13. Growth of tropical legume cover crops as influenced by nitrogen fertilization and Rhizobia

    Science.gov (United States)

    Tropical legume cover crops are important components in cropping systems due to their role in improving soil quality. Information is limited on the influence of nitrogen (N) fertilization on growth of tropical legume cover crops grown on Oxisols. A greenhouse experiment was conducted to evaluate the...

  14. No-till Snap Bean performance and weed response following Cereal Rye and Vetch cover crops

    Science.gov (United States)

    Fall-planted cover crops offer many benefits including weed suppressive residues in spring sown crops when controlled and left on the soil surface. However, vegetable growers have been slow to adapt direct seeding (no-till) into cover crop residues. Field studies were conducted in 2009 and 2010 near...

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    Conservation tillage practices are widely used to protect against soil erosion and soil C losses, whereas winter cover crops are used mainly to protect against N losses during autumn and winter. For the greenhouse gas balance of a cropping system the effect of reduced tillage and cover crops on N2O...

  16. Effect of winter cover crops on nematode population levels in north Florida.

    Science.gov (United States)

    Wang, K-H; McSorley, R; Gallaher, R N

    2004-12-01

    Two experiments were conducted in north-central Florida to examine the effects of various winter cover crops on plant-parasitic nematode populations through time. In the first experiment, six winter cover crops were rotated with summer corn (Zea mays), arranged in a randomized complete block design. The cover crops evaluated were wheat (Triticum aestivum), rye (Secale cereale), oat (Avena sativa), lupine (Lupinus angustifolius), hairy vetch (Vicia villosa), and crimson clover (Trifolium incarnatum). At the end of the corn crop in year 1, population densities of Meloidogyne incognita were lowest on corn following rye or oat (P cover crops: soybean (Glycine max), cowpea (Vigna unguiculata), sorghum-sudangrass (Sorghum bicolor x S. sudanense), sunn hemp (Crotalaria juncea), and corn. Population densities of M. incognita and Helicotylenchus dihystera were affected by previous tropical cover crops (P winter cover crops present at the time of sampling. Plots planted to sunn hemp in the fall maintained the lowest M. incognita and H. dihystera numbers. Results suggest that winter cover crops tested did not suppress plant-parasitic nematodes effectively. Planting tropical cover crops such as sunn hemp after corn in a triple-cropping system with winter cover crops may provide more versatile nematode management strategies in northern Florida.

  17. Management of Overwintering Cover Crops Influences Floral Resources and Visitation by Native Bees.

    Science.gov (United States)

    Ellis, Katherine E; Barbercheck, Mary E

    2015-08-01

    The incorporation of cover crops into annual crop rotations is one practice that is used in the Mid-Atlantic United States to manage soil fertility, suppress weeds, and control erosion. Additionally, flowering cover crops have the potential to support beneficial insect communities, such as native bees. Because of the current declines in managed honey bee colonies, the conservation of native bee communities is critical to maintaining "free" pollination services. However, native bees are negatively affected by agricultural intensification and are also in decline across North America. We conducted two experiments to assess the potential of flowering cover crops to act as a conservation resource for native bees. We evaluated the effects of cover crop diversity and fall planting date on floral resource availability and visitation by native bees for overwintering flowering cover crop species commonly used in the Mid-Atlantic region. Cover crop species, crop rotation schedule, and plant diversity significantly influenced floral resource availability. Different cover crop species not only had different blooming phenologies and winter survival responses to planting date, but attracted unique bee communities. Flower density was the primary factor influencing frequency of bee visitation across cover crop diversity and fall planting date treatments. The results from these experiments will be useful for informing recommendations on the applied use of flowering cover crops for pollinator conservation purposes.

  18. The kill date as a management tool for cover cropping success.

    Directory of Open Access Journals (Sweden)

    María Alonso-Ayuso

    Full Text Available Integrating cover crops (CC in rotations provides multiple ecological services, but it must be ensured that management does not increase pre-emptive competition with the subsequent crop. This experiment was conducted to study the effect of kill date on: (i CC growth and N content; (ii the chemical composition of residues; (iii soil inorganic N and potentially mineralizable N; and (iv soil water content. Treatments were fallow and a CC mixture of barley (Hordeum vulgare L. and vetch (Vicia sativa L. sown in October and killed on two different dates in spring. Above-ground biomass and chemical composition of CC were determined at harvest, and ground cover was monitored based on digital image analysis. Soil mineral N was determined before sowing and after killing the CC, and potentially mineralizable N was measured by aerobic incubation at the end of the experiment. Soil water content was monitored daily to a depth of 1.1 m using capacitance sensors. Under the present conditions of high N availability, delaying kill date increased barley above-ground biomass and N uptake from deep soil layers; little differences were observed in vetch. Postponing kill date increased the C/N ratio and the fiber content of plant residues. Ground cover reached >80% by the first kill date (∼1250°C days. Kill date was a means to control soil inorganic N by balancing the N retained in the residue and soil, and showed promise for mitigating N losses. The early kill date decreased the risk of water and N pre-emptive competition by reducing soil depletion, preserving rain harvested between kill dates and allowing more time for N release in spring. The soil potentially mineralizable N was enhanced by the CC and kill date delay. Therefore kill date is a crucial management variable for maximizing the CC benefits in agricultural systems.

  19. The kill date as a management tool for cover cropping success.

    Science.gov (United States)

    Alonso-Ayuso, María; Gabriel, José Luis; Quemada, Miguel

    2014-01-01

    Integrating cover crops (CC) in rotations provides multiple ecological services, but it must be ensured that management does not increase pre-emptive competition with the subsequent crop. This experiment was conducted to study the effect of kill date on: (i) CC growth and N content; (ii) the chemical composition of residues; (iii) soil inorganic N and potentially mineralizable N; and (iv) soil water content. Treatments were fallow and a CC mixture of barley (Hordeum vulgare L.) and vetch (Vicia sativa L.) sown in October and killed on two different dates in spring. Above-ground biomass and chemical composition of CC were determined at harvest, and ground cover was monitored based on digital image analysis. Soil mineral N was determined before sowing and after killing the CC, and potentially mineralizable N was measured by aerobic incubation at the end of the experiment. Soil water content was monitored daily to a depth of 1.1 m using capacitance sensors. Under the present conditions of high N availability, delaying kill date increased barley above-ground biomass and N uptake from deep soil layers; little differences were observed in vetch. Postponing kill date increased the C/N ratio and the fiber content of plant residues. Ground cover reached >80% by the first kill date (∼1250°C days). Kill date was a means to control soil inorganic N by balancing the N retained in the residue and soil, and showed promise for mitigating N losses. The early kill date decreased the risk of water and N pre-emptive competition by reducing soil depletion, preserving rain harvested between kill dates and allowing more time for N release in spring. The soil potentially mineralizable N was enhanced by the CC and kill date delay. Therefore kill date is a crucial management variable for maximizing the CC benefits in agricultural systems.

  20. SOIL CHEMICAL ATTRIBUTES AND LEAF NUTRIENTS OF ‘PACOVAN’ BANANA UNDER TWO COVER CROPS

    Directory of Open Access Journals (Sweden)

    JOSÉ EGÍDIO FLORI

    2016-01-01

    Full Text Available Banana is one of the most consumed fruits in the world, which is grown in most tropical countries. The objective of this work was to evaluate the main attributes of soil fertility in a banana crop under two cover crops and two root development locations. The work was conducted in Curaçá, BA, Brazil, between October 2011 and May 2013, using a randomized block design in split plot with five repetitions. Two cover crops were assessed in the plots, the cover 1 consisting of Pueraria phaseoloides, and the cover 2 consisting of a crop mix with Sorghum bicolor, Ricinus communis L., Canavalia ensiformis, Mucuna aterrima and Zea mays, and two soil sampling locations in the subplots, between plants in the banana rows (location 1 and between the banana rows (location 2. There were significant and independent effects for the cover crop and sampling location factors for the variables organic matter, Ca and P, and significant effects for the interaction between cover crops and sampling locations for the variables potassium, magnesium and total exchangeable bases. The cover crop mix and the between-row location presented the highest organic matter content. Potassium was the nutrient with the highest negative variation from the initial content and its leaf content was below the reference value, however not reducing the crop yield. The banana crop associated with crop cover using the crop mix provided greater availability of nutrients in the soil compared to the coverage with tropical kudzu.

  1. Cover crops do not increase C sequestration in production crops: evidence from 12 years of continuous measurements

    Science.gov (United States)

    Buysse, Pauline; Bodson, Bernard; Debacq, Alain; De Ligne, Anne; Heinesch, Bernard; Manise, Tanguy; Moureaux, Christine; Aubinet, Marc

    2017-04-01

    The numerous reports on carbon (C) loss from cropland soils have recently raised awareness on the climate change mitigation potential of these ecosystems, and on the necessity to improve C sequestration in these soils. Among the multiple solutions that are proposed, several field measurement and modelling studies reported that growing cover crops over fall and winter time could appear as an efficient solution. However, while the large majority of these studies are based on SOC stock inventories and very few information exists from the CO2 flux dynamics perspective. In the present work, we use the results from long-term (12 years) eddy-covariance measurements performed at the Lonzée Terrestrial Observatory (LTO, candidate ICOS site, Belgium) and focus on six intercrop periods managed with (3) and without (3) cover crops after winter wheat main crops, in order to compare their response to environmental factors and to investigate the impact of cover crops on Net Ecosystem Exchange (NEE). Our results showed that cumulated NEE was not significantly affected by the presence of cover crops. Indeed, while larger CO2 assimilation occurred during cover crop growth, this carbon gain was later lost by larger respiration rates due to larger crop residue amounts brought to the soil. As modelled by a Q10-like relationship, significantly larger R10 values were indeed observed during the three intercrop periods cultivated with cover crops. These CO2 flux-based results therefore tend to moderate the generally acknowledged positive impact of cover crops on net C sequestration by croplands. Our results indicate that the effect of growing cover crops on C sequestration could be less important than announced, at least at certain sites.

  2. Effect of cover crop extracts on cotton and radish radicle elongation

    Directory of Open Access Journals (Sweden)

    Randy L. Raper

    2008-06-01

    Full Text Available Research has shown that some cover crops are allelopathic and can inhibit weed germination and growth. Additionally, negative allelopathic effects have been documented in cash crops planted into cover crop residue. However, little literature exists comparing relative the allelopathic potential of cover crops producers utilize in conservation-agriculture systems. This study assessed the effects of twelve cover crop extracts on radish (Raphanus sativus L. and cotton (Gossypium hirsutum L. radicle elongation, in three trials, using an extract-agar bioassay. In Trial 1 the cover crops were black oat (Avena strigosa Schreb cv. SoilSaver, crimson clover (Trifolium incarnatum L. cv. AU Robin, white lupin (Lupinus albus L. cvs. AU Homer and AU Alpha, rye (Secale cereale L. cv. Elbon, wheat (Triticum aestivum L. cv. Vigoro Grazer, and triticale (X Triticosecale Wittmack cv. Trical 2700. In Trial 2 the cover crops were forage rape (Brassica napus L. var. napus cv. Licapo, sunn hemp (Crotalaria juncea L., Austrian winter field pea (Pisum sativum spp. arvense L. Poir, black medic (Medicago lupilina L., hairy vetch (Vicia villosa Roth, black oat cv. SoilSaver, and crimson clover cv. AU Robin. Cotton was evaluated using the same bioassay and all of the cover crops mentioned above in a single trial (Trial 3. All cover crop extracts inhibited radicle elongation compared to water. Allelopathic potential was highly variable among cultivars within a cover crop species, and within a cultivar. Allelopathic differences among cover crops give an additional weed control tool in conservation systems. However, winter cover selection may impact on cash crop performance if producers plant their crop into green residue.

  3. Soil Organic Carbon Response to Cover Crop and Nitrogen Fertilization under Bioenergy Sorghum

    Science.gov (United States)

    Sainju, U. M.; Singh, H. P.; Singh, B. P.

    2015-12-01

    Removal of aboveground biomass for bioenergy/feedstock in bioenergy cropping systems may reduce soil C storage. Cover crop and N fertilization may provide additional crop residue C and sustain soil C storage compared with no cover crop and N fertilization. We evaluated the effect of four winter cover crops (control or no cover crop, cereal rye, hairy vetch, and hairy vetch/cereal rye mixture) and two N fertilization rates (0 and 90 kg N ha-1) on soil organic C (SOC) at 0-5, 5-15, and 15-30 cm depths under forage and sweet sorghums from 2010 to 2013 in Fort Valley, GA. Cover crop biomass yield and C content were greater with vetch/rye mixture than vetch or rye alone and the control, regardless of sorghum species. Soil organic C was greater with vetch/rye than rye at 0-5 and 15-30 cm in 2011 and 2013 and greater with vetch than rye at 5-15 cm in 2011 under forage sorghum. Under sweet sorghum, SOC was greater with cover crops than the control at 0-5 cm, but greater with vetch and the control than vetch/rye at 15-30 cm. The SOC increased at the rates of 0.30 Mg C ha-1 yr-1 at 0-5 cm for rye and the control to 1.44 Mg C ha-1 yr-1 at 15-30 cm for vetch/rye and the control from 2010 to 2013 under forage sorghum. Under sweet sorghum, SOC also increased linearly at all depths from 2010 to 2013, regardless of cover crops. Nitrogen fertilization had little effect on SOC. Cover crops increased soil C storage compared with no cover crop due to greater crop residue C returned to the soil under forage and sweet sorghum and hairy vetch/cereal rye mixture had greater C storage than other cover crops under forage sorghum.

  4. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    Science.gov (United States)

    Yeo, I.-Y.; Lee, S.; Sadeghi, A. M.; Beeson, P. C.; Hively, W. D.; McCarty, G. W.; Lang, M. W.

    2014-12-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay watershed (CBW), which is located in the mid-Atlantic US, winter cover crop use has been emphasized, and federal and state cost-share programs are available to farmers to subsidize the cost of cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops to improve water quality at the watershed scale (~ 50 km2) and to identify critical source areas of high nitrate export. A physically based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data to simulate hydrological processes and agricultural nutrient cycling over the period of 1990-2000. To accurately simulate winter cover crop biomass in relation to growing conditions, a new approach was developed to further calibrate plant growth parameters that control the leaf area development curve using multitemporal satellite-based measurements of species-specific winter cover crop performance. Multiple SWAT scenarios were developed to obtain baseline information on nitrate loading without winter cover crops and to investigate how nitrate loading could change under different winter cover crop planting scenarios, including different species, planting dates, and implementation areas. The simulation results indicate that winter cover crops have a negligible impact on the water budget but significantly reduce nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading from agricultural lands was approximately 14 kg ha-1, but decreased to 4.6-10.1 kg ha-1 with cover crops resulting in a reduction rate of 27-67% at the watershed scale. Rye was the most effective species, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of cover crops (~ 30

  5. Effects of ground cover from branches of arboreal species on weed growth and maize yield

    Directory of Open Access Journals (Sweden)

    Paulo Sérgio Lima e Silva

    Full Text Available ABSTRACTCultivating maize under systems of alley cropping results in improvements to the soil, a reduction in weeds and an increase in yield. Studies using ground cover from tree shoots produce similar results. The aim of this study was to evaluate the effects on weed growth and maize yield of ground cover made up of 30 t ha-1 (fresh matter of branches from the tree species: neem (Azadirachta indica A. Juss, gliricidia [Gliricidia sepium(Jacq. Kunth ex Walp.], leucaena [Leucaena leucocephala (Lam. de Wit.] and sabiá (Mimosa caesalpiniifolia Benth.. Two treatment groups (cultivars and weed control were evaluated. The cultivars AG 1041 and AL Bandeirantes were subjected to the following treatments: no hoeing, double hoeing, and ground a cover of branches of the above species when sowing the maize. A randomised block design was used with split lots (cultivars in the lots and ten replications. The cultivars did not differ for green ear or grain yield. Double hoeing was more effective than ground cover at reducing the growth of weeds. However, both weeding and ground cover resulted in similar yields for green ears and grain, which were greater than those obtained with the unweeded maize.

  6. Soil carbon sequestration via cover crops- A meta-analysis

    Science.gov (United States)

    Poeplau, Christopher; Don, Axel

    2014-05-01

    Agricultural soils are depleted in soil organic carbon (SOC) and have thus a huge potential to sequester SOC. This can primarily be achieved by increasing carbon inputs into the soil. Replacing winter fallows by cover crop cultivation for green manure has many benefits for the soil and forms an additional carbon input. An increase in carbon concentration has been reported in several studies worldwide. However, the effect on SOC stocks, as well as the influence of environmental parameters and management on SOC dynamics is not known. We therefore conducted a meta-analysis to investigate those issues. A total of 33 studies, comprising 47 sites and 147 plots were compiled. A pedotransfer function was used to estimate bulk densities and calculate SOC stocks. SOC stock change was found to be a linear function of time since introduction, with an annual sequestration rate of 0.32 Mg C ha-1 yr-1. Since no saturation was visible in the observations, we used the model RothC to estimate a new steady state level and the resulting total SOC stock change for an artificial "average cropland". The total average SOC stock change with an annual input of 1.87 Mg C ha-1 yr-1 was 16.76 Mg C ha-1 for the average soil depth of 22 cm. We estimated a potential global SOC sequestration of 0.12±0.03 Pg C yr-1, which would compensate for 8 % of the direct annual greenhouse gas emissions from agriculture.

  7. Summer cover crops and soil amendments to improve growth and nutrient uptake of okra

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Q.R.; Li, Y.C.; Klassen, W. [University of Florida, Homestead, FL (United States). Center for Tropical Research & Education

    2006-04-15

    A pot experiment with summer cover crops and soil amendments was conducted in two consecutive years to elucidate the effects of these cover crops and soil amendments on 'Clemson Spineless 80' okra (Abelmoschus esculentus) yields and biomass production, and the uptake and distribution of soil nutrients and trace elements. The cover crops were sunn hemp (Crotalaria juncea), cowpea (Vigna unguiculata), velvetbean (Mucuna deeringiana), and sorghum sudan-grass (Sorghum bicolor x S. bicolor var. sudanense) with fallow as the control. The organic soil amendments were biosolids (sediment from wastewater plants), N-Viro Soil (a mixture of biosolids and coal ash), coal ash (a combustion by-product from power plants), co-compost (a mixture of 3 biosolids: 7 yard waste), and yard waste compost (mainly from leaves and branches of trees and shrubs, and grass clippings) with a soil-incorporated cover crop as the control. As a subsequent vegetable crop, okra was grown after the cover crops, alone or together with the organic soil amendments, had been incorporated. All of the cover crops, except sorghum sudangrass in 2002-03, significantly improved okra fruit yields and the total biomass production. Both cover crops and soil amendments can substantially improve nutrient uptake and distribution. The results suggest that cover crops and appropriate amounts of soil amendments can be used to improve soil fertility and okra yield without adverse environmental effects or risk of contamination of the fruit. Further field studies will be required to confirm these findings.

  8. Assessing winter cover crop nutrient uptake efficiency using a water quality simulation model

    Science.gov (United States)

    Yeo, In-Young; Lee, Sangchui; Sadeghi, Ali M.; Beeson, Peter C.; Hively, W. Dean; McCarty, Greg W.; Lang, Megan W.

    2013-01-01

    Winter cover crops are an effective conservation management practice with potential to improve water quality. Throughout the Chesapeake Bay Watershed (CBW), which is located in the Mid-Atlantic US, winter cover crop use has been emphasized and federal and state cost-share programs are available to farmers to subsidize the cost of winter cover crop establishment. The objective of this study was to assess the long-term effect of planting winter cover crops at the watershed scale and to identify critical source areas of high nitrate export. A physically-based watershed simulation model, Soil and Water Assessment Tool (SWAT), was calibrated and validated using water quality monitoring data and satellite-based estimates of winter cover crop species performance to simulate hydrological processes and nutrient cycling over the period of 1991–2000. Multiple scenarios were developed to obtain baseline information on nitrate loading without winter cover crops planted and to investigate how nitrate loading could change with different winter cover crop planting scenarios, including different species, planting times, and implementation areas. The results indicate that winter cover crops had a negligible impact on water budget, but significantly reduced nitrate leaching to groundwater and delivery to the waterways. Without winter cover crops, annual nitrate loading was approximately 14 kg ha−1, but it decreased to 4.6–10.1 kg ha−1 with winter cover crops resulting in a reduction rate of 27–67% at the watershed scale. Rye was most effective, with a potential to reduce nitrate leaching by up to 93% with early planting at the field scale. Early planting of winter cover crops (~30 days of additional growing days) was crucial, as it lowered nitrate export by an additional ~2 kg ha−1 when compared to late planting scenarios. The effectiveness of cover cropping increased with increasing extent of winter cover crop implementation. Agricultural fields with well-drained soils

  9. Reproduction of Meloidogyne incognita on Winter Cover Crops Used in Cotton Production.

    Science.gov (United States)

    Timper, Patricia; Davis, Richard F; Tillman, P Glynn

    2006-03-01

    Substantial reproduction of Meloidogyne incognita on winter cover crops may lead to damaging populations in a subsequent cotton (Gossypium hirsutum) crop. The amount of population increase during the winter depends on soil temperature and the host status of the cover crop. Our objectives were to quantify M. incognita race 3 reproduction on rye (Secale cereale) and several leguminous cover crops and to determine if these cover crops increase population densities of M. incognita and subsequent damage to cotton. The cover crops tested were 'Bigbee' berseem clover (Trifolium alexandrinum), 'Paradana' balansa clover (T. balansae), 'AU Sunrise' and 'Dixie' crimson clover (T. incarnatum), 'Cherokee' red clover (T. pratense), common and 'AU Early Cover' hairy vetch (Vicia villosa), 'Cahaba White' vetch (V. sativa), and 'Wrens Abruzzi' rye. In the greenhouse tests, egg production was greatest on berseem clover, Dixie crimson clover, AU Early Cover hairy vetch, and common hairy vetch; intermediate on Balansa clover and AU Sunrise crimson clover; and least on rye, Cahaba White vetch, and Cherokee red clover. In both 2002 and 2003 field tests, enough heat units were accumulated between 1 January and 20 May for the nematode to complete two generations. Both AU Early Cover and common hairy vetch led to greater root galling than fallow in the subsequent cotton crop; they also supported high reproduction of M. incognita in the greenhouse. Rye and Cahaba White vetch did not increase root galling on cotton and were relatively poor hosts for M. incognita. Only those legumes that increased populations of M. incognita reduced cotton yield. In the southern US, M. incognita can complete one to two generations on a susceptible winter cover crop, so cover crops that support high nematode reproduction may lead to damage and yield losses in the following cotton crop. Planting rye or Meloidogyne-resistant legumes as winter cover crops will lower the risk of increased nematode populations

  10. Hardwood cover crops:can they enhance loblolly pine seedling production

    Science.gov (United States)

    Paul P. Kormanik; Shi-Jean S. Sung; T.L. Kormanik; Stanley J. Zarnoch

    1995-01-01

    It has been extremely difficult to obtain more than two loblolly pine (Pinus taeda L.) crops following even effective soil fumigation with methyl bromide in southern forest tree nurseries. The traditional agronomic cover crops such as sorghum and sudex, unless followed by fumigation, do not normally produce satisfactory loblolly pine seedling crops. Various species...

  11. Evaluation of Cowpea Germplasm Lines Adapted for Use as a Cover Crop in the Southeastern US

    Science.gov (United States)

    Cowpeas (Vigna unguiculata) are desirable as a cover crop, because they are tolerant of heat, drought and poor soils, grow vigorously and compete well against weeds, and provide nitrogen for rotational crops. Cowpeas were grown extensively as a forage and green manure crop in the southeastern U.S. ...

  12. Cover crops for enriching soil carbon and nitrogen under bioenergy sorghum

    Science.gov (United States)

    Soil carbon (C) and nitrogen (N) can be enriched with cover crops under agronomic crops, but little is known about their enrichment under bioenergy crops. Legume (hairy vetch [Vicia villosa Roth]), nonlegume (rye [Secaele cereale L.]), a mixture of legume and nonlegume (hairy vetch and rye) and a co...

  13. Self-reseeding annual legumes for cover cropping in rainfed managed olive orchards

    Energy Technology Data Exchange (ETDEWEB)

    Ângelo Rodrigues, M.; Ferreira, I. Q.; Freitas, S.L.; Pires, J.M.; Arrobas, M.P.

    2015-07-01

    Given the environmental impact of nitrogen (N)-fertilizer manufacture and use, the sustainable management of agro-systems should be sought by growing N-fixing legumes. In this work, eleven self-reseeding annual legumes were grown in pure stands as mulching cover crops in a rainfed olive orchard managed without grazing animals. Dry matter yield, N content in above-ground biomass, groundcover percentage and persistence of the sown species were assessed during four growing seasons. All covers provided enough soil protection over the year, with living plants during the autumn/winter period and a mulch of dead residues during the summer. The legumes overcame a false break observed in the third year recovering the dominance of the covers in the fourth growing season. This means that the seed bank established in previous seasons ensured the persistence of the sown legume even when a gap in seed production occurred. The early-maturing cultivars produced less biomass and fixed less N (approx. 50 kg N/ha/yr present in the above-ground biomass) than the late-maturing ones, but would compete less for water since the growing cycle finished earlier in the spring. They seem best suited to being grown in dry farmed olive orchards with low N demand in drought prone regions. (Author)

  14. Ruminant Grazing of Cover Crops: Effects on Soil Properties and Agricultural Production

    Science.gov (United States)

    Poffenbarger, Hanna

    2010-01-01

    Integrating livestock into a cropping system by allowing ruminant animals to graze cover crops may yield economic and environmental benefits. The effects of grazing on soil physical properties, soil organic matter, nitrogen cycling and agricultural production are presented in this literature review. The review found that grazing cover crops…

  15. 7 CFR 1412.31 - Direct payment yields for covered commodities, except pulse crops.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Direct payment yields for covered commodities, except pulse crops. 1412.31 Section 1412.31 Agriculture Regulations of the Department of Agriculture (Continued... commodities, except pulse crops. (a) The direct payment yield for each covered commodity, except pulse...

  16. Grazing winter rye cover crop in a cotton no-till system: yield and economics

    Science.gov (United States)

    Winter cover crop adoption in conservation management systems continues to be limited in the US but could be encouraged if establishment costs could be offset. A 4-yr field experiment was conducted near Watkinsville, Georgia in which a rye (Secale cereale L.) cover crop was either grazed by catt...

  17. COVER CROPS ENHANCE SOIL ORGANIC MATTER, CARBON DYNAMICS AND MICROBIOLOGICAL FUNCTION IN A MEDITERRANEAN VINEYARD AGROECOSYSTEM

    Science.gov (United States)

    Impacts of soil tillage and cover crops on soil carbon (C) dynamics and microbiological function were investigated in a vineyard grown in California’s Mediterranean climate. We 1) compared soil organic matter (SOM), C dynamics and microbiological activity of two cover crops [Trios 102 (Triticale x T...

  18. Forage radish winter cover crop suppresses winter annual weeds in fall and before corn planting

    Science.gov (United States)

    Forage radish (Raphanus sativus L. var. longipinnatus) is a new winter cover crop in the Mid-Atlantic region. The objective of this project was to characterize the repeatability, amount, and duration of weed suppression during and after a fall-planted forage radish cover crop and to quantify the sub...

  19. US-1136, US-1137, and US-1138 Cowpea Germplasm Lines for Use as a Cover Crop

    Science.gov (United States)

    The adoption of sustainable and organic cultural practices in recent years has resulted in an increased use of cover crops. Cowpea (Vigna unguiculata L.) is an excellent warm season cover crop due to its tolerance of heat and drought stress, ability to grow well in sandy, poor, acidic soils, high b...

  20. Winter pasture and cover crops and their effects on soil and summer grain crops

    Directory of Open Access Journals (Sweden)

    Alvadi Antonio Balbinot Junior

    2011-10-01

    Full Text Available The objective of this work was to evaluate the effect of winter land use on the amount of residual straw, the physical soil properties and grain yields of maize, common bean and soybean summer crops cultivated in succession. The experiment was carried out in the North Plateau of Santa Catarina state, Brazil, from May 2006 to April 2010. Five strategies of land use in winter were evaluated: intercropping with black oat + ryegrass + vetch, without grazing and nitrogen (N fertilization (intercropping cover; the same intercropping, with grazing and 100 kg ha-1 of N per year topdressing (pasture with N; the same intercropping, with grazing and without nitrogen fertilization (pasture without N; oilseed radish, without grazing and nitrogen fertilization (oilseed radish; and natural vegetation, without grazing and nitrogen fertilization (fallow. Intercropping cover produces a greater amount of biomass in the system and, consequently, a greater accumulation of total and particulate organic carbon on the surface soil layer. However, land use in winter does not significantly affect soil physical properties related to soil compaction, nor the grain yield of maize, soybean and common bean cultivated in succession.

  1. Ecological weed management by cover cropping : effects on weed growth in autumn and weed establishment in spring

    NARCIS (Netherlands)

    Kruidhof, H.M.; Bastiaans, L.; Kropff, M.J.

    2008-01-01

    Cover crops grown in the period between two main crops have potential as an important component of a system-oriented ecological weed management strategy. In late summer and autumn, the cover crop can suppress growth and seed production of weeds, whereas the incorporation of cover crop residues in sp

  2. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Directory of Open Access Journals (Sweden)

    Daniel Paredes

    Full Text Available Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history, the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard, or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae in 2,528 olive groves in Andalusia (Spain from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  3. Is ground cover vegetation an effective biological control enhancement strategy against olive pests?

    Science.gov (United States)

    Paredes, Daniel; Cayuela, Luis; Gurr, Geoff M; Campos, Mercedes

    2015-01-01

    Ground cover vegetation is often added or allowed to generate to promote conservation biological control, especially in perennial crops. Nevertheless, there is inconsistent evidence of its effectiveness, with studies reporting positive, nil or negative effects on pest control. This might arise from differences between studies at the local scale (e.g. orchard management and land use history), the landscape context (e.g. presence of patches of natural or semi-natural vegetation near the focal orchard), or regional factors, particularly climate in the year of the study. Here we present the findings from a long-term regional monitoring program conducted on four pest species (Bactrocera oleae, Prays oleae, Euphyllura olivina, Saissetia oleae) in 2,528 olive groves in Andalusia (Spain) from 2006 to 2012. Generalized linear mixed effect models were used to analyze the effect of ground cover on different response variables related to pest abundance, while accounting for variability at the local, landscape and regional scales. There were small and inconsistent effects of ground cover on the abundance of pests whilst local, landscape and regional variability explained a large proportion of the variability in pest response variables. This highlights the importance of local and landscape-related variables in biological control and the potential effects that might emerge from their interaction with practices, such as groundcover vegetation, implemented to promote natural enemy activity. The study points to perennial vegetation close to the focal crop as a promising alternative strategy for conservation biological control that should receive more attention.

  4. MICRONUTRIENTS USE EFFICIENCY IN TROPICAL COVER CROPS AS INFLUENCED BY PHOSPHORUS FERTILIZATION

    Directory of Open Access Journals (Sweden)

    NAND KUMAR FAGERIA

    2015-01-01

    Full Text Available Deficiency of micronutrients is increasing in the recent years in cropping systems in many parts of the world and cover crops are important components of cropping systems. A greenhouse experiment was conducted to evaluate copper (Cu, iron (Fe, manganese (Mn and zinc (Zn use efficiency in 14 tropical leg-ume cover crops grown on an Oxisol. The P levels used were low (0 mg kg-1, medium (100 mg kg-1 and high (200 mg kg-1. The P X cover crops interactions were significant for Cu, Fe, Mn, and Zn use efficiency (tops dry weight/unit nutrient uptake. Hence, cover crop species varied in nutrient use efficiency with change in P levels. The micronutrient use efficiency was in the order of Cu > Zn > Mn > Fe. Higher Cu use efficiency was associated with lower uptake of this element, in the cover crop tops compared to other micronutrients. Similar-ly, lower efficiency of Fe and Mn was associated with their higher uptake in the tops of cover crops. Overall, Cu and Mn use efficiency was decreased when P level was raised from low to medium level and then it was constant. Iron use efficiency was increased with increasing P level but Zn use efficiency was constant with the addition of P fertilizer

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

    DEFF Research Database (Denmark)

    Hansen, Elly Møller

    The maize area in northern Europe has increased dramatically during the last 20 years, in Denmark from 19,000 ha in 1990 to 172,000 ha in 2010. Knowledge about nitrogen (N) leaching from maize under temperate coastal climate conditions is sparse. In 2009 an N leaching study was started in a field......, but the effect was insignificant. The effect of tillage and previous N rates were also insignificant but the present use of cover crops had a small but significant decreasing effect on leaching compared to no cover cropping. The cover crop was well established in both years but grew less vigorously during autumn...... due to strong competition from the maize crop. The experiment shows that it is difficult for the perennial ryegrass variety used as cover crop to survive until harvest of grain maize and to reduce leaching substantially....

  6. Symbiotic N2-fixation by the cover crop Pueraria phaseoloides as influenced by litter mineralization

    DEFF Research Database (Denmark)

    Vesterager, J.M.; Østerby, S.; Jensen, E.S.

    1995-01-01

    The perennial legume Pueraria phaseoloides is widely used as a cover crop in rubber and oil palm plantations. However, very little knowledge exists on the effect of litter mineralization from P. phaseoloides on its symbiotic N-2- fixation. The contribution from symbiotic N-2-fixation (Ndfa......) and litter N (Ndfl) to total plant N in P phaseoloides was determined in a pot experiment using a N-15 cross-labeling technique. For determination of N-2-fixation the non-fixing plant Axonopus compressus was used as a reference. The experiment was carried out in a growth chamber during 9 weeks with a sandy...... soil and 4 rates of ground litter (C/N=16, 2.8% N). P. phaseoloides plants supplied with the highest amount of litter produced 26% more dry matter and fixed 23% more N than plants grown in soil with no litter application, but the percentage of Ndfa decreased slightly, but significantly, from 87 to 84...

  7. PERFORMANCE OF ‘NANICÃO JANGADA’ BANANA PLANTS INTERCROPPED WITH WINTER COVER CROPS

    Directory of Open Access Journals (Sweden)

    RICARDO SFEIR DE AGUIAR

    Full Text Available ABSTRACT The use of cover crops species may be an important strategy in the pursuit of sustainability of agroecosystems, considering benefits to soil, such as improvements of physical and chemical characteristics, and weed control. The objective of this study was to evaluate the effect of winter cover crops and other soil managements on chemical soil properties, on the cycle, on the production of the first cycle and on the fruit quality of banana cv. Nanicão Jangada in Andirá – PR, Brazil. The experiment was carried out in a commercial. Planting of banana suckers from the grower area occurred in the first half of March 2011, with a spacing of 2.40 m between rows and 1.90 m between plants. The experiment was designed in randomized blocks with four replications and six plants per plot. The six treatments were: black oat (Avenastrigosa Schreb, forage turnip (Raphanus sativus L. var. oleiferus, consortium of black oat and forage turnip, chicken litter, residues of banana plants, and bare ground. The evaluations were vegetative development and life cycle of banana plants, yield and quality of fruits, soil chemical characterstics, and fresh and dry mass of green manures. The results were submitted to ANOVA (F Test, and Tukey test at 5 % probability. Black oat and black oat with forage turnip consortium were superior in biomass production. Systems of soil management had no effect on the variables, except in the periods between planting and flowering and between planting and harvest, which were shorter in the treatment of soil management with crop residues, longer in the treatment with forage turnip, and intermediate in the other treatments.

  8. Sunn hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions.

    Science.gov (United States)

    Hinds, Jermaine; Wang, Koon-Hui; Marahatta, Sharadchandra P; Meyer, Susan L F; Hooks, Cerruti R R

    2013-12-01

    Field experiments were conducted in Maryland to investigate the influence of sunn hemp cover cropping in conjunction with organic and synthetic fertilizers on the nematode community in a zucchini cropping system. Two field treatments, zucchini planted into a sunn hemp living and surface mulch (SH) and zucchini planted into bare-ground (BG) were established during three field seasons from 2009 to 2011. In 2009, although SH slightly increased nematode richness compared with BG by the first harvest (P < 0.10), it reduced nematode diversity and enrichment indices (P < 0.01 and P < 0.10, respectively) and increased the channel index (P < 0.01) compared to BG at the final harvest. This suggests a negative impact of SH on nematode community structure. The experiment was modified in 2010 and 2011 where the SH and BG main plots were further split into two subplots to investigate the added influence of an organic vs. synthetic fertilizer. In 2010, when used as a living and surface mulch in a no-till system, SH increased bacterivorous, fungivorous, and total nematodes (P < 0.05) by the final zucchini harvest, but fertilizer type did not influence nematode community structure. In 2011, when incorporated into the soil before zucchini planting, SH increased the abundance of bacterivorous and fungivorous nematodes early in the cropping season. SH increased species richness also at the end of the season (P < 0.05). Fertilizer application did not appear to influence nematodes early in the season. However, in late season, organic fertilizers increased enrichment and structure indices and decreased channel index by the end of the zucchini cropping cycle.

  9. USE OF COVER CROPS FOR WEED SUPPRESSION IN HAZELNUT (CORYLUS AVELLANA L.) IN TURKEY.

    Science.gov (United States)

    Isik, D; Dok, M; Ak, K; Macit, I; Demir, Z; Mennan, H

    2014-01-01

    Weed management is critical in hazelnut (Corylus avellana) production. Weeds reduce nutrient availability, interfere with tree growth, and reduce hand-harvesting efficiency. Field experiments were conducted to test effects of cover crops as alternative weed management strategies in hazelnut. The cover crop treatments consisted of Trifolium repens L., Festuca rubra subsp. rubra L., Festuca arundinacea Schreb., Vicia villosa Roth. And Trifolium meneghinianum Celmand fallow with no cover crop. Control plots such as weedy control, herbicide control and mechanical control were added as reference plots. The lowest weed dry biomass was obtained from Vicia villosa plots, and there were no significant differences among all other cover crop treatments. The highest cover crop dry biomass was measured in the Trifolium meneghinianum plots. Regarding the effect of cover crops on hazelnut yields, the lowest yield was ob- tained from weedy control plots, while the highest yield was obtained from F. arundinacea plots. This research indicated that cover crops could be used as living mulch in integrated weed management programs to manage weeds in the hazelnut orchards.

  10. The Potential for Cereal Rye Cover Crops to Host Corn Seedling Pathogens.

    Science.gov (United States)

    Bakker, Matthew G; Acharya, Jyotsna; Moorman, Thomas B; Robertson, Alison E; Kaspar, Thomas C

    2016-06-01

    Cover cropping is a prevalent conservation practice that offers substantial benefits to soil and water quality. However, winter cereal cover crops preceding corn may diminish beneficial rotation effects because two grass species are grown in succession. Here, we show that rye cover crops host pathogens capable of causing corn seedling disease. We isolated Fusarium graminearum, F. oxysporum, Pythium sylvaticum, and P. torulosum from roots of rye and demonstrate their pathogenicity on corn seedlings. Over 2 years, we quantified the densities of these organisms in rye roots from several field experiments and at various intervals of time after rye cover crops were terminated. Pathogen load in rye roots differed among fields and among years for particular fields. Each of the four pathogen species increased in density over time on roots of herbicide-terminated rye in at least one field site, suggesting the broad potential for rye cover crops to elevate corn seedling pathogen densities. The radicles of corn seedlings planted following a rye cover crop had higher pathogen densities compared with seedlings following a winter fallow. Management practices that limit seedling disease may be required to allow corn yields to respond positively to improvements in soil quality brought about by cover cropping.

  11. Cover crops as a gateway to greater conservation in Iowa?: Integrating crop models, field trials, economics and farmer perspectives regarding soil resilience in light of climate change

    Science.gov (United States)

    Roesch-McNally, G. E.; Basche, A.; Tyndall, J.; Arbuckle, J. G.; Miguez, F.; Bowman, T.

    2014-12-01

    Scientists predict a number of climate changes for the US Midwest with expected declines in crop productivity as well as eco-hydrological impacts. More frequent extreme rain events particularly in the spring may well increase saturated soils thus complicating agronomic interests and also exacerbate watershed scale impairments (e.g., sediment, nutrient loss). In order to build more resilient production systems in light of climate change, farmers will increasingly need to implement conservation practices (singularly or more likely in combination) that enable farmers to manage profitable businesses yet mitigate consequential environmental impacts that have both in-field and off-farm implications. Cover crops are empirically known to promote many aspects of soil and water health yet even the most aggressive recent estimates show that only 1-2% of the total acreage in Iowa have been planted to cover crops. In order to better understand why farmers are reluctant to adopt cover crops across Iowa we combined agronomic and financial data from long-term field trials, working farm trials and model simulations so as to present comprehensive data-driven information to farmers in focus group discussions in order to understand existing barriers, perceived benefits and responses to the information presented. Four focus groups (n=29) were conducted across Iowa in four geographic regions. Focus group discussions help explore the nuance of farmers' responses to modeling outputs and their real-life agronomic realities, thus shedding light on the social and psychological barriers with cover crop utilization. Among the key insights gained, comprehensive data-driven research can influence farmer perspectives on potential cover crop impacts to cash crop yields, experienced costs are potentially quite variable, and having field/farm benefits articulated in economic terms are extremely important when farmers weigh the opportunity costs associated with adopting new practices. Our work

  12. Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance under Organic Management.

    Science.gov (United States)

    Lawson, Andrew; Cogger, Craig; Bary, Andy; Fortuna, Ann-Marie

    2015-01-01

    Cover crop benefits include nitrogen accumulation and retention, weed suppression, organic matter maintenance, and reduced erosion. Organic farmers need region-specific information on winter cover crop performance to effectively integrate cover crops into their crop rotations. Our research objective was to compare cover crop seeding mixtures, planting dates, and termination dates on performance of rye (Secale cereale L.) and hairy vetch (Vicia villosa Roth) monocultures and mixtures in the maritime Pacific Northwest USA. The study included four seed mixtures (100% hairy vetch, 25% rye-75% hairy vetch, 50% rye-50% hairy vetch, and 100% rye by seed weight), two planting dates, and two termination dates, using a split-split plot design with four replications over six years. Measurements included winter ground cover; stand composition; cover crop biomass, N concentration, and N uptake; and June soil NO3(-)-N. Rye planted in mid-September and terminated in late April averaged 5.1 Mg ha(-1) biomass, whereas mixtures averaged 4.1 Mg ha(-1) and hairy vetch 2.3 Mg ha(-1). Delaying planting by 2.5 weeks reduced average winter ground cover by 65%, biomass by 50%, and cover crop N accumulation by 40%. Similar reductions in biomass and N accumulation occurred for late March termination, compared with late April termination. Mixtures had less annual biomass variability than rye. Mixtures accumulated 103 kg ha(-1) N and had mean C:N ratio Cover crop mixtures provided a balance between biomass accumulation and N concentration, more consistent biomass over the six-year study, and were more effective at reducing winter weeds compared with monocultures.

  13. Non-overwintering cover crops: a significant source of nitrogen

    NARCIS (Netherlands)

    Schröder, J.; ten Holte, L.; Janssen, B.H.

    1997-01-01

    In field experiments in 1982-89 at 2 sites in the Netherlands, potatoes cv. Bintje and sugarbeet cv. Monohil or Ovatio in a wheat/potatoes/wheat/sugarbeet rotation were preceded during winter by fallow or a green manure crop of Lolium multiflorum cv. Tetila with 0 (G0), 100 (G100) or 200 kg N/ha (G2

  14. Cover crop residue management for optimizing weed control

    NARCIS (Netherlands)

    Kruidhof, H.M.; Bastiaans, L.; Kropff, M.J.

    2009-01-01

    Although residue management seems a key factor in residue-mediated weed suppression, very few studies have systematically compared the influence of different residue management strategies on the establishment of crop and weed species. We evaluated the effect of several methods of pre-treatment and p

  15. Non-overwintering cover crops: significant source of N.

    NARCIS (Netherlands)

    Schröder, J.J.; ten Holte, L.; Janssen, B.H.

    1997-01-01

    In field experiments in 1982-89 at 2 sites in the Netherlands, potatoes cv. Bintje and sugarbeet cv. Monohil or Ovatio in a wheat/potatoes/wheat/sugarbeet rotation were preceded during winter by fallow or a green manure crop of Lolium multiflorum cv. Tetila with 0 (G0), 100 (G100) or 200 kg N/ha (G2

  16. Erosion control in orchards and vineyards by a new soil and cover crop management method

    Science.gov (United States)

    Hartl, Wilfried; Guettler, Hans; Auer, Karl; Erhart, Eva

    2016-04-01

    Cover crops are the basis for an erosion-free soil management in orchards and vineyards. The soil cover provided by the foliage and the intensive root formation counteract erosion. Cover crops provide the soil microfauna with fresh organic matter which improves soil structure and porosity. The water demand of cover crops, however, may pose problems for the water supply of the trees and vines in dry seasons. Therefore it is necessary to adjust the growth of the cover crops to the actual water conditions. In years with ample precipitation cover crops may be allowed lush vegetative growth till flowering and formation of seeds. In dry years, the growth of the cover crop must be restricted to stop the competition for water, sometimes even by cutting off the cover crop roots. The course of the weather is incalculable and rainfall may be very variable during the year, so it is sometimes necessary to adust the cover crop management several times a year. A new special equipment, which can perform all the tasks necessary for the flexible cover crop management has been developed together with the agricultural machinery manufacturers Bodenwerkstatt Ertl-Auer GmbH and Güttler GmbH. The GreenManager® device consists of three modules, namely a specific type of cultivator, a harrow and a prismatic roller with seeding equipment, which can be used separately or in combination. The GreenManager® can reduce cover crops by flattening the plants in the whole row middle, by bringing down the cover crops with the harrow, or by horizontally cutting the cover crop roots a few centimetres beneath the soil surface in the central part of the row middle or in the whole row middle. These measures reduce the water competition by cover crops without generating further losses of soil moisture through intensive soil cultivation. At the same time the risk of soil erosion is kept to a minimum, because the soil remains covered by dead plant biomass. In one passage the GreenManager® can direct

  17. Cover Crop and Liquid Manure Effects on Soil Quality Indicators in a Corn Silage System.

    Science.gov (United States)

    Due to a lack of surface residue and organic matter inputs, continuous corn (Zea mays L.) silage production is one of the most demanding cropping systems imposed on our soil resources. In this study, our objective was to determine if using cover/companion crops and/or applying low-solids liquid dair...

  18. Effects of cover crops on the nitrogen fluxes in a silage maize production system

    NARCIS (Netherlands)

    Schröder, J.J.; Dijk, van W.; Groot, de W.J.M.

    1996-01-01

    Rye and grass cover crops can potentially intercept residual soil mineral nitrogen (SMN), reduce overwinter leaching, transfer SMN to next growing seasons and reduce the fertilizer need of subsequent crops. These aspects were studied for 6 years in continuous silage maize cv. LG 2080 production syst

  19. 7 CFR 1437.504 - Notice of loss for covered tropical crops.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Notice of loss for covered tropical crops. 1437.504 Section 1437.504 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED CROP DISASTER...

  20. Soil carbon and nitrogen affected by perennial grass, cover crop, and nitrogen fertilization

    Science.gov (United States)

    Soil C and N sequestration and the potential for N leaching can be influenced by the type of perennial grass, cover crop, and N fertilization due to differences in crop yields and the amount of residue returned to the soil. We evaluated the effects of the combinations of perennial grasses (energy ca...

  1. The effect of nitrogen fertilization and cover cropping systems on sorghum grain characteristics

    Science.gov (United States)

    The practice of no-till farming has become an increasingly popular cropping system, due to increased water and soil conservation. Recently, cover cropping has been added to the system to aid in weed prevention and also increase soil fertility. The objective of this study was to determine the effect ...

  2. Influence of cover crop and intercrop systems on Bemisia argentifolli (Hemiptera: Aleyrodidae) infestation and associated squash silverleaf disorder in zucchini.

    Science.gov (United States)

    Manandhar, Roshan; Hooks, Cerruti R R; Wright, Mark G

    2009-04-01

    Field experiments were conducted to evaluate the effects of cover cropping and intercropping on population densities of silverleaf whitefly, Bemisia argentifolli Bellow and Perring, and the incidence of squash silverleaf disorder (SSL) in zucchini, Cucurbita pepo L., in Oahu, HI. Two cover crops, buckwheat (BW), Fagopyrum esculentum Moench, and white clover (WC), Trifolium repens L., or sunn hemp (SH), Crotolaria juncea L., and an intercropped vegetable, okra, Abelmonchus esculentus L., were evaluated during the 2003, 2005, and 2006 growing seasons, respectively. Population densities of whiteflies and SSL severity varied during the three field experiments. In 2003, the severity of SSL and percentage of leaves displaying symptoms were significantly lower on zucchini plants in WC than BW plots throughout the crops' growth cycle. Additionally, the percentage of leaves per plant displaying SSL symptoms was significantly greater in bare-ground (BG) compared with the pooled BW and WC treatments on each inspection date. In 2005, zucchini intercropped with okra had lower numbers of adult whiteflies and resulted in significantly lower severity of SSL than pooled BW and WC treatments. During 2006, zucchini grown with SH had significantly lower numbers of all whitefly stages (i.e., egg, immature, and adult) and less SSL severity symptoms than BW. Despite these differences in whitefly numbers and SSL severity, marketable yields were not significantly lower in BW compared with WC or SH treatment plots during the study. The mechanisms underlying these results and the feasibility of using cover crops and intercrops to manage B. argentifolli and SSL are discussed.

  3. Organic broccoli production on transition soils: Comparing cover crops, tillage and sidedress N

    OpenAIRE

    Schellenberg, D.L.; Morse, R.D.; Welbaum, G.E.

    2009-01-01

    Metadata only record Little information is available about how farmers in transition to organic practices should manage short- and long-term N fertility. The objectives of this research were (1) to evaluate the leguminous cover crops lablab (Dolichos lablab L.), soybean (Glycine max L.), sunn hemp (Crotalaria juncea L.) and a mixture of sunn hemp and cowpea (Vigna sinensis Endl.) as N sources; (2) to compare N availability and broccoli yield when cover crops were incorporated with conventi...

  4. Watershed-Scale Cover Crops Reduce Nutrient Export From Agricultural Landscapes.

    Science.gov (United States)

    Tank, J. L.; Hanrahan, B.; Christopher, S. F.; Trentman, M. T.; Royer, T. V.; Prior, K.

    2016-12-01

    The Midwestern US has undergone extensive land use change as forest, wetlands, and prairies have been converted to agroecosystems. Today, excess fertilizer nutrients from farm fields enter Midwestern agricultural streams, which degrades both local and downstream water quality, resulting in algal blooms and subsequent hypoxic "dead zones" far from the nutrient source. We are quantifying the benefits of watershed-scale conservation practices that may reduce nutrient runoff from adjacent farm fields. Specifically, research is lacking on whether the planting of winter cover crops in watersheds currently dominated by row-crop agriculture can significantly reduce nutrient inputs to adjacent streams. Since 2013, farmers have planted cover crops on 70% of croppable acres in the Shatto Ditch Watershed (IN), and "saturation level" implementation of this conservation practice has been sustained for 3 years. Every 14 days, we have quantified nutrient loss from fields by sampling nutrient fluxes from multiple subsurface tile drains and longitudinally along the stream channel throughout the watershed. Cover crops improved stream water quality by reducing dissolved inorganic nutrients exported downstream; nitrate-N and DRP concentrations and fluxes were significantly lower in tiles draining fields with cover crops compared to those without. Annual watershed nutrient export also decreased, and reductions in N and P loss ( 30-40%) exceeded what we expected based on only a 6-10% reduction in runoff due to increased watershed water holding capacity. We are also exploring the processes responsible for increased nutrient retention, where they are occurring (terrestrial vs. aquatic) and when (baseflow vs. storms). For example, whole-stream metabolism also responded to cover crop planting, showing reduced variation in primary production and respiration in years after watershed-scale planting of cover crops. In summary, widespread land cover change, through cover crop planting, can

  5. Influence of cover crop treatments on the performance of a vineyard in a humid region

    Energy Technology Data Exchange (ETDEWEB)

    Trigo-Córdoba, E.; Bouzas-Cid, Y.; Orriols-Fernández, I.; Díaz-Losada, E.; Mirás-Avalos, J.M.

    2015-07-01

    Vineyards are usually managed by tilling the inter-rows to avoid competition from other plants for soil water and nutrients. However, in humid and sub-humid climates, such as that of NW Spain, cover crops may be an advantage for controlling vine vegetative growth and improving berry composition, while reducing management costs. The current study was conducted over three consecutive growing seasons (2012-2014) to assess the effects of establishing three permanent cover crop treatments on water relations, vine physiology, yield and berry composition of a vineyard of the red cultivar ‘Mencía’ (Vitis vinifera L.) located in Leiro, Ourense. Treatments consisted of four different soil management systems: ST, soil tillage; NV, native vegetation; ER, English ryegrass (Lolium perenne L.); and SC, subterranean clover (Trifolium subterraneum L.). Midday stem water potential was more negative in the native vegetation treatment, causing significant reductions in leaf stomatal conductance on certain dates. Total vine leaf area and pruning weight was reduced in the cover crop treatments in the last year of the experiment. Yield was unaffected by the presence of a cover crop. No significant differences among treatments were observed for berry composition; however, wines were positively affected by the SC treatment (higher tannin content and colour intensity and lower malic acid concentration when compared with ST). Wines from the cover crop treatments were preferred by taste panelists. These results indicate that in humid climates cover crop treatments can be useful for reducing vine vegetative growth without compromising yield and berry quality. (Author)

  6. Oat cover cropping and soil insecticides in an integrated sugarbeet root maggot (Diptera: Otitidae) management program.

    Science.gov (United States)

    Dregseth, Robert J; Boetel, Mark A; Schroeder, Allen J; Carlson, Robert B; Armstrong, J S

    2003-10-01

    Sugarbeet, Beta vulgaris L., producers occasionally establish cereal cover crops to minimize early-season soil erosion, wind abrasion, and mechanical injury of seedlings. We evaluated the use of living oat, Avena sativa L., cover cropping as a cultural tactic to minimize feeding injury from sugarbeet root maggot, Tetanops myopaeformis (Röder), larvae at five field sites during 1996, 1998, and 1999. Sweep-net sampling yielded 4.8-, 11.2-, and 7.2-fold more flies from oat cover-cropped chlorpyrifos, terbufos, and untreated control plots, respectively, than in noncover counterparts. However, larval feeding injury in terbufos-treated plots was reduced when cover-cropped (383 seeds/m2) at St. Thomas in all years. A reduced oat seeding rate (224 seeds/m2) also enhanced root protection in terbufos-treated plots at St. Thomas in 1999. Less root injury was sustained in cover-cropped chlorpyrifos plots than in noncover counterparts at St. Thomas in 2 study yr. Oat cover cropping also frequently resulted in reduced T. myopaeformis feeding injury in the absence of a soil insecticide. Although trends toward increased yields were often evident, significant yield benefits were limited to a 6.8% root yield increase in oat cover plots when compared with noncover treatments overall at St. Thomas in 1996 and an 18.4% sucrose yield increase in terbufos-treated plots at St. Thomas in 1999. These findings suggest that beneficial interactions between planting-time soil insecticides and cereal cover crops are achievable in areas infested by T. myopaeformis. Demonstrated reductions in root feeding injury, combined with additional agronomic benefits, may warrant use of this production practice as part of an integrated management program for this key insect pest of sugarbeet.

  7. Efficacy of Cotton Root Destruction and Winter Cover Crops for Suppression of Hoplolaimus columbus.

    Science.gov (United States)

    Davis, R F; Baird, R E; McNeil, R D

    2000-12-01

    The efficacy of rye (Secale cereale) and wheat (Triticum aestivum) winter cover crops and cotton stalk and root destruction (i.e., pulling them up) were evaluated in field tests during two growing seasons for Hoplolaimus columbus management in cotton. The effect of removing debris from the field following root destruction also was evaluated. Wheat and rye produced similar amounts of biomass, and both crops produced more biomass (P Cover crops did not suppress H. columbus population levels or increase subsequent cotton yields. Cotton root destruction did not affect cotton stand or plant height the following year. Cotton root destruction lowered (P cover crop or cotton root destruction following harvest is ineffective for H. columbus management in cotton.

  8. Monitoring cover crops using radar remote sensing in southern Ontario, Canada

    Science.gov (United States)

    Shang, J.; Huang, X.; Liu, J.; Wang, J.

    2016-12-01

    Information on agricultural land surface conditions is important for developing best land management practices to maintain the overall health of the fields. The climate condition supports one harvest per year for the majority of the field crops in Canada, with a relative short growing season between May and September. During the non-growing-season months (October to the following April), many fields are traditionally left bare. In more recent year, there has been an increased interest in planting cover crops. Benefits of cover crops include boosting soil organic matters, preventing soil from erosion, retaining soil moisture, and reducing surface runoff hence protecting water quality. Optical remote sensing technology has been exploited for monitoring cover crops. However limitations inherent to optical sensors such as cloud interference and signal saturation (when leaf area index is above 2.5) impeded its operational application. Radar remote sensing on the other hand is not hindered by unfavorable weather conditions, and the signal continues to be sensitive to crop growth beyond the saturation point of optical sensors. It offers a viable means for capturing timely information on field surface conditions (with or without crop cover) or crop development status. This research investigated the potential of using multi-temporal RADARSAT-2 C-band synthetic aperture radar (SAR) data collected in 2015 over multiple fields of winter wheat, corn and soybean crops in southern Ontario, Canada, to retrieve information on the presence of cover crops and their growth status. Encouraging results have been obtained. This presentation will report the methodology developed and the results obtained.

  9. Swine manure injection with low-disturbance applicator and cover crops reduce phosphorus losses.

    Science.gov (United States)

    Kovar, J L; Moorman, T B; Singer, J W; Cambardella, C A; Tomer, M D

    2011-01-01

    Injection of liquid swine manure disturbs surface soil so that runoff from treated lands can transport sediment and nutrients to surface waters. We determined the effect of two manure application methods on P fate in a corn (Zea mays L.)-soybean [Glycine max (L.) Merr.] production system, with and without a winter rye (Secale cereale L.)-oat (Avena sativa L.) cover crop. Treatments included: (i) no manure; (ii) knife injection; and (iii) low-disturbance injection, each with and without the cover crop. Simulated rainfall runoff was analyzed for dissolved reactive P (DRP) and total P (TP). Rainfall was applied 8 d after manure application (early November) and again in May after emergence of the corn crop. Manure application increased soil bioavailable P in the 20- to 30-cm layer following knife injection and in the 5- to 20-cm layer following low-disturbance injection. The low-disturbance system caused less damage to the cover crop, so that P uptake was more than threefold greater. Losses of DRP were greater in both fall and spring following low-disturbance injection; however, application method had no effect on TP loads in runoff in either season. The cover crop reduced fall TP losses from plots with manure applied by either method. In spring, DRP losses were significantly higher from plots with the recently killed cover crop, but TP losses were not affected. Low-disturbance injection of swine manure into a standing cover crop can minimize plant damage and P losses in surface runoff while providing optimum P availability to a subsequent agronomic crop.

  10. Grass cover crop and tillage method on watermelon production on porous soils

    Science.gov (United States)

    Watermelon [Citrullus lanatus (Thunb.) Cogn.] production in the Southern Plains is often on well-drained soil, which makes conservation of water difficult. Established cover crops can conserve moisture, but it needs to be determined what cover and tillage method provides the most benefit to watermel...

  11. Cover crops increase foraging activity of omnivorous predators in seed patches and facilitate weed biological control

    Science.gov (United States)

    Omnivores are important consumers of both weed seeds and insect pests, and habitat provisions like cover crops are suggested to promote their ecosystem services in agricultural systems. However, few studies establish direct links between cover, food, and pest suppression because they are entangled a...

  12. Soil erosion control, plant diversity, and arthropod communities under heterogeneous cover crops in an olive orchard.

    Science.gov (United States)

    Gómez, José Alfonso; Campos, Mercedes; Guzmán, Gema; Castillo-Llanque, Franco; Vanwalleghem, Tom; Lora, Ángel; Giráldez, Juan V

    2017-01-30

    A 3-year experiment compared in an olive orchard the effect of different cover crops' composition on runoff, water erosion, diversity of annual plants, and arthropod communities which could provide an alternative to conventional management based on tillage (CT). The cover crops evaluated were a seeded homogeneous grass (GC), a seeded mix of ten different species (MCseeded), and a non-seeded cover by vegetation naturally present at the farm after 20 years of mowing (MCnatural). The results suggest that heterogeneous cover crops can provide a viable alternative to homogeneous ones in olives, providing similar benefits in reducing runoff and soil losses compared to management based on bare soil. The reduction in soil loss was particularly large: 46.7 in CT to 6.5 and 7.9 t ha(-1) year(-1) in GC and MCseeded, respectively. The heterogeneous cover crops resulted in greater diversity of plant species and a modification of the arthropod communities with an increased number of predators for pests. The reduction of the cost of implanting heterogeneous cover crops, improvement of the seeding techniques, and selection of species included in the mixes require additional research to promote the use of this practice which can deliver enhanced environmental benefits.

  13. Evaluation of cover crop and reduced cultivation for reducing nitrate leaching in Ireland.

    Science.gov (United States)

    Hooker, K V; Coxon, C E; Hackett, R; Kirwan, L E; O'Keeffe, E; Richards, K G

    2008-01-01

    Nitrate (NO(3)) loss from arable systems to surface and groundwater has attracted considerable attention in recent years in Ireland. Little information exists under Irish conditions, which are wet and temperate, on the effects of winter cover crops and different tillage techniques on NO(3) leaching. This study investigated the efficacy of such practices in reducing NO(3) leaching from a spring barley (Hordeum vulgare L.) system in the Barrow River valley, southeast Ireland. The study compared the effect of two tillage systems (plow-based tillage and noninversion tillage) and two over-winter alternatives (no vegetative cover and a mustard cover crop) on soil solution NO(3) concentrations at 90 cm depth over two winter drainage seasons (2003/04 and 2004/05). Soil samples were taken and analyzed for inorganic N. During both years of the study, the use of a mustard cover crop significantly reduced NO(3) losses for the plowed and reduced cultivation treatments. Mean soil solution NO(3) concentrations were between 38 and 70% lower when a cover crop was used, and total N load lost over the winter was between 18 and 83% lower. Results from this study highlight the importance of drainage volume and winter temperatures on NO(3) concentrations in soil solution and overall N load lost. It is suggested that cover crops will be of particular value in reducing NO(3) loss in temperate regions with mild winters, where winter N mineralization is important and high winter temperatures favor a long growing season.

  14. Cover crops and pruning in Bobal and Tempranillo vineyards have little influence on grapevine nutrition

    Directory of Open Access Journals (Sweden)

    Pedro Pérez-Bermúdez

    2016-06-01

    Full Text Available ABSTRACT Cover crops may improve vineyard soil properties, grapevine nutrient status and berry composition, however, factors such as cover crop type, annual rainfall, climate and irrigation may change their effects on vineyards. From 2008 to 2011, the effects of a non-permanent cover crop and two pruning techniques on soil as well as vine nutrients and grapevine performance of two vineyards (cv. Tempranillo and cv. Bobal were evaluated. For that purpose, two legumes were sown in inter-rows of hand-pruned vines in February and were tilled at flowering. Soil tillage, or cover cropping, was combined with either light pruning or severe pruning to study foliar nutrient variations. Soil N, P, K and total organic carbon (TOC were determined in samples taken from the Ap1 horizon in January prior to vine pruning. Foliar N, P, K contents were measured in leaves sampled upon grape veraison. The differences between vineyards with cover cropping and bare soils suggest that legumes positively affected soil N (1.55 vs. 1.68 g kg−1 and 1.49 vs. 1.76 g kg−1 in Bobal and Tempranillo vineyards, respectively and soil organic matter (SOM (12.5 vs. 15.5 g kg−1 and 12.9 vs. 17.2 g kg−1 in Bobal and Tempranillo vineyards, respectively. The use of cover crops did not affect grapevine yields nor quality of Bobal and Tempranillo berry . Cover crops, or light pruning, did not alter the foliar N, P, K contents of both cultivars since their concentrations were similar to those found in the leaves from vineyards with soil tillage or severe pruning.

  15. The use of cover crops to control tree invasion on a right-of-way near Tobermory Illinois: Crop establishment and tree invasion following the second growing season

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.

    1991-02-20

    In the past two decades Ontario Hydro has relied on selective herbicide applications to remove compatible trees from its transmission and distribution rights-of-way. This approach was designed to encourage a type of biological control, where the compatible ground cover slows the invasion of tree species via competitive interaction. The success is dependent upon the occurrence of species in the area which are able to successfully interfere with tree establishment and/or growth. An alternative method of establishing this control is by replacing the existing vegetation with species that have a demonstrated ability to interfere with tree establishment. A distribution line in the Tobermory area of the Bruce Peninsula became available for an experimental cover crop planting. The line was cleared of incompatible species during the winter of 1988. A random block experimental design was used to test 6 treatments at 6 sites along this right-of-way. The treatments consisted of soil scarification and seeding with Festuca rubra, Lotus corniculatus, Dactylis glomerata, Coronilla varia and Lotium multiflorum; soil scarification and no seeding; and no soil scarification and no seeding. At the end of the 1990 growing season, the crops were established in their respective plots with good frequencies (ranging from 20 to 100%). F. rubra and D. glomerata had a mean cover of 25% and could be considered as the dominant ground cover in their treatment plots. C. varia and L. corniculatus had relatively low covers of 5 and 2%. Incompatible trees were found at the study area, with densities varying at each site. Densities were not statistically affected by the treatment, but had not increased from last year. 32 refs., 11 figs., 5 tabs.

  16. Influence of cover crops on insect pests and predators in conservation tillage cotton.

    Science.gov (United States)

    Tillman, Glynn; Schomberg, Harry; Phatak, Sharad; Mullinix, Benjamin; Lachnicht, Sharon; Timper, Patricia; Olson, Dawn

    2004-08-01

    In fall 2000, an on-farm sustainable agricultural research project was established for cotton, Gossypium hirsutum L., in Tift County, Georgia. The objective of our 2-yr research project was to determine the impact of several cover crops on pest and predator insects in cotton. The five cover crop treatments included 1) cereal rye, Secale cereale L., a standard grass cover crop; 2) crimson clover, Trifolium incarnatum L., a standard legume cover crop; 3) a legume mixture of balansa clover, Trifolium michelianum Savi; crimson clover; and hairy vetch, Vicia villosa Roth; 4) a legume mixture + rye combination; and 5) no cover crop in conventionally tilled fields. Three main groups or species of pests were collected in cover crops and cotton: 1) the heliothines Heliothis virescens (F.) and Helicoverpa zea (Boddie); 2) the tarnished plant bug, Lygus lineolaris (Palisot de Beauvois); and 3) stink bugs. The main stink bugs collected were the southern green stink bug, Nezara viridula (L.); the brown stink bug, Euschistus servus (Say); and the green stink bug, Acrosternum hilare (Say). Cotton aphids, Aphis gossypii Glover, were collected only on cotton. For both years of the study, the heliothines were the only pests that exceeded their economic threshold in cotton, and the number of times this threshold was exceeded in cotton was higher in control cotton than in crimson clover and rye cotton. Heliothine predators and aphidophagous lady beetles occurred in cover crops and cotton during both years of the experiment. Geocoris punctipes (Say), Orius insidiosus (Say), and red imported fire ant, Solenopsis invicta Buren were relatively the most abundant heliothine predators observed. Lady beetles included the convergent lady beetle, Hippodamia convergens Guérin-Méneville; the sevenspotted lady beetle, Coccinella septempunctata L.; spotted lady beetle, Coleomegilla maculata (DeGeer); and the multicolored Asian lady beetle, Harmonia axyridis (Pallas). Density of G. punctipes was

  17. Structure of bacterial communities in soil following cover crop and organic fertilizer incorporation.

    Science.gov (United States)

    Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J

    2016-11-01

    Incorporation of organic material into soils is an important element of organic farming practices that can affect the composition of the soil bacterial communities that carry out nutrient cycling and other functions crucial to crop health and growth. We conducted a field experiment to determine the effects of cover crops and fertilizers on bacterial community structure in agricultural soils under long-term organic management. Illumina sequencing of 16S rDNA revealed diverse communities comprising 45 bacterial phyla in corn rhizosphere and bulk field soil. Community structure was most affected by location and by the rhizosphere effect, followed by sampling time and amendment treatment. These effects were associated with soil physicochemical properties, including pH, moisture, organic matter, and nutrient levels. Treatment differences were apparent in bulk and rhizosphere soils at the time of peak corn growth in the season following cover crop and fertilizer application. Cover crop and fertilizer treatments tended to lower alpha diversity in early season samples. However, winter rye, oilseed radish, and buckwheat cover crop treatments increased alpha diversity in some later season samples compared to a no-amendment control. Fertilizer treatments and some cover crops decreased relative abundance of members of the ammonia-oxidizing family Nitrosomonadaceae. Pelleted poultry manure and Sustane® (a commercial fertilizer) decreased the relative abundance of Rhizobiales. Our data point to a need for future research exploring how (1) cover crops influence bacterial community structure and functions, (2) these effects differ with biomass composition and quantity, and (3) existing soil conditions and microbial community composition influence how soil microbial populations respond to agricultural management practices.

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

    Directory of Open Access Journals (Sweden)

    Ahmed Elobeid

    2013-03-01

    Full Text Available 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, and T4: 168-112-224 N-P-K kg/ha, using four replications. The Hansel variety eggplant yield was significantly higher than the Kamo variety. Eggplant yields from CC treatments for both varieties were significantly higher (p < 0.001 than the yields from NC treatments. No significant difference was observed in the yields between T1 and T2 treatments, but the yields from T3 were significantly higher than T1 and T2 and yields from T4 were significantly higher than T3 yields. N released through mineralization of cover crop mixture ranged from 13.33 g/kg at the beginning of the growing season and increased to 18.32 g/kg at the end of the growing season. These results suggest that Japanese eggplants can be successfully grown in the Piedmont area of North Carolina in rotation with cover crops for higher yields.

  19. Upland rice under no-tillage preceded by crops for soil cover and nitrogen fertilization

    Directory of Open Access Journals (Sweden)

    Edemar Moro

    2013-12-01

    Full Text Available The grain yield of upland rice under no-tillage has been unsatisfactory and one reason could be the nitrate/ammonium balance in the soil. Cover crops and nitrogen fertilization can be used to change the nitrate/ammonium relation in the soil and improve conditions for the development of upland rice in the no-tillage (NT system. The aim was to study the effect of cover crops and nitrogen sources on grain yield of upland rice under no tillage. The study was carried out on the Fazenda Experimental Lageado, in Botucatu, State of São Paulo, Brazil, in an Oxisol area under no-tillage for six years. The experiment was arranged in a randomized block split-plot design with four replications. The plots consisted of six cover crop species (Brachiaria brizantha, B. decumbens, B. humidicola, B. ruziziensis, Pennisetum americanum, and Crotalaria spectabilis and the split-plots of seven forms of N fertilizer management. Millet is the best cover crop to precede upland rice under NT. The best form of N application, as nitrate, is in split rates or total rate at topdressing or an ammonium source with or without a nitrification inhibitor, in split doses. When the cover crops C. spectabilis, B. brizantha, B. decumbens, B. humidicola, and B. ruziziensis preceded rice, they induced the highest grain yield when rice was fertilized with N as ammonium sulfate source + nitrification inhibitor in split rates or total dose at topdressing.

  20. Effect of leguminous cover crops on soil biological activity in pots of Citrus unshiu Marcovitch

    Directory of Open Access Journals (Sweden)

    Cristina Abbate

    2011-02-01

    Full Text Available Little is known about the effects of cover crops on soil properties in citrus orchards. To fill this gap, this work was aimed to determine the effects of leguminous cover crops on the chemical and biological properties of the soil and on the structure of the microbial community in pots of Citrus unshiu (Marcovitch. After amendment with cover crops, an increase in total organic C (TOC, total extractable C (TEC, and total N (TN contents were observed irrespective of the type of soil. Substrate induced respiration (SIR, and potentially mineralisable nitrogen (PMN, tested three times in one year, were higher in soils with leguminous cover crops while no significant differences were observed in protease and deaminase activity. The effect on the chemical and biochemical properties of the soil was more evident in plots containing Trifolium subterraneum. No changes were observed in the microbial communities studied (_-proteobacteria, _-proteobacteria, nitrogen-fixing, and ammonia oxidizers irrespective of the kind of cover crop or type of soil, neither were variations noted during the trial.

  1. Does grazing of cover crops impact biologically active soil C and N fractions under inversion and no tillage management

    Science.gov (United States)

    Cover crops are a key component of conservation cropping systems. They can also be a key component of integrated crop-livestock systems by offering high-quality forage during short periods between cash crops. The impact of cattle grazing on biologically active soil C and N fractions has not receiv...

  2. Changes in Soil Organic Carbon Fractions in Response to Cover Crops in an Orange Orchard

    Directory of Open Access Journals (Sweden)

    Francisco Éder Rodrigues de Oliveira

    2016-01-01

    Full Text Available ABSTRACT The cultivation of cover crops intercropped with fruit trees is an alternative to maintain mulch cover between plant rows and increase soil organic carbon (C stocks. The objective of this study was to evaluate changes in soil total organic C content and labile organic matter fractions in response to cover crop cultivation in an orange orchard. The experiment was performed in the state of Bahia, in a citrus orchard with cultivar ‘Pera’ orange (Citrus sinensis at a spacing of 6 × 4 m. A randomized complete block design with three replications was used. The following species were used as cover crops: Brachiaria (Brachiaria decumbes – BRAQ, pearl millet (Pennisetum glaucum – MIL, jack bean (Canavalia ensiformis – JB, blend (50 % each of jack bean + millet (JB/MIL, and spontaneous vegetation (SPV. The cover crops were broadcast-seeded between the rows of orange trees and mechanically mowed after flowering. Soil sampling at depths of 0.00-0.10, 0.10-0.20, and 0.20-0.40 m was performed in small soil trenches. The total soil organic C (SOC content, light fraction (LF, and the particulate organic C (POC, and oxidizable organic C fractions were estimated. Total soil organic C content was not significantly changed by the cover crops, indicating low sensitivity in reacting to recent changes in soil organic matter due to management practices. Grasses enabled a greater accumulation of SOC stocks in 0.00-0.40 m compared to all other treatments. Jack bean cultivation increased LF and the most labile oxidizable organic C fraction (F1 in the soil surface and the deepest layer tested. Cover crop cultivation increased labile C in the 0.00-0.10 m layer, which can enhance soil microbial activity and nutrient absorption by the citrus trees. The fractions LF and F1 may be suitable indicators for monitoring changes in soil organic matter content due to changes in soil management practices.

  3. The use of legume cover crops in no-tillage broccoli and cabbage production

    OpenAIRE

    Seward, David L.

    1985-01-01

    Field experiments were conducted in 1983 and 1984 to compare conventional tillage (CT) versus no-tillage (NT) production of broccoli and cabbage. The tillage treatments were applied in combination with four rates of applied nitrogen fertilizer and three cover crops: hairy vetch (Vigia villosa Roth), Austrian winter pea (Fisum arvenu L.), and cereal rye (Secale cereale L.). Transplants of 'Premium Crop' broccoli (Brassica oleracea var. italica Plenck) and 'Market Prize'...

  4. Spectral Indices to Improve Crop Residue Cover Estimation under Varying Moisture Conditions

    Directory of Open Access Journals (Sweden)

    Miguel Quemada

    2016-08-01

    Full Text Available Crop residues on the soil surface protect the soil against erosion, increase water infiltration and reduce agrochemicals in runoff water. Crop residues and soils are spectrally different in the absorption features associated with cellulose and lignin. Our objectives were to: (1 assess the impact of water on the spectral indices for estimating crop residue cover (fR; (2 evaluate spectral water indices for estimating the relative water content (RWC of crop residues and soils; and (3 propose methods that mitigate the uncertainty caused by variable moisture conditions on estimates of fR. Reflectance spectra of diverse crops and soils were acquired in the laboratory over the 400–2400-nm wavelength region. Using the laboratory data, a linear mixture model simulated the reflectance of scenes with various fR and levels of RWC. Additional reflectance spectra were acquired over agricultural fields with a wide range of crop residue covers and scene moisture conditions. Spectral indices for estimating crop residue cover that were evaluated in this study included the Normalized Difference Tillage Index (NDTI, the Shortwave Infrared Normalized Difference Residue Index (SINDRI and the Cellulose Absorption Index (CAI. Multivariate linear models that used pairs of spectral indices—one for RWC and one for fR—significantly improved estimates of fR using CAI and SINDRI. For NDTI to reliably assess fR, scene RWC should be relatively dry (RWC < 0.25. These techniques provide the tools needed to monitor the spatial and temporal changes in crop residue cover and help determine where additional conservation practices may be required.

  5. Effect of Winter Cover Crops on Soil Nitrogen Availability, Corn Yield, and Nitrate Leaching

    Directory of Open Access Journals (Sweden)

    S. Kuo

    2001-01-01

    Full Text Available Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3 leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L., annual ryegrass (Lolium multiflorum, and hairy vetch (Vicia villosa, and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L. yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation since 1987. In addition to the cover crop treatments, there were four N fertilizer rates (0, 67, 134, and 201 kg N ha-1, referred to as N0, N1, N2, and N3, respectively applied to corn. The experiment was a randomized split-block design with three replications for each treatment. Lysimeters were installed in 1987 at 0.75 m below the soil surface for leachate collection for the N0, N2, and N3 treatments. The result showed that vetch monoculture had the most influence on soil N availability and corn yield, followed by the bicultures. Rye or ryegrass monoculture had either no effect or an adverse effect on corn yield and soil N availability. Leachate NO3-N concentration was highest where vetch cover crop was planted regardless of N rates, which suggests that N mineralization of vetch N continued well into the fall and winter. Leachate NO3-N concentration increased with increasing N fertilizer rates and exceeded the U.S. Environmental Protection Agency’s drinking water standard of 10 mg N l�1 even at recommended N rate for corn in this region (coastal Pacific Northwest. In comparisons of the average NO3-N concentration during the period of high N leaching, monocultured rye and ryegrass or bicultured rye/vetch and ryegrass/vetch very effectively decreased N leaching in 1998 with dry fall weather. The amount of N available for leaching (determined based on the presidedress nitrate test, the amount of N fertilizer applied, and N uptake correlated well with average NO3

  6. Effect of winter cover crops on soil nitrogen availability, corn yield, and nitrate leaching.

    Science.gov (United States)

    Kuo, S; Huang, B; Bembenek, R

    2001-10-25

    Biculture of nonlegumes and legumes could serve as cover crops for increasing main crop yield, while reducing NO3 leaching. This study, conducted from 1994 to 1999, determined the effect of monocultured cereal rye (Secale cereale L.), annual ryegrass (Lolium multiflorum), and hairy vetch (Vicia villosa), and bicultured rye/vetch and ryegrass/vetch on N availability in soil, corn (Zea mays L.) yield, and NO3-N leaching in a silt loam soil. The field had been in corn and cover crop rotation since 1987. In addition to the cover crop treatments, there were four N fertilizer rates (0, 67, 134, and 201 kg N ha(-1), referred to as N0, N1, N2, and N3, respectively) applied to corn. The experiment was a randomized split-block design with three replications for each treatment. Lysimeters were installed in 1987 at 0.75 m below the soil surface for leachate collection for the N 0, N 2, and N 3 treatments. The result showed that vetch monoculture had the most influence on soil N availability and corn yield, followed by the bicultures. Rye or ryegrass monoculture had either no effect or an adverse effect on corn yield and soil N availability. Leachate NO3-N concentration was highest where vetch cover crop was planted regardless of N rates, which suggests that N mineralization of vetch N continued well into the fall and winter. Leachate NO3-N concentration increased with increasing N fertilizer rates and exceeded the U.S. Environmental Protection Agency's drinking water standard of 10 mg N l(-1) even at recommended N rate for corn in this region (coastal Pacific Northwest). In comparisons of the average NO3-N concentration during the period of high N leaching, monocultured rye and ryegrass or bicultured rye/vetch and ryegrass/vetch very effectively decreased N leaching in 1998 with dry fall weather. The amount of N available for leaching (determined based on the presidedress nitrate test, the amount of N fertilizer applied, and N uptake) correlated well with average NO3-N during

  7. Influence of cover crop treatments on the performance of a vineyard in a humid region

    Directory of Open Access Journals (Sweden)

    Emiliano Trigo-Córdoba

    2015-12-01

    Full Text Available Vineyards are usually managed by tilling the inter-rows to avoid competition from other plants for soil water and nutrients. However, in humid and sub-humid climates, such as that of NW Spain, cover crops may be an advantage for controlling vine vegetative growth and improving berry composition, while reducing management costs. The current study was conducted over three consecutive growing seasons (2012-2014 to assess the effects of establishing three permanent cover crop treatments on water relations, vine physiology, yield and berry composition of a vineyard of the red cultivar ‘Mencía’ (Vitis vinifera L. located in Leiro, Ourense. Treatments consisted of four different soil management systems: ST, soil tillage; NV, native vegetation; ER, English ryegrass (Lolium perenne L.; and SC, subterranean clover (Trifolium subterraneum L.. Midday stem water potential was more negative in the native vegetation treatment, causing significant reductions in leaf stomatal conductance on certain dates. Total vine leaf area and pruning weight was reduced in the cover crop treatments in the last year of the experiment. Yield was unaffected by the presence of a cover crop. No significant differences among treatments were observed for berry composition; however, wines were positively affected by the SC treatment (higher tannin content and colour intensity and lower malic acid concentration when compared with ST. Wines from the cover crop treatments were preferred by taste panelists. These results indicate that in humid climates cover crop treatments can be useful for reducing vine vegetative growth without compromising yield and berry quality.

  8. Estimating ground water recharge from topography, hydrogeology, and land cover.

    Science.gov (United States)

    Cherkauer, Douglas S; Ansari, Sajjad A

    2005-01-01

    Proper management of ground water resources requires knowledge of the rates and spatial distribution of recharge to aquifers. This information is needed at scales ranging from that of individual communities to regional. This paper presents a methodology to calculate recharge from readily available ground surface information without long-term monitoring. The method is viewed as providing a reasonable, but conservative, first approximation of recharge, which can then be fine-tuned with other methods as time permits. Stream baseflow was measured as a surrogate for recharge in small watersheds in southeastern Wisconsin. It is equated to recharge (R) and then normalized to observed annual precipitation (P). Regression analysis was constrained by requiring that the independent and dependent variables be dimensionally consistent. It shows that R/P is controlled by three dimensionless ratios: (1) infiltrating to overland water flux, (2) vertical to lateral distance water must travel, and (3) percentage of land cover in the natural state. The individual watershed properties that comprise these ratios are now commonly available in GIS data bases. The empirical relationship for predicting R/P developed for the study watersheds is shown to be statistically viable and is then tested outside the study area and against other methods of calculating recharge. The method produces values that agree with baseflow separation from streamflow hydrographs (to within 15% to 20%), ground water budget analysis (4%), well hydrograph analysis (12%), and a distributed-parameter watershed model calibrated to total streamflow (18%). It has also reproduced the temporal variation over 5 yr observed at a well site with an average error < 12%.

  9. Rye cover crop and gamagrass strip effects on NO3 concentration and load in tile drainage.

    Science.gov (United States)

    Kaspar, T C; Jaynes, D B; Parkin, T B; Moorman, T B

    2007-01-01

    A significant portion of the NO3 from agricultural fields that contaminates surface waters in the Midwest Corn Belt is transported to streams or rivers by subsurface drainage systems or "tiles." Previous research has shown that N fertilizer management alone is not sufficient for reducing NO3 concentrations in subsurface drainage to acceptable levels; therefore, additional approaches need to be devised. We compared two cropping system modifications for NO3 concentration and load in subsurface drainage water for a no-till corn (Zea mays L.)-soybean (Glycine max [L.] Merr.) management system. In one treatment, eastern gamagrass (Tripsacum dactyloides L.) was grown in permanent 3.05-m-wide strips above the tiles. For the second treatment, a rye (Secale cereale L.) winter cover crop was seeded over the entire plot area each year near harvest and chemically killed before planting the following spring. Twelve 30.5x42.7-m subsurface-drained field plots were established in 1999 with an automated system for measuring tile flow and collecting flow-weighted samples. Both treatments and a control were initiated in 2000 and replicated four times. Full establishment of both treatments did not occur until fall 2001 because of dry conditions. Treatment comparisons were conducted from 2002 through 2005. The rye cover crop treatment significantly reduced subsurface drainage water flow-weighted NO3 concentrations and NO3 loads in all 4 yr. The rye cover crop treatment did not significantly reduce cumulative annual drainage. Averaged over 4 yr, the rye cover crop reduced flow-weighted NO3 concentrations by 59% and loads by 61%. The gamagrass strips did not significantly reduce cumulative drainage, the average annual flow-weighted NO3 concentrations, or cumulative NO3 loads averaged over the 4 yr. Rye winter cover crops grown after corn and soybean have the potential to reduce the NO3 concentrations and loads delivered to surface waters by subsurface drainage systems.

  10. The Effects of Winter Cover Crops and Plant Growth Promoting Rhizobacteria on some Soil Fertility Aspects and Crop Yield in an Organic Production System of Ocimum basilicum L.

    OpenAIRE

    M. Jahan; M.B Amiri; J Shabahang; Ahmadi, F; F. Soleymani

    2014-01-01

    Sustainable agriculture systems emphasized on the on-farm inputs likes use of biofertilizers, crop rotation and cover crops. This experiment was conducted in a split plots arrangement with two factors based on randomized complete block design with three replications during years 2009-2010, at Research Farm of Ferdowsi University of Mashhad. The main factor consisted of cultivation and no cultivation of cover crops in autumn. The sub factor was biofertilizer application with four levels, inclu...

  11. Effect of a Terminated Cover Crop and Aldicarb on Cotton Yield and Meloidogyne incognita Population Density.

    Science.gov (United States)

    Wheeler, T A; Leser, J F; Keeling, J W; Mullinix, B

    2008-06-01

    Terminated small grain cover crops are valuable in light textured soils to reduce wind and rain erosion and for protection of young cotton seedlings. A three-year study was conducted to determine the impact of terminated small grain winter cover crops, which are hosts for Meloidogyne incognita, on cotton yield, root galling and nematode midseason population density. The small plot test consisted of the cover treatment as the main plots (winter fallow, oats, rye and wheat) and rate of aldicarb applied in-furrow at-plant (0, 0.59 and 0.84 kg a.i./ha) as subplots in a split-plot design with eight replications, arranged in a randomized complete block design. Roots of 10 cotton plants per plot were examined at approximately 35 days after planting. Root galling was affected by aldicarb rate (9.1, 3.8 and 3.4 galls/root system for 0, 0.59 and 0.84 kg aldicarb/ha), but not by cover crop. Soil samples were collected in mid-July and assayed for nematodes. The winter fallow plots had a lower density of M. incognita second-stage juveniles (J2) (transformed to Log(10) (J2 + 1)/500 cm(3) soil) than any of the cover crops (0.88, 1.58, 1.67 and 1.75 Log(10)(J2 + 1)/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). There were also fewer M. incognita eggs at midseason in the winter fallow (3,512, 7,953, 8,262 and 11,392 eggs/500 cm(3) soil for winter fallow, oats, rye and wheat, respectively). Yield (kg lint per ha) was increased by application of aldicarb (1,544, 1,710 and 1,697 for 0, 0.59 and 0.84 kg aldicarb/ha), but not by any cover crop treatments. These results were consistent over three years. The soil temperature at 15 cm depth, from when soils reached 18 degrees C to termination of the grass cover crop, averaged 9,588, 7,274 and 1,639 centigrade hours (with a minimum threshold of 10 degrees C), in 2005, 2006 and 2007, respectively. Under these conditions, potential reproduction of M. incognita on the cover crop did not result in a yield penalty.

  12. How are arbuscular mycorrhizal associations related to maize growth performance during short-term cover crop rotation?

    Science.gov (United States)

    Higo, Masao; Takahashi, Yuichi; Gunji, Kento; Isobe, Katsunori

    2017-07-31

    Better cover crop management options aiming to maximize the benefits of arbuscular mycorrhizal fungi (AMF) to subsequent crops are largely unknown. We investigated the impact of cover crop management methods on maize growth performance and assemblages of AMF colonizing maize roots in a field trial. The cover crop treatments comprised Italian ryegrass, wheat, brown mustard and fallow in rotation with maize. The diversity of AMF communities among cover crops used for maize management was significantly influenced by the cover crop and time course. Cover crops did not affect grain yield and aboveground biomass of subsequent maize but affected early growth. A structural equation model indicated that the root colonization, AMF diversity and maize phosphorus uptake had direct strong positive effects on yield performance. AMF variables and maize performance were related directly or indirectly to maize grain yield, whereas root colonization had a positive effect on maize performance. AMF may be an essential factor that determines the success of cover crop rotational systems. Encouraging AMF associations can potentially benefit cover cropping systems. Therefore, it is imperative to consider AMF associations and crop phenology when making management decisions. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  13. Organic farming and cover crops as an alternative to mineral fertilizers to improve soil physical properties

    Science.gov (United States)

    Sánchez de Cima, Diego; Luik, Anne; Reintam, Endla

    2015-10-01

    For testing how cover crops and different fertilization managements affect the soil physical properties in a plough based tillage system, a five-year crop rotation experiment (field pea, white potato, common barley undersown with red clover, red clover, and winter wheat) was set. The rotation was managed under four different farming systems: two conventional: with and without mineral fertilizers and two organic, both with winter cover crops (later ploughed and used as green manure) and one where cattle manure was added yearly. The measurements conducted were penetration resistance, soil water content, porosity, water permeability, and organic carbon. Yearly variations were linked to the number of tillage operations, and a cumulative effect of soil organic carbon in the soil as a result of the different fertilization amendments, organic or mineral. All the systems showed similar tendencies along the three years of study and differences were only found between the control and the other systems. Mineral fertilizers enhanced the overall physical soil conditions due to the higher yield in the system. In the organic systems, cover crops and cattle manure did not have a significant effect on soil physical properties in comparison with the conventional ones, which were kept bare during the winter period. The extra organic matter boosted the positive effect of crop rotation, but the higher number of tillage operations in both organic systems counteracted this effect to a greater or lesser extent.

  14. Artichoke (Cynara scolymus L. as cash-cover crop in an organic vegetable system

    Directory of Open Access Journals (Sweden)

    Anna LENZI

    2015-11-01

    Full Text Available In organic vegetable systems green manure crops play an important role as a nitrogen source, but they cover the soil for several months without producing a direct income. Globe artichoke (Cynara scolymus L. provides both heads to be harvested and particularly abundant plant residues to be possibly incorporated into the soil, so it may play a double role of cash and cover crop. This paper describes an on-farm study in which seed-propagated artichoke, cultivated as an annual crop, preceded zucchini squash and lettuce cultivated in sequence within a vegetable organic system. Artichoke produced about 7 t ha-1 of saleable heads and left, after harvest, 50.3 t ha-1 of fresh biomass usable as green manure. Zucchini squash and lettuce following artichoke showed a significant increase in yield when artichoke residues were incorporated into the soil. Furthermore, a residual positive effect of green manure on soil fertility was detected after lettuce harvest. 

  15. Soil Persistence of Metarhizium anisopliae Applied to Manage Sugarbeet Root Maggot in a Cover Crop Microenvironment

    Science.gov (United States)

    The sugarbeet root maggot, Tetanops myopaeformis (Röder), is a major insect pest of sugarbeet, Beta vulgaris L., in North Dakota, Minnesota, and Idaho. Three field trials using the insect pathogen Metarhizium anisopliae (Metch.) Sorok. ATCC 62176 in conjunction with cover crops were conducted in 200...

  16. Nitrous oxide emissions in cover crop-based corn production systems

    Science.gov (United States)

    Davis, Brian Wesley

    Nitrous oxide (N2O) is a potent greenhouse gas; the majority of N2O emissions are the result of agricultural management, particularly the application of N fertilizers to soils. The relationship of N2O emissions to varying sources of N (manures, mineral fertilizers, and cover crops) has not been well-evaluated. Here we discussed a novel methodology for estimating precipitation-induced pulses of N2O using flux measurements; results indicated that short-term intensive time-series sampling methods can adequately describe the magnitude of these pulses. We also evaluated the annual N2O emissions from corn-cover crop (Zea mays; cereal rye [Secale cereale], hairy vetch [Vicia villosa ], or biculture) production systems when fertilized with multiple rates of subsurface banded poultry litter, as compared with tillage incorporation or mineral fertilizer. N2O emissions increased exponentially with total N rate; tillage decreased emissions following cover crops with legume components, while the effect of mineral fertilizer was mixed across cover crops.

  17. Organic supplemental nitrogen sources for field corn production following a hairy vetch cover crop

    Science.gov (United States)

    The combined use of legume cover crops and animal byproduct organic amendments could provide agronomic and environmental benefits to organic farmers by increasing corn grain yield while optimizing N and P inputs. To test this hypothesis we conducted a two-year field study and a laboratory soil incu...

  18. Fuzzy Multi Attributive Comparison of Roller Designs used to Terminate a Cover Crop

    Science.gov (United States)

    Cover crops are a vital part of conservation tillage systems, but they have to be managed appropriately to get their full benefits. These benefits include weed pressure reduction caused by alleopathy, improving soil properties due to mulch effects and increased soil organic matter. In recent years,...

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

    DEFF Research Database (Denmark)

    Abdollahi, Lotfollah; Munkholm, Lars Juhl

    This paper examines the effect of different tillage treatments and cover crop on soil physical, chemical and biological properties of a sandy loam soil in a long-term field trial set up in 2007 at Foulum, Denmark. The experimental design is a split plot design with different tillage practices...

  20. Multiple microbial activity-based measures reflect effects of cover cropping and tillage on soils

    Science.gov (United States)

    Agricultural producers, conservation professionals, and policy makers are eager to learn of soil analytical techniques and data that document improvement in soil health by agricultural practices such as no-till and incorporation of cover crops. However, there is considerable uncertainty within the r...

  1. Can cover crops reduce the hydrological connectivity in rainfed orchards with limited water availability?

    NARCIS (Netherlands)

    A. Meerkerk; B. van Wesemael; L.H. Cammeraat

    2007-01-01

    Land degradation forms a severe problem in the extensive olive and almond plantations in Southeast Spain. Under rainfed conditions, the canopy cover of these systems is typically below 30%: the soil is frequently tilled to avoid competition for water between the tree crop and weeds and to increase t

  2. Cover crop effects on soil microbial communities and enzyme activity in semiarid agroecosystems

    Science.gov (United States)

    The objective of this study was to compare a fallow-winter wheat (Triticum aestivum L.) rotation to several cover crop-winter wheat rotations under dryland and irrigated conditions in the semiarid US High Plains. We carried out a study that included two sites (Sidney, NE, and Akron, CO), and three s...

  3. Quantitative understanding of the performance of upland rice – cover legume cropping systems in West Africa

    NARCIS (Netherlands)

    Akanvou, R.K.

    2001-01-01

    Keywords: upland rice, relay intercropping, modelling, cover crops, improved fallow.Reducing the long fallow period by replacing the natural fallow with fast growing legume species to improve soil fertility, control weeds or to grow additional forage necessitate selection of suitable species for tho

  4. Soil microbial communities under cacao agroforestry and cover crop systems in Peru

    Science.gov (United States)

    Cacao (Theobroma cacao) trees are grown in tropical regions worldwide for chocolate production. We studied the effects of agroforestry management systems and cover cropping on soil microbial communities under cacao in two different replicated field experiments in Peru. Two agroforestry systems, Imp...

  5. Effects of organic fertilization and cover crops on organic pepper production

    Science.gov (United States)

    The requirement for certified organic vegetable producers to implement a soil-building plan has led to the development of soil fertility systems based on combinations of organic fertilizers and cover crops. In order to determine optimal soil fertility combinations, conventional and organic bell pepp...

  6. Soil physical properties and grape yield influenced by cover crops and management systems

    Directory of Open Access Journals (Sweden)

    Jaqueline Dalla Rosa

    2013-10-01

    Full Text Available The use of cover crops in vineyards is a conservation practice with the purpose of reducing soil erosion and improving the soil physical quality. The objective of this study was to evaluate cover crop species and management systems on soil physical properties and grape yield. The experiment was carried out in Bento Gonçalves, RS, Southern Brazil, on a Haplic Cambisol, in a vineyard established in 1989, using White and Rose Niagara grape (Vitis labrusca L. in a horizontal, overhead trellis system. The treatments were established in 2002, consisting of three cover crops: spontaneous species (SS, black oat (Avena strigosa Schreb (BO, and a mixture of white clover (Trifolium repens L., red clover (Trifolium pratense L. and annual rye-grass (Lolium multiflorum L. (MC. Two management systems were applied: desiccation with herbicide (D and mechanical mowing (M. Soil under a native forest (NF area was collected as a reference. The experimental design consisted of completely randomized blocks, with three replications. The soil physical properties in the vine rows were not influenced by cover crops and were similar to the native forest, with good quality of the soil structure. In the inter-rows, however, there was a reduction in biopores, macroporosity, total porosity and an increase in soil density, related to the compaction of the surface soil layer. The M system increased soil aggregate stability compared to the D system. The treatments affected grapevine yield only in years with excess or irregular rainfall.

  7. Benefits of Vetch and Rye Cover Crops to Sweet Corn under No-Tillage

    NARCIS (Netherlands)

    Zotarelli, L.; Avila, L.; Scholberg, J.M.S.; Alves, B.J.R.

    2009-01-01

    Leguminous cover crops (CCs) may reduce N fertilizer requirements by fixing N biologically and storing leftover N-fertilizer applied in the previous year. The objective of this study was to determine the contribution of CCs [rye (Secale cereal L.) and hairy vetch (Vicia villosa Roth)] on plant N nut

  8. Rhizosphere microorganisms affected by soil solarization and cover cropping in Capsicum annuum and Phaseolus lunatus agroecosystems

    Science.gov (United States)

    Field experiments were conducted to evaluate the effects of soil solarization or cover cropping on bell pepper (Capsicum annuum) and lima bean (Phaseolus lunatus, L.) rhizosphere microorganisms. In Experiment I, flat surface solarization (FSS), raised bed solarization (RBS), cowpea (Vigna unguiculat...

  9. The mechanism for weed suppression by a forage radish cover crop

    Science.gov (United States)

    In the Mid-Atlantic region, forage radish (Raphanus sativus L. var. longipinnatus) winter cover crops planted prior to 1 September suppress winter annual weeds from fall until early April. Little is known about the mechanism of this weed suppression. Published research reports suggest that allelopat...

  10. 7 CFR 1437.502 - Coverage periods and fees for covered tropical crops.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 10 2010-01-01 2010-01-01 false Coverage periods and fees for covered tropical crops. 1437.502 Section 1437.502 Agriculture Regulations of the Department of Agriculture (Continued) COMMODITY CREDIT CORPORATION, DEPARTMENT OF AGRICULTURE LOANS, PURCHASES, AND OTHER OPERATIONS NONINSURED...

  11. Utilization of sunn hemp for cover crops and weed control in temperate climates

    Science.gov (United States)

    The need to develop increasingly integrated pest management and sustainable food production systems has encouraged a greater interest to thoroughly evaluate effective utilization of cover crops in agricultural systems. Sunn hemp, a tropical legume that originated most likely from the Indo-Pakistani ...

  12. Sunn Hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions

    Science.gov (United States)

    Plantings of sunn hemp as a cover crop have been experimentally shown to improve soil health, reduce plant-parasitic nematodes, and increase nematode-antagonistic microorganisms. However, these studies have been largely conducted in tropical and subtropical regions. To investigate the impacts of sun...

  13. Sunn hemp as a cover crop to reduce nitrogen inputs for winter wheat

    Science.gov (United States)

    The tropical legume sunn hemp (Crotalaria juncea L.) has the potential to perform as a beneficial cover crop in the southeastern United States due to its ability to accumulate large amounts of biomass and symbiotic nitrogen (N) in a short period of time during the summer months. Planting sunn hemp,...

  14. Long-term effects of compost and cover crops on soil phosphorus in two California agroecosystems

    Science.gov (United States)

    Inefficient P use in agriculture results in soil P accumulation and losses to surrounding ecosystems, highlighting the need to reduce external inputs and use them more efficiently. Composts reduce the need for mineral fertilizers by recycling P from wastes at the regional scale, whereas cover crops ...

  15. Estimation of runoff mitigation by morphologically different cover crop root systems

    Science.gov (United States)

    Yu, Yang; Loiskandl, Willibald; Kaul, Hans-Peter; Himmelbauer, Margarita; Wei, Wei; Chen, Liding; Bodner, Gernot

    2016-07-01

    Hydrology is a major driver of biogeochemical processes underlying the distinct productivity of different biomes, including agricultural plantations. Understanding factors governing water fluxes in soil is therefore a key target for hydrological management. Our aim was to investigate changes in soil hydraulic conductivity driven by morphologically different root systems of cover crops and their impact on surface runoff. Root systems of twelve cover crop species were characterized and the corresponding hydraulic conductivity was measured by tension infiltrometry. Relations of root traits to Gardner's hydraulic conductivity function were determined and the impact on surface runoff was estimated using HYDRUS 2D. The species differed in both rooting density and root axes thickness, with legumes distinguished by coarser axes. Soil hydraulic conductivity was changed particularly in the plant row where roots are concentrated. Specific root length and median root radius were the best predictors for hydraulic conductivity changes. For an intensive rainfall simulation scenario up to 17% less rainfall was lost by surface runoff in case of the coarsely rooted legumes Melilotus officinalis and Lathyrus sativus, and the densely rooted Linum usitatissimum. Cover crops with coarse root axes and high rooting density enhance soil hydraulic conductivity and effectively reduce surface runoff. An appropriate functional root description can contribute to targeted cover crop selection for efficient runoff mitigation.

  16. US-1136, US-1137, and US-1138 cowpea lines for cover crop use

    Science.gov (United States)

    Following five years of field evaluation, three cowpea populations were selected as best adapted for use as a cover crop. A pure line selection procedure was used to develop genetically uniform lines from the segregating populations. Field evaluations demonstrated that the lines grow rapidly for u...

  17. Phosphatase activity in sandy soil influenced by mycorrhizal and non-mycorrhizal cover crops

    Directory of Open Access Journals (Sweden)

    Alceu Kunze

    2011-06-01

    Full Text Available Cover crops may difffer in the way they affect rhizosphere microbiota nutrient dynamics. The purpose of this study was to evaluate the effect of mycorrhizal and non-mycorrhizal cover crops on soil phosphatase activity and its persistence in subsequent crops. A three-year experiment was carried out with a Typic Quartzipsamment. Treatments were winter species, either mycorrhizal black oat (Avena strigosa Schreb or the non-mycorrhizal species oilseed radish (Raphanus sativus L. var. oleiferus Metzg and corn spurry (Spergula arvensis L.. The control treatment consisted of resident vegetation (fallow in the winter season. In the summer, a mixture of pearl millet (Pennisetum americanum L. with sunnhemp (Crotalaria juncea L. or with soybean (Glycine max L. was sown in all plots. Soil cores (0-10 cm and root samples were collected in six growing seasons (winter and summer of each year. Microbial biomass P was determined by the fumigation-extraction method and phosphatase activity using p-nitrophenyl-phosphate as enzyme substrate. During the flowering stage of the winter cover crops, acid phosphatase activity was 30-35 % higher in soils with the non-mycorrhizal species oilseed radish, than in the control plots, regardless of the amount of P immobilized in microbial biomass. The values of enzyme activity were intermediate in the plots with corn spurry and black oat. Alkaline phosphatase activity was 10-fold lower and less sensitive to the treatments, despite the significant relationship between the two phosphatase activities. The effect of plant species on the soil enzyme profile continued in the subsequent periods, during the growth of mycorrhizal summer crops, after completion of the life cycle of the cover crops.

  18. Influence of Seeding Ratio, Planting Date, and Termination Date on Rye-Hairy Vetch Cover Crop Mixture Performance under Organic Management.

    Directory of Open Access Journals (Sweden)

    Andrew Lawson

    Full Text Available Cover crop benefits include nitrogen accumulation and retention, weed suppression, organic matter maintenance, and reduced erosion. Organic farmers need region-specific information on winter cover crop performance to effectively integrate cover crops into their crop rotations. Our research objective was to compare cover crop seeding mixtures, planting dates, and termination dates on performance of rye (Secale cereale L. and hairy vetch (Vicia villosa Roth monocultures and mixtures in the maritime Pacific Northwest USA. The study included four seed mixtures (100% hairy vetch, 25% rye-75% hairy vetch, 50% rye-50% hairy vetch, and 100% rye by seed weight, two planting dates, and two termination dates, using a split-split plot design with four replications over six years. Measurements included winter ground cover; stand composition; cover crop biomass, N concentration, and N uptake; and June soil NO3(--N. Rye planted in mid-September and terminated in late April averaged 5.1 Mg ha(-1 biomass, whereas mixtures averaged 4.1 Mg ha(-1 and hairy vetch 2.3 Mg ha(-1. Delaying planting by 2.5 weeks reduced average winter ground cover by 65%, biomass by 50%, and cover crop N accumulation by 40%. Similar reductions in biomass and N accumulation occurred for late March termination, compared with late April termination. Mixtures had less annual biomass variability than rye. Mixtures accumulated 103 kg ha(-1 N and had mean C:N ratio <17:1 when planted in mid-September and terminated in late April. June soil NO3(--N (0 to 30 cm depth averaged 62 kg ha(-1 for rye, 97 kg ha(-1 for the mixtures, and 119 kg ha(-1 for hairy vetch. Weeds comprised less of the mixtures biomass (20% weeds by weight at termination compared with the monocultures (29%. Cover crop mixtures provided a balance between biomass accumulation and N concentration, more consistent biomass over the six-year study, and were more effective at reducing winter weeds compared with monocultures.

  19. Database for estimating tree responses of walnut and other hardwoods to ground cover management practices

    Science.gov (United States)

    J.W. Van Sambeek

    2010-01-01

    The ground cover in plantings of walnut and other hardwoods can substantially affect tree growth and seed production. The number of alternative ground covers that have been suggested for establishment in tree plantings far exceeds the number that have already been tested with walnut and other temperate hardwoods. Knowing how other hardwood species respond to ground...

  20. Morphostructural characterization of soil conventionally tilled with mechanized and animal traction with and without cover crop

    Directory of Open Access Journals (Sweden)

    Ricardo Ralisch

    2010-12-01

    Full Text Available The structural stability and restructuring ability of a soil are related to the methods of crop management and soil preparation. A recommended strategy to reduce the effects of soil preparation is to use crop rotation and cover crops that help conserve and restore the soil structure. The aim of this study was to evaluate and quantify the homogeneous morphological units in soil under conventional mechanized tillage and animal traction, as well as to assess the effect on the soil structure of intercropping with jack bean (Canavalia ensiformis L.. Profiles were analyzed in April of 2006, in five counties in the Southern-Central region of Paraná State (Brazil, on family farms producing maize (Zea mays L., sometimes intercropped with jack bean. The current structures in the crop profile were analyzed using Geographic Information Systems (GIS and subsequently principal component analysis (PCA to generate statistics. Morphostructural soil analysis showed a predominance of compact units in areas of high-intensity cultivation under mechanized traction. The cover crop did not improve the structure of the soil with low porosity and compact units that hamper the root system growth. In areas exposed to animal traction, a predominance of cracked units was observed, where roots grew around the clods and along the gaps between them.

  1. Summer cover crops reduce atrazine leaching to shallow groundwater in southern Florida.

    Science.gov (United States)

    Potter, Thomas L; Bosch, David D; Joo, Hyun; Schaffer, Bruce; Muñoz-Carpena, Rafael

    2007-01-01

    At Florida's southeastern tip, sweet corn (Zea Mays) is grown commercially during winter months. Most fields are treated with atrazine (6-chloro-N-ethyl-N'-[1-methylethyl]-1,3,5-triazine-2,4-diamine). Hydrogeologic conditions indicate a potential for shallow groundwater contamination. This was investigated by measuring the parent compound and three degradates--DEA (6-chloro-N-[1-methylethyl]-1,3,5-triazine-2,4-diamine), DIA (6-chloro-N-ethyl)-1,3,5-triazine-2,4-diamine, and HA (6-hydroxy-N-[1-methylethyl]-1,3,5-triazine-2,4-diamine)--in water samples collected beneath sweet corn plots treated annually with the herbicide. During the study, a potential mitigation measure (i.e., the use of a cover crop, Sunn Hemp [Crotalaria juncea L.], during summer fallow periods followed by chopping and turning the crop into soil before planting the next crop) was evaluated. Over 3.5 yr and production of four corn crops, groundwater monitoring indicated leaching of atrazine, DIA, and DEA, with DEA accounting for more than half of all residues in most samples. Predominance of DEA, which increased after the second atrazine application, was interpreted as an indication of rapid and extensive atrazine degradation in soil and indicated that an adapted community of atrazine degrading organisms had developed. A companion laboratory study found a sixfold increase in atrazine degradation rate in soil after three applications. Groundwater data also revealed that atrazine and degradates concentrations were significantly lower in samples collected beneath cover crop plots when compared with concentrations below fallow plots. Together, these findings demonstrated a relatively small although potentially significant risk for leaching of atrazine and its dealkylated degradates to groundwater and that the use of a cover crop like Sunn Hemp during summer months may be an effective mitigation measure.

  2. Nitrogen Transfer from Cover Crop Residues to Onion Grown under Minimum Tillage in Southern Brazil

    Directory of Open Access Journals (Sweden)

    Leoncio de Paula Koucher

    2017-08-01

    Full Text Available ABSTRACT Nitrogen derived from cover crop residues may contribute to the nutrition of onion grown under minimum tillage (MT and cultivated in rotation. The aim of this study was to evaluate the N transferred from different cover crop residues to the onion crop cultivated under MT in southern Brazil. In June 2014, oilseed radish, black oat, and oilseed radish + black oat residues labeled with 15N were deposited on the soil surface before transplanting onions. During the growth season and at harvest, young expanded onion leaves, complete plants, and samples from different soil layers were collected and analyzed for recovery of 15N-labeled residue. Oilseed radish decomposed faster than other residues and 4 % of residue N was recovered in leaves and bulbs at harvest, but in general, N in plant organs was derived from sources other than the cover crop residues. In addition, leaf N was in the proper range for all treatments and was adequately mobilized to the bases for bulbing. The N derived from decomposing residues contributed little to onion development and the use of these plants should be chosen based on their advantages for physical and biological soil quality.

  3. Winter annual cover crop has only minor effects on major corn arthropod pests.

    Science.gov (United States)

    Davis, Holly N; Currie, Randall S; Klocke, Norman L; Buschman, Lawrent L

    2010-04-01

    We studied the effects of downy brome, Bromus tectorum L., winter cover crop on several corn, Zea mays L., pests in the summer crop after the cover crop. An experiment was conducted that consisted of two trials with two levels of irrigation, two levels of weed control, and two levels of downy brome. Corn was grown three consecutive years after the downy brome grown during the winter. Banks grass mites, Oligonychus pratensis (Banks), twospotted spider mites, Tetranychus urticae Koch, and predatory mites from the genus Neoseiulus were present in downy brome at the beginning of the growing season. They moved into corn, but their numbers did not differ significantly across the treatments. Larval western corn rootworm, Diabrotica virgifera virgifera LeConte, feeding on corn roots was evaluated the second and third years of corn, production. Irrigation and herbicide treatments had no significant effects on rootworm injury levels. In one trial, rootworm injury ratings were significantly greater in treatments with a history of high versus low brome, but this effect was not significant in the other trial. Rootworm injury seemed to be similar across plots with different surface soil moistures. This suggests that the use of a winter cover crop such as downy brome will not have a major negative impact the arthropods studied.

  4. Establishment of three permanent cover crop seed mixtures in Hungarian vineyards

    Science.gov (United States)

    Miglécz, Tamas; Valkó, Orsolya; Donkó, Ádám; Deák, Balázs; Török, Péter; Kelemen, András; Drexler, Dóra; Tóthmérész, Béla

    2015-04-01

    In organic vineyard farming sowing high diversity cover crop seed mixtures offers a great opportunity to overcome high-priority problems mitigating vineyard cultivation, such as gain erosion control, save soil fertility, improve soil microbial activity and control weeds. Furthermore, we can also improve the biodiversity and ecosystem services of vineyards. Mainly non-native or low diversity seed mixtures are used for cover cropping containing some grass, grain or Fabaceae species. We studied vegetation development after sowing native high-diversity seed mixtures in four vineyards in an on farm field trial. We compared the effects of 4 treatments: (i) Biocont-Ecowin mixture (12 species), (ii) Fabaceae mixture (9 species), (iii) Grass-forb mixture (16 species) and control (no seed sowing). Study sites were located in Tokaj wine region, East Hungary. Seed mixtures were sown in March, 2012. After sowing, we recorded the percentage cover of vascular plant species in the end of June 2012, 2013 and 2014 in altogether 80 permanent plots. In the first year the establishment and weed control of Biocont-Ecowin and Legume seed mixture was the best. For the second year in inter-rows sown with Grass-herb and Legume seed mixtures we detected decreasing weed cover scores, while in inter-rows sown with Biocont-Ecowin seed mixture and in control inter-rows we detected higher weed cover scores. In the third year we still detected lower weed cover scores in inter-rows sown with Grass-forb and Legume seed mixtures, however on several sites we also detected decreasing cover of sown species. All sown species were detected in our plots during the time of the study, however some species were present only with low cover scores or only in a few plots. Out of the sown species Lotus corniculatus, Medicago lupulina, Plantago lanceolata, Trifolium repens, T. pratense and Coronilla varia established the most successfully, and had high cover scores on most sites even in the second and third year

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

    Science.gov (United States)

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

  6. Mechanical wounding under field conditions: A potential tool to increase the allelopathic inhibitory effect of cover crops on weeds?

    NARCIS (Netherlands)

    Kruidhof, H.M.; Dam, van N.M.; Ritz, C.; Lotz, L.A.P.; Kropff, M.J.; Bastiaans, L.

    2014-01-01

    To increase the inhibitory effect of soil-incorporated cover crop residues on germination and early growth of weeds, the allelochemical content of the cover crop at the time of soil incorporation should be maximal. We investigated whether mechanical damaging in spring induced the production of allel

  7. Evaluating the relationship between biomass, percent groundcover and remote sensing indices across six winter cover crop fields in Maryland

    Science.gov (United States)

    Planting cover crops is an effective method to reduce both nitrogen leaching and sedimentation into waterways. Winter cover crops are planted post-harvest on corn and soybean fields to scavenge residual nitrogen that remains in the soil, and to meet soil erosion guidelines, providing positive water...

  8. Effects of winter cover crop, soil amendment, and variety on organic rice production and greenhouse gas emissions

    Science.gov (United States)

    Nitrogen supply and disease are two main challenges in organic rice production. Cover crop and soil amendment can be options to increase soil N while keeps rice health. The objective of this study was to test the effects of cover crop and soil amendment on the production of organic rice. Three popul...

  9. Cover crop management practices-implications for early season weed control in conservation tillage corn cotton rotation

    Science.gov (United States)

    Use of the winter cover crops is an integral component of the conservation systems in corn (Zea mays L.) and cotton (Gossypium hirsutum L.). A field experiment was initiated in 2004 to evaluate weed suppression provided by winter cover crops in a conservation tillage corn and cotton rotation. Rotati...

  10. A powered roller/crimper for walk-behind tractors to terminate cover crops in conservation agriculture

    Science.gov (United States)

    Roller/crimper implements have been used in large conservation farming systems to terminate cover crops near maturity and flatten them down to create a mulch through which cash crops can be planted directly into the cover residue. On small farms, tractors are usually small and less powerful relative...

  11. Cover cropping to reduce nitrate loss through subsurface drainage in the northern U.S. corn belt.

    Science.gov (United States)

    Strock, J S; Porter, P M; Russelle, M P

    2004-01-01

    Despite the use of best management practices for nitrogen (N) application rate and timing, significant losses of nitrate nitrogen (NO3(-)-N) in drainage discharge continue to occur from row crop cropping systems. Our objective was to determine whether a autumn-seeded winter rye (Secale cereale L.) cover crop following corn (Zea mays L.) would reduce NO3(-)-N losses through subsurface tile drainage in a corn-soybean [Glycine mar (L.) Merr.] cropping system in the northern Corn Belt (USA) in a moderately well-drained soil. Both phases of the corn-soybean rotation, with and without the winter rye cover crop following corn, were established in 1998 in a Normania clay loam (fine-loamy, mixed, mesic Aquic Haplustoll) soil at Lamberton, MN. Cover cropping did not affect subsequent soybean yield, but reduced drainage discharge, flow-weighted mean nitrate concentration (FWMNC), and NO3(-)-N loss relative to winter fallow, although the magnitude of the effect varied considerably with annual precipitation. Three-year average drainage discharge was lower with a winter rye cover crop than without (p = 0.06). Over three years, subsurface tile-drainage discharge was reduced 11% and NO3(-)-N loss was reduced 13% for a corn-soybean cropping system with a rye cover crop following corn than with no rye cover crop. We estimate that establishment of a winter rye cover crop after corn will be successful in one of four years in southwestern Minnesota. Cover cropping with rye has the potential to be an effective management tool for reducing NO3(-)-N loss from subsurface drainage discharge despite challenges to establishment and spring growth in the north-central USA.

  12. Comparison of species-rich cover crop mixtures in Hungarian vineyards

    Science.gov (United States)

    Donkó, Adam; Miglécz, Tamas; Valkó, Orsolya; Török, Peter; Deák, Balazs; Kelemen, Andras; Zanathy, Gabor; Drexler, Dora

    2014-05-01

    In case of vine growing, agricultural practices of the past decades - as mechanical cultivation on steep vineyard slopes - can endanger the soil of vineyards. Moreover, climate change scenarios predict heavier rainstorms, which can also promote the degradation of the soil. These are some of the reasons why sustainable floor management plays an increasingly important role in viticulture recently. The use of cover crops in the inter-row has a special importance, especially on steep slopes and in case of organic farming to provide conditions for environmental friendly soil management. Species-rich cover crop seed mixtures may help to prevent erosion and create easier cultivation circumstances. Furthermore they have a positive effect on soil structure, soil fertility and ecosystem functions. However, it is important to find suitable seed mixtures for specific production sites, consisting ideally of native species from local provenance, adapted to the local climate/vine region/vineyard. Requirements for suitable cover crop species are as follows: they should save the soil from erosion and also from compaction caused by the movement of workers and machines, they should not compete significantly with the grapevines, or influence produce quality. We started to develop and apply several species-rich cover crop seed mixtures in spring 2012. During the experiments, three cover crop seed mixtures (Biocont-Ecovin mixture, mixture of legumes, mixture of grasses and herbs) were compared in vineyards of the Tokaj and Szekszárd vine regions of Hungary. Each mixture was sown in three consecutive inter-rows at each experimental site (all together 10 sites). Besides botanical measurements, yield, must quality, and pruning weight was studied in every treatment. The botanical survey showed that the following species of the mixtures established successfully and prospered during the years 2012 and 2013: Coronilla varia, Lotus corniculatus, Medicago lupulina, Onobrychis viciifolia

  13. The Effects of Winter Cover Crops and Plant Growth Promoting Rhizobacteria on some Soil Fertility Aspects and Crop Yield in an Organic Production System of Ocimum basilicum L.

    Directory of Open Access Journals (Sweden)

    M Jahan

    2014-03-01

    Full Text Available Sustainable agriculture systems emphasized on the on-farm inputs likes use of biofertilizers, crop rotation and cover crops. This experiment was conducted in a split plots arrangement with two factors based on randomized complete block design with three replications during years 2009-2010, at Research Farm of Ferdowsi University of Mashhad. The main factor consisted of cultivation and no cultivation of cover crops in autumn. The sub factor was biofertilizer application with four levels, included 1-Nitroxin® (containing Azotobacter spp. and Azospirillum spp., 2-Biophosphorous® (Bacillus sp. and Pseudomonas sp., 3-Nitroxin® + Biophosphorous® and 4-Control. Results showed that most characteristics, e.g. seed yield and harvest index were increased with no cover crop cultivation. However in control treatment, the biological yield, seed yield and harvest index were more than biofertilizeres treatments, as Nitroxin® and Biophosphorous® ranked after the control. Amongst the biofertilizers, Biophosphorus® had the most positive effects. The maximum grain weight was obtained from Nitroxin®+ Biophosphorous® treatment. The interaction effects of biofertilizer and cover crops were significant among some characteristics. The results showed that the interaction between biofertilizers and no cover crop cultivation was significant, as use of the biofertilizers especially Nitroxin® and Biophosphorous® in no cover crop condition increased the amounts of biological yield and seed yield.

  14. Tillage, cover-crop residue management, and irrigation incorporation impact on fomesafen runoff.

    Science.gov (United States)

    Potter, Thomas L; Truman, Clint C; Webster, Theodore M; Bosch, David D; Strickland, Timothy C

    2011-07-27

    Intensive glyphosate use has contributed to the evolution and occurrence of glyphosate-resistant weeds that threaten production of many crops. Sustained use of this highly valued herbicide requires rotation and/or substitution of herbicides with different modes of action. Cotton growers have shown considerable interest in the protoporphyrinogen oxidase inhibitor, fomesafen. Following registration for cotton in 2008, use has increased rapidly. Environmental fate data in major use areas are needed to appropriately evaluate risks. Field-based rainfall simulation was used to evaluate fomesafen runoff potential with and without irrigation incorporation in a conventional tillage system (CT) and when conservation tillage (CsT) was practiced with and without cover crop residue rolling. Without irrigation incorporation, relatively high runoff, about 5% of applied, was measured from the CT system, indicating that this compound may present a runoff risk. Runoff was reduced by >50% when the herbicide was irrigation incorporated after application or when used with a CsT system. Data indicate that these practices should be implemented whenever possible to reduce fomesafen runoff risk. Results also raised concerns about leaching and potential groundwater contamination and crop injury due to rapid washoff from cover crop residues in CsT systems. Further work is needed to address these concerns.

  15. Reducing nitrate loss in tile drainage water with cover crops and water-table management systems.

    Science.gov (United States)

    Drury, C F; Tan, C S; Welacky, T W; Reynolds, W D; Zhang, T Q; Oloya, T O; McLaughlin, N B; Gaynor, J D

    2014-03-01

    Nitrate lost from agricultural soils is an economic cost to producers, an environmental concern when it enters rivers and lakes, and a health risk when it enters wells and aquifers used for drinking water. Planting a winter wheat cover crop (CC) and/or use of controlled tile drainage-subirrigation (CDS) may reduce losses of nitrate (NO) relative to no cover crop (NCC) and/or traditional unrestricted tile drainage (UTD). A 6-yr (1999-2005) corn-soybean study was conducted to determine the effectiveness of CC+CDS, CC+UTD, NCC+CDS, and NCC+UTD treatments for reducing NO loss. Flow volume and NO concentration in surface runoff and tile drainage were measured continuously, and CC reduced the 5-yr flow-weighted mean (FWM) NO concentration in tile drainage water by 21 to 38% and cumulative NO loss by 14 to 16% relative to NCC. Controlled tile drainage-subirrigation reduced FWM NO concentration by 15 to 33% and cumulative NO loss by 38 to 39% relative to UTD. When CC and CDS were combined, 5-yr cumulative FWM NO concentrations and loss in tile drainage were decreased by 47% (from 9.45 to 4.99 mg N L and from 102 to 53.6 kg N ha) relative to NCC+UTD. The reductions in runoff and concomitant increases in tile drainage under CC occurred primarily because of increases in near-surface soil hydraulic conductivity. Cover crops increased corn grain yields by 4 to 7% in 2004 increased 3-yr average soybean yields by 8 to 15%, whereas CDS did not affect corn or soybean yields over the 6 yr. The combined use of a cover crop and water-table management system was highly effective for reducing NO loss from cool, humid agricultural soils.

  16. BRS Centauro – oat cultivar for ground cover and grazing

    Directory of Open Access Journals (Sweden)

    Alfredo do Nascimento Junior

    2015-04-01

    Full Text Available Plants and seeds of oat cultivar BRS Centauro, of the species Avena brevis Roth., are highly uniform. The crop cycle is long, the suitability as fodder excellent, and leaf production particularly high, resulting in better quality forage than that of the black oat forage controls.

  17. Soil microbial functionality in response to the inclusion of cover crop mixtures in agricultural systems

    Energy Technology Data Exchange (ETDEWEB)

    Chavarría, D.N.; Verdenelli, R.A.; Muñoz, M.J.; Conforto, C.; Restovich, S.B.; Andriulo, A.E.; Meriles, J.M.; Vargas-Gil, S.

    2016-11-01

    Agricultural systems where monoculture prevails are characterized by fertility losses and reduced contribution to ecosystem services. Including cover crops (CC) as part of an agricultural system is a promising choice in sustainable intensification of those demanding systems. We evaluated soil microbial functionality in cash crops in response to the inclusion of CC by analyzing soil microbial functions at two different periods of the agricultural year (cash crop harvest and CC desiccation) during 2013 and 2014. Three plant species were used as CC: oat (Avena sativa L.), vetch (Vicia sativa L.) and radish (Raphanus sativus L.) which weresown in two different mixtures of species: oat and radish mix (CC1) and oat, radish and vetch mix (CC2), with soybean monoculture and soybean/corn being the cash crops. The study of community level physiological profiles showed statistical differences in respiration of specific C sources indicating an improvement of catabolic diversity in CC treatments. Soil enzyme activities were also increased with the inclusion of CC mixtures, with values of dehydrogenase activity and fluorescein diacetate hydrolysis up to 38.1% and 35.3% higher than those of the control treatment, respectively. This research evidenced that CC inclusion promotes soil biological quality through a contribution of soil organic carbon, improving the sustainability of agrosystems. The use of a CC mixture of three plant species including the legume vetch increased soil biological processes and catabolic diversity, with no adverse effects on cash crop grain yield. (Author)

  18. Soil microbial functionality in response to the inclusion of cover crop mixtures in agricultural systems

    Directory of Open Access Journals (Sweden)

    Diego N. Chavarría

    2016-06-01

    Full Text Available Agricultural systems where monoculture prevails are characterized by fertility losses and reduced contribution to ecosystem services. Including cover crops (CC as part of an agricultural system is a promising choice in sustainable intensification of those demanding systems. We evaluated soil microbial functionality in cash crops in response to the inclusion of CC by analyzing soil microbial functions at two different periods of the agricultural year (cash crop harvest and CC desiccation during 2013 and 2014. Three plant species were used as CC: oat (Avena sativa L., vetch (Vicia sativa L. and radish (Raphanus sativus L. which were sown in two different mixtures of species: oat and radish mix (CC1 and oat, radish and vetch mix (CC2, with soybean monoculture and soybean/corn being the cash crops. The study of community level physiological profiles showed statistical differences in respiration of specific C sources indicating an improvement of catabolic diversity in CC treatments. Soil enzyme activities were also increased with the inclusion of CC mixtures, with values of dehydrogenase activity and fluorescein diacetate hydrolysis up to 38.1% and 35.3% higher than those of the control treatment, respectively. This research evidenced that CC inclusion promotes soil biological quality through a contribution of soil organic carbon, improving the sustainability of agrosystems. The use of a CC mixture of three plant species including the legume vetch increased soil biological processes and catabolic diversity, with no adverse effects on cash crop grain yield.

  19. Cover plants with potential use for crop-livestock integrated systems in the Cerrado region

    Directory of Open Access Journals (Sweden)

    Arminda Moreira de Carvalho

    2011-10-01

    Full Text Available The objective of this work was to evaluate the effects of lignin, hemicellulose, and cellulose concentrations in the decomposition process of cover plant residues with potential use in no-tillage with corn, for crop-livestock integrated system, in the Cerrado region. The experiment was carried out at Embrapa Cerrados, in Planaltina, DF, Brazil in a split plot experimental design. The plots were represented by the plant species and the subplots by harvesting times, with three replicates. The cover plants Urochloa ruziziensis, Canavalia brasiliensis, Cajanus cajan, Pennisetum glaucum, Mucuna aterrima, Raphanus sativus, Sorghum bicolor were evaluated together with spontaneous plants in the fallow. Cover plants with lower lignin concentrations and, consequently, higher residue decomposition such as C. brasiliensis and U. ruziziensis promoted higher corn yield. High concentrations of lignin inhibit plant residue decomposition and this is favorable for the soil cover. Lower concentrations of lignin result in accelerated plant decomposition, more efficient nutrient cycling, and higher corn yield.

  20. Management of Rotylenchulus reniformis in pineapple, Ananas comosus, by intercycle cover crops.

    Science.gov (United States)

    Wang, K-H; Sipes, B S; Schmitt, D P

    2002-06-01

    The effects of intercycle cover crops on Rotylenchulus reniformis population densities in pineapple were evaluated in one greenhouse and two field experiments. In the greenhouse, Crotalaria juncea, Brassica napus, and Tagetes erecta were planted for 3 months and then incorporated. These treatments were compared to weedy fallow with or without 1,3-dichloropropene (1,3-D) in three soils (Makawao fallow, Wahiawa fallow, and Wahiawa pineapple) naturally infested with R. reniformis. All cover crop incorporation suppressed R. reniformis numbers in cowpea more than did the weedy treatment in the Makawao (P < 0.05) but not in the Wahiawa soils. Crotalaria juncea treatment increased bacterivorous nematodes and nematode-trapping fungal population densities more than the other treatments in Makawao fallow and Wahiawa pineapple-planted soils. The field trials included the same plants as well as Sinapis alba. Treatments with Crotalaria juncea and 1,3-D maintained lower R. reniformis population densities on pineapple longer than other cover crops or weedy fallow treatments. Crotalaria juncea could have suppressed R. reniformis because it is a poor host and because it enhances nematode-trapping fungi when incorporated into soil. Treatment with 1,3-D reduced microbial activities but produced the greatest pineapple yield.

  1. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study

    Energy Technology Data Exchange (ETDEWEB)

    Cassigneul, A. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France); INRA, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Benoit, P.; Bergheaud, V.; Dumeny, V.; Etiévant, V. [INRA, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Goubard, Y. [AgroParisTech, UMR 1402 ECOSYS, 78850 Thiverval-Grignon (France); Maylin, A. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France); Justes, E. [INRA, UMR 1248 AGIR Auzeville — BP 52 627, 31 326, Castanet-Tolosan cedex (France); Alletto, L. [Université de Toulouse — École d' ingénieurs de Purpan, UMR 1248 AGIR — 75, Voie du TOEC BP 57 611, 31 076, Toulouse cedex 3 (France)

    2016-03-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of {sup 14}C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. {sup 14}C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH{sub 4}OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends {sup 14}C-glyphosate degradation half-life from 7 to 28 days depending on the CC. {sup 14}C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity. - Highlights: • Glyphosate sorption on cover crop residues increases with their decomposition degree. • Glyphosate degradation and mineralization are lower in mulch than in soil. • Nonextractable residue formation is one of the main dissipation pathways of glyphosate in cover crop mulch.

  2. [Diversity and stability of arthropod community in peach orchard under effects of ground cover vegetation].

    Science.gov (United States)

    Jiang, Jie-xian; Wan, Nian-feng; Ji, Xiang-yun; Dan, Jia-gui

    2011-09-01

    A comparative study was conducted on the arthropod community in peach orchards with and without ground cover vegetation. In the orchard with ground cover vegetation, the individuals of beneficial, neutral, and phytophagous arthropods were 1.48, 1.84 and 0.64 times of those in the orchard without ground cover vegetation, respectively, but the total number of arthropods had no significant difference with that in the orchard without ground cover vegetation. The species richness, Shannon's diversity, and Pielou's evenness index of the arthropods in the orchard with ground cover vegetation were 83.733 +/- 4.932, 4.966 +/- 0.110, and 0.795 +/- 0.014, respectively, being significantly higher than those in the orchard without ground cover vegetation, whereas the Berger-Parker's dominance index was 0.135 +/- 0.012, being significantly lower than that (0.184 +/- 0.018) in the orchard without ground cover vegetation. There were no significant differences in the stability indices S/N and Sd/Sp between the two orchards, but the Nn/Np, Nd/Np, and Sn/Sp in the orchard with ground cover vegetation were 0.883 +/- 0.123. 1714 +/- 0.683, and 0.781 +/- 0.040, respectively, being significantly higher than those in the orchard without ground cover vegetation. Pearson's correlation analysis indicated that in the orchard with ground cover vegetation, the Shannon's diversity index was significantly negatively correlated with Nd/Np, Sd/Sp, and S/N but had no significant correlations with Nn/Np and Sn/Sp, whereas in the orchard without ground cover vegetation, the diversity index was significantly positively correlated with Nn/Np and Nd/Np and had no significant correlations with Sd/Sp, Sn/Sp, and S/N.

  3. Effect of cover crops management in aggregate stability of a vineyard in Central Spain.

    Science.gov (United States)

    Ruiz-Colmenero, Marta; Bienes, Ramon; Marques, Maria-Jose

    2010-05-01

    Our research focuses in cover crop treatments used to avoid soil degradation in hillsides. The soil-plant interaction can influence the soil structure. In this study we pay special attention to the soil aggregates in a hillside vineyard (average slope of 14%), under Mediterranean semiarid climatic conditions (average annual temperature 14°C, annual rainfall around 400 mm), in the South East of Madrid located at an altitude of 800 masl. The soil classification according to USDA (2006) is Calcic Haploxeralf. Its particle size yields 58% sand, 18% silt and 24% clay, so that according to USDA classification it is a sandy clay loam soil. The bulk density of the first 10 cm of topsoil is 1.2 g cm-3 and its real density is 2.4 g cm-3. It has low organic matter content: 1.3 ± 0.1% (Walkley and Black, 1934). Three treatments were tested: i) traditional tillage ii) soil covered by Brachypodium distachyon allowing self-sowing, and iii) soil covered by Secale cereale, mown in early spring. In each treatment the aggregate stability was measured. These cover crops were established in a 2m wide strip at the center of the rows. We have collected samples of soil for each treatment along 2 years and we analyzed the aggregates, trying to find changes in their stability. Aggregates of 4 to 4.75 mm diameter were selected by dry sieving. The stability was measured with Drop-test: CND and TDI (Imeson and Vis, 1984). An improvement in the stability of aggregates was observed after two years of cover crop treatment. There are significant differences among the treatments analyzed with Kolmogorov-Smirnov test, being Brachypodium distachyon the treatment with more stable aggregates, it is necessary a mean higher than 8 drops to disintegrate every aggregate completely. Organic carbon was also measured by Loss on Ignition method (Schulte and Hopkins, 1996). This method can lead to an overestimation of the organic matter in soil samples but is considered suitable for aggregates. Again, those

  4. Green manuring effect of pure and mixed barley - hairy vetch winter cover crops on maize and processing tomato N nutrition

    DEFF Research Database (Denmark)

    Tosti, Giacomo; Benincasa, Paolo; Farneselli, Michela;

    2012-01-01

    with the appropriate critical N dilution curves. The results highlight the effectiveness of mixtures for the management of the winter cover crop practice. In the two considered years, the species proportion influences the aboveground biomass (ranging from 2.90 to 5.94 Mg ha-1) and N accumulation (ranging from 73......Adopting mixtures between legumes and non legumes can be an efficient tool to merge the advantages of the single species in the fall-sown cover crop practice. Nevertheless there is a lack of information on how the species proportion may affect N accumulation and C/N of the cover crops and how...... tomato (Lycopersicon esculentum Mill.). Cover crop N accumulation and C/N ratio were monitored during the whole growing cycle, and CO2 flux from the soil was measured after their incorporation into the soil. N status of the following cash crops was evaluated by comparing the observed data...

  5. Effect of management systems and cover crops on organic matter dynamics of soil under vegetables

    Directory of Open Access Journals (Sweden)

    Rodrigo Fernandes de Souza

    2014-06-01

    Full Text Available Vegetable production in conservation tillage has increased in Brazil, with positive effects on the soil quality. Since management systems alter the quantity and quality of organic matter, this study evaluated the influence of different management systems and cover crops on the organic matter dynamics of a dystrophic Red Latosol under vegetables. The treatments consisted of the combination of three soil tillage systems: no-tillage (NT, reduced tillage (RT and conventional tillage (CT and of two cover crops: maize monoculture and maize-mucuna intercrop. Vegetables were grown in the winter and the cover crops in the summer for straw production. The experiment was arranged in a randomized block design with four replications. Soil samples were collected between the crop rows in three layers (0.0-0.05, 0.05-0.10, and 0.10-0.30 m twice: in October, before planting cover crops for straw, and in July, during vegetable cultivation. The total organic carbon (TOC, microbial biomass carbon (MBC, oxidizable fractions, and the carbon fractions fulvic acid (C FA, humic acid (C HA and humin (C HUM were determined. The main changes in these properties occurred in the upper layers (0.0-0.05 and 0.05-0.10 m where, in general, TOC levels were highest in NT with maize straw. The MBC levels were lowest in CT systems, indicating sensitivity to soil disturbance. Under mucuna, the levels of C HA were lower in RT than NT systems, while the C FA levels were lower in RT than CT. For vegetable production, the C HUM values were lowest in the 0.05-0.10 m layer under CT. With regard to the oxidizable fractions, the tillage systems differed only in the most labile C fractions, with higher levels in NT than CT in the 0.0-0.05 m layer in both summer and winter, with no differences between these systems in the other layers. The cabbage yield was not influenced by the soil management system, but benefited from the mulch production of the preceding maize-mucuna intercrop as cover

  6. [Effects of winter cover crop on methane and nitrous oxide emission from paddy field].

    Science.gov (United States)

    Tang, Hai-ming; Tang, Wen-guang; Shuai, Xi-qiang; Yang, Guang-li; Tang, Hai-tao; Xiao, Xiao-Ping

    2010-12-01

    Static chamber-GC technique was employed to study the effects of different treatment winter cover crops, including no-tillage and directly sowing ryegrass (T1), no-tillage and directly sowing Chinese milk vetch (T2), tillage and transplanting rape (T3), no-tillage and directly sowing rape (T4), and fallowing (CK), on the CH4 and N2O emission from double cropping rice paddy field. During the growth period of test winter cover crops, the CH4 and N2O emission in treatments T1-T4 was significantly higher than that in CK (P winter cover crops returned to field, the CH4 emission from early and late rice fields in treatments T1, T2, T3, and T4 was larger than that in CK. In early rice field, treatments T1 and T2 had the largest CH4 emission (21.70 and 20.75 g x m(-2)); while in late rice field, treatments T3 and T4 had the largest one (58.90 and 54.51 g x m(-2) respectively). Treatments T1-T4 also had larger N2O emission from early and late rice fields than the CK did. The N2O emission from early rice field in treatments T1, T2, T3, and T4 was increased by 53.7%, 12.2%, 46.3%, and 29.3%, and that from late rice field in corresponding treatments was increased by 28.6%, 3.8%, 34.3%, and 27.6%, respectively, compared with CK.

  7. Legume ground covers alter defoliation response of black walnut saplings to drought and anthracnose

    Science.gov (United States)

    J. W. Van Sambeek

    2003-01-01

    Growth and premature defoliation of black walnut saplings underplanted 5 or 6 years earlier with six different ground covers were quantified in response to a summer drought or anthracnose. Walnut saplings growing with ground covers of hairy vetch, crownvetch, and to a lesser extent sericea lespedeza continued to have more rapid height and diameter growth than saplings...

  8. Mycorrhiza formation and nutrient concentration in leeks (¤Allium porrum¤) in relation to previous crop and cover crop management on high P soils

    DEFF Research Database (Denmark)

    Sørensen, J.N.; Larsen, J.; Jakobsen, I.

    2005-01-01

    cover crops. Experiments on soils with moderate to high P content (26-50 mg kg(-1) bicarbonate-extractable P) showed that the previous crop influenced mycorrhiza formation, uptake of P, Zn, and Cu, and early growth of leek seedlings. A cover crop of black medic, established the previous autumn...... or tillage treatments. Differences in colonization, nutrient uptake and plant growth diminished during the growing period and at the final harvest date, the effects on plant production disappeared. High soil P level or high soil inoculum level was most likely responsible for the limited response of increased...

  9. ROLE OF ALLELOPATHY IN THE STIMULATORY AND INHIBITORY EFFECTS OF HAIRY VETCH COVER CROP RESIDUE IN NO-TILLAGE SUSTAINABLE PRODUCTION SYSTEMS

    Science.gov (United States)

    Cover crops can provide multiple benefits to sustainable cropping systems including building soil organic matter, controlling soil and nutrient losses from fields, moderating radiation and moisture exchange, releasing nutrients for subsequent crops, and suppressing weed and pest populations. Many o...

  10. Remote sensing weeds, cover crop residue, and tillage practices in soybean

    Science.gov (United States)

    Koger, Clifford Hubert

    Research was conducted to evaluate the potential of remote sensing for detecting weeds in soybean. The first objective was to evaluate the potential of multispectral imagery for detection of late-season weed-infestations. The second objective was to identify bands derived from hyperspectral data capable of discriminating small, early-season pitted morningglory intermixed with soybean from weed-free soybean in different tillage and cover crop residue systems. The final objective was to determine the success of wavelet-based analysis of ground-collected hyperspectral data for discriminating reflectance patterns of pitted morningglory intermixed with soybean from weed-free soybean. Late-season weed infestations were discriminated from weed-free soybean with at least 90% accuracy when using green, red, and near-infrared spectral bands and a normalized difference vegetation index as classification variables in discriminant analysis. Discriminant analysis functions formed for one data set and tested on another set were 81 to 90% accurate in discriminating weed-infestations when soybean growth stage between data sets did not differ substantially. For the second objective, reflectance data were collected between 350 and 2,500 nm in 2151 discrete bands, with spectral bandwidths of 1.4 nm between 350 and 1050 nm and 1.0 nm from 1000 to 2500 nm. Eight 50-nm bands (1 ultraviolet, 2 visible, 4 near-infrared, 1 mid-infrared) were used to classify reflectance properties of pitted morningglory intermixed with soybean from weed-free soybean with 83 to 100% accuracy within the different tillage/residue systems. Pitted morningglory growth stage influenced detection capabilities more than tillage and residue systems. The ability to discriminate pitted morningglory intermixed with soybean from weed-free soybean was attributed to differences in reflectance properties of pitted morningglory and soybean, not from increase in total vegetation biomass in the pitted morningglory intermixed

  11. Alelopatia de cultivos de cobertura vegetal sobre plantas infestantes = Allelopathy of cover crop on weed plants

    Directory of Open Access Journals (Sweden)

    Luciene Kazue Tokura

    2006-07-01

    Full Text Available O presente trabalho avaliou o potencial alelopático de cultivos de cobertura vegetal de trigo, aveia preta, milheto, nabo forrageiro e colza sobre o desenvolvimento de plantas infestantes e verificou qual das coberturas vegetais exerce maior controle sobre as mesmas. Os cultivos de cobertura vegetal foram implantados sob preparo convencional (uma aração e uma gradagem no Núcleo Experimental de Engenharia Agrícola (NEEA, da Universidade Estadual do Oeste do Paraná (Unioeste, Cascavel, Estado do Paraná. Mensalmente, realizou-se o acompanhamento e identificação das plantas infestantes emersas nas áreas de cobertura vegetal no período de agosto de 2000 a agosto de 2001. Os resultados obtidos permitiram concluir que das espécies encontradas, o capim marmelada foi o que apresentou maior potencial alelopático e a erva-de-santa-maria o menor. As coberturasvegetais que apresentaram melhor controle do total de plantas infestantes presentes na área experimental, incluindo àquelas com reconhecido potencial alelopático, foram aveia preta, colza, nabo forrageiro e milheto.This work evaluated the cover crop allelopathic potential of wheat, black oat, pearl millet, turnip and rape on the development of weed plants. It also verified which cover crop has larger control on the weed plants. The cover crop was implanted under conventional tillage (one disk plowing plus one disk harrowing in the Experimental Nucleus of Agricultural Engineering (NEEA, of the State University of the West of Paraná (Unioeste, Cascavel, Paraná State. Monthly (from August 2000 to August 2001, weed plants identification in the cover crop area was made. Results showed that from the found species, the alexander grass was the one that presented larger allelopathic potential, and, the mexican-tea was the one that presented smaller control. The vegetable coverings that presented larger control of the total of weed plants in the experimental area, including those with

  12. Green manuring effect of pure and mixed barley - hairy vetch winter cover crops on maize and processing tomato N nutrition

    DEFF Research Database (Denmark)

    Tosti, Giacomo; Benincasa, Paolo; Farneselli, Michela

    2012-01-01

    Adopting mixtures between legumes and non legumes can be an efficient tool to merge the advantages of the single species in the fall-sown cover crop practice. Nevertheless there is a lack of information on how the species proportion may affect N accumulation and C/N of the cover crops and how...... tomato (Lycopersicon esculentum Mill.). Cover crop N accumulation and C/N ratio were monitored during the whole growing cycle, and CO2 flux from the soil was measured after their incorporation into the soil. N status of the following cash crops was evaluated by comparing the observed data...... be important to take the characteristics of the following cash crop into account....

  13. Variation on the amount of winter cover crops residues on weeds incidence and soil seed bank during an agricultural year

    Directory of Open Access Journals (Sweden)

    Márcia Maria Mauli

    2011-08-01

    Full Text Available This study analyzed possible interferences associated to the amount of crop residues produced by the black oats and the consortium of black oats, common vetch and forage turnip on weeds incidence and soil seed bank. It was a field trial with seven treatments and five replications. The cover crop was sown at throwing, cut at 100 days and residues were put on each respective plot, using a proportion of normal amount of produced straw, either its half and double. The heaviest weights were obtained from cover crop consortium and their application decreased weeds incidence in such area. The seeds bank and other analyzed parameters did not show statistical differences. According to these results, it was concluded that winter cover crop could be used in crops rotation with soybean.

  14. Law school design blends functionalism, energy conservation. [Earth-covered with ground-cover growing on roof

    Energy Technology Data Exchange (ETDEWEB)

    1976-08-01

    Construction is under way on a new University of Minnesota Law School Building, whose distinctive features include a stepped design on its southern elevation and an earth-covered roof to promote energy conservation. The design is described with emphasis on the library facilities. Energy conservation was a major design factor. The portion of the earth-covered roof will be 15 inches thick planted with low ground-cover vegetation. Overall ..mu.. value of the building envelope will be 0.11. (MCW)

  15. Cover crops for managing weeds, soil chemical fertility and nutritional status of organically grown orange orchard in Sicily

    Directory of Open Access Journals (Sweden)

    Rosario Paolo Mauro

    2015-06-01

    Full Text Available Cover crops can offer significant advantages in the agronomic management of citrus orchards in Mediterranean environments. Therefore, a three-year research was conducted in eastern Sicily aimed at studying the effects of four cover crop sequences (Sinapis arvensis-Trigonella foenum-graecum-T. foenum-graecum; Medicago scutellata-Avena sativa-Lolium perenne; Vicia faba minor-A. sativa-A. sativa; A. sativa-V. faba. minor-L. perenne on weeds, major soil chemical properties and nutritional status of an organically grown orange orchard. The results highlighted that, among the studied cover crop sequences, Vicia faba-Avena-Avena was the most beneficial for weeds control within the orchard (92%, of cover crop cover, and 586 and 89 g DW m–2 of cover crop aboveground biomass and weeds aboveground biomass, respectively. Overall, the chemical fertility of the soil was positively influenced. In particular, it was observed an increase of the content of total nitrogen and available phosphorus in the soil by both Sinapis-Trigonella-Trigonella (0.75 g kg–1 and 59.0 mg kg–1, respectively and Vicia faba-Avena-Avena (0.70 g kg–1 and 56.0 mg kg–1, respectively cover crop sequences. Medicago-Avena-Lolium sequence seemed to be the most useful to ensure a better nutritional status of the orange orchard.

  16. Effects of green manure cover crops on Spodoptera litura (Lepidoptera: Noctuidae) populations.

    Science.gov (United States)

    Tuan, Shu-Jen; Li, Nian-Jhen; Yeh, Chih-Chun; Tang, Li-Cheng; Chi, Hsin

    2014-06-01

    Spodoptera litura (F.) is an important pest of numerous agro-economic crops, including green manure cover crops. In Taiwan, sesbania (Sesbanin roxburghii Merr.), sunn hemp (Crotalaria juncea L.), and rapeseed (Brassicae campestris L. variety chinensis) are the most popular green manure crops; sesbania and sunn hemp are commonly planted in warm seasons, whereas rapeseed is grown in the winter. In this study, life-table data for S. litura reared on these three green manures were collected to evaluate their roles as refuges of this pest. The net reproductive rate, intrinsic rate of increase, and finite rate of increase of S. litura were the highest when reared on sesbania (1428.1 offspring, 0.2327 d(-1), 1.2621 d(-1)), followed by sunn hemp (778.4 offspring, 0.2070 d(-1), 1.2300 d(-1)) and rapeseed (737.6 offspring, 0.2040 d(-1), 1.2263 d(-1)). The high growth rates on these green manure crops show that they can serve as potential breeding sites for S. litura. Population projection demonstrated the rapid growth of S. litura on sesbania, sunn hemp, and rapeseed as well. Because most growers have traditionally ignored pest management in green manure fields, the mass emergence of S. litura in these fields may cause unexpected infestations in nearby vegetable, corn, and peanut crops. This study shows that the use of green manures as sources of nutrients should be critically reassessed and an area-wide pest management program should be instituted by taking the population of S. litura in green manure fields into consideration.

  17. Allelopathic cover crop of rye for integrated weed control in sustainable agroecosystems

    Directory of Open Access Journals (Sweden)

    Vincenzo Tabaglio

    2013-02-01

    Full Text Available The allelopathic potential of rye (Secale cereale L. is mainly due to phytotoxic benzoxazinones, compounds that are produced and accumulated in young tissues to different degrees depending on cultivar and environmental influences. Living rye plants exude low levels of benzoxazinones, while cover crop residues can release from 12 to 20 kg ha–1. This paper summarizes the results obtained from several experiments performed in both controlled and field environments, in which rye was used as a cover crop to control summer weeds in a following maize crop. Significant differences in benzoxazinoid content were detected between rye cultivars. In controlled environments, rye mulches significantly reduced germination of some broadleaf weeds. Germination and seedling growth of Amaranthus retroflexus and Portulaca oleracea were particularly affected by the application of rye mulches, while Chenopodium album was hardly influenced and Abutilon theophrasti was advantaged by the presence of the mulch. With reference to the influence of agronomic factors on the production of benzoxazinoids, nitrogen fertilization increased the content of allelochemicals, although proportionally less than dry matter. The field trial established on no-till maize confirmed the significant weed suppressiveness of rye mulch, both for grass and broadleaf weeds. A significant positive interaction between nitrogen (N fertilization and notillage resulting in the suppression of broadleaf weeds was observed. The different behavior of the weeds in the presence of allelochemicals was explained in terms of differential uptake and translocation capabilities. The four summer weeds tested were able to grow in the presence of low amounts of benzoxazolin-2(3H-one (BOA, between 0.3 and 20 mmol g–1 fresh weight. Although there were considerable differences in their sensitivity to higher BOA concentrations, P. oleracea, A. retroflexus, and Ch. album represented a group of species with a consistent

  18. Selective weed suppression by cover crop residues: effects of seed mass and timing of species’sensitivity

    NARCIS (Netherlands)

    Kruidhof, H.M.; Gallandt, E.R.; Haramoto, E.R.; Bastiaans, L.

    2011-01-01

    Laboratory bioassays have shown that large-seeded species better tolerate cover crop residue–mediated stress than small-seeded species. This provides the potential for selective suppression of small-seeded weeds in large-seeded crops. We conducted two field experiments in which seedling emergence of

  19. 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)

    Brozyna, Michal Adam; Petersen, Søren O; Chirinda, Ngoni

    2013-01-01

    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...... 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...

  20. Cloud Cover Assessment for Operational Crop Monitoring Systems in Tropical Areas

    Directory of Open Access Journals (Sweden)

    Isaque Daniel Rocha Eberhardt

    2016-03-01

    Full Text Available The potential of optical remote sensing data to identify, map and monitor croplands is well recognized. However, clouds strongly limit the usefulness of optical imagery for these applications. This paper aims at assessing cloud cover conditions over four states in the tropical and sub-tropical Center-South region of Brazil to guide the development of an appropriate agricultural monitoring system based on Landsat-like imagery. Cloudiness was assessed during overlapping four months periods to match the typical length of crop cycles in the study area. The percentage of clear sky occurrence was computed from the 1 km resolution MODIS Cloud Mask product (MOD35 considering 14 years of data between July 2000 and June 2014. Results showed high seasonality of cloud occurrence within the crop year with strong variations across the study area. The maximum seasonality was observed for the two states in the northern part of the study area (i.e., the ones closer to the Equator line, which also presented the lowest averaged values (15% of clear sky occurrence during the main (summer cropping period (November to February. In these locations, optical data faces severe constraints for mapping summer crops. On the other hand, relatively favorable conditions were found in the southern part of the study region. In the South, clear sky values of around 45% were found and no significant clear sky seasonality was observed. Results underpin the challenges to implement an operational crop monitoring system based solely on optical remote sensing imagery in tropical and sub-tropical regions, in particular if short-cycle crops have to be monitored during the cloudy summer months. To cope with cloudiness issues, we recommend the use of new systems with higher repetition rates such as Sentinel-2. For local studies, Unmanned Aircraft Vehicles (UAVs might be used to augment the observing capability. Multi-sensor approaches combining optical and microwave data can be another

  1. Long-term effect of tillage, nitrogen fertilization and cover crops on soil organic carbon and total nitrogen content

    OpenAIRE

    2011-01-01

    Metadata only record No-till practices, in conjunction with cover crops and nitrogen fertilization, have been shown to augment soil organic carbon content and total nitrogen content. However, interactions between these components in a no-till system are not well-known. This study offers a long-term (1993-2008) comparative analysis of conventional versus no-till practices as well as a some insight regarding the synergies between no-till, nitrogen fertilization, and cover crops. Maize, wheat...

  2. Interannual changes in snow cover and its impact on ground surface temperatures in Livingston Island (Antarctica)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2015-04-01

    In permafrost areas the seasonal snow cover is an important factor on the ground thermal regime. Snow depth and timing are important in ground insulation from the atmosphere, creating different snow patterns and resulting in spatially variable ground temperatures. The aim of this work is to characterize the interactions between ground thermal regimes and snow cover and the influence on permafrost spatial distribution. The study area is the ice-free terrains of northwestern Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". Air and ground temperatures and snow thickness data where analysed from 4 sites along an altitudinal transect in Hurd Peninsula from 2007 to 2012: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). The data covers 6 cold seasons showing different conditions: i) very cold with thin snow cover; ii) cold with a gradual increase of snow cover; iii) warm with thick snow cover. The data shows three types of periods regarding the ground surface thermal regime and the thickness of snow cover: a) thin snow cover and short-term fluctuation of ground temperatures; b) thick snow cover and stable ground temperatures; c) very thick snow cover and ground temperatures nearly constant at 0°C. a) Thin snow cover periods: Collado Ramos and Ohridski sites show frequent temperature variations, alternating between short-term fluctuations and stable ground temperatures. Nuevo Incinerador displays during most of the winter stable ground temperatures; b) Cold winters with a gradual increase of the snow cover: Nuevo Incinerador, Collado Ramos and Ohridski sites show similar behavior, with a long period of stable ground temperatures; c) Thick snow cover periods: Collado Ramos and Ohridski show long periods of stable ground, while Nuevo Incinerador shows temperatures close to 0°C since the beginning of the winter, due to early snow cover

  3. Nutrient cycling potential of camelina (Camelina sativa L. Crantz.) as a cover crop in the US Northern Great Plains

    Science.gov (United States)

    Berti, Marisol; Samarappuli, Dulan

    2017-04-01

    Camelina [Camelina sativa (L.) Crantz.] is an industrial oilseed crop in the Brassicaceae family with multiple uses. Currently, camelina is not used as a cover crop, but it has the potential to be used as such in maize-soybean-wheat cropping systems. The objectives of this study were to determine the agronomic performance and nutrient scavenging potential of winter camelina in comparison with other common cover crops. Experiments were conducted in Fargo, ND in 2015 and 2016, and in Prosper, ND in 2015. The experimental design was a randomized complete block design with a split-plot arrangement with three replicates. The main plot was the sowing date and the subplot were camelina cultivars as well as other common cover crops in the area. Sowing dates were targeted to 15 August and September 1, although the final dates varied slightly each year. Biomass yield, N content of the biomass N uptake and P uptake was evaluated. Winter camelina N and P uptake ranged between 21 and 30.5 kg N ha-1 and 3.4 to 5.3 kg P ha-1. The nutrient scavenging potential of winter camelina was similar to other cover crops although slightly lower than turnip (Brassica rapa L.), radish (Raphanus sativus L.), and rape (Brassica napus L.) cultivars which had significantly higher P uptake than winter camelina and the other cover crops in the study. An evaluation of spring regrowth and cover indicated that only rye, winter camelina, and pennycress (Thlaspi arvense L.) survived the winter, although a few plants of triticale (x Trticosecale Witt.) and rape were found on a few plots. Because of the high variability on the plots there were no significant differences among the surviving cover crops on soil coverage. The soil coverage for rye cultivars was 25 and 35% and for camelina cv. Bison was 27%.In 2016, biomass yield was not significant for sowing date, cultivars, or their interaction. Winter camelina cultivars biomass yield fluctuated between 1.15 and 2.33 Mg dry matter ha-1 on the first sowing

  4. Ground beetle (Coleoptera: Carabidae) assemblages in conventional and diversified crop rotation systems.

    Science.gov (United States)

    O'Rourke, Megan E; Liebman, Matt; Rice, Marlin E

    2008-02-01

    Ground beetles (Coleoptera: Carabidae) are important in agro-ecosystems as generalist predators of invertebrate pests and weed seeds and as prey for larger animals. However, it is not well understood how cropping systems affect ground beetles. Over a 2-yr period, carabids were monitored two times per month using pitfall traps in a conventional chemical input, 2-yr, corn/soybean rotation system and a low input, 4-yr, corn/soybean/triticale-alfalfa/alfalfa rotation system. Carabid assemblages were largely dominated by a few species across all cropping treatments with Poecilus chalcites Say comprising >70% of pitfall catches in both years of study. Overall carabid activity density and species richness were higher in the low input, 4-yr rotation compared with the conventionally managed, 2-yr rotation. There were greater differences in the temporal activity density and species richness of carabids among crops than within corn and soybean treatments managed with different agrichemical inputs and soil disturbance regimes. Detrended correspondence analysis showed strong yearly variation in carabid assemblages in all cropping treatments. The increase in carabid activity density and species richness observed in the 4-yr crop rotation highlights the potential benefits of diverse crop habitats for carabids and the possibility for managing natural enemies by manipulating crop rotations.

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

    Science.gov (United States)

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

    2016-12-01

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

  6. Impact of vetch cover crop on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia

    Science.gov (United States)

    Demelash, Nigus; Klik, Andreas; Holzmann, Hubert; Ziadat, Feras; Strohmeier, Stefan; Bayu, Wondimu; Zucca, Claudio; Abera, Atikilt

    2016-04-01

    Cover crops improve the sustainability and quality of both natural system and agro ecosystem. In Gumara-Maksegnit watershed which is located in Lake Tana basin, farmers usually use fallow during the rainy season for the preceding chickpea production system. The fallowing period can lead to soil erosion and nutrient losses. A field experiment was conducted during growing seasons 2014 and 2015 to evaluate the effect of cover crops on runoff, soil loss, soil chemical properties and yield of chickpea in North Gondar, Ethiopia. The plot experiment contained four treatments arranged in Randomized Complete Block Design with three replications: 1) Control plot (Farmers' practice: fallowing- without cover crop), 2) Chickpea planted with Di-ammonium phosphate (DAP) fertilizer with 46 k ha-1 P2O5 and 23 k ha-1 nitrogen after harvesting vetch cover crop, 3) Chick pea planted with vetch cover crop incorporated with the soil as green manure without fertilizer, 4) Chick pea planted with vetch cover crop and incorporated with the soil as green manure and with 23 k ha-1 P2O5 and 12.5 k ha-1 nitrogen. Each plot with an area of 36 m² was equipped with a runoff monitoring system. Vetch (Vicia sativa L.) was planted as cover crop at the onset of the rain in June and used as green manure. The results of the experiment showed statistically significant (P 0.05) on average plant height, average number of branches and hundred seed weight. Similarly, the results indicated that cover crop has a clear impact on runoff volume and sediment loss. Plots with vetch cover crop reduce the average runoff by 65% and the average soil loss decreased from 15.7 in the bare land plot to 8.6 t ha-1 with plots covered by vetch. In general, this result reveales that the cover crops, especially vetch, can be used to improve chickpea grain yield in addition to reduce soil erosion in the watershed.

  7. The role of rabbit density and the diversity of weeds in the development of cover crops in olive groves

    Directory of Open Access Journals (Sweden)

    José Guerrero-Casado

    2015-09-01

    Full Text Available Cover crops are an effective means to reduce soil erosion and to provide food and shelter for wildlife. However, in areas of intensive farming, which are characterised by the scarcity of weed communities, wild herbivores may focus their grazing on cover crops, which could make their implementation difficult. In this work, we test whether rabbit grazing can prevent the growth of herbaceous cover crops in olive groves in Southern Spain in addition to assessing the role of rabbit abundance and diversity of weeds in the development of cover crops. This question has been addressed by sowing Bromus rubens between the rows of five olive groves in Cordoba province (Spain. We then monitored the surface covered by B. rubens, along with both diversity of weed communities and rabbit abundance. Two rabbit exclusion areas were also placed in each olive grove in order to assess the impact of rabbits on the development of cover crops. Our results showed that the surface occupied by B. rubens was considerably higher in the rabbit exclusion areas (mean 56.8 ± 5.65 % than in those areas in which they could feed (mean 35.6 ± 4.32 %. The coverage occupied by cover crops was higher in areas with lower rabbit density, although this relationship was modulated by the weed diversity index, since in areas with the same rabbit abundance the coverage was higher in those with a richer weed community. These findings suggest that high rabbit abundances can prevent the development of herbaceous cover crops in olive groves, particularly in areas in which alternative food resources (measured as weed diversity are scarce.

  8. The role of rabbit density and the diversity of weeds in the development of cover crops in olive groves

    Energy Technology Data Exchange (ETDEWEB)

    Guerrero-Casado, J.; Carpio, A.J.; Prada, L.M.; Tortosa, F.S.

    2015-07-01

    Cover crops are an effective means to reduce soil erosion and to provide food and shelter for wildlife. However, in areas of intensive farming, which are characterised by the scarcity of weed communities, wild herbivores may focus their grazing on cover crops, which could make their implementation difficult. In this work, we test whether rabbit grazing can prevent the growth of herbaceous cover crops in olive groves in Southern Spain in addition to assessing the role of rabbit abundance and diversity of weeds in the development of cover crops. This question has been addressed by sowing Bromus rubens between the rows of five olive groves in Cordoba province (Spain). We then monitored the surface covered by B. rubens, along with both diversity of weed communities and rabbit abundance. Two rabbit exclusion areas were also placed in each olive grove in order to assess the impact of rabbits on the development of cover crops. Our results showed that the surface occupied by B. rubens was considerably higher in the rabbit exclusion areas (mean 56.8 ± 5.65 %) than in those areas in which they could feed (mean 35.6 ± 4.32 %). The coverage occupied by cover crops was higher in areas with lower rabbit density, although this relationship was modulated by the weed diversity index, since in areas with the same rabbit abundance the coverage was higher in those with a richer weed community. These findings suggest that high rabbit abundances can prevent the development of herbaceous cover crops in olive groves, particularly in areas in which alternative food resources (measured as weed diversity) are scarce. (Author)

  9. Allelopathic cover crop prior to seeding is more important than subsequent grazing/mowing in grassland establishment

    Science.gov (United States)

    Milchunas, Daniel G.; Vandever, Mark W.; Ball, Leonard O.; Hyberg, Skip

    2011-01-01

    The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat–fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area

  10. Influence of cover crops and crop residue treatment on soil organic carbon stocks evaluated in Swedish long-term field experiments

    Science.gov (United States)

    Poeplau, Christopher; Bolinder, Martin A.; Börjesson, Gunnar; Kätterer, Thomas

    2015-04-01

    Soil organic carbon (SOC) stocks in agricultural soils are strongly controlled by management. In this study we quantified the effect of cover crops and crop residue management on SOC stocks in Swedish long-term experiments. Eight pairs of cover crop (undersown ryegrass) vs. no cover crop were investigated in Swedish long-term field experiments (16 to 24 years). Yields of the main crop were not affected by the cover crop. Cover crops significantly increased SOC stocks, with a mean carbon sequestration rate in all experiments (excluding one) of 0.32±0.29 Mg C ha-1 yr-1. Interestingly, this sequestration is similar to that estimated for a U.S.experiment, where ryegrass growth is much less temperature- and light-limited than under Swedish conditions. This sequestration rate is also the same as that recently reported for many other cover crops in a global meta-analysis but less than SOC changes in ley-dominated rotations which under Nordic conditions were shown to accumulate in average 0.5 Mg C ha-1 yr-1 more carbon compared to exclusively annual cropping systems. Thus, originally introduced in agricultural rotations to reduce nitrate leaching, cover crops are also an effective practice to increase SOC stocks, even at relatively high latitudes. The effect of crop residue treatment was studied in 16 pairs of straw incorporated (SI) vs. straw removed (SR) treatments in six Swedish long-term field experiments. Data series on SOC with 5-28 sampling dates during 27-53 years were analysed using ICBM, a dynamic SOC model. At five out of six sites, the humification coefficient for straw (hlitter; the fraction of straw C that is entering the slow C pool) was much smaller (0-0.09) than the ICBM default h-value for plant material estimated in previous studies (0.125). The derived hlitter-values and thus the stabilization of straw-derived carbon increased significantly with clay content. For an Italian site (with five pairs of SI vs. SR) that was used for model validation we found

  11. Eficácia de glyphosate em plantas de cobertura Efficacy of glyphosate in cover crops

    Directory of Open Access Journals (Sweden)

    P.C. Timossi

    2006-09-01

    Full Text Available Objetivou-se comparar a eficácia de três dosagens do herbicida glyphosate para a dessecação de Brachiaria decumbens, B. brizantha cv. Marandu e vegetação espontânea, visando a adoção do sistema plantio direto. Utilizou-se delineamento experimental de blocos ao acaso, num esquema fatorial 3 x 3, com quatro repetições. Testaram-se três tipos de cobertura vegetal e três dosagens de glyphosate (1,44, 2,16 e 2,88 kg ha-1. Aos 7, 14, 21 e 28 dias após a aplicação (DAA, foram feitas avaliações visuais da porcentagem de controle das coberturas vegetais e, aos 45 DAA, avaliações visuais da porcentagem de reinfestação da área. Conclui-se que, para as espécies que compunham a vegetação espontânea, o uso de 1,44 kg ha-1 proporcionou bom controle, sem no entanto evitar rebrotes de Digitaria insularis. Para as braquiárias, a mesma taxa de controle foi observada a partir de 2,16 kg ha-1. A camada de palha das braquiárias sobre o solo não foi capaz de suprimir a emergência de Cyperus rotundus, Alternanthera tenella, Raphanus raphanistrum, Bidens pilosa e Euphorbia heterophylla.This work aimed to compare rates of glyphosate to desiccate Brachiaria decumbens, B. brizantha cv. Marandu and spontaneous plants (weeds, aiming to adopt the no-tillage system. A randomized block experimental design in a factorial scheme was used (3x3, with four replications. The factors consisted of three species of cover crops and three rates of glyphosate (1.44, 2.16 and 2.88 kg ha-1. At 7, 14, 21 and 28 days after application of the herbicide, visual evaluations of the percentage of cover crop control were carried out and at 45 days of the reinfestation percentage of the area. It was concluded that the spontaneous plants presented a good control at 1.44 kg ha-1, without, however, preventing Digitaria insularis sprouts. The same control rate starting at 2.16 kg ha-1 was observed for the Brachiaria species. The straw layer of these cover crops on the soil

  12. Diseases of Ornamental and Shade Trees, Shrubs, Vines, and Ground Covers.

    Science.gov (United States)

    Nichols, Lester P.

    This agriculture extension service publication from Pennsylvania State University covers the identification and control of common ornamental trees, shrubs, and ground cover diseases. The publication is divided into sections. The first section discusses the diseases of ornamental and shade trees, including general diseases and diseases of specific…

  13. Cover crops influence soil microorganisms and phytoextraction of copper from a moderately contaminated vineyard.

    Science.gov (United States)

    Mackie, K A; Schmidt, H P; Müller, T; Kandeler, E

    2014-12-01

    We investigated the ability of summer (Avena sativa [oat], Trifolium incarnatum [crimson clover], Chenopodium [goosefoot]) and winter (Vicia villosa [hairy vetch], Secale Cereale L. [Rye], Brassica napus L. partim [rape]) cover crops, including a mixed species treatment, to extract copper from an organic vineyard soil in situ and the microbial communities that may support it. Clover had the highest copper content (14.3mgCukg(-1) DM). However, it was the amount of total biomass production that determined which species was most effective at overall copper removal per hectare. The winter crop rye produced significantly higher amounts of biomass (3532kgDMha(-1)) and, therefore, removed significantly higher amounts of copper (14,920mgCuha(-1)), despite less accumulation of copper in plant shoots. The maximum annual removal rate, a summation of best performing summer and winter crops, would be 0.033kgCuha(-1)y(-1). Due to this low annual extraction efficiency, which is less than the 6kgCuha(-1)y(-1) permitted for application, phytoextraction cannot be recommended as a general method of copper extraction from vineyards. Copper concentration did not influence aboveground or belowground properties, as indicated by sampling at two distances from the grapevine row with different soil copper concentrations. Soil microorganisms may have become tolerant to the copper levels at this site. Microbial biomass and soil enzyme activities (arylsulfatase and phosphatase) were instead driven by seasonal fluxes of resource pools. Gram+ bacteria were associated with high soil moisture, while fungi seemed to be driven by extractable carbon, which was linked to high plant biomass. There was no microbial group associated with the increased phytoextraction of copper. Moreover, treatment did not influence the abundance, activity or community structure of soil microorganisms. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Conversion to No-Till Improves Maize Nitrogen Use Efficiency in a Continuous Cover Cropping System

    Science.gov (United States)

    Habbib, Hazzar; Verzeaux, Julien; Nivelle, Elodie; Roger, David; Lacoux, Jérôme; Catterou, Manuella; Hirel, Bertrand; Dubois, Frédéric; Tétu, Thierry

    2016-01-01

    A two-year experiment was conducted in the field to measure the combined impact of tilling and N fertilization on various agronomic traits related to nitrogen (N) use efficiency and to grain yield in maize cultivated in the presence of a cover crop. Four years after conversion to no-till, a significant increase in N use efficiency N harvest index, N remobilization and N remobilization efficiency was observed both under no and high N fertilization conditions. Moreover, we observed that grain yield and grain N content were higher under no-till conditions only when N fertilizers were applied. Thus, agronomic practices based on continuous no-till appear to be a promising for increasing N use efficiency in maize. PMID:27711154

  15. Fate of glyphosate and degradates in cover crop residues and underlying soil: A laboratory study.

    Science.gov (United States)

    Cassigneul, A; Benoit, P; Bergheaud, V; Dumeny, V; Etiévant, V; Goubard, Y; Maylin, A; Justes, E; Alletto, L

    2016-03-01

    The increasing use of cover crops (CC) may lead to an increase in glyphosate application for their destruction. Sorption and degradation of (14)C-glyphosate on and within 4 decaying CC-amended soils were compared to its fate in a bare soil. (14)C-Glyphosate and its metabolites distribution between mineralized, water-soluble, NH4OH-soluble and non-extractable fractions was determined at 5 dates during a 20 °C/84-d period. The presence of CC extends (14)C-glyphosate degradation half-life from 7 to 28 days depending on the CC. (14)C-Glyphosate dissipation occurred mainly through mineralization in soils and through mineralization and bound residue formation in decaying CC. Differences in sorption and degradation levels were attributed to differences in composition and availability to microorganisms. CC- and soil-specific dissipation patterns were established with the help of explicit relationships between extractability and microbial activity.

  16. Tillage systems and cover crops on soil physical properties after soybean cultivation

    Directory of Open Access Journals (Sweden)

    Rafael B. Teixeira

    Full Text Available ABSTRACT Soil management alters soil physical attributes and may affect crop yield. In order to evaluate soil physical attributes in layers from 0 to 0.40 m and soybean grain yield, in the 2012/2013 agricultural year, an essay was installed in the experimental area of the Federal University of Mato Grosso do Sul (UFMS/CPCS. Soil tillage systems were: conventional tillage (CT, minimum tillage (MT and no tillage (DS, the cover crops used were millet, sunn hemp and fallow. The experimental design was randomized blocks with split plots. For the layer of 0.20-0.30 m, millet provided the best results for soil bulk density, macro and microporosity. The resistance to penetration (RP was influenced in the layer of 0-0.10 m, and millet provided lower RP. The DS provided the lowest RP values for the layer of 0.10-0.20 m. The treatments did not influence yield or thousand-seed weight.

  17. Simulating long-term impacts of cover crops and climate change on crop production and environmental outcomes in the midwestern United States

    Science.gov (United States)

    It is critical to evaluate conservation practices that protect soil and water resources from climate change in the Midwestern United States, a region that produces one-quarter of the world’s soybeans and one-third of the world’s maize. An over-winter cover crop in a maize-soybean rotation offers mul...

  18. Seeding date affects fall growth of winter canola (Brassica napus L. ‘Baldur’) and its performance as a winter cover crop in central Iowa

    Science.gov (United States)

    In recent years, interest has increased in finding non-grass cover crop species that could be planted after soybean (Glycine max (L) Merr.) and before corn (Zea mays L.) in Iowa crop rotations. In this study, we investigate the use of winter canola (Brassica napus L.) as an alternative cover crop fo...

  19. Effect of the different cover crops on the soil moisture in a Hungarian vineyard

    Science.gov (United States)

    Donkó, Ádám; Miglécz, Tamás; Valkó, Orsolya; Deák, Balázs; Kelemen, András; Török, Péter; Tóthmérész, Béla; Drexler, Dóra

    2017-04-01

    Since many years it is well known that the one-sided mechanical soil cultivation of vineyard inter-rows has many disadvantages. Growers can choose from alternative tillage technologies, such as the usage of green manure, or covering the inter-rows with straw mulch. Another possible technology is tto cover the inter-rows with species-rich seed mixtures. However, selection of the most suitable species is crucial; we have to take into consideration the age of the vines, and the specific characteristics of the vineyards involved. Species rich cover crop technology has many advantages: 1) it helps to prevent erosion and creates easier cultivation circumstances, 2) it has a positive effect on soil structure, soil fertility and ecosystem services, 3) we can create native mixtures from local provenance, adapted to the local climate/vine region/vineyard which enhances the nature conservation value of our site. But, they should not compete significantly with the grapevines, or negatively influence produce quality. In the year of 2012 we created, and started to study three different cover-crop mixtures in Hungarian wine regions under on-farm conditions: Biocont-Ecovin mixture, Mixture of Legumes, Mixture of Grass and Herbs. The results of the botanical surveys, yield and pruning weight were published in many papers and presentations before (e.g. Miglécz et al. 2015, Donkó et al. 2016). Besides the above measures, one key point of the effectiveness and sustainability of the living mulch vegetation is the level of soil moisture. That is why we started to investigate the soil moisture (vol %) of different treatments (Biocont-Ecovin mixture, Mixture of Legumes, Mixture of Grass and Herbs, coverage with Lolium perenne, and Control (spontaneous weed flora)) in at the Feind Winery in Balatonfőkajár (Hungary). The investigated variety is Welschriesling on loamy soil (Tihany Formation), planted in 2010. The seed mixtures were sown in the spring of 2013. We measured soil moisture

  20. Carbon supply and storage in tilled and nontilled soils as influenced by cover crops and nitrogen fertilization.

    Science.gov (United States)

    Sainju, Upendra M; Singh, Bharat P; Whitehead, Wayne F; Wang, Shirley

    2006-01-01

    Soil carbon (C) sequestration in tilled and nontilled areas can be influenced by crop management practices due to differences in plant C inputs and their rate of mineralization. We examined the influence of four cover crops {legume [hairy vetch (Vicia villosa Roth)], nonlegume [rye (Secale cereale L.)], biculture of legume and nonlegume (vetch and rye), and no cover crops (or winter weeds)} and three nitrogen (N) fertilization rates (0, 60 to 65, and 120 to 130 kg N ha(-1)) on C inputs from cover crops, cotton (Gossypium hirsutum L.), and sorghum [Sorghum bicolor (L.) Moench)], and soil organic carbon (SOC) at the 0- to 120-cm depth in tilled and nontilled areas. A field experiment was conducted on Dothan sandy loam (fine-loamy, siliceous, thermic Plinthic Paleudults) from 1999 to 2002 in central Georgia. Total C inputs to the soil from cover crops, cotton, and sorghum from 2000 to 2002 ranged from 6.8 to 22.8 Mg ha(-1). The SOC at 0 to 10 cm fluctuated with C input from October 1999 to November 2002 and was greater from cover crops than from weeds in no-tilled plots. In contrast, SOC values at 10 to 30 cm in no-tilled and at 0 to 60 cm in chisel-tilled plots were greater for biculture than for weeds. As a result, C at 0 to 30 cm was sequestered at rates of 267, 33, -133, and -967 kg C ha(-1) yr(-1) for biculture, rye, vetch, and weeds, respectively, in the no-tilled plot. In strip-tilled and chisel-tilled plots, SOC at 0 to 30 cm decreased at rates of 233 to 1233 kg C ha(-1) yr(-1). The SOC at 0 to 30 cm increased more in cover crops with 120 to 130 kg N ha(-1) yr(-1) than in weeds with 0 kg N ha(-1) yr(-1), regardless of tillage. In the subtropical humid region of the southeastern United States, cover crops and N fertilization can increase the amount of C input and storage in tilled and nontilled soils, and hairy vetch and rye biculture was more effective in sequestering C than monocultures or no cover crop.

  1. Cover-crops - improvement of soil fertility and provision of biomass

    Science.gov (United States)

    Kirchmeyr, Franz; Szerencsits, Manfred

    2017-04-01

    Besides climate change, erosion, inadequate crop rotation and intensive tillage may turn arable land into marginal land. On the other hand, reclamation approaches which include arable farming methods may result only in short-term success if they do not consider their effects on humus content and erosion. Additionally, effective reclamation will also have to address the growing need for food production besides biomass provision. Therefore, we investigated if cover or catch crops (CC) may accomplish both goals: Improve soil quality and humus content even if CC-biomass is used for biogas production. Humus content and soil fertility: In comparison to complete fallow in a crop rotation with silage maize and cereals the humus balance can be improved from -50 to +280 kg humus carbon (C) ha-1 year-1 through additional CC (4.5 t DM ha-1) used for biogas production and an equivalent amount of digestate returned to the field. With a CC-yield of 2.5 t DM ha-1 the humus balance results in 220 kg C ha-1 year-1. It is still slightly higher if the same CC remains on the field as green manure (170 kg C ha-1 year-1). Additionally it is important to consider that 20 - 50 % of the assimilated carbon can be found in the plant roots and that roots and root exudates as well as CC harvest residues provide fresh organic matter for soil life. Furthermore, biomass production of cover crops was considerably higher, if they were used for biogas production because of earlier cultivation and later harvest than mulching. Erosion control: The risk of erosion can be reduced by approx. 50 % in comparison to complete fallow if CC with 2.5 t DM ha-1 remain on the field as green manure. A comparable reduction can be achieved, if CC with 4.5 t DM ha-1 are harvested for biogas production. Because of better weed suppression, tilth and soil structure of CC with higher biomass, it is more likely to apply conservation tillage and avoid ploughing. Without ploughing a CC with 4.5 t DM ha-1 used for biogas the

  2. The efficacy of winter cover crops to stabilize soil inorganic nitrogen after fall-applied anhydrous ammonia.

    Science.gov (United States)

    Lacey, Corey; Armstrong, Shalamar

    2015-03-01

    There is a dearth of knowledge on the ability of cover crops to increase the effectiveness of fall-applied nitrogen (N). The objective of this study was to investigate the efficacy of two cover crop species to stabilize inorganic soil N after a fall application of N. Fall N was applied at a rate of 200 kg N ha into living stands of cereal rye, tillage radish, and a control (no cover crop) at the Illinois State University Research and Teaching Farm in Lexington, Illinois. Cover crops were sampled to determine N uptake, and soil samples were collected in the spring at four depths to 80 cm to determine the distribution of inorganic N within the soil profile. Tillage radish (131.9-226.8 kg ha) and cereal rye (188.1-249.9 kg ha N) demonstrated the capacity to absorb a minimum of 60 to 80% of the equivalent rate of fall-applied N, respectively. Fall applying N without cover crops resulted in a greater percentage of soil NO-N (40%) in the 50- to 80-cm depth, compared with only 31 and 27% when tillage radish and cereal rye were present at N application. At planting, tillage radish stabilized an average of 91% of the equivalent rate of fall-applied N within the 0- to 20-cm, depth compared with 66 and 57% for the cereal rye and control treatments, respectively. This study has demonstrated that fall applying N into a living cover crop stand has the potential to reduce the vulnerability of soil nitrate and to stabilize a greater concentration of inorganic N within the agronomic depths of soil.

  3. Estimation of Evapotranspiration from Fields with and without Cover Crops Using Remote Sensing and in situ Methods

    Directory of Open Access Journals (Sweden)

    Christopher Hay

    2012-11-01

    Full Text Available Estimation of actual evapotranspiration (ETa based on remotely sensed imagery is very valuable in agricultural regions where ETa rates can vary greatly from field to field. This research utilizes the image processing model METRIC (Mapping Evapotranspiration at high Resolution with Internalized Calibration to estimate late season, post-harvest ETa rates from fields with a cover crop planted after a cash crop (in this case, a rye/radish/pea mixture planted after spring wheat. Remotely sensed EToF (unit-less fraction of grass-based reference ET, ETo maps were generated using Erdas Imagine software for a 260 km2 area in northeastern South Dakota, USA. Meteorological information was obtained from a Bowen-Ratio Energy Balance System (BREBS located within the image. Nine image dates were used for the growing season, from May through October. Five of those nine were captured during the cover crop season. METRIC was found to successfully differentiate between fields with and without cover crops. In a blind comparison, METRIC compared favorably with the estimated ETa rates found using the BREBS (ETλE, with a difference in total estimated ETa for the cover crop season of 7%.

  4. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    Science.gov (United States)

    Hai-Ming, Tang; Xiao-Ping, Xiao; Wen-Guang, Tang; Ye-Chun, Lin; Ke, Wang; Guang-Li, Yang

    2014-01-01

    Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L.) system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice-rice-ryegrass (Lolium multiflorum L.) (R-R-Ry), rice-rice-Chinese milk vetch (Astragalus sinicus L.) (R-R-Mv), rice-rice-rape (Brassica napus L.) (R-R-Ra) and rice-rice with winter fallow (R-R-Fa). The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (Pwinter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality.

  5. Combining mechanical rhizome removal and cover crops for Elytrigia repens control in organic barley systems

    DEFF Research Database (Denmark)

    Melander, B; Nørremark, M; Kristensen, E F

    2013-01-01

    of vegetative propagules located within the plough layer to allow for quick re-establishment of a plant cover. A field experiment comparing the effects of conventional practices (stubble cultivation) with different combinations of rotary cultivation (One, Two or four passes) and cover crops (none vs. rye......-vetch-mustard mixture) on Elytrigia repens rhizome removal, shoot growth and suppression of a subsequent barley crop was examined in two growing seasons. Four passes with a modified rotary cultivator, where each pass was followed by rhizome removal, reduced E. repens shoot growth in barley by 84% and 97%. In general...

  6. Impact of climate change on water balance components in Mediterranean rainfed olive orchards under tillage or cover crop soil management

    Science.gov (United States)

    Rodríguez-Carretero, María Teresa; Lorite, Ignacio J.; Ruiz-Ramos, Margarita; Dosio, Alessandro; Gómez, José A.

    2013-04-01

    The rainfed olive orchards in Southern Spain constitute the main socioeconomic system of the Mediterranean Spanish agriculture. These systems have an elevated level of complexity and require the accurate characterization of crop, climate and soil components for a correct management. It is common the inclusion of cover crops (usually winter cereals or natural cover) intercalated between the olive rows in order to reduce water erosion. Saving limited available water requires specific management, mowing or killing these cover crops in early spring. Thus, under the semi-arid conditions in Southern Spain the management of the cover crops in rainfed olive orchards is essential to avoid a severe impact to the olive orchards yield through depletion of soil water. In order to characterize this agricultural system, a complete water balance model has been developed, calibrated and validated for the semi-arid conditions of Southern Spain, called WABOL (Abazi et al., 2013). In this complex and fragile system, the climate change constitutes a huge threat for its sustainability, currently limited by the availability of water resources, and its forecasted reduction for Mediterranean environments in Southern Spain. The objective of this study was to simulate the impact of climate change on the different components of the water balance in these representative double cropping systems: transpiration of the olive orchard and cover crop, runoff, deep percolation and soil water content. Four climatic scenarios from the FP6 European Project ENSEMBLES were first bias corrected for temperatures and precipitation (Dosio and Paruolo, 2011; Dosio et al., 2012) and, subsequently, used as inputs for the WABOL model for five olive orchard fields located in Southern Spain under different conditions of crop, climate, soils and management, in order to consider as much as possible of the variability detected in the Spanish olive orchards. The first results indicate the significant effect of the cover

  7. Comparison of the remotely sensed start of the season and ground phenology observations of the cereal crops

    Science.gov (United States)

    Bohovic, Roman; Hlavinka, Petr; Semerádová, Daniela; Bálek, Jan; Trnka, Mirek

    2015-04-01

    Phenology monitoring such as start of the season of agricultural crops are important characteristics observed on the ground basis by the farmers and authorities already for the long time. Due to costs, coverage, site disparities and time demands of ground observations is remote sensing phenology an interesting option. Satellite observations enable monitoring of the ground vegetation already at sufficient resolution and in country and regional scale at the same time. However, ground and remote sensing phenology differ in nature of its object. First is focused on single species and limited individuals at the observation spot. Remote sensing is from its construction definition able to monitor area-wide vegetation communities. To understand these differences and to set the procedures to overcome it is the aim of this study. Case study area covers Czech Republic in Central Europe with typical four season temperate climate that strongly influence the vegetation. Daily MODIS (Moderate Resolution Imaging Spectroradiometer) remote sensing data in 250 by 250 meters resolution were used to compute NDVI (normalized difference vegetation index). Iterative developed method for the filtering of NDVI time series since 2000 up till now is crucial for overcoming missing periods mainly due to atmospheric conditions. From improved curve of NDVI start of the season is derived as absolute threshold value of 50% NDVI. Comparison of remotely sensed start of the season with observations of emergence of spring barley and beginning of leaf sheath elongation for winter wheat was done. Data were correlated at 90 ground stations across Czech Republic between the years 2000 and 2012. Correlations at original 250x250 meters resolution and aggregations of 5x5 km were investigated. Different land cover classes were considered for aggregated areas. Correlation of start of the season shows lower results for spring barley caused by strong influence of winter signal and crop sowing date by farmers

  8. The use of cover crops to increase soil organic carbon in Mediterranean vineyards

    Science.gov (United States)

    García-Díaz, Andrés; Bienes Allas, Ramón; Sastre Rodriguez, Blanca

    2016-04-01

    In Central Spain the vineyards are commonly managed with conventional tillage (CT) to remove water and nutrient competition between the spontaneous vegetation and the vine plants. The continuous tillage promotes high mineralization rates resulting in soils with low organic matter content and prone to erosion. Consequently the increase of soil organic carbon (SOC) in Mediterranean soils has been a main concern in the last years. It is necessary to carry out different soil managements to enhance soil fertility and reduce erosion through the increase of SOC. The aim of this study was to assess the capacity of cover crops (CC) to increase SOC in vineyards in Mediterranean climate. The experiment consisted in four vineyards in four different locations (different type of soil and microclimate), in the same region, to analyze the influence of CC on different conditions. A seeded CC (Brachypodium distachyon L. P. Beauv) and spontaneous vegetation were performed to compare to CT. The Brachypodium distachyon cover was seeded in December, 2012. We analyzed the organic carbon content and bulk density after three agronomy seasons. The samples were taken in the summer of 2015 at the depth of 0-5 cm. The bulk density of Brachypodium distachyon was 1.42 t•m-3, which was statistically significant comparing to both CT (1.33 t•m-3) and spontaneous vegetation (1.34 t•m-3). The SOC percentage of CT, Brachypodium distachyon and spontaneous vegetation was 0.82, 0.96 and 1.10 respectively. Only spontaneous vegetation showed statistically significant differences compared to CT. The results were highly variable depending on the vineyard. The spontaneous vegetation was the most effective CC increasing SOC with an average of 2 t•ha-1 more than CT in three agronomy seasons. These results point out the different efficiency of CC and the high influence of local conditions on SOC increase.

  9. The ability of cover crops to reduce nitrogen and phosphorus losses from arable land in southern Scandinavia and Finland

    DEFF Research Database (Denmark)

    Aronsson, H.; Hansen, Elly Møller; Thomsen, Ingrid Kaag

    2016-01-01

    This review summarizes current knowledge from the literature and experimental studies on the role of cover crops (CCs) in reducing nitrogen (N) leaching and phosphorus (P) losses to waters under the marine and humid continental climate conditions of southern Scandinavia and Finland. Field leaching...

  10. Soil chemistry affects revegetation establishment with and without cover crops in northern mixed grass prairie after energy development

    Science.gov (United States)

    We measured rangeland health and perennial grass establishment in twelve interim reclamations as part of oil extraction activity. Sites at Ft. Berthold Indian Reservation in North Dakota were planted with two different perennial grass mixes, with and without an oat cover crop in late summer/fall of ...

  11. Enhancing management of fall-applied poultry litter with cover crop and subsurface band placement in no-till cotton

    Science.gov (United States)

    Whether yield reduction risk of cotton fertilized with fall-applied poultry litter in regions with warm fall or winter months can be minimized by applying the litter in subsurface bands in conjunction with winter cover crop is unknown. A field study was conducted in Mississippi to test whether litte...

  12. Biomass and nitrogen accumulation of hairy vetch-cereal rye cover crop mixtures as influenced by species proportions

    Science.gov (United States)

    The performance and suitability of a legume-grass cover crop mixture for specific functions may be influenced by the proportions of each species in the mixture. The objectives of this study were to: 1) evaluate aboveground biomass and species biomass proportions at different hairy vetch (Vicia villo...

  13. Expression of allelopathy in the soil environment: Soil concentration and activity of benzoxazinoid compounds released by rye cover crop residue

    Science.gov (United States)

    The activity of allelopathic compounds is often reduced in the soil environment where processes involving release from donor plant material, soil adsorption and degradation, and uptake by receptor plants naturally result in complex interactions. Rye (Secale cereale L.) cover crops are known to supp...

  14. Allelopathic influence of a wheat or rye cover crop on growth and yield of no-till cotton

    Science.gov (United States)

    TECHNICAL ABSTRACT No-till planting cotton into small grain cover crops has many benefits including reducing soil erosion and allelopathic suppression of weeds. It is suggested that the potentials of allelopathy on cotton plants. Nevertheless, little is known about the actual effects of alleloche...

  15. Screening Green Manure Cover Crops for their Allelopathic Effects on Some Important Weeds Found in Zimbabwe

    Directory of Open Access Journals (Sweden)

    Runzika, M.

    2013-08-01

    Full Text Available Weed control is a serious problem in smallholder conservation agriculture farming areas in Zimbabwe. Green Manure Cover Crops (GMCCs, which improve soil fertility and reduce weeds through allelopathy, are likely to reduce the cost of weed control in these areas. A laboratory study was conducted at the University of Zimbabwe to investigate the effect of extracts of eleven GMCCs on the germination percentage, radicle and plumule length of Bidens pilosa, Eleusine indica and Pennisatum glaucum (pearl millet. A green house experiment was also done to determine the allelopathic potential of these GMCC extracts applied as soil incorporated residues on the emergence and dry matter production of E. indica, B. pilosa and Acanthospermum hispidum. GMCC extracts significantly reduced germination, radicle and plumule length of Pennisatum glaucum (P < 0.05 except for Crotalaria grahamiana and Raphanus sativas which had no effect on germination of Pearl millet. The emergence and dry matter of B. pilosa, E. indica and A. hispidum were significantly reduced by these legumes (P < 0.05 with the exception of common vetch (Vicia sativa which stimulated the emergence of A. hispidum. Most of the legumes that were used in this study have allelopathic effects on B. pilosa, E. indica and A. hispidum.

  16. Phosphorus export by runoff from agricultural field plots with different crop cover in Lake Taihu watershed

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Runoff and soil losses from agricultural fields are investigated as major nonpoint sources of phosphorus (P) entering lakes of Eastern China. There is relatively little information on P transport from ricefield and cropland of Lake Taihu watershed in Eastern China. Soil and P in surface runoff from a series of plots in the watershed were evaluated under simulated rainfall conditions. The objectives of this study were to evaluate theeffects of crop cover, slope, and fertilizer application on P concentrations in surface runoff and eroded soil. Accumulated sediment yields varied from 7.1 to 300 g/m2 for croplands, depending on management practices. For all experiment plots, weighted average concentrations of total-P (TP), dissolved P (DP) and particulate P (PP) are much higher than 0.02 mg/L, the limiting concentration in lake water. This result showed the potential contamination of lake water from agricultural surface runoff. Accumulated TP losses were 3.8 and 18.8 mg/m2 for ricefield and cropland, respectively. The estimated annual loss of TP was 0.74 kg/(hm2鷄) for cropland. Most of P loss is in PP form, which accounts for more than 90% of TP loss for cropland.

  17. Modeled Impacts of Cover Crops and Vegetative Barriers on Corn Stover Availability and Soil Quality

    Energy Technology Data Exchange (ETDEWEB)

    Ian J. Bonner; David J. Muth Jr.; Joshua B. Koch; Douglas L. Karlen

    2014-06-01

    Environmentally benign, economically viable, and socially acceptable agronomic strategies are needed to launch a sustainable lignocellulosic biofuel industry. Our objective was to demonstrate a landscape planning process that can ensure adequate supplies of corn (Zea mays L.) stover feedstock while protecting and improving soil quality. The Landscape Environmental Assessment Framework (LEAF) was used to develop land use strategies that were then scaled up for five U.S. Corn Belt states (Nebraska, Iowa, Illinois, Indiana, and Minnesota) to illustrate the impact that could be achieved. Our results show an annual sustainable stover supply of 194 million Mg without exceeding soil erosion T values or depleting soil organic carbon [i.e., soil conditioning index (SCI)?>?0] when no-till, winter cover crop, and vegetative barriers were incorporated into the landscape. A second, more rigorous conservation target was set to enhance soil quality while sustainably harvesting stover. By requiring erosion to be <1/2 T and the SCI-organic matter (OM) subfactor to be >?0, the annual sustainable quantity of harvestable stover dropped to148 million Mg. Examining removal rates by state and soil resource showed that soil capability class and slope generally determined the effectiveness of the three conservation practices and the resulting sustainable harvest rate. This emphasizes that sustainable biomass harvest must be based on subfield management decisions to ensure soil resources are conserved or enhanced, while providing sufficient biomass feedstock to support the economic growth of bioenergy enterprises.

  18. Coberturas vegetais no desenvolvimento vegetativo de plantas de pessegueiro Crop covers in the vegetative development of peach trees

    Directory of Open Access Journals (Sweden)

    Leo Rufato

    2007-04-01

    Full Text Available A utilização de cultivos de cobertura em pomares de pessegueiro no Brasil ainda é pouco difundida, apesar de haver diversas espécies de cobertura vegetal com potencial para tanto. Neste trabalho, estudaram-se os efeitos da a utilização de cinco espécies de plantas para cobertura vegetal de inverno: aveia-preta, chícharo, ervilha forrageira; nabo forrageiro; tremoço-azul, quatro consorciações entre elas e mais a testemunha, com vegetação espontânea sobre o desenvolvimento vegetativo de plantas de pessegueiro cv. Maciel sobre capedeboscq. Todas as espécies vegetais avaliadas adaptaram-se como cobertura vegetal nas condições edafoclimáticas da região Sul do Rio Grande do Sul. As coberturas vegetais, com exceção, sobretudo, do nabo forrageiro, incrementaram o desenvolvimento das plantas de pessegueiro.The use of the crop covers in Brazilian peach orchards is still not so spread, though there are several species of crop covers with the potential have the effect studied. This research presents the effects of the five plant species use for winter vegetal crop covers: Avena strigosa, Lathyrus sativus, Pisum sativum subesp. arvense, Raphanus sativus var. oleiferus, Lupinus angustifolius, four combinations among these species and the control treatments (native vegetation, with spontaneous vegetationon the vegetative development of "Maciel" peach tree under Capdeboscq rootstock. All of the crop covers evaluated adapted themselves to the soil and climate conditions of the south of "Rio Grande do Sul'. The crop covers, except the Raphanus sativus var. oleiferus, increased positively the phenological and vegetative development of peach trees; the Lupinus angustifolius also increased the phenological and vegetative development of plants.

  19. Use Of Crop Canopy Size To Estimate Water Requirements Of Vegetable Crops

    Science.gov (United States)

    Planting time, plant density, variety, and cultural practices vary widely for horticultural crops. It is difficult to estimate crop water requirements for crops with these variations. Canopy size, or factional ground cover, as an indicator of intercepted sunlight, is related to crop water use. We...

  20. Allelopathic effects of two cover crops Commelina diffusa Burm. F. and Tradescantia zebrina Shunltz on Coffea arabica L.

    Directory of Open Access Journals (Sweden)

    Georgina Berroa Navarro

    2016-03-01

    Full Text Available Allelopathic effect of the cover crops Tradescantia zebrina Shunltz (cucaracha and Commelina diffusa Burm. F. (canutillo were evaluated on Coffea arabica Lin. seeds Caturra Rojo variety. Germination tests were carried out “in vitro” and it was evaluated the root longitude, percentage of total germination and period of germination, as well as the height of the plant and the emergency percentage for the incorporation tests to the soil. It was also carried out, to both over crops, the preliminary chemical qualitative characterization. The results showed that the extracts of T. zebrina and of C. diffusa stimulated the “in vitro” germination and growth of C. arabica at different concentration levels. The incorporation to the soil of the extracts of C. diffusa stimulated the development of the plants of C. arabica, in a significant way, that supposes a considerable advantage in that concerns to the employment of these cover crops, when not implying noxious effects beside all the benefits implied when using cover crops. These last ones go from the protection and improvement of the properties of the soil, to the control of the spontaneous flora in the coffee agroecosystems.

  1. Impact of Cover Cropping and Landscape Positions on Nitrous Oxide Emissions in Northeastern Agroecosystems

    Science.gov (United States)

    Han, Z.; Walter, M. T.; Drinkwater, L. E.

    2015-12-01

    Studies investigating agricultural nitrous oxide (N2O) emissions tend to rely on plot-scale experiments. However, to understand the impacts of agricultural practices at a larger scale, it is essential to consider the variability of landscape characteristics along with management treatments. This study compared N2O emissions from a fertilizer-based, conventionally managed farm and an organically managed farm that uses legume cover crops as a primary nutrient source. The objective of the study was to assess how management regimes and slope positions interact to impact N2O emissions and soil characteristics. The field experiment was conducted in two adjacent grain farms in upstate New York that both have been under consistent management for 20 years. In the organic farm, red clover was frost-seeded into a winter grain (spelt), and then incorporated in the spring as a nutrient source for the subsequent corn plants. In contrast, the conventionally managed farm used inorganic fertilizer as the nutrient source. Gas measurement was conducted at two landscape positions at both farms: 1) shoulder and 2) toeslope positions. Comparable N2O emissions were found in the clover-corn phase in the organic site and the bare fallow-corn phase in the conventional site. The spelt-corn phase in the organic farm had the lowest N2O emissions. Soil nitrate concentration was the best predictor for seasonal average N2O emissions. The impact of landscape position on N2O emissions was only found in the conventional site, which was driven by higher denitrfication at toeslopes. In the organic farm, such effect was confounded by higher clover biomass at shoulder slopes. Our study shows that the impact of landscape characteristics on N2O emissions could differ across sites based on the complex interplay between environmental conditions and management.

  2. Estimation of snow cover distribution in Beas basin, Indian Himalaya using satellite data and ground measurements

    Indian Academy of Sciences (India)

    H S Negi; A V Kulkarni; B S Semwal

    2009-10-01

    In the present paper,a methodology has been developed for the mapping of snow cover in Beas basin,Indian Himalaya using AWiFS (IRS-P6)satellite data.The complexities in the mapping of snow cover in the study area are snow under vegetation,contaminated snow and patchy snow. To overcome these problems,field measurements using spectroradiometer were carried out and reflectance/snow indices trend were studied.By evaluation and validation of different topographic correction models,it was observed that,the normalized difference snow index (NDSI)values remain constant with the variations in slope and aspect and thus NDSI can take care of topography effects.Different snow cover mapping methods using snow indices are compared to find the suitable mapping technique.The proposed methodology for snow cover mapping uses the NDSI (estimated using planetary re flectance),NIR band reflectance and forest/vegetation cover information.The satellite estimated snow or non-snow pixel information using proposed methodology was validated with the snow cover information collected at three observatory locations and it was found that the algorithm classify all the sample points correctly,once that pixel is cloud free.The snow cover distribution was estimated using one year (2004 –05)cloud free satellite data and good correlation was observed between increase/decrease areal extent of seasonal snow cover and ground observed fresh snowfall and standing snow data.

  3. Developing novel farming systems: effective use of nutrients from cover crops in intensive organic farming

    NARCIS (Netherlands)

    Burgt, van der G.J.H.M.; Scholberg, J.M.S.; Koopmans, C.J.

    2011-01-01

    On-farm nitrogen fixation is a driving force in organic agriculture. The efficiency with which this nitrogen is used can be increased by using alfalfa or grass-clover crops directly as fertilizer on other fields: cut-and-carry fertilizers. In two crops in two years, the use of several types of

  4. Weed Flora and Dormant-season cover crops have no effects on arbuscular mycorrhizae of grapevine

    Science.gov (United States)

    We tested the hypotheses that mycorrhizal colonization of a perennial crop increases with a high frequency of mycorrhizal hosts within the plant community, and that a high diversity of mycorrhizal hosts is associated with a high diversity of arbuscular mycorrhizal fungi (AMF) on the perennial crop. ...

  5. Fractional Vegetation Cover of East African Wetlands Observed on Ground and from Space

    Science.gov (United States)

    Schmidt, M.; Amler, E.; Guerschmann, J. P.; Scarth, P.; Behn, K.; Thonfeld, F.

    2016-08-01

    Wetlands are important ecosystems providing numerous ecosystem services. They are of particular importance to communities in East Africa where agriculture is the most important economic sector and where food availability to households critical. During an intensive field campaign in the dry season of 2013 were Fractional Vegetation Cover (FVC) measurements, botanical vegetation cover and vegetation structure estimates acquired in three wetland test sites within the East African region. FVC cover data were collated in three strata: ground layer, midstorey and overstorey (woody vegetation greater than 2 m). Fractional cover estimates for the green and no-green vegetative fraction were calculated for Landsat MODIS imagery. These FVC data products were evaluated a) with FVC field data and b) relative to each other for their usability in the East African region. First results show some promise for further studies.

  6. Short-term response of soil spiders to cover-crop removal in an organic olive orchard in a Mediterranean setting.

    Science.gov (United States)

    Cárdenas, Manuel; Castro, Juan; Campos, Mercedes

    2012-01-01

    This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity.

  7. Short-Term Response of Soil Spiders to Cover-Crop Removal in an Organic Olive Orchard in a Mediterranean Setting

    Science.gov (United States)

    Cárdenas, Manuel; Castro, Juan; Campos, Mercedes

    2012-01-01

    This study shows that disturbance caused by cover-crop removal (CCR) in an organic olive orchard affects ground-spider populations. The effect of CCR on various organic olive-orchard plots was assessed by monitoring the abundance and diversity of ground-dwelling spiders. Covered plots in the organic olive orchard were compared with uncovered plots where the covers had been removed mechanically. CCR positively affected the most abundant spider species Zodarion styliferum (Simon) (Araneae: Zodariidae) as well as other species of running spiders belonging to the families Gnaphosidae and Lycosidae. Over time, the two types of plots did not significantly differ in diversity or dominance. Similarly, no differences were detected between the study plots in terms of the distribution of individuals when a cluster-similarity analysis was performed. This lack of difference in diversity might be due to the spatial scale used in the study or climatology. Because of their general effects, CCR profoundly changed the abundance of spiders in the olive orchard, but with no clear impact on spider diversity. PMID:22938154

  8. Ground cover influence on evaporation and stable water isotopes in soil water

    Science.gov (United States)

    Magdalena Warter, Maria; Jiménez-Rodríguez, Cesar D.; Coenders-Gerrits, Miriam; Teuling, Adriaan J. Ryan

    2017-04-01

    Forest ecosystems are characterized by complex structures which influence hydrological processes such as evaporation. The vertical stratification of the forest modifies the effect of the evaporation process due to the composition and local distribution of species within the forest. The evaluation of it will improve the understanding of evaporation in forest ecosystems. To determine the influence of forest understory on the fractionation front, four ground cover types were selected from the Speulderbos forest in the Netherlands. The native species of Thamariskmoss (Thuidium thamariscinum), Rough Stalked Feathermoss (Brachythecium rutabulum), and Haircapmoss (Polytrichum commune) as well as one type of litter made up of Douglas-Fir needles (Pseudotsuga menziesii) were used to analyse the rate of evaporation and changes on the isotopic concentration of the soil water on an in-situ basis in a controlled environment. Over a period of 4 weeks soil water content and atmospheric conditions were continuously measured, while the rainfall simulations were performed with different amounts and timings. The reference water added to the boxes keeps a stable composition along the trial period with a δ ^2H value of -42.59±1.15 \\permil} and δ 18O of -6.01±0.21 \\permil}. The evaporation front in the four ground covers is located between 5 and 10 cm depth and deuterium excess values are bigger than 5 \\permil. The litter layer of Douglas-Fir needles is the cover with higher fractionation in respect to the added water at 10 cm depth (δ ^2H: -29.79 \\permil), while the Haircapmoss keeps the lower fractionation rate at 5 cm and 10 cm (δ ^2H: -33.62 and δ ^2H: -35.34 \\permil). The differences showed by the soil water beneath the different ground covers depict the influence of ground cover on fractionation rates of the soil water, underlining the importance of the spatial heterogeneity of the evaporation front in the first 15 cm of soil.

  9. Nitrate-nitrogen concentrations in the perched ground water under seepage-irrigated potato cropping systems.

    Science.gov (United States)

    Munoz-Arboleda, F; Mylavarapu, R; Hutchinson, C; Portier, K

    2008-01-01

    Excessive nitrogen rates for potato production in northeast Florida have been declared as a potential source of nitrate pollution in the St. Johns River watershed. This 3-yr study examined the effect of N rates (0, 168, and 280 kg ha(-1)) split between planting and 40 d after planting on the NO(3)-N concentration in the perched ground water under potato (Solanum tuberosum cv. Atlantic) in rotation with sorghum sudan grass hybrid (Sorghum vulgare x Sorghum vulgare var. sudanese, cv. SX17), cowpea (Vigna unguiculata cv. Iron Clay), and greenbean (Phaseolus vulgare cv. Espada). Soil solution from the root zone and water from the perched ground water under potato were sampled periodically using lysimeters and wells, respectively. Fertilization at planting increased the NO(3)-N concentration in the perched ground water, but no effect of the legumes in rotation with potatoes on nitrate leaching was detected. Fertilization of green bean increased NO(3)-N concentration in the perched ground water under potato planted in the following season. The NO(3)-N concentration in the soil solution within the potato root zone followed a similar pattern to that of the perched ground water but with higher initial values. The NO(3)-N concentration in the perched ground water was proportional to the rainfall magnitude after potato planting. A significant increase in NO(3)-N concentration in the perched ground water under cowpea planted in summer after potato was detected for the side-dressing of 168 kg ha(-1) N applied to potato 40 d after planting but not at the 56 kg ha(-1) N side-dress. Elevation in NO(3)-N concentration in the perched ground water under sorghum was not significant, supporting its use as an effective N catch crop.

  10. Organic weed conrol and cover crop residue integration impacts on weed control, quality, and yield and economics in conservation tillage tomato - A case study

    Science.gov (United States)

    The increased use of conservation tillage in vegetable production requires more information be developed on the role of cover crops in weed control, tomato quality and yield. Three conservation-tillage systems utilizing crimson clover, brassica and cereal rye as winter cover crops were compared to ...

  11. Planting date impacts on soil water management, plant growth, and weeds in cover-crop-based no-till corn production

    Science.gov (United States)

    Low input and organic farmers are increasingly utilizing cover crop mulches in maize production. Many farmers are delaying planting corn into these high residue environments to allow greater growth of the cover crop to maximize nitrogen fixation and improve mechanical termination with roller crimpe...

  12. Effect of cover crops on common bean yield and soil physical properties under no-till system - doi: 10.4025/actascitechnol.v34i4.11989

    Directory of Open Access Journals (Sweden)

    Edleusa Pereira Seidel

    2012-10-01

    Full Text Available The aim of this study was to evaluate dry matter production of cover crops (oats, turnip, vetch and spontaneous plants and their effect on bean yield and physical properties of soil after succession. The experimental design was randomized blocks, and treatments consisted of four species of cover crops: oat, turnip, vetch and spontaneous plants, with five replications. The cover crops were sown in winter; when in full bloom, they were cut close to the ground and left underground. The bean crop was then sown underneath this residue in a no-till system. The results show that the cover crop that yielded the most dry matter was oats with 4,900 kg ha-1, which did not differ statistically from turnip with a yield of 4,000 kg ha-1. The spontaneous plants produced the least amount of dry matter and differed from the other treatments. The development of vetch was hampered by the environmental conditions of Marechal Cândido Rondon, State of Paraná, with dry matter yield of 2,375 kg ha-1. The highest bean yield (1,204 kg ha-1 was found for the planting carried out in succession to oat, and the lowest after succession of vetch (697 kg ha-1 and spontaneous plants (575 kg ha-1. Cover crops had no effect on macroporosity and total porosity of soil depth from 0.05 to 0.20 m. There was a statistical difference in soil bulk density in the layer from 0.05 to 0.10 m, and bulk density (1.18 kg dm-3 was obtained in the treatment where the bean crop was cultivated after spontaneous plants.

  13. Sensitivity of crop cover to climate variability: insights from two Indian agro-ecoregions.

    Science.gov (United States)

    Mondal, Pinki; Jain, Meha; DeFries, Ruth S; Galford, Gillian L; Small, Christopher

    2015-01-15

    Crop productivity in India varies greatly with inter-annual climate variability and is highly dependent on monsoon rainfall and temperature. The sensitivity of yields to future climate variability varies with crop type, access to irrigation and other biophysical and socio-economic factors. To better understand sensitivities to future climate, this study focuses on agro-ecological subregions in Central and Western India that span a range of crops, irrigation, biophysical conditions and socioeconomic characteristics. Climate variability is derived from remotely-sensed data products, Tropical Rainfall Measuring Mission (TRMM - precipitation) and Moderate Resolution Imaging Spectroradiometer (MODIS - temperature). We examined green-leaf phenologies as proxy for crop productivity using the MODIS Enhanced Vegetation Index (EVI) from 2000 to 2012. Using both monsoon and winter growing seasons, we assessed phenological sensitivity to inter-annual variability in precipitation and temperature patterns. Inter-annual EVI phenology anomalies ranged from -25% to 25%, with some highly anomalous values up to 200%. Monsoon crop phenology in the Central India site is highly sensitive to climate, especially the timing of the start and end of the monsoon and intensity of precipitation. In the Western India site, monsoon crop phenology is less sensitive to precipitation variability, yet shows considerable fluctuations in monsoon crop productivity across the years. Temperature is critically important for winter productivity across a range of crop and management types, such that irrigation might not provide a sufficient buffer against projected temperature increases. Better access to weather information and usage of climate-resilient crop types would play pivotal role in maintaining future productivity. Effective strategies to adapt to projected climate changes in the coming decades would also need to be tailored to regional biophysical and socio-economic conditions.

  14. Cover cropping under temperate conditions: influence of growth period and incorporation time

    DEFF Research Database (Denmark)

    Thomsen, Ingrid Kaag; Hansen, Elly Møller

    . To encourage increased use of CC and to lessen the consequences on choice of main crop new innovative ways of using CC should be considered. This study tested the potential for using CC that could allow for repeated winter wheat growing and still permit CC in breaks between crops. Cruciferous CC (Raphanus...... sativus L., Sinapis alba L.) spread in a growing winter wheat crop in July and incorporated in September (Autumn CC) before sowing the following winter wheat was compared with the same CC cultivars sown after harvest and incorporated in spring (Winter CC). The cruciferous CC were compared with Winter CC...

  15. Assessing post-fire ground cover in Mediterranean shrublands with field spectrometry and digital photography

    Science.gov (United States)

    Montorio Llovería, Raquel; Pérez-Cabello, Fernando; García-Martín, Alberto

    2016-09-01

    Fire severity can be assessed by identifying and quantifying the fractional abundance of post-fire ground cover types, an approach with great capacity to predict ecosystem response. Focused on shrubland formations of Mediterranean-type ecosystems, three burned areas (Ibieca and Zuera wildfires and Peñaflor experimental fire) were sampled in the summers of 2006 and 2007. Two different ground measurements were made for each of the 356 plots: (i) 3-band high spatial resolution photography (HSRP) and (ii) the hemispherical-conical reflectance factor (HCRF) in the visible to near-infrared spectral range (VNIR, 400-900 nm). Stepwise multiple lineal regression (SMLR) models were fitted to spectral variables (HCRF, first derivative spectra or FDS, and four absorption indices) to estimate the fractional cover of seven post-fire ground cover types (vegetation and soil - unburned and charred components - and ash - char and ash, individually and as a combined category). Models were developed and validated at the Peñaflor site (training, n = 217; validation, n = 88) and applied to the samples from the Ibieca and Zuera sites (n = 51). The best results were observed for the abundance estimations of green vegetation (Radj.20.70-0.90), unburned soil (Radj.20.40-0.75), and the combination of ashes (Radj.20.65-0.80). In comparison of spectral data, FDS outperforms reflectance or absorption data because of its higher accuracy levels and, importantly, its greater capacity to yield generalizable models. Future efforts should be made to improve the estimation of intermediate severity levels and upscaling the developed models. In the context of fire severity assessment, our study demonstrates the potential of hyperspectral data to estimate in a quick and objective manner post-fire ground cover fractions and thus provide valuable information to guide management responses.

  16. Land cover for Ukraine: the harmonization of remote sensing and ground-based data

    Science.gov (United States)

    Lesiv, M.; Shchepashchenko, D.; Shvidenko, A.; See, L. M.; Bun, R.

    2012-12-01

    This study focuses on the development of a land cover map of the Ukraine through harmonization of remote sensing and ground-based data. At present there is no land cover map of the Ukraine available that is of sufficient accuracy for use in environmental modeling. The existing remote sensing data are not enough accurate. In this study we compare the territory of the Ukraine from three global remote sensing products (GlobCover 2009, MODIS Land Cover and GLC-2000) using a fuzzy logic methodology in order to capture the uncertainty in the classification of land cover. The results for the Ukraine show that GlobCover 2009, MODIS Land Cover and GLC-2000 have a fuzzy agreement of 65%. We developed a weighted algorithm for the creation of a land cover map based on an integration of a number of global land cover and remote sensing products including the GLC-2000, GlobCover 2009, MODIS Land Cover, the Vegetation Continuous Fields product, digital map of administrative units and forest account data at the local level. This weighted algorithm is based on the results of comparing these products and an analysis of a dataset of validation points for different land cover types in the Ukraine. We applied this algorithm to generate a forest land cover type map. This raster map contains a forest expectation index that was calculated for each pixel. Forest land was then allocated based on forest statistics at the local level. Areas with a higher forest expectation index were allocated with forest first until the results matched the forest statistics. The result is the first digital map of forest (with a spatial resolution of 300m) for the Ukraine, which consistent with forest and land accounts, remote sensing datasets and GIS products. The forest land was well defined in forest rich areas (i.e. in the northern part of the Ukraine, the Carpathians and the Crimea); well less accurate areas were identified in the steppe due to heterogeneous land cover. Acknowledgements. This research was

  17. Fall cover cropping can increase arbuscular mycorrhizae in soils supporting intensive agricultural production

    Science.gov (United States)

    Intensive agricultural practices, such as tillage, monocropping, seasonal fallow periods, and inorganic nutrient application have been shown to reduce arbuscular mycorrrhizal fungi (AMF) populations and thus may reduce benefits frequently provided to crops by AMF, such as nutrient acquisition, disea...

  18. Covering of heating load of object by using ground heat as a renewable energy source

    Directory of Open Access Journals (Sweden)

    Čenejac Aleksandra R.

    2012-01-01

    Full Text Available Rational use of energy, improving energy performance of buildings and use of renewable energy sources are the most important measures for reducing consumption of non-renewable primary energy (solid, liquid, and gaseous fuels, environmental protection and for the future sustainable development of mankind. In the total primary energy consumption great part is related to building industry, for heating spaces in which people stay and live. Renewable energy sources (RES present natural resources and they are one of the alternatives that allow obtaining heat for heating buildings, and by that they provide a significant contribution to the energy balance of a country. This paper analyzes the participation of ground source as RES, when the vertical (the probe in the ground and horizontal (registry in the ground heat exchangers are used for covering heating load of the building.

  19. Molecular diversity and distribution of indigenous arbuscular mycorrhizal communities colonizing roots of two different winter cover crops in response to their root proliferation.

    Science.gov (United States)

    Higo, Masao; Isobe, Katsunori; Miyazawa, Yusuke; Matsuda, Yukiya; Drijber, Rhae A; Torigoe, Yoichi

    2016-02-01

    A clear understanding of how crop root proliferation affects the distribution of the spore abundance of arbuscular mycorrhizal fungi (AMF) and the composition of AMF communities in agricultural fields is imperative to identify the potential roles of AMF in winter cover crop rotational systems. Toward this goal, we conducted a field trial using wheat (Triticum aestivum L.) or red clover (Trifolium pratense L.) grown during the winter season. We conducted a molecular analysis to compare the diversity and distribution of AMF communities in roots and spore abundance in soil cropped with wheat and red clover. The AMF spore abundance, AMF root colonization, and abundance of root length were investigated at three different distances from winter crops (0 cm, 7.5 cm, and 15 cm), and differences in these variables were found between the two crops. The distribution of specific AMF communities and variables responded to the two winter cover crops. The majority of Glomerales phylotypes were common to the roots of both winter cover crops, but Gigaspora phylotypes in Gigasporales were found only in red clover roots. These results also demonstrated that the diversity of the AMF colonizing the roots did not significantly change with the three distances from the crop within each rotation but was strongly influenced by the host crop identity. The distribution of specific AMF phylotypes responded to the presence of wheat and red clover roots, indicating that the host crop identity was much more important than the proliferation of crop roots in determining the diversity of the AMF communities.

  20. Occurrence and Structure of Arbuscular Mycorrhizal Fungal Communities in Cassava after Cultivation of Cover Crops as Observed by the “PCR-DGGE” Technique

    Directory of Open Access Journals (Sweden)

    Elaine dos Santos Heberle

    2015-10-01

    Full Text Available ABSTRACT Cassava (Manihot esculenta Crantz is a highly mycotrophic crop, and prior soil cover may affect the density of arbuscular mycorrhizal fungi (AMFs, as well as the composition of the AMFs community in the soil. The aim of this study was to evaluate the occurrence and the structure of AMFs communities in cassava grown after different cover crops, and the effect of the cover crop on mineral nutrition and cassava yield under an organic farming system. The occurrence and structure of the AMFs community was evaluated through polymerase chain reaction (PCR and denaturing gradient gel electrophoresis (DGGE. A randomized block experimental design was used with four replications. Six different cover crop management systems before cassava were evaluated: black oats, vetch, oilseed radish, intercropped oats + vetch, intercropped oats + vetch + oilseed radish, plus a control (fallow treatment mowed every 15 days. Oats as a single crop or oats intercropped with vetch or with oilseed radish increased AMFs inoculum potential in soil with a low number of propagules, thus benefiting mycorrhizal colonization of cassava root. The treatments did not affect the structure of AMFs communities in the soil since the AMFs communities were similar in cassava roots in succession to different cover crops. AMFs colonization was high despite high P availability in the soil. The cassava crop yield was above the regional average, and P levels in the leaves were adequate, regardless of which cover crop treatments were used. One cover crop cycle prior to the cassava crop was not enough to observe a significant response in variables, P in plant tissue, crop yield, and occurrence and structure of AMFs communities in the soil. In the cassava roots in succession, the plant developmental stage affected the groupings of the structure of the AMF community.

  1. Effects of winter cover crops residue returning on soil enzyme activities and soil microbial community in double-cropping rice fields.

    Directory of Open Access Journals (Sweden)

    Tang Hai-Ming

    Full Text Available Residue management in cropping systems is useful to improve soil quality. However, the studies on the effects of residue management on the enzyme activities and microbial community of soils in South China are few. Therefore, the effects of incorporating winter cover crop residue with a double-cropping rice (Oryza sativa L. system on soil enzyme activities and microbial community in Southern China fields were studied. The experiment has conducted at the experimental station of the Institute of Soil and Fertilizer Research, Hunan Academy of Agricultural Science, China since winter 2004. Four winter cropping systems were used: rice-rice-ryegrass (Lolium multiflorum L. (R-R-Ry, rice-rice-Chinese milk vetch (Astragalus sinicus L. (R-R-Mv, rice-rice-rape (Brassica napus L. (R-R-Ra and rice-rice with winter fallow (R-R-Fa. The result indicated that the enzyme activities in the R-R-Ry, R-R-Mv and R-R-Ra systems were significantly higher (P<0.05 than in the R-R-Fa system during the early and late rice season. The β-glucosidase activities reached peak values at the tillering stage after residue application, and alkaline phosphatase activities reached peak values at the booting stage after residue application, respectively, the activities of β-glucosidase and alkaline phosphatase gradually decreased after this. Arylsulfatase activities reached peak values at the maturity stage. Arylamidase activities reached peak values at the maturity stage. The numbers of aerobic bacteria, actinomycete and fungus of residue treatments were significantly higher (P<0.05 than that the R-R-Ra system. However, the number of anaerobic bacteria under the R-R-Ry and R-R-Mv systems was significantly lower (P<0.05 than that under the R-R-Fa system during early rice and late rice growth stage. Thus, incorporation of winter cover crops into rotations may increase enzyme activities and microbial community in soil and therefore improve soil quality.

  2. The effects of a winter cover crop on Diabrotica virgifera (Coleoptera: Chrysomelidae) populations and beneficial arthropod communities in no-till maize.

    Science.gov (United States)

    Lundgren, Jonathan G; Fergen, Janet K

    2010-12-01

    The effects of an autumn-planted, spring-killed, grass cover crop (Elymus trachycaulus [Link] Gould ex Shinners) on populations of Diabrotica virgifera virgifera LeConte and its predator community were evaluated in South Dakota maize fields over two seasons. Abundance and size of D. virgifera larvae and adults and sex ratio of adults were measured in maize produced under two treatments (i.e., a winter cover crop or bare soil), as were maize root damage and the abundance and diversity of the predator communities collected on the soil surface and in the soil column. First and second instars and adults of D. virgifera were similarly abundant in the two treatments, but third instars were significantly fewer in maize planted after a winter cover crop. Larvae developed at different rates in the two treatments, and second instars were significantly smaller (head capsule width and body length) in the maize planted after a cover crop. First and third instars and adults were of similar size in the two treatments, and adult sex ratios were also similar. Although initially similar, predator populations increased steadily in the cover-cropped maize, which led to a significantly greater predator population by the time D. virgifera pupated. There was significantly less root damage in the cover-cropped maize. Predator communities were similarly diverse in both treatments. Predator abundance per plot was significantly and negatively correlated with the abundance of third instars per plot. Clearly, winter cover crops reduce D. virgifera performance and their damage to the crop, and we suspect that this reduction is caused by both environmental effects of the treatment on D. virgifera size and development, and of increased predation on the third instars of the pest. Additional data on the impact of cover crops on actual predation levels, grain yield and quality, and farmer profitability, and correlations among pest performance, crop characteristics, and predator populations and

  3. The Effect of Biofertilizers and Winter Cover Crops on Essential Oil Production and Some Agroecological Characteristics of Basil (Ocimum basilicum L.

    Directory of Open Access Journals (Sweden)

    M Jahan

    2013-04-01

    Full Text Available In searching for new strategies of medicinal plant production with high yield but without undesirable compounds or effects, it is important to investigate unconventional alternatives such as application of PGPR and cover crops cultivation. This experiment was conducted in a split plots arrangement with two factors based on randomized complete block design with three replications during years 2009-10, at Research Farm of Ferdowsi University of Mashhad. Cultivation and no cultivation of cover crops in autumn assigned to the main plots. The sub factor was biofertilizer application with four levels, included 1-Nitroxin (containing Azotobacter spp. and Azospirillum spp., 2-Biophosphorous (Bacillus sp. and Pseudomonas sp., 3-Nitroxin + Biophosphorous and 4-Control. During growing season plants were harvested by three cuts. Results showed that total shoots dry weight, leaves yield and LAI in plants under no cover crop cultivation had a significant advantage. Biofertilizers increased most characteristics e.g. fresh and dry total shoot yield, dry leaves and LAI. The interaction between fertilizer and cover crop was significant, as the highest yield of fresh shoots was observed in mix of nitroxin and biophosphorous with no cover crop, the highest and the lowest of leaf and green area index were obtained in plants treated by nitroxin without cover crop and biophosphorous with cover crop, respectively. Plants harvested in cut 3 had the lowest LAI and other two cuts had no significant difference concerning this trait. The highest and the lowest fresh and dry shoot yield were observed in cut 2 and 1, respectively. The most essential oil yield was in cut 2 and 3 (without significant difference and cut 1 was the lowest. The results showed that the interaction between biofertilizers and no cover crop cultivation was significant, as use of the biofertilizers especially nitroxin and biophosphorous in no cover crop condition enhanced the most characteristics of

  4. The use of cover crops to control tree invasion on a right-of-way near Tobermory. IV. Crop persistance and tree invasion in the third growing season

    Energy Technology Data Exchange (ETDEWEB)

    Brown, D.

    1992-04-08

    A study was carried out to determine the ability of grasses, legumes, and the natural right-of-way vegetation cover to interfere with tree invasion. The location, in the Tobermory area of the Bruce Peninsula, was used to test 6 treatments at 6 sites, consisting of: soil scarification and seeding with creeping red fescue (Festuca rubra); soil scarification and seeding with juno orchard grass (Dactylis glomerata); soil scarification and seeding with birdsfoot trefoil (Lotus corniculatus); soil scarification and seeding with a mixture of penngift crown vetch (Coronilla varia) and perennial ryegrass (Lolium multiflorum); soil scarification with no seeding; and no soil scarification and no seeding. A design change in 1991 involved the addition of a slow release fertilizer and planting of green ash (Flaxinus pennsylvanica), sugar maple (Acer saccharum) and hybrid poplar (Populus sp.) to directly measure the interference potential of the crops. Orchard grass had the highest frequency (93[plus minus]3%), the largest cover (32[plus minus]7%) and the tallest canopy. Red fescue was present with a similarly high frequency and cover but did not appear to be as vigorous as the orchard grass. The frequencies of birdsfoot trefoil and crown vetch declined, and had extremely poor covers. The density of incompatible trees varied at each site but was not affected by the treatments. 41 refs., 6 figs., 7 tabs.

  5. The influence of cover crops and tillage on actual and potential soil erosion in an olive grove

    Science.gov (United States)

    Sastre, Blanca; Bienes, Ramón; García-Díaz, Andrés; Panagopoulos, Thomas; José Marqués, Maria

    2014-05-01

    The study was carried out in an olive grove in central Spain (South of Madrid; Tagus River Basin). In this semi-arid zone, the annual mean temperature is 13.8 ºC and the annual precipitation is 395 mm. Olive groves are planted in an erosion prone area due to steep slopes up to 15%. Soil is classified as Typic Haploxerept with clay loam texture. The land studied was formerly a vineyard, but it was replaced by the studied olive grove in 2004. It covers approximately 3 ha and olive trees are planted every 6 x 7 metres. They were usually managed by tillage to decrease weed competition. This conventional practice results in a wide surface of bare soil prone to erosion processes. In the long term soil degradation may lead to increase the desertification risk in the area. Storms have important consequences in this shallow and vulnerable soil, as more than 90 Mg ha-1 have been measured after one day with 40 mm of rainfall. In order to avoid this situation, cover crops between the olive trees were planted three years ago: sainfoin (Onobrychis viciifolia), barley (Hordeum vulgare), and purple false brome (Brachypodium distachyon), and they were compared with annual spontaneous vegetation after a minimum tillage treatment (ASV). The results regarding erosion control were positive. We observed (Oct. 2012/Sept. 2013) annual soil loss up to 11 Mg ha-1 in ASV, but this figure was reduced in the sown covers, being 8 Mg ha-1 in sainfoin treatment, 3,7 Mg ha-1 in barley treatment, and only 1,5 Mg ha-1 in false brome treatment. Those results are used to predict the risk of erosion in long term. Moreover, soil organic carbon (SOC) increased with treatments, this is significant as it reduces soil erodibility. The increases were found both in topsoil (up to 5 cm) and more in depth, in the root zone (from 5 to 10 cm depth). From higher to lower SOC values we found the false brome (1.05%), barley (0.92%), ASV (0.79%) and sainfoin (0.71%) regarding topsoil. In the root zone (5-10 cm depth

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

    Directory of Open Access Journals (Sweden)

    Marzena Błażewicz-Woźniak

    2015-03-01

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

  7. Reduced-tillage organic corn production in a hairy vetch cover crop

    Science.gov (United States)

    There is much interest in developing no-tillage systems for organic farming, however, potential limitations include the inability to control weeds and to provide sufficient crop available N. A three-year field experiment was conducted on organically-certified land to explore the use of roller-crimp...

  8. Kenaf (Hibiscus cannabinus) and cowpea (Vigna unguiculata) as sugarcane cover crops

    Science.gov (United States)

    A Louisiana sugarcane field is typically replanted every four years due to declining yields, and, although, it is a costly process, it is both necessary and an opportunity to maximize the financial return during the next four year cropping cycle. Fallow planting systems (FPS) during the fallow perio...

  9. Weed hosts and relative weed and cover crop susceptibility to Rotylenchulus reniformis in the Mississippi Delta

    Science.gov (United States)

    The reniform nematode (Rotylenchulus reniformis) causes economic losses in cotton and soybean in the southeastern United States, and has the ability to reproduce on more than 300 plant species. Even when the host crop is protected through the use of nematicides or host plant resistance, the potentia...

  10. Impact of the variability of the seasonal snow cover on the ground surface regimes in Hurd Peninsula (Livingston Island, Antarctic)

    Science.gov (United States)

    Nieuwendam, Alexandre; Ramos, Miguel; Vieira, Gonçalo

    2014-05-01

    Seasonally snow cover has a great impact on the thermal regime of the active layer and permafrost. Ground temperatures over a year are strongly affected by the timing, duration, thickness, structure and physical and thermal properties of snow cover. The purpose of this communication is to characterize the shallow ground thermal regimes, with special reference to the understanding of the influence snow cover in permafrost spatial distribution, in the ice-free areas of the north western part of Hurd Peninsula in the vicinity of the Spanish Antarctic Station "Juan Carlos I" and Bulgarian Antarctic Station "St. Kliment Ohridski". We have analyzed and ground temperatures as well as snow thickness data in four sites distributed along an altitudinal transect in Hurd Peninsula from 2007 to 2013: Nuevo Incinerador (25 m asl), Collado Ramos (110 m), Ohridski (140 m) and Reina Sofia Peak (275 m). At each study site, data loggers were installed for the monitoring of air temperatures (at 1.5 m high), ground temperatures (5, 20 and 40 cm depth) and for snow depth (2, 5, 10, 20, 40, 80 and 160 cm) at 4-hour intervals. The winter data suggests the existence of three types of seasonal stages regarding the ground surface thermal regime and the thickness of snow cover: (a) shallow snow cover with intense ground temperatures oscillations; (b) thick snow cover and low variations of soil temperatures; and (c) stability of ground temperatures. Ground thermal conditions are also conditioned by a strong variability. Winter data indicates that Nuevo Incinerador site experiences more often thicker snow cover with higher ground temperatures and absence of ground temperatures oscillations. Collado Ramos and Ohridski show frequent variations of snow cover thickness, alternating between shallow snow cover with high ground temperature fluctuation and thick snow cover and low ground temperature fluctuation. Reina Sofia in all the years has thick snow cover with little variations in soil

  11. Mechanizing Weakly Ground Termination Proving of Term Rewriting Systems by Structural and Cover-Set Inductions

    Institute of Scientific and Technical Information of China (English)

    Su Feng

    2005-01-01

    The paper presents three formal proving methods for generalized weakly ground terminating property, i.e.,weakly terminating property in a restricted domain of a term rewriting system, one with structural induction, one with cover-set induction, and the third without induction, and describes their mechanization based on a meta-computation model for term rewriting systems-dynamic term rewriting calculus. The methods can be applied to non-terminating, nonconfluent and/or non-left-linear term rewriting systems. They can do "forward proving" by applying propositions in the proof, as well as "backward proving" by discovering lemmas during the proof.

  12. Ground-based hyperspectral remote sensing to discriminate biotic stress in cotton crop

    Science.gov (United States)

    Nigam, Rahul; Kot, Rajsi; Sandhu, Sandeep S.; Bhattacharya, Bimal K.; Chandi, Ravinder S.; Singh, Manjeet; Singh, Jagdish; Manjunath, K. R.

    2016-05-01

    develop on the undersides of leaves. The most common pest species such as greenhouse white fly (Trialeurodes vaporariorum) and sweet potato white fly (Bemisia tabaci) have a wide host range that includes many weeds and crops. White flies normally lay their tiny oblong eggs on the undersides of leaves. The eggs hatch, and the young white flies gradually increase in size through four nymphal stages called instars. The first nymphal stage (crawler) is barely visible even with a hand lens. The crawlers move around for several hours before settling to begin feeding. Later nymphal stages are immobile, oval, and flattened, with greatly reduced legs and antennae, like small scale insects. The winged adult emerges from the last nymphal stage (sometimes called a pupa, although whiteflies don't have a true complete metamorphosis). All stages feed by sucking plant juices from leaves and excreting excess liquid as drops of honeydew as they feed. White flies use their piercing, needle like mouthparts to suck sap from phloem, the food-conducting tissues in plant stems and leaves. Large populations can cause leaves to turn yellow, appear dry, or fall off plants. Like aphids, white flies excrete sugary liquid called honeydew, so leaves may be sticky or covered with black sooty mold that grows on honeydew. The honeydew attracts ants, which interfere with the activities of natural enemies that may control white flies and other pests. High white fly infestation was reported at several locations in Punjab during year 2015. The application of non-destructive methods to detect vegetation stress at an early stage of its development is very important for pest management in commercially important crops. Earlier few studies have been done to characterize reflectance spectra of nutrient stress nitrogen deficiency and irrigation management for cotton but no literature is available regarding characterization of spectral reflectance to study white fly infestation. Therefore, the primary objectives of

  13. Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

    Science.gov (United States)

    Lee, Sangchul; Yeo, In-Young; Sadeghi, Ali M; McCarty, Gregory W; Hively, W Dean; Lang, Megan W

    2016-01-01

    The adoption rate of winter cover crops (WCCs) as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB) is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT) and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE) reduced NO3-N loads by ~49.3% compared to the baseline (no WCC). The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean), with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

  14. Impacts of Watershed Characteristics and Crop Rotations on Winter Cover Crop Nitrate-Nitrogen Uptake Capacity within Agricultural Watersheds in the Chesapeake Bay Region.

    Directory of Open Access Journals (Sweden)

    Sangchul Lee

    Full Text Available The adoption rate of winter cover crops (WCCs as an effective conservation management practice to help reduce agricultural nutrient loads in the Chesapeake Bay (CB is increasing. However, the WCC potential for water quality improvement has not been fully realized at the watershed scale. This study was conducted to evaluate the long-term impact of WCCs on hydrology and NO3-N loads in two adjacent watersheds and to identify key management factors that affect the effectiveness of WCCs using the Soil and Water Assessment Tool (SWAT and statistical methods. Simulation results indicated that WCCs are effective for reducing NO3-N loads and their performance varied based on planting date, species, soil characteristics, and crop rotations. Early-planted WCCs outperformed late-planted WCCs on the reduction of NO3-N loads and early-planted rye (RE reduced NO3-N loads by ~49.3% compared to the baseline (no WCC. The WCCs were more effective in a watershed dominated by well-drained soils with increased reductions in NO3-N fluxes of ~2.5 kg N·ha-1 delivered to streams and ~10.1 kg N·ha-1 leached into groundwater compared to poorly-drained soils. Well-drained agricultural lands had higher transport of NO3-N in the soil profile and groundwater due to increased N leaching. Poorly-drained agricultural lands had lower NO3-N due to extensive drainage ditches and anaerobic soil conditions promoting denitrification. The performance of WCCs varied by crop rotations (i.e., continuous corn and corn-soybean, with increased N uptake following soybean crops due to the increased soil mineral N availability by mineralization of soybean residue compared to corn residue. The WCCs can reduce N leaching where baseline NO3-N loads are high in well-drained soils and/or when residual and mineralized N availability is high due to the cropping practices. The findings suggested that WCC implementation plans should be established in watersheds according to local edaphic and agronomic

  15. Evaluation of Cover Crops with Potential for Use in Anaerobic Soil Disinfestation (ASD) for Susceptibility to Three Species of Meloidogyne.

    Science.gov (United States)

    Kokalis-Burelle, Nancy; Butler, David M; Rosskopf, Erin N

    2013-12-01

    Several cover crops with potential for use in tropical and subtropical regions were assessed for susceptibility to three common species of root-knot nematode, Meloidogyne arenaria, M. incognita, and M. javanica. Crops were selected based on potential use as organic amendments in anaerobic soil disinfestation (ASD) applications. Nematode juvenile (J2) numbers in soil and roots, egg production, and host plant root galling were evaluated on arugula (Eruca sativa, cv. Nemat), cowpea (Vigna unguiculata, cv. Iron & Clay), jack bean (Canavalia ensiformis, cv. Comum), two commercial mixtures of Indian mustard and white mustard (Brassica juncea & Sinapis alba, mixtures Caliente 61 and Caliente 99), pearl millet (Pennisetum glaucum, cv. Tifleaf III), sorghum-sudangrass hybrid (Sorghum bicolor × S. bicolor var. sudanense, cv. Sugar Grazer II), and three cultivars of sunflower (Helianthus annuus, cvs. 545A, Nusun 660CL, and Nusun 5672). Tomato (Solanum lycopersicum, cv. Rutgers) was included in all trials as a susceptible host to all three nematode species. The majority of cover crops tested were less susceptible than tomato to M. arenaria, with the exception of jack bean. Sunflower cv. Nusun 5672 had fewer M. arenaria J2 isolated from roots than the other sunflower cultivars, less galling than tomato, and fewer eggs than tomato and sunflower cv. 545A. Several cover crops did not support high populations of M. incognita in roots or exhibit significant galling, although high numbers of M. incognita J2 were isolated from the soil. Arugula, cowpea, and mustard mixture Caliente 99 did not support M. incognita in soil or roots. Jack bean and all three cultivars of sunflower were highly susceptible to M. javanica, and all sunflower cultivars had high numbers of eggs isolated from roots. Sunflower, jack bean, and both mustard mixtures exhibited significant galling in response to M. javanica. Arugula, cowpea, and sorghum-sudangrass consistently had low numbers of all three

  16. Cover Image Identification of Plant Species for Crop Pollinator Habitat Enhancement in the Northern Prairies

    Directory of Open Access Journals (Sweden)

    Diana Bizecki Robson

    2014-09-01

    Full Text Available Wild pollinators have a positive impact on the productivity of insect-pollinated crops. Consequently, landowners are being encouraged to maintain and grow wildflower patches to provide habitat for important pollinators. Research on plant-pollinator interaction matrices indicates that a small number of “core” plants provide a disproportionately high amount of pollen and nectar to insects. This matrix data can be used to help design wildflower plantings that provide optimal resources for desirable pollinators. Existing interaction matrices from three tall grass prairie preserves in the northern prairies were used to identify core plant species that are visited by wild pollinators of a common insect-pollinated crop, namely canola (Brassica napus L.. The wildflower preferences of each insect taxon were determined using quantitative insect visitation and floral abundance data. Phenology data were used to calculate the degree of floral synchrony between the wildflowers and canola. Using this information I ranked the 41 wildflowers that share insect visitors with canola according to how useful they are for providing pollinators with forage before and after canola flowers. The top five species were smooth blue aster (Symphyotrichum laeve (L. A. & D. Löve, stiff goldenrod (Solidago rigida L., wild bergamot (Monarda fistulosa L., purple prairie-clover (Dalea purpurea Vent. and Lindley’s aster (Symphyotrichum ciliolatum (Lindl. A. & D. Löve. By identifying the most important wild insects for crop pollination, and determining when there will be “pollen and nectar gaps”, appropriate plant species can be selected for companion plantings to increase pollinator populations and crop production.

  17. Evidence of wintertime CO2 emission from snow-covered grounds in high latitudes

    Institute of Scientific and Technical Information of China (English)

    方精云; 唐艳鸿KOIZUMI; Hiroshi(Division; of; Plant; Ecology; National; Institute; of; Agro-Environmental; Sciences; Tsukuba; 305; Japan)BEKKU; Yukiko(National; Polar; Institute; Tokyo; 192; Japan)

    1999-01-01

    In order to measure CO2 flux in wintertime arctic ecosystems, CO2 gas was sampled from various snow-covered grounds by using a closed chamber method during the First China Arctic Scientific Expedition from March to May in 1995. The CO2 gas samples were measured by using an infra-red analyzer (IRGA). The results showed that (ⅰ) CO2 emission was detected from all kinds of the snow-covered grounds, which provides direct evidence that the arctic tundra is functioning as a source of atmospheric CO2; (ⅱ) CO2 release was also detected from the permanent ice profile and icecap, and (ⅲ) CO2 evolution from terrestrial ecosystems in higher latitudes increased with an increase of surface temperature in accordance with the exponential function. This indicates a close coincidence with that under normal temperature conditions, and provides a useful method for predicting change in CO2 flux in the arctic ecosystems with the global climate change.

  18. Use of nitrogen from fertilizer and cover crops by upland rice in an Oxisol under no-tillage in the Cerrado

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Edson Cabral da; Muraoka, Takashi; Bendassolli, Jose Alberto, E-mail: edsoncabralsilva@gmail.com, E-mail: muraoka@cena.usp.br, E-mail: jab@cena.usp.br [Centro de Energia Nuclear na Agricultura (CENA/USP), Piracicaba, SP (Brazil); Franzini, Vinicius Ide, E-mail: vinicius.franzini@embrapa.br [Embrapa Amazonia Oriental, Belem, PA (Brazil); Sakadevan, Karuppan, E-mail: K.Sakadevan@iaea.org [Joint FAO/IAEA, Division of Nuclear Techniques in Food and Agriculture, Soil and Water Management and Crop Nutrition Subprogram, Vienna International Centre, Vienna (Austria); Buzetti, Salatier; Arf, Orivaldo, E-mail: sbuzetti@agr.feis.unesp.br, E-mail: arf@agr.feis.unesp.br [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Ilha Solteira, SP (Brazil). Faculdade de Engenharia; Soares, Frederico Antonio Loureiro, E-mail: fredalsoares@hotmail.com [Instituto Federal Goiano, Rio Verde, GO (Brazil)

    2016-06-15

    The objective of this work was to evaluate the effects of cover crops on the yield of upland rice (Oryza sativa) grown under no-tillage system, in the presence and absence of N fertilizer, as well as to quantify, in the field, the use efficiency of N from urea and cover crops by upland rice, through the {sup 15}N isotope dilution technique. The field experiment was carried out in the municipality of Selviria, in the state of Mato Grosso do Sul, Brazil, in an Oxisol (Rhodic Hapludox) in the Cerrado (Brazilian savanna) region. The experimental design was a randomized complete block with 15 treatments and four replicates, in a 5 x 3 factorial arrangement. The treatments were four cover crops (Crotalaria juncea, Cajanus cajan, Mucuna pruriens, and Pennisetum glaucum) + spontaneous vegetation (fallow in off-season), combined with three forms of N fertilization: control treatment, without N fertilizer application; 20 kg ha{sup -1} N at sowing; and 20 kg ha{sup -1} N at sowing plus 60 kg ha{sup -1} N as topdressing. Rice is not affected by N fertilizer application as topdressing, when legume cover crops are used. The use of legume cover crops provides higher grain yield and use of fertilizer-N by rice than that of millet or fallow. Legume cover crops promote an effect equivalent to that of the application of 60 kg ha{sup -1} N as urea on rice yield. (author)

  19. Assessing the Economic Impact of Inversion Tillage, Cover Crops, and Herbicide Regimes in Palmer Amaranth (Amaranthus palmeri Infested Cotton

    Directory of Open Access Journals (Sweden)

    Leah M. Duzy

    2016-01-01

    Full Text Available Cotton (Gossypium hirsutum L. producers in Alabama are faced with a rapidly expanding problem that decreases yields and increases production costs: herbicide-resistant weeds. Producers increasingly rely on integrated weed management strategies that raise production costs. This analysis evaluated how tillage, cover crops, and herbicide regime affected net returns above variable treatment costs (net returns for cotton production in Alabama from 2009 to 2011 under pressure from Palmer amaranth (Amaranthus palmeri S. Wats.. Annual net returns were compared for two tillage treatments (inversion and noninversion tillage, three cover crops (crimson clover [Trifolium incarnatum L.], cereal rye [Secale cereal L.], and winter fallow, and three herbicide regimes (PRE, POST, and PRE+POST. Results indicate that under heavy Palmer amaranth population densities one year of inversion tillage followed by two years of noninversion tillage, along with a POST or PRE+POST herbicide application had the highest net returns in the first year; however, the economic benefit of inversion tillage, across all herbicide treatments, was nonexistent in 2010 and 2011. Cotton producers with Palmer amaranth infestations would likely benefit from cultural controls, in conjunction with herbicide applications, as part of their weed management system to increase net returns.

  20. Experimental evaluation of ALS point cloud ground extraction over different land cover in the Malopolska Province

    Science.gov (United States)

    Korzeniowska, Karolina; Mandlburger, Gottfried; Klimczyk, Agata

    2013-04-01

    The paper presents an evaluation of different terrain point extraction algorithms for Airborne Laser Scanning (ALS) point clouds. The research area covers eight test sites in the Małopolska Province (Poland) with varying point density between 3-15points/m² and surface as well as land cover characteristics. In this paper the existing implementations of algorithms were considered. Approaches based on mathematical morphology, progressive densification, robust surface interpolation and segmentation were compared. From the group of morphological filters, the Progressive Morphological Filter (PMF) proposed by Zhang K. et al. (2003) in LIS software was evaluated. From the progressive densification filter methods developed by Axelsson P. (2000) the Martin Isenburg's implementation in LAStools software (LAStools, 2012) was chosen. The third group of methods are surface-based filters. In this study, we used the hierarchic robust interpolation approach by Kraus K., Pfeifer N. (1998) as implemented in SCOP++ (Trimble, 2012). The fourth group of methods works on segmentation. From this filtering concept the segmentation algorithm available in LIS was tested (Wichmann V., 2012). The main aim in executing the automatic classification for ground extraction was operating in default mode or with default parameters which were selected by the developers of the algorithms. It was assumed that the default settings were equivalent to the parameters on which the best results can be achieved. In case it was not possible to apply an algorithm in default mode, a combination of the available and most crucial parameters for ground extraction were selected. As a result of these analyses, several output LAS files with different ground classification were achieved. The results were described on the basis of qualitative and quantitative analyses, both being in a formal description. The classification differences were verified on point cloud data. Qualitative verification of ground extraction was

  1. AN ASSESSMENT OF CITIZEN CONTRIBUTED GROUND REFERENCE DATA FOR LAND COVER MAP ACCURACY ASSESSMENT

    Directory of Open Access Journals (Sweden)

    G. M. Foody

    2015-08-01

    Full Text Available It is now widely accepted that an accuracy assessment should be part of a thematic mapping programme. Authoritative good or best practices for accuracy assessment have been defined but are often impractical to implement. Key reasons for this situation are linked to the ground reference data used in the accuracy assessment. Typically, it is a challenge to acquire a large sample of high quality reference cases in accordance to desired sampling designs specified as conforming to good practice and the data collected are normally to some degree imperfect limiting their value to an accuracy assessment which implicitly assumes the use of a gold standard reference. Citizen sensors have great potential to aid aspects of accuracy assessment. In particular, they may be able to act as a source of ground reference data that may, for example, reduce sample size problems but concerns with data quality remain. The relative strengths and limitations of citizen contributed data for accuracy assessment are reviewed in the context of the authoritative good practices defined for studies of land cover by remote sensing. The article will highlight some of the ways that citizen contributed data have been used in accuracy assessment as well as some of the problems that require further attention, and indicate some of the potential ways forward in the future.

  2. Ground penetrating radar detection of subsnow liquid overflow on ice-covered lakes in interior Alaska

    Directory of Open Access Journals (Sweden)

    A. Gusmeroli

    2012-07-01

    Full Text Available Lakes are abundant throughout the pan-Arctic region. For many of these lakes ice cover lasts for up to two thirds of the year. This frozen cover allows human access to these lakes, which are therefore used for many subsistence and recreational activities, including water harvesting, fishing, and skiing. Safe access to these lakes may be compromised, however, when, after significant snowfall, the weight of the snow acts on the ice and causes liquid water to spill through weak spots and overflow at the snow-ice interface. Since visual detection of subsnow liquid overflow (SLO is almost impossible our understanding on SLO processes is still very limited and geophysical methods that allow SLO detection are desirable. In this study we demonstrate that a commercially available, lightweight 1GHz, ground penetrating radar system can detect and map extent and intensity of SLO. Radar returns from wet snow-ice interfaces are at least twice as much in strength than returns from dry snow-ice interface. The presence of SLO also affects the quality of radar returns from the base of the lake ice. During dry conditions we were able to profile ice thickness of up to 1 m, conversely, we did not retrieve any ice-water returns in areas affected by SLO.

  3. Dynamics of nonpersistent aphid-borne viruses in lettuce crops covered with UV-absorbing nets.

    Science.gov (United States)

    Legarrea, S; Betancourt, M; Plaza, M; Fraile, A; García-Arenal, F; Fereres, A

    2012-04-01

    Aphid-transmitted viruses frequently cause severe epidemics in lettuce grown under Mediterranean climates. Spatio-temporal dynamics of aphid-transmitted viruses and its vector were studied on lettuce (Lactuca sativa L.) grown under tunnels covered by two types of nets: a commercial UV-absorbing net (Bionet) and a Standard net. A group of plants infected by Cucumber mosaic virus (CMV, family Bromoviridae, genus Cucumovirus) and Lettuce mosaic virus (LMV, family Potyviridae, genus Potyvirus) was transplanted in each plot. The same virus-infected source plants were artificially infested by the aphid Macrosiphum euphorbiae (Thomas). Secondary spread of insects was weekly monitored and plants were sampled for the detection of viruses every two weeks. In 2008, the infection rate of both CMV and LMV were lower under the Bionet than under the Standard cover, probably due to the lower population density and lower dispersal rate achieved by M. euphorbiae. However, during spring of 2009, significant differences in the rate of infection between the two covers were only found for LMV six weeks after transplant. The spatial distribution of the viruses analysed by SADIE methodology was "at random", and it was not associated to the spatial pattern of the vector. The results obtained are discussed analyzing the wide range of interactions that occurred among UV-radiation, host plant, viruses, insect vector and environmental conditions. Our results show that UV-absorbing nets can be recommended as a component of an integrated disease management program to reduce secondary spread of lettuce viruses, although not as a control measure on its own.

  4. Air photo evidence of historical land cover change in the highlands: Wetlands and grasslands give way to crops and woodlots

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    Christian A. Kull

    2012-12-01

    Full Text Available Madagascar’s high plateau – where people farm, graze cattle, and set periodic fire in a grass dominated landscape – receives disproportionately little conservation attention. An aerial photograph-based analysis of land - cover change in the latter half of the 20th century, based on a stratified random sample of twenty eight sites, reveals dramatic trends associated with an increas­ing human population that is building a cultural landscape of villages and agro-ecosystems to assure its livelihoods. On average across the sample sites, about 23 % of grassland areas present in 1949–1950 were converted to crops fields, farm trees and built - up areas by the 1990s. Of all land - cover transitions, the most dramatic changes included the loss of approximately 60 % of wetlands and 37 % of riparian forests. These land covers, which are dispersed along the fine - grained dendritic stream network, are habitat for crayfish, frogs, and other fauna, yet are also prized locations in the rice - based Malagasy agricultural system. The results of this study suggest that attention be given to highland grassland, wetland and riparian forest ecosystem restoration and conservation; however, any on - the - ground initiatives should incorporate respect for local needs and allow sustainable use of these ecosystems, given their cultural and subsistence importance. RÉSUMÉLes hautes terres malgaches, dominées par une végétation herbacée, sont des paysages fortement marqués par la gestion productive qu’y exerce l’Homme ; qu’il s’agisse des pratiques culturales, de l’élevage ou de la manipulation des régimes du feu. Cette région ne reçoit généralement pas d’intérêt pour la conservation de la biodiversité. Cet article présente les résultats d’une étude régionale de changement d’occupation des sols et des dynamiques des formations végétales des hautes terres au cours de la deuxième moitié du XXe siècle. L’étude est basée sur

  5. A comparative analysis to quantify the biogeochemical and biogeophysical cooling effects on climate of a white mustard cover crop

    Science.gov (United States)

    Ferlicoq, Morgan; Ceschia, Eric; Brut, Aurore; Tallec, Tiphaine; Carrer, Dominique; Pique, Gaetan; Ferroni, Nicole

    2017-04-01

    During the COP21, agriculture was recognised as a strategic sector and an opportunity to strengthen climate mitigation. In particular, the "4 per 1000" initiative relies upon solutions that refer to agro-ecology, conservation agriculture, … that could lead to increase carbon storage. Among those agro-ecology practices, including cover crops during fallow periods is considered as a fundamental agronomic lever for storing carbon. However, if biogeochemical benefits of cover-crops (CC) have already been addressed, their biogeophysical effects on climate have never been quantified and compared to biogeochemical effects. This comparative study (CC vs. bare soil), quantified and compared biogeochemical (including carbon storage) and biophysical effects (albedo and energy partitioning effect) of CC on climate. An experimental campaign was performed in 2013 in Southwest France, during the fallow period following a winter-wheat crop (and before a maize). The experimental plot was divided in two: the northern part was maintained in bare soil (BS) while white-mustard (WM) was grown during 3-months on the southern part. On each subplot, continuous measurements of CO2, latent and sensible fluxes (by eddy covariance) and solar radiation were acquired. Also, N2O emissions were measured by means of automatic chambers on each subplots. Moreover, by using a Life-Cycle-Analysis approach, each component of the greenhouse gas budget (GHGB) was quantified for each subplot, including emissions associated to field operations (FO). To quantify the albedo induced radiative forcing (RFα) caused by the white-mustard, the bare soil subplot was used as a reference state (IPCC, 2007). Finally, the net radiative forcing for each subplot was calculated as the sum of biogeochemical and biogeophysical (albedo effect) radiative forcing. The white-mustard allowed a net CO2 fixation of 63 g C-eq.m-2, corresponding to 20% of the net annual CO2 flux that year (-332 g C-eq.m-2). Through the WM seeds

  6. Intercomparison of Unmanned Aerial Vehicle and Ground-Based Narrow Band Spectrometers Applied to Crop Trait Monitoring in Organic Potato Production.

    Science.gov (United States)

    Domingues Franceschini, Marston Héracles; Bartholomeus, Harm; van Apeldoorn, Dirk; Suomalainen, Juha; Kooistra, Lammert

    2017-06-18

    Vegetation properties can be estimated using optical sensors, acquiring data on board of different platforms. For instance, ground-based and Unmanned Aerial Vehicle (UAV)-borne spectrometers can measure reflectance in narrow spectral bands, while different modelling approaches, like regressions fitted to vegetation indices, can relate spectra with crop traits. Although monitoring frameworks using multiple sensors can be more flexible, they may result in higher inaccuracy due to differences related to the sensors characteristics, which can affect information sampling. Also organic production systems can benefit from continuous monitoring focusing on crop management and stress detection, but few studies have evaluated applications with this objective. In this study, ground-based and UAV spectrometers were compared in the context of organic potato cultivation. Relatively accurate estimates were obtained for leaf chlorophyll (RMSE = 6.07 µg·cm(-2)), leaf area index (RMSE = 0.67 m²·m(-2)), canopy chlorophyll (RMSE = 0.24 g·m(-2)) and ground cover (RMSE = 5.5%) using five UAV-based data acquisitions, from 43 to 99 days after planting. These retrievals are slightly better than those derived from ground-based measurements (RMSE = 7.25 µg·cm(-2), 0.85 m²·m(-2), 0.28 g·m(-2) and 6.8%, respectively), for the same period. Excluding observations corresponding to the first acquisition increased retrieval accuracy and made outputs more comparable between sensors, due to relatively low vegetation cover on this date. Intercomparison of vegetation indices indicated that indices based on the contrast between spectral bands in the visible and near-infrared, like OSAVI, MCARI2 and CIg provided, at certain extent, robust outputs that could be transferred between sensors. Information sampling at plot level by both sensing solutions resulted in comparable discriminative potential concerning advanced stages of late blight incidence. These results indicate that optical sensors

  7. Effect of cover crops on greenhouse gas emissions in an irrigated field under integrated soil fertility management

    Science.gov (United States)

    Guardia, Guillermo; Abalos, Diego; García-Marco, Sonia; Quemada, Miguel; Alonso-Ayuso, María; Cárdenas, Laura M.; Dixon, Elizabeth R.; Vallejo, Antonio

    2016-09-01

    Agronomical and environmental benefits are associated with replacing winter fallow by cover crops (CCs). Yet, the effect of this practice on nitrous oxide (N2O) emissions remains poorly understood. In this context, a field experiment was carried out under Mediterranean conditions to evaluate the effect of replacing the traditional winter fallow (F) by vetch (Vicia sativa L.; V) or barley (Hordeum vulgare L.; B) on greenhouse gas (GHG) emissions during the intercrop and the maize (Zea mays L.) cropping period. The maize was fertilized following integrated soil fertility management (ISFM) criteria. Maize nitrogen (N) uptake, soil mineral N concentrations, soil temperature and moisture, dissolved organic carbon (DOC) and GHG fluxes were measured during the experiment. Our management (adjusted N synthetic rates due to ISFM) and pedo-climatic conditions resulted in low cumulative N2O emissions (0.57 to 0.75 kg N2O-N ha-1 yr-1), yield-scaled N2O emissions (3-6 g N2O-N kg aboveground N uptake-1) and N surplus (31 to 56 kg N ha-1) for all treatments. Although CCs increased N2O emissions during the intercrop period compared to F (1.6 and 2.6 times in B and V, respectively), the ISFM resulted in similar cumulative emissions for the CCs and F at the end of the maize cropping period. The higher C : N ratio of the B residue led to a greater proportion of N2O losses from the synthetic fertilizer in these plots when compared to V. No significant differences were observed in CH4 and CO2 fluxes at the end of the experiment. This study shows that the use of both legume and nonlegume CCs combined with ISFM could provide, in addition to the advantages reported in previous studies, an opportunity to maximize agronomic efficiency (lowering synthetic N requirements for the subsequent cash crop) without increasing cumulative or yield-scaled N2O losses.

  8. Ground cover rice production system facilitates soil carbon and nitrogen stocks at regional scale

    Directory of Open Access Journals (Sweden)

    M. Liu

    2015-02-01

    Full Text Available Rice production is increasingly challenged by irrigation water scarcity, however covering paddy rice soils with films (ground cover rice production system: GCRPS can significantly reduce water demand as well as overcome temperature limitations at the beginning of the vegetation period resulting in increased grain yields in colder regions of rice production with seasonal water shortages. It has been speculated that the increased soil aeration and temperature under GCRPS may result in losses of soil organic carbon and nitrogen stocks. Here we report on a regional scale experiment, conducted by sampling paired adjacent Paddy and GCRPS fields at 49 representative sites in the Shiyan region, which is typical for many mountainous areas across China. Parameters evaluated included soil C and N stocks, soil physical and chemical properties, potential carbon mineralization rates, fractions of soil organic carbon and stable carbon isotopic composition of plant leaves. Furthermore, root biomass was quantified at maximum tillering stage at one of our paired sites. Against expectations the study showed that: (1 GCRPS significantly increased soil organic C and N stocks 5–20 years following conversion of production systems, (2 there were no differences between GCRPS and Paddy in soil physical and chemical properties for the various soil depths with the exception of soil bulk density, (3 GCRPS had lower mineralization potential for soil organic C compared with Paddy over the incubation period, (4 GCRPS showed lower δ15N in the soils and plant leafs indicating less NH3 volatilization in GCRPS than in Paddy; and (5 GCRPS increased yields and root biomass in all soil layers down to 40 cm depth. Our results suggest that GCRPS is an innovative rice production technique that not only increases yields using less irrigation water, but that it also is environmentally beneficial due to increased soil C and N stocks at regional scale.

  9. Evaluating the relationship between biomass, percent groundcover and remote sensing indices across six winter cover crop fields in Maryland, United States

    Science.gov (United States)

    Prabhakara, Kusuma; Hively, W. Dean; McCarty, Gregory W.

    2015-07-01

    Winter cover crops are an essential part of managing nutrient and sediment losses from agricultural lands. Cover crops lessen sedimentation by reducing erosion, and the accumulation of nitrogen in aboveground biomass results in reduced nutrient runoff. Winter cover crops are planted in the fall and are usually terminated in early spring, making them susceptible to senescence, frost burn, and leaf yellowing due to wintertime conditions. This study sought to determine to what extent remote sensing indices are capable of accurately estimating the percent groundcover and biomass of winter cover crops, and to analyze under what critical ranges these relationships are strong and under which conditions they break down. Cover crop growth on six fields planted to barley, rye, ryegrass, triticale or wheat was measured over the 2012-2013 winter growing season. Data collection included spectral reflectance measurements, aboveground biomass, and percent groundcover. Ten vegetation indices were evaluated using surface reflectance data from a 16-band CROPSCAN sensor. Restricting analysis to sampling dates before the onset of prolonged freezing temperatures and leaf yellowing resulted in increased estimation accuracy. There was a strong relationship between the normalized difference vegetation index (NDVI) and percent groundcover (r2 = 0.93) suggesting that date restrictions effectively eliminate yellowing vegetation from analysis. The triangular vegetation index (TVI) was most accurate in estimating high ranges of biomass (r2 = 0.86), while NDVI did not experience a clustering of values in the low and medium biomass ranges but saturated in the higher range (>1500 kg/ha). The results of this study show that accounting for index saturation, senescence, and frost burn on leaves can greatly increase the accuracy of estimates of percent groundcover and biomass for winter cover crops.

  10. Condition of forest crops and soil cover at reclaimed dump of coal mine

    Directory of Open Access Journals (Sweden)

    V. A. Androkhanov

    2016-04-01

    Full Text Available The investigation of processes of recovery of disturbed land at the urban areas is a new, urgent problem for indus-trialized centers. Currently disturbed areas where recovery operations are conducted by various reclamation tech-nologies are within the city of Novokuznetsk area in Kuznetsk Basin. Monitoring investigations to determine their environmental condition and the level of natural ingredients recovery have not been conducted at these areas until recently. The lack of such information does not allow efficient analysis of the conducted reclamation activities and determination of the prospects for recovery and further use of such land. The paper presents the results of an inves-tigation of forest plantations and areas with natural revegetation of disturbed areas, and the complex of soil studies to determine the basic physical and agrochemical characteristics of young soils formed on the disturbed surface is conducted. Based on these studies the vegetation and soil cover were characterized and the soil-ecological condition of the reclaimed areas from the 1970’ stailings pile of «Baidaevskij» coal mine was assessed. As a result of reclama-tion activities, the sites with different plant communities are formed at the tailings pile surface. Botanic composition at the reclaimed areas represented species able to operate successfully in a technogenic landscapes. Because the grand dump territory is reclaimed by the forest approach the statement of forest is characterized by the special aspects, such as high density of planting with little crown density, high opacity and low level of stable forest recovery. The tailings pile sites reclaimed by different methods are characterized by specific soil-ecological condition, which can be used to assess the efficiency of reclamation. Soil-ecological assessment of the conducted reclamation efficiency is carried out on the basis of assessment of the soil, formed on the surface of the disturbed area. The more

  11. Data on the abundance of the banana weevil Cosmopolites sordidus and of the earwig Euborellia caraibea in bare soil and cover crop plots

    Directory of Open Access Journals (Sweden)

    Dominique Carval

    2016-06-01

    Full Text Available The data presented in this article are related to the research article entitled “Cover cropping reduces the abundance of the banana weevil Cosmopolites sordidus but does not reduce its damage to the banana plants” (Carval et al., in press [1]. This article describes how the abundance of the banana weevil, Cosmopolites sordidus, and the abundance of the earwig Euborellia caraibea were affected by the addition of a cover crop. The field data set is made publicly available to enable critical or extended analyzes.

  12. Basis for the development of a scenario for ground water risk assessment of plant protection products to banana crop in the frame work of regulation 1107/2009

    Science.gov (United States)

    Alonso-Prados, Elena; Fernández-Getino, Ana Patricia; Alonso-Prados, Jose Luis

    2014-05-01

    The risk assessment to ground water of pesticides and their main metabolites is a data requirement under regulation 1107/2009, concerning the placing of plant protection products on the market. Predicted environmental concentrations (PEC) are calculated according to the recommendations of Forum for the Co-ordination of pesticide fate models and Their Use (FOCUS). The FOCUS groundwater working group developed scenarios for the main crops in European Union. However there are several crops which grow under specific agro-environmental conditions not covered by these scenarios and it is frequent to use the defined scenarios as surrogates. This practice adds an uncertainty factor in the risk assessment. One example is represented by banana crop which in Europe is limited to sub-tropical environmental conditions and with specific agronomic practices. The Canary Islands concentrates the higher production of banana in the European Union characterized by volcanic soils. Banana is located at low altitudes where soils have been eroded or degraded, and it is a common practice to transport soil materials from the high-mid altitudes to the low lands for cultivation. These cultivation plots are locally named "sorribas". These volcanic soils, classified as Andosols according to the FAO classification, have special physico-chemical properties due to noncrystalline materials and layer silicates. The good stability of these soils and their high permeability to water make them relatively resistant to water erosion. Physical properties of volcanic clayey soils are strongly affected by allophone and Fe and Al oxyhidroxides. The rapid weathering of porous volcanic material results in accumulation of stable organo-mineral complexes and short-range-order mineral such as allophane, imogolite and ferrihydrite. These components induce strong aggregation that partly favors properties such as: reduced swelling, increased aggregate stability of clay minerals, high soil water retention capacity

  13. Citizen science land cover classification based on ground and satellite imagery: Case study Day River in Vietnam

    Science.gov (United States)

    Nguyen, Son Tung; Minkman, Ellen; Rutten, Martine

    2016-04-01

    Citizen science is being increasingly used in the context of environmental research, thus there are needs to evaluate cognitive ability of humans in classifying environmental features. With the focus on land cover, this study explores the extent to which citizen science can be applied in sensing and measuring the environment that contribute to the creation and validation of land cover data. The Day Basin in Vietnam was selected to be the study area. Different methods to examine humans' ability to classify land cover were implemented using different information sources: ground based photos - satellite images - field observation and investigation. Most of the participants were solicited from local people and/or volunteers. Results show that across methods and sources of information, there are similar patterns of agreement and disagreement on land cover classes among participants. Understanding these patterns is critical to create a solid basis for implementing human sensors in earth observation. Keywords: Land cover, classification, citizen science, Landsat 8

  14. The Effect of Biofertilizers and Winter Cover Crops on Essential Oil Production and Some Agroecological Characteristics of Basil (Ocimum basilicum L.)

    OpenAIRE

    M. Jahan; M.B Amiri; F Dehghani Pour; M.K Tahhami

    2013-01-01

    In searching for new strategies of medicinal plant production with high yield but without undesirable compounds or effects, it is important to investigate unconventional alternatives such as application of PGPR and cover crops cultivation. This experiment was conducted in a split plots arrangement with two factors based on randomized complete block design with three replications during years 2009-10, at Research Farm of Ferdowsi University of Mashhad. Cultivation and no cultivation of cover c...

  15. Estimating Cotton Nitrogen Nutrition Status Using Leaf Greenness and Ground Cover Information

    Directory of Open Access Journals (Sweden)

    Farrah Melissa Muharam

    2015-05-01

    Full Text Available Assessing nitrogen (N status is important from economic and environmental standpoints. To date, many spectral indices to estimate cotton chlorophyll or N content have been purely developed using statistical analysis approach where they are often subject to site-specific problems. This study describes and tests a novel method of utilizing physical characteristics of N-fertilized cotton and combining field spectral measurements made at different spatial scales as an approach to estimate in-season chlorophyll or leaf N content of field-grown cotton. In this study, leaf greenness estimated from spectral measurements made at the individual leaf, canopy and scene levels was combined with percent ground cover to produce three different indices, named TCCLeaf, TCCCanopy, and TCCScene. These indices worked best for estimating leaf N at early flowering, but not for chlorophyll content. Of the three indices, TCCLeaf showed the best ability to estimate leaf N (R2 = 0.89. These results suggest that the use of green and red-edge wavelengths derived at the leaf scale is best for estimating leaf greenness. TCCCanopy had a slightly lower R2 value than TCCLeaf (0.76, suggesting that the utilization of yellow and red-edge wavelengths obtained at the canopy level could be used as an alternative to estimate leaf N in the absence of leaf spectral information. The relationship between TCCScene and leaf N was the lowest (R2 = 0.50, indicating that the estimation of canopy greenness from scene measurements needs improvement. Results from this study confirmed the potential of these indices as efficient methods for estimating in-season leaf N status of cotton.

  16. Emergency and growth of cover crops in function of the sowing depth / Emergência e crescimento de plantas de cobertura em função da profundidade de semeadura

    Directory of Open Access Journals (Sweden)

    Fabiano André Petter

    2009-07-01

    Full Text Available The objective of this study was evaluated emergence of four cover crops at different seeding depths, in order to use them intercropped and oversown with annual crops. The experiment was installed in a greenhouse, and it was organized as a 5 × 7 factorial combination, with crop of fve cover crops: Pennisetum glaucum var. ADR 300, ADR 500, and BN2, Eleusine coracana (fnger millet, and a cober crop( hybrid sorghum with sudan-grass [Sorghum bicolor x Sorghum sudanese]; seven cover crops seeding depths: (0 cm without any mulch; 0 cm with a mulch of leaves over the seeds;1; 4; 8; 10; and 15 cm.The cover crops were cropping in vases for 40 days. It was evaluated emergence index, emergence time, plant height, green biomass and dry biomass of the above-ground part, leaf area, root dry biomass and root length density. There was reduction of emergence when cover crops was seeded at zero cm depth with a mulch of leaves, except for the E. coracana, that had a better performance in the oversown. Pearl millets and hybrid S. bicolor x S. sudanense show up some restrictions when used in simultaneous consortium. The 15 cm sowing depth must not be used.O objetivo do trabalho foi avaliar a emergência de cinco plantas de cobertura em diferentes profundidades de semeadura, visando à obtenção de informações que subsidiem sua utilização na consorciação e sobressemeadura de culturas anuais. O experimento foi conduzido em casa-de-vegetação, no delineamento experimental de blocos ao acaso, em esquema fatorial 5 x 7, composto pelas plantas de cobertura Pennisetum glaucum var. ADR 300, ADR 500 e BN2, Eleusine coracana e cober crop [híbrido de sorgo com capim-sudão (Sorghum bicolor x Sorghum sudanense], e por sete profundidades de semeadura das plantas de cobertura (0 cm sem presença de folhas de soja sobre as sementes, 0 com presença de folhas de soja sobre as sementes, 1, 4, 8, 10 e 15 cm. As sementes foram semeadas em vasos e as plantas cultivadas por 40

  17. Effects of break crops, and of wheat volunteers growing in break crops or in set-aside or conservation covers, all following crops of winter wheat, on the development of take-all (Gaeumannomyces graminis var. tritici) in succeeding crops of winter wheat.

    Science.gov (United States)

    Jenkyn, Jf; Gutteridge, Rj; White, Rp

    2014-11-01

    Experiments on the Rothamsted and Woburn Experimental Farms studied the effects on take-all of different break crops and of set-aside/conservation covers that interrupted sequences of winter wheat. There was no evidence for different effects on take-all of the break crops per se but the presence of volunteers, in crops of oilseed rape, increased the amounts of take-all in the following wheat. Severity of take-all was closely related to the numbers of volunteers in the preceding break crops and covers, and was affected by the date of their destruction. Early destruction of set-aside/conservation covers was usually effective in preventing damaging take-all in the following wheat except, sometimes, when populations of volunteers were very large. The experiments were not designed to test the effects of sowing dates but different amounts of take-all in the first wheats after breaks or covers apparently affected the severity of take-all in the following (second) wheats only where the latter were relatively late sown. In earlier-sown second wheats, take-all was consistently severe and unrelated to the severity of the disease in the preceding (first) wheats. Results from two very simple experiments suggested that substituting set-aside/conservation covers for winter wheat, for 1 year only, did not seriously interfere with the development of take-all disease or with the development or maintenance of take-all decline (TAD). With further research, it might be possible for growers wishing to exploit TAD to incorporate set-aside/conservation covers into their cropping strategies, and especially to avoid the worst effects of the disease on grain yield during the early stages of epidemics.

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

    Directory of Open Access Journals (Sweden)

    Halima Mohammed Lawal

    2017-05-01

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

  19. Estimation of above ground biomass for multi-stemmed short-rotation woody crops

    Science.gov (United States)

    Brian A. Byrd; Wilson G. Hood; Michael C. Tyree; Dylan N. Dillaway

    2015-01-01

    With the increasing interest in short-rotation woody crop (SRWC) systems, an accurate yet quick, non-destructive means for determining aboveground biomass is necessary from both management and research perspectives.

  20. Notice of Release of US-1136, US-1137, and US-1138 Cowpea Gerplasm Lines with Potential For Use As A Cover Crop

    Science.gov (United States)

    In 1998, field screening trials were initiated to identify cowpea (Vigna unguiculata L.) populations suitable for use as a weed-suppressing cover crop. After the preliminary field studies, eleven populations were selected for more detailed evaluations. After three additional years of evaluation, e...

  1. Optimization of removal and recycling ratio of cover crop biomass using carbon balance to sustain soil organic carbon stocks in a mono-rice paddy system

    NARCIS (Netherlands)

    Haque, Md. Mozammel; Kim, Sang Yun; Kim, Gil Won; Kim, Pil Joo

    2015-01-01

    The cultivation of a winter cover crop as green manure is strongly recommended to improve soil quality in mono-rice paddy systems; however, the biomass is largely removed to feed cattle in many Asian regions. To determine the minimum recycling ratio of the biomass that can sustain soil organic carbo

  2. Planting Date and Seeding Rate Effects on Sunn Hemp Biomass and Nitrogen Production for a Winter Cover Crop

    Directory of Open Access Journals (Sweden)

    Kipling S. Balkcom

    2011-01-01

    Full Text Available Sunn hemp (Crotalaria juncea L. is a tropical legume that produces plant biomass and nitrogen (N quickly. Our objectives were to assess the growth of a new sunn hemp cultivar breed to produce seed in a temperate climate and determine the residual N effect on a rye (Secale cereale L. cover crop in east-central Alabama from 2007 to 2009. Plant populations, plant height, stem diameter, biomass production, and N content were determined for two sunn hemp planting dates, following corn (Zea mays L. and wheat (Triticum aestivum L. harvest, across different seeding rates (17, 34, 50, and 67 kg/ha. Rye biomass was measured the following spring. Sunn hemp biomass production was inconsistent across planting dates, but did relate to growing degree accumulation. Nitrogen concentrations were inversely related to biomass production, and subsequent N contents corresponded to biomass levels. Neither planting date nor seeding rate affected rye biomass production, but rye biomass averaged over both planting dates following wheat/sunn hemp averaged 43% and 33% greater than rye following fallow. Rye biomass following corn/sunn hemp was equivalent to fallow plots. Early planting dates are recommended for sunn hemp with seeding rates between 17 and 34 kg/ha to maximize biomass and N production.

  3. High quality residues from cover crops favor changes in microbial community and enhance C and N sequestration

    Directory of Open Access Journals (Sweden)

    Ileana Frasier

    2016-04-01

    Full Text Available The objective of the study was to evaluate the effect of a change in management on the soil microbial community and C sequestration. We conducted a 3-year field study in La Pampa (Argentina with rotation of sorghum (Sorghum bicolor in zero tillage alternating with rye (Secale cereale and vetch (Vicia villosa ssp. dasycarpa. Soil was sampled once a year at two depths. Soil organic matter fractions, dissolved organic matter, microbial biomass (MBC and community composition (DNA extraction, qPCR, and phospholipid FAME profiles were determined. Litter, aerial- and root biomass were collected and all material was analyzed for C and N. Results showed a rapid response of microbial biomass to a bacterial dominance independent of residue quality. Vetch had the highest diversity index, while the fertilized treatment had the lowest one. Vetch–sorghum rotation with high N mineralization rates and diverse microbial community sequestered more C and N in stable soil organic matter fractions than no-till sorghum alone or with rye, which had lower N turnover rates. These results reaffirm the importance of enhanced soil biodiversity for maintaining soil ecosystem functioning and services. The supply of high amounts of N-rich residues as provided by grass–legume cover crops could fulfill this objective.

  4. Water consumption and water-saving characteristics of a ground cover rice production system

    Science.gov (United States)

    Jin, Xinxin; Zuo, Qiang; Ma, Wenwen; Li, Sen; Shi, Jianchu; Tao, Yueyue; Zhang, Yanan; Liu, Yang; Liu, Xiaofei; Lin, Shan; Ben-Gal, Alon

    2016-09-01

    The ground cover rice production system (GCRPS) offers a potentially water-saving alternative to the traditional paddy rice production system (TPRPS) by furrow irrigating mulched soil beds and maintaining soils under predominately unsaturated conditions. The guiding hypothesis of this study was that a GCRPS would decrease both physiological and non-physiological water consumption of rice compared to a TPRPS while either maintaining or enhancing production. This was tested in a two-year field experiment with three treatments (TPRPS, GCRPSsat keeping root zone average soil water content near saturated, and GCRPS80% keeping root zone average soil water content as 80-100% of field water capacity) and a greenhouse experiment with four treatments (TPRPS, GCRPSsat, GCRPSfwc keeping root zone average soil water content close to field water capacity, and GCRPS80%). The water-saving characteristics of GCRPS were analyzed as a function of the measured soil water conditions, plant parameters regarding growth and production, and water input and consumption. In the field experiment, significant reduction in both physiological and non-physiological water consumption under GCRPS lead to savings in irrigation water of ∼61-84% and reduction in total input water of ∼35-47%. Compared to TPRPS, deep drainage was reduced ∼72-88%, evaporation was lessened ∼83-89% and transpiration was limited ∼6-10% under GCRPS. In addition to saving water, plant growth and grain yield were enhanced under GCRPS due to increased soil temperature in the root zone. Therefore, water use efficiencies (WUEs), based on transpiration, irrigation and total input water, were respectively improved as much as 27%, 609% and 110% under GCRPS. Increased yield attributed to up to ∼19%, decreased deep drainage accounted for ∼75%, decreased evaporation accounted for ∼14% and reduced transpiration for ∼5% of the enhancement in WUE of input water under GCRPS, while increased runoff and water storage had

  5. Sunn hemp as a ground cover to manage fall armyworm populations

    Science.gov (United States)

    Fall armyworm (FAW), Spodoptera frugiperda, is a serious pest of sweet corn in south Florida and a pest of other vegetable, row, and forage crops in the southeastern, mid-Atlantic, and central U.S. It is a migratory pest, moving north each season from overwintering areas in southern Texas and south...

  6. The role of snow cover in ground thermal conditions in three sites with contrasted topography in Sierra Nevada (Spain)

    Science.gov (United States)

    Oliva, Marc; Salvador, Ferran; Gómez Ortiz, Antonio; Salvà, Montserrat

    2014-05-01

    Snow cover has a high capacity to insulate the soil from the external thermal influences. In regions of high snowfall, such as the summit areas of the highest Iberian mountain ranges, the presence of a thick snow cover may condition the existence or inexistence of permafrost conditions. In order to analyze the impact of the thickness, duration and interannual variability of snow cover on the ground thermal regime in the massif of Sierra Nevada, we have analyzed soil temperatures at a depth of 2 cm for the period 2006-2012 in three sites of contrasting topography as well as air temperatures for the same period: (a) Corral del Veleta (3100 m) in a rock glacier located in the northern Veleta cirque, with high and persistent snow cover. (b) Collado de los Machos (3300 m), in a summit area with relict stone circles, with little snow accumulation due to wind effect. (c) Río Seco (3000 m), in a solifluction lobe located in this southern glacial cirque with moderate snowfall. Considering the air and 2 cm depth soil temperature records, the freezing degree-days were calculated for each year from November to May in order to characterize the role of snow as a thermal insulator of the ground during the cold season (Frauenfeld et al., 2007). In all cases, the highest values of freezing degree-days correspond to years with little snowfall (2006-2007, 2007-2008, 2011-2012), while in years with a thicker snow cover (2008-2009, 2009-2010, 2010-2011) the total freezing degree-days were significantly lower. The accumulation of freezing degree-days is maximum at the wind-exposed site of Collado de los Machos, where the wind redistributes snow and favours the penetration of cold into the ground. The opposite pattern occurs in the Veleta cirque, where most persistent snow cover conditions determine lower accumulated freezing degree-days than in Collado de los Machos and Rio Seco.

  7. Plantas de cobertura de solo como hospedeiras alternativas de Colletotrichum guaranicola Cover crops as intermediate hosts to Colletotrichum guaranicola

    Directory of Open Access Journals (Sweden)

    L.J. Mileo

    2006-12-01

    Full Text Available As plantas de cobertura de solo usadas para suprimir o crescimento de plantas daninhas podem hospedar fungos fitopatogênicos. Para testar essa hipótese, elaborou-se este trabalho com o objetivo de avaliar o comportamento de nove espécies de plantas como possíveis hospedeiras do fungo Colletotrichum guaranicola. O experimento foi conduzido em casa de vegetação sob delineamento inteiramente casualizado, com quatro repetições. Cada vaso com três plantas da mesma espécie representou uma unidade experimental. As espécies que constituíram os tratamentos foram: Arachis pintoi, Calopogonium mucunoides, Chamaecrista rotundifolia, Crotalaria striata, Desmodium ovalifolium, Flemingia congesta, Mucuna aterrima, Pueraria phaseoloides e Tephrosia candida. Quarenta dias após a semeadura, as plantas foram inoculadas com suspensão de esporos de C. guaranicola na concentração de 10(5 conídios mL¹, enquanto as plantas testemunhas receberam somente água. As plantas foram mantidas em câmara úmida por 48 horas. Diariamente, foram feitas observações por 15 dias após a inoculação, para visualizar sintomas da doença. As espécies que não apresentaram sintomas de C. guaranicola foram Arachis pintoi, Chamaecrista rotundifolia, Desmodium ovalifolium, Flemingia congesta e Tephrosia candida, e as que manifestaram sintomas após a inoculação foram Calopogonium mucunoides, Crotalaria striata, Mucuna aterrima e Pueraria phaseoloides, que podem ser fontes de inóculo do patógeno da antracnose para o guaranazeiro.Cover crops used to suppress weed growth can be intermediate hosts to phytopathogenic fungi. To test this hypothesis, nine species of cover crops were evaluated as hosts to Colletotrichum guaranicola. The experiment was arranged in a randomized design, with four replicates, and conducted under greenhouse conditions. Each vase with three plants of one species constituted one plot. The species treated were: Arachis pintoi, Calopogonium

  8. Assessing alternative measures of tree canopy cover: Photo-interpreted NAIP and ground-based estimates

    Science.gov (United States)

    Chris Toney; Greg Liknes; Andy Lister; Dacia Meneguzzo

    2012-01-01

    In preparation for the development of the National Land Cover Database (NLCD) 2011 tree canopy cover layer, a pilot project for research and method development was completed in 2010 by the USDA Forest Service Forest Inventory and Analysis (FIA) program and Remote Sensing Applications Center (RSAC).This paper explores one of several topics investigated during the NLCD...

  9. Migration and Enrichment of Arsenic in the Rock-Soil-Crop Plant System in Areas Covered with Black Shale, Korea

    Directory of Open Access Journals (Sweden)

    Ji-Min Yi

    2003-01-01

    Full Text Available The Okchon black shale, which is part of the Guryongsan Formation or the Changri Formation of Cambro-Ordovician age in Korea provides a typical example of natural geological materials enriched with potentially toxic elements such as U, V, Mo, As, Se, Cd, and Zn. In this study, the Dukpyung and the Chubu areas were selected to investigate the migration and enrichment of As and other toxic elements in soils and crop plants in areas covered with black shale. Rock and soil samples digested in 4-acid solution (HCl+HNO3+HF+HClO4 were analyzed for As and other heavy metals by ICP-AES and ICP-MS, and plant samples by INAA. Mean concentration of As in Okchon black shale is higher than those of both world average values of shale and black shale. Especially high concentration of 23.2 mg As kg-1 is found in black shale from the Dukpyung area. Mean concentration of As is highly elevated in agricultural soils from the Dukpyung (28.2 mg kg-1 and the Chubu areas (32.6 mg kg-1. As is highly elevated in rice leaves from the Dukpyung (1.14 mg kg-1 and the Chubu areas (1.35 mg kg-1. The biological absorption coefficient (BAC of As in plant species decreases in the order of rice leaves > corn leaves > red pepper = soybean leaves = sesame leaves > corn stalks > corn grains. This indicates that leafy plants tend to accumulate As from soil to a greater degree than cereal products such as grains.

  10. Nitrous oxide emissions from soils amended by cover-crops and under plastic film mulching: Fluxes, emission factors and yield-scaled emissions

    Science.gov (United States)

    Kim, Gil Won; Das, Suvendu; Hwang, Hyun Young; Kim, Pil Joo

    2017-03-01

    Assessment of nitrous oxide (N2O) emission factor (EF) for N2O emission inventory from arable crops fertilized with different nitrogen sources are under increased scrutiny because of discrepancies between the default IPCC EFs and low EFs reported by many researchers. Mixing ratio of leguminous and non-leguminous cover crop residues incorporation and plastic film mulching (PFM) in upland soil has been recommended as a vital agronomic practice to enhance yield and soil quality. However, how these practices together affect N2O emissions, yield-scaled emissions and the EFs remain uncertain. Field experiments spanning two consecutive years were conducted to evaluate the effects of PFM on N2O emissions, yield-scaled emissions and the seasonal EFs in cover crop residues amended soil during maize cultivation. The mixture of barley (Hordeum vulgare) and hairy vetch (Vicia villosa) seeds with 75% recommended dose (RD 140 kg ha-1) and 25% recommended dose (RD 90 kg ha-1), respectively, were broadcasted during the fallow period and 0, 25, 50 and 100% of the total aboveground harvested biomass that correspond to 0, 76, 152 and 304 kg N ha-1 were incorporated before maize transplanting. It was found that the mean seasonal EFs from cover crop residues amended soil under No-mulching (NM) and PFM were 1.13% (ranging from 0.81 to 1.23%) and 1.49% (ranging from 1.02 to 1.63%), respectively, which are comparable to the IPCC (2006) default EF (1%) for emission inventories of N2O from crop residues. The emission fluxes were greatly influenced by NH4+sbnd N, NO3--N, DOC and DON contents of soil. The cumulative N2O emissions markedly increased with the increase in cover crop residues application rates and it was more prominent under PFM than under NM. However, the yield-scaled emissions markedly decreased under PFM compared to NM due to the improved yield. With relatively low yield-scaled N2O emissions, 25% biomass mixing ratio of barley and hairy vetch (76 kg N ha-1) under PFM could be

  11. Energy efficiency for establishment and management of cover crops; Eficiencia energetica na implantacao e manejo de plantas de cobertura do solo

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, R.; Gamero, C.A.; Boller, W.

    2000-07-01

    An experiment was conducted in Botucatu, SP, Brazil to evaluate the energy balance involved in the establishment and management of cover crops and also to determine specific heating seeds and biomass of different species of cover crops. Black oat (Avena strigosa Schreb), forage radish (Raphanus sativus L. var. oleiferus Metzg) and lupinus (Lupinus angustifolius L.) were grown in a randomized block design, in twelve replicates. Oat showed higher energy production as compared to lupinus, while higher specific heat were determined for forage radish seeds and also for lupinus and oat biomass. While fuel and fertilizers were the most important energy inputs for the establishment and management of oat and forage radish, seeds and fuel were the most used energy input for lupinus. (author)

  12. Assessing the effectiveness of winter cover crop on nitrate reduction in two-paired sub-basins on the Coastal Plain of the Chesapeake Bay Watershed

    Science.gov (United States)

    Lee, S.; Yeo, I. Y.; Sadeghi, A. M.; Mccarty, G.; Hively, W. D.; Lang, M. W.

    2014-12-01

    Best management practices (BMPs) have been widely adopted to improve water quality throughout the Chesapeake Bay Watershed (CBW). Winter cover crops (WCC) use has been highlighted for the reduction of nitrate leaching over the fallow season. Although various WCC practices are currently conducted in local croplands, the water quality improvement benefits of WCC have not been studied thoroughly at the watershed scale. The objective of this study is to assess the long-term impacts of WCC on reducing nitrate loadings using a processed-based watershed model, Soil and Water Assessment Tool (SWAT). Remote sensing based estimates of WCC biomass will be used to calibrate plant growth processes of SWAT and its nutrient cycling. The study will be undertaken in two-paired agricultural watersheds in the Coastal Plain of CBW. Multiple WCC practice scenarios will be prepared to investigate how nitrate loading varies with crop species, planting dates, and implementation areas. The performance of WCC on two-paired watersheds will be compared in order to understand the effects of different watershed characteristics on nitrate uptake by crops. The results will demonstrate the nitrate reduction efficiency of different WCC practices and identify the targeting area for WCC implementation at the watershed scale. This study will not only integrate remote sensing data into the physically based model but also extend our understandings of WCC functions. This will provide key information for effective conservation decision making. Key words: Water quality, Chesapeake Bay Watershed, Winter Cover Crop, Soil and Water Assessment Tool (SWAT)

  13. Effects of Covering Different Crops on Konjac Growth and Yield%覆盖不同作物对魔芋生长和产量的影响

    Institute of Scientific and Technical Information of China (English)

    董坤; 卢俊; 李成云

    2014-01-01

    We studied the effects of covering different crops on the growth and development, disease incidence, yield and economic benefit of konjac in winter from 2012 to 2013 in Fuyuan county of Yunnan province. The results showed that, different covering crops affected emergence time of konjac, and seedlings germinated earliest of the treatment without covering crop, while seedlings germinated latest of the two treatments covering with smooth vetch and rape respectively. Meanwhile, covering with smooth vetch, rape and pea could control and prevent soft rot of konjac. Crops covering affected konjac yield, and the treatments covered with rape and garlic respectively had higher yield than the control treatment, while the other treatments had lower yield than the control treatment. The two treatments covered with garlic and rape had higher economic benefit of 141 264 and 135 665 Yuan/hm2, which were 25 506 and 19 907 Yuan/hm2 higher than that of the control treatment respectively, while the yields of the other treatments were lower than that of the control treatment.%2012-2013年,在云南省富源县冬季开展大田试验,研究不同覆盖作物对魔芋的生长发育、发病率、产量及经济效益的影响。试验结果表明,覆盖不同的作物会影响魔芋的出苗时间和倒苗时间,不覆盖的出苗最早,覆盖苕子和油菜的出苗最晚,倒苗时间则刚好相反;覆盖苕子、油菜、豌豆对魔芋软腐病的防治有一定作用;覆盖油菜和大蒜的魔芋产量比对照高,其余处理则比对照低;覆盖大蒜的产值最高,1 hm2达141264元,比对照(不覆盖)的115758元高25506元,其次是覆盖油菜,1 hm2达135665元,比对照(不覆盖)高19907元,其余都比对照低。

  14. Assessment of the AquaCrop model for use in simulation of irrigated winter wheat canopy cover, biomass, and grain yield in the North China Plain.

    Directory of Open Access Journals (Sweden)

    Xiu-liang Jin

    Full Text Available Improving winter wheat water use efficiency in the North China Plain (NCP, China is essential in light of current irrigation water shortages. In this study, the AquaCrop model was used to calibrate, and validate winter wheat crop performance under various planting dates and irrigation application rates. All experiments were conducted at the Xiaotangshan experimental site in Beijing, China, during seasons of 2008/2009, 2009/2010, 2010/2011 and 2011/2012. This model was first calibrated using data from 2008/2009 and 2009/2010, and subsequently validated using data from 2010/2011 and 2011/2012. The results showed that the simulated canopy cover (CC, biomass yield (BY and grain yield (GY were consistent with the measured CC, BY and GY, with corresponding coefficients of determination (R(2 of 0.93, 0.91 and 0.93, respectively. In addition, relationships between BY, GY and transpiration (T, (R(2 = 0.57 and 0.71, respectively was observed. These results suggest that frequent irrigation with a small amount of water significantly improved BY and GY. Collectively, these results indicate that the AquaCrop model can be used in the evaluation of various winter wheat irrigation strategies. The AquaCrop model predicted winter wheat CC, BY and GY with acceptable accuracy. Therefore, we concluded that AquaCrop is a useful decision-making tool for use in efforts to optimize wheat winter planting dates, and irrigation strategies.

  15. Assessment of the AquaCrop model for use in simulation of irrigated winter wheat canopy cover, biomass, and grain yield in the North China Plain.

    Science.gov (United States)

    Jin, Xiu-liang; Feng, Hai-kuan; Zhu, Xin-kai; Li, Zhen-hai; Song, Sen-nan; Song, Xiao-yu; Yang, Gui-Jun; Xu, Xin-gang; Guo, Wen-shan

    2014-01-01

    Improving winter wheat water use efficiency in the North China Plain (NCP), China is essential in light of current irrigation water shortages. In this study, the AquaCrop model was used to calibrate, and validate winter wheat crop performance under various planting dates and irrigation application rates. All experiments were conducted at the Xiaotangshan experimental site in Beijing, China, during seasons of 2008/2009, 2009/2010, 2010/2011 and 2011/2012. This model was first calibrated using data from 2008/2009 and 2009/2010, and subsequently validated using data from 2010/2011 and 2011/2012. The results showed that the simulated canopy cover (CC), biomass yield (BY) and grain yield (GY) were consistent with the measured CC, BY and GY, with corresponding coefficients of determination (R(2)) of 0.93, 0.91 and 0.93, respectively. In addition, relationships between BY, GY and transpiration (T), (R(2) = 0.57 and 0.71, respectively) was observed. These results suggest that frequent irrigation with a small amount of water significantly improved BY and GY. Collectively, these results indicate that the AquaCrop model can be used in the evaluation of various winter wheat irrigation strategies. The AquaCrop model predicted winter wheat CC, BY and GY with acceptable accuracy. Therefore, we concluded that AquaCrop is a useful decision-making tool for use in efforts to optimize wheat winter planting dates, and irrigation strategies.

  16. Quantifying the impact of cloud cover on ground radiation flux measurements using hemispherical images

    NARCIS (Netherlands)

    Roupioz, L.; Colin, J.; Jia, L.; Nerry, F.; Menenti, M.

    2015-01-01

    Linking observed or estimated ground incoming solar radiation with cloud coverage is difficult since the latter is usually poorly described in standard meteorological observation protocols. To investigate the benefits of detailed observation and characterization of cloud coverage and distribution

  17. Overland flow connectivity in olive orchard plots with cover crops and conventional tillage, and under different rainfall scenarios

    Science.gov (United States)

    López-Vicente, Manuel; García-Ruiz, Roberto; Guzmán, Gema; Vicente-Vicente, José Luis; Gómez, José Alfonso

    2016-04-01

    The study of overland flow connectivity (QC) allows understanding the redistribution dynamics of runoff and soil components as an emergent property of the spatio-temporal interactions of hydrological and geomorphic processes. However, very few studies have dealt with runoff connectivity in olive orchards. In this study we simulated QC in four olive orchard plots, located on the Santa Marta farm (37° 20' 33.6" N, 6° 13' 44" W), in Seville province (Andalusia) in SW Spain. The olive plantation was established in 1985 with trees planted at 8 m x 6 m. Each bounded plot is 8 m wide (between 2 tree lines) and 60 m long (total area of 480 m2), laid out with the longest dimension parallel to the maximum slope and to the tree lines. The slope is uniform, with an average steepness of 11%. Two plots (P2 and P4) were devoted to conventional tillage (CT) consisting of regular chisel plow passes depending on weed growth. Another set of two plots had two types of cover crops (CC) in the inter tree rows (the area outside the vertical olive canopy projection): uniform CC of Lolium multiflorum (P3) and a mixture of L. rigidum and L. multiflorum together with other species (P5). The tree rows were treated with herbicide to keep bare soil. We selected the Index of runoff and sediment Connectivity (IC) of Borselli et al. (2008) to simulate three rainfall scenarios: i) low rainfall intensity (Sc-LowInt) and using the MD flow accumulation algorithm; ii) moderate rainfall intensity (Sc-ModInt) and using MD8; and iii) high rainfall intensity (Sc-HighInt) and using D8. After analysing the values of rainfall intensity during two hydrological years (Oct'09-Sep'10 and Oct'10-Sep'11) we associated the three scenarios with the followings months: Sc-LowInt during the period Jan-Mar, that summarizes 42% of all annual rainfall events; Sc-ModInt during Oct-Nov and Apr-May (32% of all events); and Sc-HighInt during the period Jun-Sep and in December (26% of all events). Instead of using the C

  18. The effect of plant growth promoting rhizobacteria (PGPR on quantitative and qualitative characteristics of Sesamum indicum L. with application of cover crops of Lathyrus sp. and Persian clover (Trifolium resopinatum L.

    Directory of Open Access Journals (Sweden)

    M. Jahan

    2016-05-01

    Full Text Available Cover crops cultivation and application of plant growth rhizobacteria are the key factors to enhance agroecosystem health. A field experiment was conducted at the Research Farm of Faculty of Agriculture, Ferdowsi University of Mashhad, Iran, during growing season of 2009-2010. A split plot arrangement based on a complete randomized block design with three replications was used. Cultivation and no cultivation of Lathyrus sp. and Persian clover (Trifolium resopinatum in autumn assigned to the main plots. The sub plot factor consisted of three different types of biofertilizers plus control, including 1-nitroxin (containing of Azotobacter sp. and Azospirillum sp., 2- phosphate solubilizing bacteria (PSB (containing of Bacillus sp. and Pseudomonas sp., 3- biosulfur (containing of Thiobacillus ssp. and 4- control (no fertilizer. The results showed the effect of cover crops on seed number and seed weight per plant, biological and seed yield was significant, as the seed yield increased of 9 %. In general, biofertilizers showed superiority due to the most studied traits compared to control. Nitroxin, PSB and biosulfur increased biological yield of 44, 28 and 26 % compared to control, respectively. Cover crops and biofertilizers interactions, showed significant effect on all studied traits, as the highest and the lowest harvest index resulted in cover crop combined with biofertilizers (22.1% and cultivation and no cultivation of cover crops combined with control (15.3%, respectively. The highest seed oil and protein content resulted from cover crops plus biofertilizers (42.4% and cover crops plus PSB (22.5%, respectively. In general, the results showed cover crops cultivation in combination with biofertilizers application could be an ecological alternative for chemical fertilizers, in addition of achieving advantages of cover crops. According to the results, it should be possible to design an ecological cropping system and produce appropriate and healthy

  19. The In-Transit Vigilant Covering Tour Problem of Routing Unmanned Ground Vehicles

    Science.gov (United States)

    2012-08-01

    15 Figure 2. A classic VRP ...17 Figure 3. Solution for a VRP ........................................................................................18 Figure 4. Solution...of NP-hard problems, such as the Traveling Salesman Problem (TSP), Vehicle Routing Problem ( VRP ), and Covering Salesman Problem (CSP) etc. We will

  20. Sistemas de preparo do solo, plantas de cobertura e produtividade da cultura da mandioca Soil tillage systems, cover crops and productivity in cassava

    Directory of Open Access Journals (Sweden)

    Auro Akio Otsubo

    2008-03-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos do uso de plantas de cobertura e de sistemas de preparo do solo, no desenvolvimento e na produtividade da cultura da mandioca (Manihot esculenta Crantz. O trabalho foi conduzido em Argissolo Vermelho, sob sistema convencional de preparo do solo, e em cultivo mínimo sobre palhada de mucuna-cinza (Stizolobium cinereum Piper & Tracy, sorgo granífero [Sorghum bicolor (L. Moench] e milheto [Pennisetum americanum (L. K. Schum.]. Aos dezoito meses após o plantio da mandioca, foram avaliados: altura de plantas, produção de massa de matéria seca da parte aérea, número de raízes tuberosas, produtividade, percentagem de matéria seca e de amido nas raízes tuberosas e índice de colheita. Observou-se que o sistema convencional de preparo do solo pode ser substituído, na cultura da mandioca, pela prática do cultivo mínimo, associada ao uso de coberturas vegetais, por promover incrementos significativos na produtividade da cultura, especialmente, quando se utiliza o milheto como planta de cobertura. O uso de plantas de cobertura no pré-cultivo de mandioca, em sistema de preparo mínimo do solo, representa uma alternativa eficiente para um melhor manejo dessa cultura.The objective of this work was to evaluate the effects of cover crops and soil tillage systems in the development and yield of cassava (Manihot esculenta Crantz. The experiment was carried out in an Arenic Hapludult under conventional tillage, and in a minimum tillage system over mucuna (Stizolobium cinereum Piper & Tracy, sorghum [Sorghum bicolor (L. Moench] and millet straw [Pennisetum americanum (L. K. Schum.]. Eighteen months after cassava planting, the following variables were evaluated: plant height, shoot dry matter production, number of roots, yield, dry matter and starch content on storage roots, and harvest index. It was observed that conventional tillage could be replaced by minimum tillage in cassava crop, when associated

  1. Mapping wind erosion hazard in Australia using MODIS-derived ground cover, soil moisture and climate data

    Science.gov (United States)

    Yang, X.; Leys, J.

    2014-03-01

    This paper describes spatial modeling methods to identify wind erosion hazard (WEH) areas across Australia using the recently available time-series products of satellite-derived ground cover, soil moisture and wind speed. We implemented the approach and data sets in a geographic information system to produce WEH maps for Australia at 500 m ground resolution on a monthly basis for the recent thirteen year period (2000-2012). These maps reveal the significant wind erosion hazard areas and their dynamic tendencies at paddock and regional scales. Dust measurements from the DustWatch network were used to validate the model and interpret the dust source areas. The modeled hazard areas and changes were compared with results from a rule-set approach and the Computational Environmental Management System (CEMSYS) model. The study demonstrates that the time series products of ground cover, soil moisture and wind speed can be jointly used to identify landscape erodibility and to map seasonal changes of wind erosion hazard across Australia. The time series wind erosion hazard maps provide detailed and useful information to assist in better targeting areas for investments and continuous monitoring, evaluation and reporting that will lead to reduced wind erosion and improved soil condition.

  2. Permafrost, Seasonally Frozen Ground, Snow Cover and Vegetation in the USSR

    Science.gov (United States)

    1984-12-01

    Late Quaternary History and the Formation of Sedi- ments in the Marginal and Inland Seas (Pozdnechetvertichnaia Istorlia i Sedimentogenez...rasprostraneniia snezhnogo pokrova na poverkhnosti sushi zemnogo shara). In Geography of Snow Cover (Geo- grafiya Snezhnogo Prokrova). Moscow: Izdat...Papers, 18(3): 198-202. (36-1668) Vigdorchik, M.E. (1980) Arctic Pleistocene History and the Development of Submarine Permafrost. Boulder

  3. [Effects of ground cover and water-retaining agent on winter wheat growth and precipitation utilization].

    Science.gov (United States)

    Wu, Ji-Cheng; Guan, Xiu-Juan; Yang, Yong-Hui

    2011-01-01

    An investigation was made at a hilly upland in western Henan Province to understand the effects of water-retaining agent (0, 45, and 60 kg x hm(-2)), straw mulching (3000 and 6000 kg x hm(-2)), and plastic mulching (thickness straw- or plastic mulching was combined with the use of water-retaining agent. Comparing with the control, all the measures increased the soil moisture content at different growth stages by 0.1%-6.5%. Plastic film mulching had the best water-retention effect before jointing stage, whereas water-retaining agent showed its best effect after jointing stage. Soil moisture content was the lowest at flowering and grain-filling stages. Land cover increased the grain yield by 2.6%-20.1%. The yield increment was the greatest (14.2%-20.1%) by the combined use of straw mulching and water-retaining agent, followed by plastic mulching combined with water-retaining agent (11.9% on average). Land cover also improved the precipitation use efficiency (0.4-3.2 kg x mm(-1) x hm(-2)) in a similar trend as the grain yield. This study showed that land cover and water-retaining agent improved soil moisture and nutrition conditions and precipitation utilization, which in turn, promoted the tillering of winter wheat, and increased the grain number per ear and the 1000-grain mass.

  4. The Impact of Time Difference between Satellite Overpass and Ground Observation on Cloud Cover Performance Statistics

    Directory of Open Access Journals (Sweden)

    Jędrzej S. Bojanowski

    2014-12-01

    Full Text Available Cloud property data sets derived from passive sensors onboard the polar orbiting satellites (such as the NOAA’s Advanced Very High Resolution Radiometer have global coverage and now span a climatological time period. Synoptic surface observations (SYNOP are often used to characterize the accuracy of satellite-based cloud cover. Infrequent overpasses of polar orbiting satellites combined with the 3- or 6-h SYNOP frequency lead to collocation time differences of up to 3 h. The associated collocation error degrades the cloud cover performance statistics such as the Hanssen-Kuiper’s discriminant (HK by up to 45%. Limiting the time difference to 10 min, on the other hand, introduces a sampling error due to a lower number of corresponding satellite and SYNOP observations. This error depends on both the length of the validated time series and the SYNOP frequency. The trade-off between collocation and sampling error call for an optimum collocation time difference. It however depends on cloud cover characteristics and SYNOP frequency, and cannot be generalized. Instead, a method is presented to reconstruct the unbiased (true HK from HK affected by the collocation differences, which significantly (t-test p < 0.01 improves the validation results.

  5. Effect of heavy metals on seed germination and seedling growth of common ragweed and roadside ground cover legumes.

    Science.gov (United States)

    Bae, Jichul; Benoit, Diane L; Watson, Alan K

    2016-06-01

    In southern Québec, supplement roadside ground covers (i.e. Trifolium spp.) struggle to establish near edges of major roads and thus fail to assist turf recruitment. It creates empty niches vulnerable to weed establishment such as common ragweed (Ambrosia artemisiifolia). We hypothesized that heavy metal stresses may drive such species shifts along roadside edges. A growth chamber experiment was conducted to assess effects of metals (Zn, Pb, Ni, Cu, and Cd) on germination and seedling behaviors of roadside weed (A. artemisiifolia) and ground cover legumes (Coronilla varia, Lotus corniculatus, and Trifolium arvense). All metals inhibited T. arvense germination, but the effect was least on A. artemisiifolia. Low levels of Pb and Ni promoted germination initiation of A. artemisiifolia. Germination of L. corniculatus was not affected by Zn, Pb, and Ni, but inhibited by Cu and Cd. Germination of C. varia was decreased by Ni, Cu, and Cd and delayed by Zn and Pb. Metal additions hindered seedling growth of all test species, and the inhibitory effect on the belowground growth was greater than on the aboveground growth. Seedling mortality was lowest in A. artemisiifolia but highest in T. arvense when exposed to the metal treatments. L. corniculatus and C. varia seedlings survived when subjected to high levels of Zn, Pb, and Cd. In conclusion, the successful establishment of A. artemisiifolia along roadside edges can be associated with its greater tolerance of heavy metals. The findings also revealed that L. corniculatus is a potential candidate for supplement ground cover in metal-contaminated roadside edges in southern Québec, especially sites contaminated with Zn and Pb.

  6. Anticipating potential biodiversity conflicts for future biofuel crops in South Africa: Incorporating land cover information with Species Distribution Models

    CSIR Research Space (South Africa)

    Blanchard, R

    2012-10-01

    Full Text Available Using spatial techniques to determine the threat of land-use change is a useful tool in mitigating against potential biodiversity losses. We investigate the potential suitability and likely impacts of energy crops not currently grown in South Africa...

  7. Stover removal and cover crops effects on corn production and water use under full and limited irrigation

    Science.gov (United States)

    Corn (Zea mays L.) residue removal in irrigated cropping systems for livestock forage or cellulosic ethanol is of great interest in south-central Nebraska. Irrigation water restrictions in the region have also resulted in adoption of limited-irrigation strategies. Little is known regarding the inter...

  8. Comparing distinct ground-based lightning location networks covering the Netherlands

    Science.gov (United States)

    de Vos, Lotte; Leijnse, Hidde; Schmeits, Maurice; Beekhuis, Hans; Poelman, Dieter; Evers, Läslo; Smets, Pieter

    2015-04-01

    Lightning can be detected using a ground-based sensor network. The Royal Netherlands Meteorological Institute (KNMI) monitors lightning activity in the Netherlands with the so-called FLITS-system; a network combining SAFIR-type sensors. This makes use of Very High Frequency (VHF) as well as Low Frequency (LF) sensors. KNMI has recently decided to replace FLITS by data from a sub-continental network operated by Météorage which makes use of LF sensors only (KNMI Lightning Detection Network, or KLDN). KLDN is compared to the FLITS system, as well as Met Office's long-range Arrival Time Difference (ATDnet), which measures Very Low Frequency (VLF). Special focus lies on the ability to detect Cloud to Ground (CG) and Cloud to Cloud (CC) lightning in the Netherlands. Relative detection efficiency of individual flashes and lightning activity in a more general sense are calculated over a period of almost 5 years. Additionally, the detection efficiency of each system is compared to a ground-truth that is constructed from flashes that are detected by both of the other datasets. Finally, infrasound data is used as a fourth lightning data source for several case studies. Relative performance is found to vary strongly with location and time. As expected, it is found that FLITS detects significantly more CC lightning (because of the strong aptitude of VHF antennas to detect CC), though KLDN and ATDnet detect more CG lightning. We analyze statistics computed over the entire 5-year period, where we look at CG as well as total lightning (CC and CG combined). Statistics that are considered are the Probability of Detection (POD) and the so-called Lightning Activity Detection (LAD). POD is defined as the percentage of reference flashes the system detects compared to the total detections in the reference. LAD is defined as the fraction of system recordings of one or more flashes in predefined area boxes over a certain time period given the fact that the reference detects at least one

  9. After the fire: benefits of reduced ground cover for vervet monkeys (Cercopithecus aethiops).

    Science.gov (United States)

    Jaffe, Karin Enstam; Isbell, Lynne A

    2009-03-01

    Here we describe changes in ranging behavior and other activities of vervet monkeys (Cercopithecus aethiops) after a wildfire eliminated grass cover in a large area near the study group's home range. Soon after the fire, the vervets ranged farther away from tall trees that provide refuge from mammalian predators, and moved into the burned area where they had never been observed to go before the fire occurred. Visibility at vervet eye-level was 10 times farther in the burned area than in unburned areas. They traveled faster, and adult females spent more time feeding and less time scanning bipedally in the burned area than in the unburned area. The burned area's greater visibility may have lowered the animals' perceived risk of predation there, and may have provided them with an unusual opportunity to eat acacia ants.

  10. Culturas de cobertura e qualidade física de um Latossolo em plantio direto Cover crops and physical quality of a Latosol under no-tillage

    Directory of Open Access Journals (Sweden)

    Rui da S. Andrade

    2009-08-01

    Full Text Available Com este trabalho se objetivou determinar o efeito de culturas de cobertura na qualidade física de um Latossolo Vermelho distrófico em plantio direto. O experimento foi irrigado por pivô central e conduzido na Embrapa Arroz e Feijão, em Santo Antônio de Goiás, GO, no delineamento de blocos ao acaso, com oito repetições. Os tratamentos consistiram de oito culturas de cobertura: braquiária; milho consorciado com braquiária; guandu anão; milheto; mombaça; sorgo; estilosantes e crotalária. As sete primeiras vêm sendo cultivadas no verão desde dezembro de 2001 e a crotalária a partir de novembro de 2003. No inverno de cada ano e após dessecação dessas culturas, foi implantado o feijoeiro irrigado e, em fevereiro de 2006, determinados o conteúdo de matéria orgânica do solo, alguns atributos físicos e sua qualidade física, por meio do índice S. As culturas de cobertura, especialmente as gramíneas, favoreceram a agregação do solo na camada superficial. O cultivo do solo modificou a sua estrutura comparativamente à mata nativa, aumentando sua densidade e reduzindo a macroporosidade, porosidade total e qualidade física. Entre as culturas de cobertura guandu, crotalária e milho consorciado com braquiária, foram as que mantiveram a camada superficial do solo com boa qualidade física.The objective of this study was to determine the effect of cover crop mulches on the physical quality of a distrophic Red Latosol (Oxisol under no-tillage. The experiment was carried out under center pivot at Embrapa Rice & Beans, in Santo Antônio de Goiás, GO, in a randomized block design, with eight replications. The treatments consisted of eight cover crops: Brachiaria brizantha; corn associated with B. brizantha; pigeon pea; millet; Panicum maximum; sorghum; Stylosanthes guianensis; and Crotalaria juncea. The first seven crops had been cultivated in summer season since December 2001 and C. juncea since November 2003. In the winter season

  11. Improvement of soil carbon sink by cover crops in olive orchards under semiarid conditions. Influence of the type of soil and weed

    Directory of Open Access Journals (Sweden)

    F. Márquez-García

    2013-05-01

    Full Text Available The olive tree is one of the most important crops in Spain, and the main one in the region of Andalusia. Most orchards are rain-fed, with high slopes where conventional tillage (CT is the primary soil management system used. These conditions lead to high erosion and a significant transport of organic carbon (OC. Moreover, soil tillage accelerates the oxidation of the OC. Cover crops (CC are the conservation agriculture (CA approach for woody crops. They are grown in-between tree rows to protect the soil against water erosion and their organic residues also help to increase the soil carbon (C sink. Soil and OC losses associated to the sediment were measured over four seasons (2003-07 using micro-plots for the collection of runoff and sediment in five experimental fields located in rain-fed olive orchards in Andalusia. Two soil management systems were followed, CC and CT. Furthermore, the changes in soil C in both systems were analyzed at a depth of 0-25 cm. CC reduced erosion by 80.5%, and also OC transport by 67.7%. In addition, Cover crops increased soil C sink by 12.3 Mg ha-1 year-1 of carbon dioxide (CO2 equivalent, with respect to CT. CC in rainfed olive orchards in a Mediterranean climate could be an environmental friendly and profitable system for reducing erosion and increasing the soil C sink. However, C fixing rate is not regular, being very high for the initial years after shifting from CT to CC and gradually decreasing over time.

  12. Associations between soil bacterial community structure and nutrient cycling functions in long-term organic farm soils following cover crop and organic fertilizer amendment.

    Science.gov (United States)

    Fernandez, Adria L; Sheaffer, Craig C; Wyse, Donald L; Staley, Christopher; Gould, Trevor J; Sadowsky, Michael J

    2016-10-01

    Agricultural management practices can produce changes in soil microbial populations whose functions are crucial to crop production and may be detectable using high-throughput sequencing of bacterial 16S rRNA. To apply sequencing-derived bacterial community structure data to on-farm decision-making will require a better understanding of the complex associations between soil microbial community structure and soil function. Here 16S rRNA sequencing was used to profile soil bacterial communities following application of cover crops and organic fertilizer treatments in certified organic field cropping systems. Amendment treatments were hairy vetch (Vicia villosa), winter rye (Secale cereale), oilseed radish (Raphanus sativus), buckwheat (Fagopyrum esculentum), beef manure, pelleted poultry manure, Sustane(®) 8-2-4, and a no-amendment control. Enzyme activities, net N mineralization, soil respiration, and soil physicochemical properties including nutrient levels, organic matter (OM) and pH were measured. Relationships between these functional and physicochemical parameters and soil bacterial community structure were assessed using multivariate methods including redundancy analysis, discriminant analysis, and Bayesian inference. Several cover crops and fertilizers affected soil functions including N-acetyl-β-d-glucosaminidase and β-glucosidase activity. Effects, however, were not consistent across locations and sampling timepoints. Correlations were observed among functional parameters and relative abundances of individual bacterial families and phyla. Bayesian analysis inferred no directional relationships between functional activities, bacterial families, and physicochemical parameters. Soil functional profiles were more strongly predicted by location than by treatment, and differences were largely explained by soil physicochemical parameters. Composition of soil bacterial communities was predictive of soil functional profiles. Differences in soil function were

  13. Improvement of soil carbon sink by cover crops in olive orchards under semiarid conditions. Influence of the type of soil and weed

    Energy Technology Data Exchange (ETDEWEB)

    Marquez-Garcia, F.; Gonzalez-Sanchez, E. J.; Castro-Garcia, S.; Ordonez-Fernandez, R.

    2013-06-01

    The olive tree is one of the most important crops in Spain, and the main one in the region of Andalusia. Most orchards are rain-fed, with high slopes where conventional tillage (CT) is the primary soil management system used. These conditions lead to high erosion and a significant transport of organic carbon (OC). Moreover, soil tillage accelerates the oxidation of the OC. Cover crops (CC) are the conservation agriculture (CA) approach for woody crops. They are grown in-between tree rows to protect the soil against water erosion and their organic residues also help to increase the soil carbon (C) sink. Soil and OC losses associated to the sediment were measured over four seasons (2003-07) using micro-plots for the collection of runoff and sediment in five experimental fields located in rain-fed olive orchards in Andalusia. Two soil management systems were followed, CC and CT. Furthermore, the changes in soil C in both systems were analyzed at a depth of 0-25 cm. CC reduced erosion by 80.5%, and also OC transport by 67.7%. In addition, CC increased soil C sink by 12.3 Mg ha{sup -}1 year{sup -}1 of carbon dioxide (CO{sub 2}) equivalent, with respect to CT. Cover crops in rainfed olive orchards in a Mediterranean climate could be an environmental friendly and profitable system for reducing erosion and increasing the soil C sink. However, C fixing rate is not regular, being very high for the initial years after shifting from CT to CC and gradually decreasing over time. (Author) 57 refs.

  14. Root-knot Nematode Management and Yield of Soybean as Affected by Winter Cover Crops, Tillage Systems, and Nematicides.

    Science.gov (United States)

    Minton, N A; Parker, M B

    1987-01-01

    Management of Meloidogyne incognita on soybean as affected by winter small grain crops or fallow, two tillage systems, and nematicides was studied. Numbers of M. incognita did not differ in plots planted to wheat and rye. Yields of soybean planted after these crops also did not differ. Numbers of M. incognita were greater in fallow than in rye plots, but soybean yield was not affected by the two treatments. Soybean yields were greater in subsoil-plant than in moldboard plowed plots. Ethylene dibromide reduced nematode population densities more consistently than aldicarb and phenamiphos. Also, ethylene dibromide increased yields the most and phenamiphos the least. There was a positive correlation (P = 0.001) of seed size (weight of 100 seeds) with yield (r = 0.79), indicating that factors affecting yield also affected seed size.

  15. Synergistic Effects of Agronet Covers and Companion Cropping on Reducing Whitefly Infestation and Improving Yield of Open Field-Grown Tomatoes

    Directory of Open Access Journals (Sweden)

    Stella Mutisya

    2016-09-01

    Full Text Available Tomatoes (Lycopersicon esculentum Mill are one of the biggest vegetable crops in the world, supplying a wide range of vitamins, minerals and fibre in human diets. In the tropics, tomatoes are predominantly grown under sub-optimal conditions by subsistence farmers, with exposure to biotic and abiotic stresses in the open field. Whitefly (Bemisia tabaci Gennadius is one of the major pests of the tomato, potentially causing up to 100% yield loss. To control whitefly, most growers indiscriminately use synthetic insecticides which negatively impact the environment, humans, and other natural pest management systems, while also increasing cost of production. This study sought to investigate the effectiveness of agronet covers and companion planting with aromatic basil (Ocimum basilicum L. as an alternative management strategy for whitefly in tomatoes and to evaluate the use of these treatments ontomato growth and yield. Two trials were conducted at the Horticulture Research and Training Field, Egerton University, Njoro, Kenya. Treatments comprised a combination of two factors, (1 growing environment (agronet and no agronet and (2 companion planting with a row of basil surrounding tomato plants, a row of basil in between adjacent rows of tomato, no companion planting. Agronet covers and companion cropping with a row of basil planted between adjacent tomato rows significantly lowered B. tabaci infestation in tomatoes by 68.7%. Better tomato yields were also recorded in treatments where the two treatments were used in combination. Higher yield (13.75 t/ha was obtained from tomatoes grown under agronet cover with a basil row planted in between adjacent rows of the tomato crop compared to 5.9 t/ha in the control. Non-marketable yield was also lowered to5.9 t/ha compared to 9.8 t/ha in the control following the use of the two treatments in combination. The results of this study demonstrate the potential viability of using companion cropping and agronet

  16. Temporal monitoring of the soil freeze-thaw cycles over snow-cover land by using off-ground GPR

    KAUST Repository

    Jadoon, Khan

    2013-07-01

    We performed off-ground ground-penetrating radar (GPR) measurements over a bare agricultural field to monitor the freeze-thaw cycles over snow-cover. The GPR system consisted of a vector network analyzer combined with an off-ground monostatic horn antenna, thereby setting up an ultra-wideband stepped-frequency continuous-wave radar. Measurements were performed during nine days and the surface of the bare soil was exposed to snow fall, evaporation and precipitation as the GPR antenna was mounted 110 cm above the ground. Soil surface dielectric permittivity was retrieved using an inversion of time-domain GPR data focused on the surface reflection. The GPR forward model used combines a full-waveform solution of Maxwell\\'s equations for three-dimensional wave propagation in planar layered media together with global reflection and transmission functions to account for the antenna and its interactions with the medium. Temperature and permittivity sensors were installed at six depths to monitor the soil dynamics in the top 8 cm depth. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and permittivity data and in particular freeze and thaw events were clearly visible. A good agreement of the trend was observed between the temperature, permittivity and GPR time-lapse data with respect to five freeze-thaw cycles. The GPR-derived permittivity was in good agreement with sensor observations. The proposed method appears to be promising for the real-time mapping and monitoring of the frozen layer at the field scale. © 2013 IEEE.

  17. Land Cover and Crop Type Classification along the Season Based on Biophysical Variables Retrieved from Multi-Sensor High-Resolution Time Series

    Directory of Open Access Journals (Sweden)

    François Waldner

    2015-08-01

    Full Text Available With the ever-increasing number of satellites and the availability of data free of charge, the integration of multi-sensor images in coherent time series offers new opportunities for land cover and crop type classification. This article investigates the potential of structural biophysical variables as common parameters to consistently combine multi-sensor time series and to exploit them for land/crop cover classification. Artificial neural networks were trained based on a radiative transfer model in order to retrieve high resolution LAI, FAPAR and FCOVER from Landsat-8 and SPOT-4. The correlation coefficients between field measurements and the retrieved biophysical variables were 0.83, 0.85 and 0.79 for LAI, FAPAR and FCOVER, respectively. The retrieved biophysical variables’ time series displayed consistent average temporal trajectories, even though the class variability and signal-to-noise ratio increased compared to NDVI. Six random forest classifiers were trained and applied along the season with different inputs: spectral bands, NDVI, as well as FAPAR, LAI and FCOVER, separately and jointly. Classifications with structural biophysical variables reached end-of-season overall accuracies ranging from 73%–76% when used alone and 77% when used jointly. This corresponds to 90% and 95% of the accuracy level achieved with the spectral bands and NDVI. FCOVER appears to be the most promising biophysical variable for classification. When assuming that the cropland extent is known, crop type classification reaches 89% with spectral information, 87% with the NDVI and 81%–84% with biophysical variables.

  18. Efeitos de quantidades de fitomassa de adubos verdes na supressão de plantas daninhas Effects of cover crop biomass quantities on weed suppression

    Directory of Open Access Journals (Sweden)

    F.J. Severino

    2001-08-01

    Full Text Available Com o objetivo de avaliar as correlações entre a utilização de diferentes quantidades de fitomassa, incorporada ou na superfície do solo, dos adubos verdes amendoim-forrageiro (Arachis pintoi, crotalária (Crotalaria juncea e feijão-guandu-anão (Cajanus cajan na redução da emergência e produção de fitomassa seca das plantas daninhas capim-braquiária (Brachiaria decumbens, capim-colonião (Panicum maximum e picão-preto (Bidens pilosa, foi instalado um experimento em casa de vegetação do Departamento de Produção Vegetal da ESALQ/USP-Piracicaba. O delineamento experimental utilizado foi o de blocos casualizados, com os tratamentos em quatro repetições, em esquema fatorial 3 x 6 x 3 x 2, sendo três adubos verdes (A. pintoi, C. juncea e C. cajan, seis quantidades de fitomassa (0; 0,5; 1; 2; 4; e 8 vezes a quantidade de adubo verde produzido pela média de campo, três plantas daninhas (B. decumbens, P. maximum e B. pilosa e duas formas de distribuição da fitomassa dos adubos verdes (na superfície do solo e de 0 a 5 cm de profundidade. As características avaliadas durante a condução do experimento foram as seguintes: densidade de plantas daninhas/vaso e produção de fitomassa seca das plantas daninhas (g/vaso, determinadas aos 15 e aos 30 dias após a instalação do experimento. Os resultados permitiram concluir que a fitomassa dos adubos verdes, nas duas formas utilizadas, reduz significativamente as populações das plantas daninhas testadas. As correlações ocorrem de maneira distinta pelos diferentes adubos verdes, sendo o feijão-guandu-anão, de forma geral, o mais efetivo na supressão das plantas daninhas.Different biomass quantities of the cover crops Arachis pintoi Krapov. & W.C. Gregory, Crotalaria juncea and Cajanus cajan were either incorporated or spread on the surface of the soil to study their effect on the emergence and dry mass production of the weeds Brachiaria decumbens, Panicum maximum and Bidens

  19. Carbon sequestration potential of residues of different types of cover crops in olive groves under mediterranean climate

    Energy Technology Data Exchange (ETDEWEB)

    Repullo-Ruiberriz de Torres, M. A.; Carbonell-Bojollo, R.; Alcantara-Brana, C.; Rodriguez-Lizana, A.; Ordonez-Fernandez, R.

    2012-11-01

    The maintenance of plant cover between olive grove lanes until the beginning of spring is a soil management alternative that is gradually being adopted by olive growers. As well as protecting the soil from erosion, plant covers have other advantages such as improving the physicochemical properties of the soil, favouring its biodiversity and contributing towards the capturing of atmospheric carbon and its fixation in the soil. A trial was conducted over three growing seasons in an olive plantation situated in southern Spain. It was designed to evaluate the C fixation potential of the residues of the cover species Brachypodium distachyon, Eruca vesicaria, Sinapis alba and of spontaneous weeds; and also to study the decomposition dynamics of plant residues after mowing cover. After 156 and 171 days of decomposition, the species that released the largest amount of C was Brachypodium with values of 2,157 and 1,666 kg ha{sup -}1 respectively, while the lowest values of 461 and 509 kg ha{sup -}1 were obtained by spontaneous weeds. During the third season (163 days of decomposition) and due to the weather conditions restricting the emergence and growth of cover, spontaneous weeds released the most C with a value of 1,494 kg ha{sup -}1 . With respect to the fixation of C, Sinapis records the best results with an increase in soil organic C (SOC) concentration of 7,690 kg ha{sup -}1 . Considering the three seasons and a depth of 20 cm, the behaviour sequence of the different species in favouring the fixation of soil organic C was Sinapis > Brachypodium > spontaneous weeds > Eruca. (Author) 34 refs.

  20. Modelagem da proteção do solo por plantas de cobertura no sul de Minas Gerais = Modeling of soil protection by cover crops in southern Minas Gerais, Brazil.

    Directory of Open Access Journals (Sweden)

    Diego Antonio França de Freitas

    2012-08-01

    Full Text Available A cobertura do solo é o fator de maior importância relativa no controle da erosão hídrica. Assim, objetivou-se no presente estudo elaborar a modelagem da cobertura vegetal de vinte e quatro plantas de cobertura, em diversos sistemas de plantio e históricos de uso, com potencial para cultivo no Sul de Minas Gerais. Para avaliação da cobertura vegetal foram realizadas avaliações no campo utilizando uma régua de classificação da cobertura vegetal, sendo o delineamento experimental inteiramente casualizado, com três repetições, utilizado neste experimento. As plantas cultivadas sobre a palhada de feijãoirrigado apresentaram alto índice de cobertura do solo, o que pode estar relacionado à maior disponibilidade de nutrientes deixado por esta cultura na palhada e a maior reserva de água no solo, promovido pela irrigação do feijão. O milheto cultivado em nível e sobre a palhada de milheto e feijão-de-porco apresentou o menor índice de cobertura entre as plantas testadas. Na região sul de Minas Gerais os padrões de chuvas ocorrem em maior quantidade nos períodos de outubro a março, com elevação em dezembro e janeiro. Neste período o solo deve estar protegido do impacto da gota de chuva, pois o risco de erosão hídrica é maior. Assim, a utilização das plantas de cobertura é de grande importância, pois estas protegem o solo do impacto direto dasgotas de chuvas e diminuem os picos de temperatura do solo, sendo que estas devem ser cultivadas, preferencialmente, sobre a palhada de feijão.The ground cover is the most important factor relative to control erosion. Thus, the objective of this study was to develop a model plant cover for 24 cover crops used in several cropping systems and historical use, with potential for cultivation in southern Minas Gerais State, Brazil. To evaluate the vegetation cover field assessments using the strip land cover classification. A completely randomized design with three replications was

  1. Nutrição e produtividade do amendoim em sucessão ao cultivo de plantas de cobertura no sistema plantio direto Peanut crop nutrition and yield in no-tillage system in succession to cover crops growth

    Directory of Open Access Journals (Sweden)

    Carlos Alexandre Costa Crusciol

    2007-11-01

    Full Text Available O objetivo deste trabalho foi avaliar a produção de matéria seca e o acúmulo de nutrientes por plantas de cobertura e o efeito do manejo da palhada na nutrição e produtividade do amendoim da seca, em sucessão, no sistema plantio direto. O experimento foi instalado em um Latossolo Vermelho distroférrico, em Botucatu, SP. O delineamento utilizado foi o de blocos ao acaso, em parcelas subdivididas, com quatro repetições. As parcelas foram constituídas por três espécies de plantas de cobertura: braquiária - Brachiaria brizantha, cultivar Marandu; milheto - Pennisetum glaucum, cultivar BN 2; e panicum - Panicum maximum, cultivar Mombaça. As subparcelas foram constituídas pela ausência e presença do manejo mecânico da palhada, 20 dias após o manejo químico, mediante o uso de triturador de palha horizontal. O milheto apresentou a maior produção de matéria seca e o menor teor de nutrientes na parte aérea, aos 71 dias após a emergência, em comparação com a braquiária e o panicum. As quantidades de nutrientes acumuladas na parte aérea das plantas de cobertura foram semelhantes. A espécie de planta de cobertura do solo e o manejo mecânico da palhada não influenciam a nutrição e a produtividade do amendoim no sistema plantio direto.The objective of this work was to evaluate cover crops shoot dry matter production and nutrients accumulation and the effect of straw mulch mechanical management on the dry season peanut crop nutrition and yield, in no-tillage system. The experiment was carried out on a dystroferric Hapludox, in Botucatu, SP, Brazil. A randomized blocks design, in a splitplot array, with four replications, was used. The plots were composed by cover crops: palisadegrass - Brachiaria brizantha cv. Marandu; pearl millet - Pennisetum glaucum cv. BN 2; and guineagrass - Panicum maximum cv. Mombaça. The subplots were composed by absence or presence of straw mulch mechanical management, by horizontal crusher use, 20

  2. AgRISTARS: Early warning and crop condition assessment. Plant cover, soil temperature, freeze, water stress, and evapotranspiration conditions

    Science.gov (United States)

    Wiegand, C. L. (Principal Investigator); Nixon, P. R.; Gausman, H. W.; Namken, L. N.; Leamer, R. W.; Richardson, A. J.

    1981-01-01

    Emissive (10.5 to 12.5 microns) and reflective (0.55 to 1.1 microns) data for ten day scenes and infrared data for six night scenes of southern Texas were analyzed for plant cover, soil temperature, freeze, water stress, and evapotranspiration. Heat capacity mapping mission radiometric temperatures were: within 2 C of dewpoint temperatures, significantly correlated with variables important in evapotranspiration, and related to freeze severity and planting depth soil temperatures.

  3. The impact of no-tillage cultivation and white mustard as a cover crop on weed infestation and yield of carrot and red beet

    Directory of Open Access Journals (Sweden)

    Andrzej Borowy

    2015-03-01

    Full Text Available In a two-year field experiment, no-tillage cultivation using white mustard (Sinapis alba L. ‘Bardena’, 30 kg ha−1, as a cover crop did not influence emergence of red beet (Beta vulgaris L. ‘Czerwona Kula REW’ and had a favorable effect on emergence of carrot (Daucus carota L. ‘Berlikumer 2 – Perfekcja REW’. However, further growth of both vegetables was significantly slower under no-tillage cultivation. Both vegetables produced a higher yield of roots and the diameter of these roots was bigger under conventional cultivation. The effect of cultivation method on the content of total nitrogen, phosphorus, potassium, calcium and magnesium in carrot and red beet leaves varied, while the content of dry matter, monosaccharides and total sugars was significantly higher in the roots of both vegetables harvested under no-tillage cultivation. The number of weeds growing on no-tilled plots covered with mustard mulch 4 weeks after seed sowing was lower by about 75%, but their fresh weight was higher more than 6 times in comparison to that under conventional cultivation. This was caused by the emergence of wintering and winter hardy weeds in places not covered by mustard plants in the autumn of the year preceding the cultivation of vegetables. Next year, they started to grow in the early spring and some of them produced a considerable amount of fresh weight and attained the flowering stage in the middle of April.

  4. Study of seasonal snow cover influencing the ground thermal regime on western flank of Da Xing'anling Mountains, northeastern China

    Institute of Scientific and Technical Information of China (English)

    XiaoLi Chang; HuiJun Jin; YanLin Zhang; HaiBin Sun

    2015-01-01

    Although many studies relevant to snow cover and permafrost have focused on alpine, arctic, and subarctic areas, there is still a lack of understanding of the influences of seasonal snow cover on the thermal regime of the soils in permafrost regions in the mid-latitudes and boreal regions, such as that on the western flank of the Da Xing'anling (Hinggan) Mountains, northeastern China. This paper gives a detailed analysis on meteorological data series from 2001 to 2010 provided by the Gen'he Weather Station, which is located in a talik of discontinuous permafrost zone and with sparse meadow on the observation field. It is inferred that snow cover is important for the ground thermal regime in the middle Da Xing'anling Mountains. Snow cover of 10-cm in thickness and five to six months in duration (generally November to next March) can reduce the heat loss from the ground to the atmosphere by 28%, and by 71% if the snow depth increases to 36 cm. Moreover, the occurrence of snow cover resulted in mean annual ground surface temperatures 4.7–8.2°C higher than the mean annual air temperatures recorded at the Gen'he Weather Station. The beginning date for stable snow cover establishment (SE date) and the initial snow depth (SDi) also had a great influences on the ground freezing process. Heavy snowfall before ground surface freeze-up could postpone and retard the freezing process in Gen'he. As a result, the duration of ground freezing was shortened by at least 20 days and the maximum depth of frost penetration was as much as 90 cm shallower.

  5. Ciclagem de nutrientes por plantas de cobertura na entressafra em um solo de cerrado Nutrient cycling in off-season cover crops on a Brazilian savanna soil

    Directory of Open Access Journals (Sweden)

    Carlo Adriano Boer

    2007-09-01

    Full Text Available O objetivo deste trabalho foi avaliar o acúmulo e a liberação de nutrientes (N, P, K, Ca, Mg e S de resíduos culturais de plantas de cobertura na entressafra, em condições de Cerrado. O experimento foi conduzido em um Latossolo Vermelho distroférrico com textura argilosa. As plantas de cobertura avaliadas foram: amaranto (Amaranthus cruentus L., milheto (Pennisetum glaucum L. e capim-pé-de-galinha (Eleusine coracana (L. Gaertn.. O delineamento experimental utilizado foi o de blocos ao acaso, no esquema de parcelas subdivididas, com quatro repetições. Na fase de florescimento das espécies, foi avaliada a produção de matéria seca e o acúmulo de nutrientes. A fim de avaliar a liberação de nutrientes dos resíduos culturais, o material vegetal de cada espécie foi acondicionado em sacolas de náilon, as quais foram dispostas sobre o solo e seu conteúdo analisado em intervalos de 30 dias, até 240 dias após sua instalação. As maiores quantidades de nutrientes acumulados na fitomassa das plantas de cobertura foram observadas no milheto e no capim-pé-de-galinha. O potássio foi o nutriente acumulado em maior quantidade, chegando a atingir 416,9 kg ha-1 no milheto. As maiores taxas de liberação de nutrientes foram observadas nos resíduos culturais do amaranto.The objective of this work was to evaluate the accumulation and the liberation of nutrients (N, P, K, Ca, Mg and S of cultural residues by three species of cover crops, in off-season. Tested cover crops were amaranthus (Amaranthus cruentus L., pearl millet (Pennisetum glaucum L. and finger millet (Eleusine coracana (L. Gaertn.. The experiment was carried out in a Typic Haplorthox clay texture soil. A randomized block desing in a split-plot array in time, with four replications, was used. At the flowering of the species, the production of dry matter and the accumulation of nutrients were evaluated. Proportional samples of dry matter of each cover crop species were placed in

  6. Unmasking the soil cover's disruption by use of a dynamic model of measurement aerospace parameters of ground vegetation

    Directory of Open Access Journals (Sweden)

    E. V. Vysotskaya

    2016-03-01

    Full Text Available The "Introduction" describes topicality and importance of revealing the soil cover's disruption for a wide range of fields. It was shown that spectral brightness and colorimetric parameters of ground vegetation can be used for this task. However, a traditional scheme of data processing for remote sensing requires a long-term observations and can not always be applied, if quick decision-making is necessary or there is lack of information. Such cases require the use of special methods, one of which is a dynamic model developed with authors' participation based on the following basic relationships: (+,- (-, - (+, 0, (-, 0 (0,0. The section "Brief description of a dynamic model" describes the basic principles of dynamic systems used to solve the problem. Using above-mentioned relationships, the dynamics of a system consisting of several components is constructed and its main properties are listed. The main feature of this model is that the identification of structure and parameters of the dynamic system does not required sequential order of observations (as for models based on time series. This feature of the model enables for identifying the system's parameters of dynamics of the natural system to use information from a single picture taken from the spacecraft rather than long-term observations. The section "Materials and Methods" describes specific colorimetric parameters used to analyze the vegetation cover. The section "Obtained results" contains an example of the model's application to a satellite image for detecting the differences in two sites of a field with vegetation. One site is a recultivated area near the liquidated gas-oil well, another site is non-recultivated area at a considerable distance from the well (500-1000 m. The simulation results are described by eight signed graphs (4 graphs for each sites, whose structure allows to identify the system differences between the two cases. The section "Conclusions" summarizes the results of

  7. A comparison of ground and satellite observations of cloud cover to saturation pressure differences during a cold air outbreak

    Energy Technology Data Exchange (ETDEWEB)

    Alliss, R.J.; Raman, S. [North Carolina State Univ., Raleigh, NC (United States)

    1996-04-01

    The role of clouds in the atmospheric general circulation and the global climate is twofold. First, clouds owe their origin to large-scale dynamical forcing, radiative cooling in the atmosphere, and turbulent transfer at the surface. In addition, they provide one of the most important mechanisms for the vertical redistribution of momentum and sensible and latent heat for the large scale, and they influence the coupling between the atmosphere and the surface as well as the radiative and dynamical-hydrological balance. In existing diagnostic cloudiness parameterization schemes, relative humidity is the most frequently used variable for estimating total cloud amount or stratiform cloud amount. However, the prediction of relative humidity in general circulation models (GCMs) is usually poor. Even for the most comprehensive GCMs, the predicted relative humidity may deviate greatly from that observed, as far as the frequency distribution of relative humidity is concerned. Recently, there has been an increased effort to improve the representation of clouds and cloud-radiation feedback in GCMs, but the verification of cloudiness parameterization schemes remains a severe problem because of the lack of observational data sets. In this study, saturation pressure differences (as opposed to relative humidity) and satellite-derived cloud heights and amounts are compared with ground determinations of cloud cover over the Gulf Stream Locale (GSL) during a cold air outbreak.

  8. Qualitative attributes and postharvest conservation of green ears of maize grown on different cover crops in organic no-till system

    Directory of Open Access Journals (Sweden)

    Luiz Fernando Favarato

    Full Text Available ABSTRACT Postharvest quality of sweet maize varies depending on the type of seed, soil, quality of fertilizer, climatic conditions, and stage of maturation. This study aimed to evaluate the post-harvest quality and shelf life of green ears of maize grown on three soil covers in organic no-till sytem. The study was conducted in the municipality of Domingos Martins, ES (20° 22'16.91" S and 41° 03' 41.83" W. The experiment was arranged in a randomized block design with six replications and five treatments, consisting of three cover crops in organic no-till system: black-oat straw, white lupin, oat/lupin intercrop and two systems, organic and conventional, without straw. Maize double hybrid AG-1051 was sown in a spacing of 1.00 x 0.20 m. The variables evaluated included relative percentage of grain, straw and cob, pH, titratable acidity, soluble solids, grain moisture and shelf life. The use of different straws in the organic no-till system does not influence the postharvest quality of green ears. Ears packed in polystyrene trays with plastic film are suitable for marketing until the fifth day of storage at room temperature.

  9. Effects of post-fire salvage logging and a skid trail treatment on ground cover, soils, and sediment production in the interior western United States

    Science.gov (United States)

    Joseph W. Wagenbrenner; Lee H. MacDonald; Robert N. Coats; Peter R. Robichaud; Robert E. Brown

    2015-01-01

    Post-fire salvage logging adds another set of environmental effects to recently burned areas, and previous studies have reported varying impacts on vegetation, soil disturbance, and sediment production with limited data on the underlying processes. Our objectives were to determine how: (1) ground-based post-fire logging affects surface cover, soil water repellency,...

  10. Utilização do nitrogênio (15N residual de coberturas de solo e da uréia pela cultura do milho Utilization of residual nitrogen (15N from cover crop and urea by corn

    Directory of Open Access Journals (Sweden)

    Edson Cabral da Silva

    2006-12-01

    study was to evaluate the use of residual nitrogen from urea, sunnhemp (Crotalaria juncea and millet (Pennisetum americanum labeled with 15N, applied to no-tillage corn in the previous growing season, in a Red Latosol of the Cerrado. The study was conducted in an experimental farm of the Sao Paulo State University (UNESP, Ilha Solteira, in Selvíria county (MS, Brazil, in different areas. The experiment had a randomized complete block design, with 15 treatments and four replications. Treatments were applied to corn crop in the 2001/02 and 2003/04 growing seasons. Theey were distributed in a 3 x 5 factorial layout, representing the combination of three cover crops: sunnhemp, millet and spontaneous vegetation (fallow and five N rates (as urea: 0, 30, 80, 130, and 180 kg ha-1 of N. After corn harvest, the two areas were fallowed in the dry season and were followed by corn crop in the 2002/03 (experiment 1 and 2003/04 (experiment 2 growing seasons, using the same fertilizer rate on all plots to distinguish the residual effect of N sources. The average use of residual N from the millet and sunnhemp residues (above-ground part by corn crop was less than 3.5 and 3 %, respectively, of the initial amount. The corn uptake of residual N from urea increased in a quadratic manner in experiment 1 and linearly in experiment Two as a response to the applied N rates, and the recover was below 3 %. The cover crop type did not affect the use of residual N of urea by corn, and vice-versa.

  11. Developing ground penetrating radar (GPR) for enhanced root and soil organic carbon imaging: Optimizing bioenergy crop adaptation and agro-ecosystem services

    Science.gov (United States)

    Hays, D. B.; Delgado, A.; Bruton, R.; Dobreva, I. D.; Teare, B.; Jessup, R.; Rajan, N.; Bishop, M. P.; Lacey, R.; Neely, H.; Hons, F.; Novo, A.

    2016-12-01

    Selection of the ideal high biomass energy feedstock and crop cultivars for our national energy and production needs should consider not only the value of the harvested above ground feedstock, but also the local and global environmental services it provides in terms of terrestrial carbon (C) phyto-sequestration and improved soil organic matter enrichment. Selection of ideal crops cultivars is mature, while biofuel feedstock is well under way. What is lacking, however, is high throughput phenotyping (HTP) and integrated real-time data analysis technologies for selecting ideal genotypes within these crops that also confer recalcitrant high biomass or perennial root systems not only for C phyto-sequestration, but also for adaptation to conservation agro-ecosystems, increasing soil organic matter and soil water holding capacity. In no-till systems, significant studies have shown that increasing soil organic carbon is derived primarily from root and not above ground biomass. As such, efforts to increase plant soil phyto-sequestration will require a focus on developing optimal root systems within cultivated crops. We propose to achieve a significant advancement in the use of ground penetrating radar (GPR) as one approach to phenotype root biomass and 3D architecture, and to quantify soil carbon sequestration. In this context, GPR can be used for genotypic selection in breeding nurseries and unadapted germplasm with favorable root architectures, and for assessing management and nutrient practices that promote root growth. GPR has been used for over a decade to successfully map coarse woody roots. Only few have evaluated its efficacy for imaging finer fibrous roots found in grasses, or tap root species. The objectives of this project is to: i) Empirically define the optimal ground penetrating radar (GPR)-antenna array for 3D root and soil organic carbon imaging and quantification in high biomass grass systems; and ii) Develop novel 3- and 4-dimensional data analysis

  12. Manejo de nitrogênio no milho sob plantio direto com diferentes plantas de cobertura, em Latossolo Vermelho Nitrogen management in corn under no-tillage with different cover crops in a Rhodic Hapludox soil

    Directory of Open Access Journals (Sweden)

    Edson Cabral da Silva

    2006-03-01

    Full Text Available O objetivo deste trabalho foi definir a melhor dose e época de aplicação, e a eficiência de utilização do N, utilizando-se uréia marcada com 15N, pelo milho cultivado sob plantio direto, em sucessão à crotalária (Crotalaria juncea, ao milheto (Pennisetum americanum e à vegetação espontânea (pousio, em um Latossolo Vermelho no Cerrado. O delineamento experimental foi o de blocos ao acaso, com 24 tratamentos e quatro repetições, em esquema fatorial incompleto, 3x3x2 + 6: três doses de N (80, 130 e 180 kg ha-1; três sistemas de cobertura do solo (crotalária, milheto e pousio; duas épocas de aplicação do N (estádio quatro ou oito folhas; e seis tratamentos adicionais (três sem aplicação de N e três que receberam 30 kg ha-1 de N na semeadura. O cultivo do milho em sucessão à crotalária proporciona maior quantidade na planta e aproveitamento pela planta do N proveniente do fertilizante e maior produtividade de grãos. A aplicação do N ao milho com quatro folhas proporciona maior produtividade de grãos, comparada à aplicação com oito folhas, quando em sucessão ao milheto.The objective of this work was to evaluate the best rate and time for N application, and N utilization using urea-15N, by corn crop grown under no-tillage system, in succession to sun hemp (Crotalaria juncea L., millet (Pennisetum americanum and to the spontaneous vegetation (fallow ground, in a Rhodic Hapludox soil in Cerrrado. The experimental design was randomized complete blocks, with 24 treatments and four replications, in an incomplete factorial 3x3x2 + 6: three N rates (80, 130 and 180 kg ha-1 N; three preceding cover crops (sun hemp, millet and fallow ground; two N application time (four leaves or eight leaves stage; and six additional treatments (three without N application and three that received 30 kg ha-1 N at seeding. The corn grown in succession to sun hemp provided higher amount of N derived from fertilizer, N utilization efficiency

  13. CHEMICAL ATTRIBUTES OF A SOIL CULTIVATED WITH DIFFERENT COVER CROPS ATRIBUTOS QUÍMICOS DE SOLO CULTIVADO COM DIFERENTES CULTURAS DE COBERTURA

    Directory of Open Access Journals (Sweden)

    Luís Fernando Stone

    2010-08-01

    Full Text Available  

    The effect of cover crops annually implanted in the summer, since 2001, under no-tillage system, on the soil chemical attributes was evaluated. The experiment was carried out in Embrapa Rice & Beans, in Santo Antônio de Goiás, GO, Brazil, in a Dystrophic Red Latosol (Red Oxisol. Brachiaria brizantha, corn (Zea mays L. associated with B. brizantha, pigeon pea, millet, Panicum maximum, sorghum, Stylosanthes guianensis, and sunn hemp were used as cover crops. Sixty days after the cut of the cover crops, common bean crop was implanted, under a central pivot sprinkler irrigation system. In November 2001, 2005, and 2006, soil samples were collected in the depths of 0-5 cm, 5-10 cm, and 10-20 cm. Immediately after the 2005 sampling, it was applied 4,000 kg ha-1 of dolomitic lime, in all the experimental area. Cover crops affected soil pH and magnesium content in the superficial layer. Soil under millet showed higher phosphorus content in subsuperficial layers, in relation to the initial values. The soil P and Cu contents were higher in the subsuperficial layers, while the other chemical attributes were higher in the superficial layer. There was movement of Ca and Mg in the soil profile, one year after the application of lime in the soil surface.

  14. Macrofauna invertebrada edáfica em cultivo de mandioca sob sistemas de cobertura do solo Edaphic invertebrate macrofauna in cassava cultivation under vegetable cover crops

    Directory of Open Access Journals (Sweden)

    Rogério Ferreira da Silva

    2007-06-01

    Full Text Available O objetivo deste trabalho foi avaliar o efeito do cultivo da mandioca em diferentes sistemas de cobertura do solo na densidade e diversidade da comunidade da macrofauna de invertebrados edáfica. O trabalho foi conduzido no Município de Glória de Dourados, MS, num Argissolo Vermelho, sob sistema convencional (SC, plantio direto sobre palhada de mucuna (PDMu, sorgo (PDSo e milheto (PDMi, além de sistema com vegetação nativa (VN, como referencial para comparação. As avaliações foram realizadas em quatro épocas distintas: abril/2003 (antes do plantio, novembro/2003 (6 meses após o plantio, abril/2004 (11 meses após o plantio e novembro/2004 (18 meses após o plantio. Houve efeito da interação entre os sistemas avaliados e as épocas de amostragens sobre a densidade, riqueza e diversidade da macrofauna invertebrada do solo. Entre os grupos da macrofauna invertebrada do solo, cupins, formigas e coleópteros (imaturo e adulto foram predominantes no ambiente estudado. O uso de plantas de cobertura no pré-cultivo de mandioca no sistema plantio direto proporcionou condições para a recomposição da comunidade de macrofauna invertebrada do solo, o que indica que as espécies utilizadas, mucuna, sorgo e milheto, representam alternativas promissoras para melhor manejo dessa cultura.The objective of this work was to evaluate the effect of cassava cultivation under different vegetable cover crops according to the density and diversity of soil invertebrate macrofauna. Field experiment was carried out at Glória de Dourados, Mato Grosso do Sul State, Brazil, on an Oxisol, under conventional drilling (SC, no-tillage system under Stizolobium cinereum (PDMu, Sorghum bicolor (PDSo and Pennisetum glaucum (PDMi mulching, with comparison of native vegetation system (VN. Evaluations were performed in April/2003 (before sowing, November/2003 (6 months after sowing, April/2004 (11 months after sowing and November/2004 (18 months after sowing. Significant

  15. An Investigation of Widespread Ozone Damage to the Soybean Crop in the Upper Midwest Determined From Ground-Based and Satellite Measurements

    Science.gov (United States)

    Fishman, Jack; Creilson, John K.; Parker, Peter A.; Ainsworth, Elizabeth A.; Vining, G. Geoffrey; Szarka, John; Booker, Fitzgerald L.; Xu, Xiaojing

    2010-01-01

    Elevated concentrations of ground-level ozone (O3) are frequently measured over farmland regions in many parts of the world. While numerous experimental studies show that O3 can significantly decrease crop productivity, independent verifications of yield losses at current ambient O3 concentrations in rural locations are sparse. In this study, soybean crop yield data during a 5-year period over the Midwest of the United States were combined with ground and satellite O3 measurements to provide evidence that yield losses on the order of 10% could be estimated through the use of a multiple linear regression model. Yield loss trends based on both conventional ground-based instrumentation and satellite-derived tropospheric O3 measurements were statistically significant and were consistent with results obtained from open-top chamber experiments and an open-air experimental facility (SoyFACE, Soybean Free Air Concentration Enrichment) in central Illinois. Our analysis suggests that such losses are a relatively new phenomenon due to the increase in background tropospheric O3 levels over recent decades. Extrapolation of these findings supports previous studies that estimate the global economic loss to the farming community of more than $10 billion annually.

  16. Epiphyte-cover on seagrass (Zostera marina L. leaves impedes plant performance and radial O2 loss from the below-ground tissue

    Directory of Open Access Journals (Sweden)

    Kasper Elgetti Brodersen

    2015-08-01

    Full Text Available The O2 budget of seagrasses is a complex interaction between several sources and sinks, which is strongly regulated by light availability and mass transfer over the diffusive boundary layer (DBL surrounding the plant. Epiphyte growth on leaves may thus strongly affect the O2 availability of the seagrass plant and its capability to aerate its rhizosphere as a defence against plant toxins.We used electrochemical and fiber-optic microsensors to quantify the O2 flux, DBL and light microclimate around leaves with and without filamentous algal epiphytes. We also quantified the below-ground radial O2 loss from roots (~1 mm from the root-apex to elucidate how this below-ground oxic microzone was affected by the presence of epiphytes.Epiphyte-cover on seagrass leaves (~21% areal cover resulted in reduced light quality and quantity for photosynthesis, thus leading to reduced plant fitness. A ~4 times thicker diffusive boundary layer around leaves with epiphyte-cover impeded gas (and nutrient exchange with the surrounding water-column and thus the amount of O2 passively diffusing into the leaves in darkness. During light exposure of the leaves, radial oxygen loss from the below-ground tissue was ~2 times higher from plants without epiphyte-cover. In contrast, no O2 was detectable at the surface of the root-cap tissue of plants with epiphyte-cover during darkness, leaving the plants more susceptible to sulphide intrusion.Epiphyte growth on seagrass leaves thus negatively affects the light climate and O2 uptake in darkness, hampering the plants performance and thereby reducing the oxidation capability of its below-ground tissue.

  17. Testing the enemies hypothesis in peach orchards in two different geographic areas in eastern China: the role of ground cover vegetation.

    Directory of Open Access Journals (Sweden)

    Nian-Feng Wan

    Full Text Available Many studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province during a continuous three-year (2010-2012 investigation, we sampled arthropod pests and predators in Trifolium repens L. and in tree canopies of peach orchards with and without the ground cover plant T. repens. No significant differences were found in the abundances of the main groups of arthropod pests and predators in T. repens between Hudai and Xinchang. The abundance, richness, Simpson's index, Shannon-Wiener index, and Pielou evenness index of canopy predators in ground cover areas increased by 85.5, 27.5, 3.5, 16.7, and 7.9% in Xinchang, and by 87.0, 27.6, 3.5, 17.0 and 8.0% in Hudai compared to those in the controls, respectively. The average abundance of Lepidoptera, Coleoptera, Homoptera, true bugs and Acarina canopy pests in ground cover areas decreased by 9.2, 10.2, 17.2, 19.5 and 14.1% in Xinchang, and decreased by 9.5, 8.2, 16.8, 20.1 and 16.6% in Hudai compared to that in control areas, respectively. Our study also found a higher density of arthropod species resources in T. repens, as some omnivorous pests and predators residing in T. repens could move between the ground cover and the orchard canopy. In conclusion, ground cover in peach orchards supported the enemies hypothesis, as indicated by the fact that ground cover T. repens promoted the abundance and diversity of predators and reduced the number of arthropod pests in tree canopies in both geographical areas.

  18. Phytoseiidae (Acari: Mesostigmata) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants.

    Science.gov (United States)

    Childers, Carl C; Denmark, Harold A

    2011-08-01

    Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the family Phytoseiidae (Acari: Mesostigmata) in central and south central Florida. Inner and outer canopy leaves, open flowers, fruit, twigs, and trunk scrapings were sampled monthly between September 1994 and January 1996. Vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards. The two remaining orchards were on full herbicide programs and ground cover plants were absent. Thirty-three species of phytoseiid mites were identified from 35,405 specimens collected within citrus tree canopies within the seven citrus orchards, and 8,779 specimens from vines and ground cover plants within five of the seven orchards. The six most abundant phytoseiid species found within citrus tree canopies were: Euseius mesembrinus (Dean) (20,948), Typhlodromalus peregrinus (Muma) (8,628), Iphiseiodes quadripilis (Banks) (2,632), Typhlodromips dentilis (De Leon) (592), Typhlodromina subtropica Muma and Denmark (519), and Galendromus helveolus (Chant) (315). The six most abundant species found on vines or ground cover plants were: T. peregrinus (6,608), E. mesembrinus (788), T. dentilis (451), I. quadripilis (203), T. subtropica (90), and Proprioseiopsis asetus (Chant) (48). The remaining phytoseiids included: Amblyseius aerialis (Muma), A. herbicolus (Chant), A. largoensis (Chant), A. multidentatus (Chant), A. sp. near multidentatus, A. obtusus (Koch), Chelaseius vicinus (Muma), Euseius hibisci Chant, Galendromus gratus (Chant), Metaseiulus mcgregori (Chant), Neoseiulus mumai (Denmark), N. vagus (Denmark), Phytoscutus sexpilis (Muma), Phytoseiulus macropilis (Banks), Proprioseiopsis detritus (Muma), P. dorsatus (Muma), P. macrosetae (Banks), P. rotundus (Muma), P. solens (De Leon), Typhlodromips deleoni (Muma), T. dillus (De Leon), T. dimidiatus (De Leon), T. mastus Denmark and Muma, T. simplicissimus (De Leon), and T. sp

  19. Testing the enemies hypothesis in peach orchards in two different geographic areas in eastern China: the role of ground cover vegetation.

    Science.gov (United States)

    Wan, Nian-Feng; Ji, Xiang-Yun; Jiang, Jie-Xian

    2014-01-01

    Many studies have supported the enemies hypothesis, which suggests that natural enemies are more efficient at controlling arthropod pests in polyculture than in monoculture agro-ecosystems. However, we do not yet have evidence as to whether this hypothesis holds true in peach orchards over several geographic locations. In the two different geographic areas in eastern China (Xinchang a town in the Shanghai municipality, and Hudai, a town in Jiangsu Province) during a continuous three-year (2010-2012) investigation, we sampled arthropod pests and predators in Trifolium repens L. and in tree canopies of peach orchards with and without the ground cover plant T. repens. No significant differences were found in the abundances of the main groups of arthropod pests and predators in T. repens between Hudai and Xinchang. The abundance, richness, Simpson's index, Shannon-Wiener index, and Pielou evenness index of canopy predators in ground cover areas increased by 85.5, 27.5, 3.5, 16.7, and 7.9% in Xinchang, and by 87.0, 27.6, 3.5, 17.0 and 8.0% in Hudai compared to those in the controls, respectively. The average abundance of Lepidoptera, Coleoptera, Homoptera, true bugs and Acarina canopy pests in ground cover areas decreased by 9.2, 10.2, 17.2, 19.5 and 14.1% in Xinchang, and decreased by 9.5, 8.2, 16.8, 20.1 and 16.6% in Hudai compared to that in control areas, respectively. Our study also found a higher density of arthropod species resources in T. repens, as some omnivorous pests and predators residing in T. repens could move between the ground cover and the orchard canopy. In conclusion, ground cover in peach orchards supported the enemies hypothesis, as indicated by the fact that ground cover T. repens promoted the abundance and diversity of predators and reduced the number of arthropod pests in tree canopies in both geographical areas.

  20. Cobertura vegetal, vermicompost y actividad microbiana del suelo en la producción de tomate Soil cover crop, vermicompost and soil microbial activity in the tomato production

    Directory of Open Access Journals (Sweden)

    Manuel Villarreal-Romero

    Full Text Available Se estudió en el cultivo de tomate, el efecto combinado de fertilización química de N, P y K con aplicación de vermicompost, cobertura vegetal del suelo con Mucuna pruriens y labranza mínima; en contraste, al sistema de labranza convencional con fertilización química y acolchado plástico del suelo; para la nutrición de las plantas, medición de algunos parámetros de calidad del fruto y la actividad microbiana del suelo de 2007 a 2008. Se establecieron cinco tratamientos para la siembra del tomate, en los dos tipos de manejo del cultivo. Los resultados mostraron rendimientos similares y calidad poscosecha (firmeza y pérdida de peso de fruto y absorción de N, P, K, Ca y Mg por las plantas de tomate, entre la labranza convencional del cultivo y el de uso de cobertura vegetal del suelo, labranza mínima y fertilización con vermicompost más 250 N-55 P-100 K. Los frutos procedentes de tratamiento T2 presentaron un comportamiento adecuado en firmeza y pérdida de peso en el estudio poscosecha y este resultado fue estadísticamente igual a los frutos del T5 durante el estudio. Las plantas de M. pruriens acumularon en su biomasa nitrógeno fijado de la atmósfera y residual del suelo en cantidad importante que estuvo disponible para el cultivo de tomate. La colonización micorrízica en las plantas de tomate y la liberación de CO2 del suelo, fueron más altas con la cobertura vegetal y vermicompost que el sistema de manejo convencional del cultivo.The combined effect of N, P and K chemical fertilizers with vermicompost was studied in tomato planting, vegetation cover of the soil with Mucuna pruriens and minimal farming; in contrast to the conventional farming system with chemical fertilizers and plastic soil padding, for plant nutrition, measurement of some fruit quality parameters and soil microbial activity from 2007 to 2008. The tomato underwent five treatments in two types of crop management. Results showed similar yields and

  1. Protection against productivity versus erosion vineyards. Testing of vegetal covers in slope crops; Proteccion contra la erosion versus productividad en venidos. Ensayos de cubiertas vegetales en cultivos en pendiente

    Energy Technology Data Exchange (ETDEWEB)

    Marques, M. J.; Ruiz-Colmenero, M.; Garcia-Munoz, S.; Cabello, F.; Munoz-Organero, G.; Perez-Jimenez, M. A.; Bienes, R.

    2009-07-01

    Temporary and permanent cover crops were used in three rain fed vineyards in the Center of Spain. They were sown in the middle of the strips to assess their ability to control erosion as well as their influence on grape production. Data from the year 2008 are compared with those obtained with traditional tillage treatment. The permanent cover formed by Brachypodium distachyon showed better ability to control erosion but it produced a decrease in production in young vines. barley and rye treatments were temporary covers, mowed in spring. They also reduced the erosion compared with the tillage however they did not appear to affect the vineyard production. (Author)

  2. STRUCTURE AND CHARACTERISTICS OF TI-AL-NI SYSTEM COVERING, APPLIED ON THE STEEL GROUND USING ELECTRON-BEAM HEATING

    Directory of Open Access Journals (Sweden)

    I. V. Murashova

    2011-01-01

    Full Text Available The morphology of the system Ti-Al-Ni covering, received by means of self-distributing high-temperature synthesis, initiated by electron-beam heating, on the basis of steel St3 is investigated.

  3. Trends of six month nighttime ground-based cloud cover values over Manila Observatory (14.64N, 121.07E)

    Science.gov (United States)

    Gacal, G. F. B.; Lagrosas, N.

    2016-12-01

    The ground reflects thermal radiation during nighttime. Clouds reflect this radiation to the ground and cause increase in ambient temperature. In this study, trends of nighttime cloud cover are analyzed using a commercial camera (Canon Powershot A2300) that is operated continuously to capture images of clouds at 5 minute interval. The camera is situated inside a rain-proof box with a glass oculus and is placed on the rooftop of the Manila Observatory building. To detect pixels with clouds, the pictures are converted from its native JPEG format to grayscale format. The pixels are then screened for clouds by looking at the values of pixels with and without clouds. In grayscale format, pixels with clouds have greater pixel values than pixels without clouds. Based on the observations, a threshold pixel value of 17 is employed to discern pixels with clouds from pixels without clouds. When moon is present in the image, the grayscale image, which is in 8-bit unsigned integer format, is converted into double format. The moon signals are modelled using a two dimensional Gaussian function and is subtracted from the converted image (Gacal et al, 2016). This effectively removes the moon signals but preserves the cloud signals. This method is applied to the data collected from the months of January, February, March, October, November and December 2015. In Manila, dry months are from November to April. Wet months are from May to October. The trends of nighttime cloud cover values over Manila Observatory are shown in the figure below. Frequency distribution of cloud cover values of the first and last three months of the year show that dry and wet months have higher and lower frequency of low cloud cover values, respectively. The trend also exhibits a decrease of cloud cover from October to December but increases back from January until March. This is exhibited in the decrease in the frequency of cloud cover values in the 20%-100% range from October to December. This can be

  4. IN-SEASON ASSESSMENT OF WHEAT CROP HEALTH USING VEGETATION INDICES BASED ON GROUND MEASURED HYPER SPECTRAL DATA

    Directory of Open Access Journals (Sweden)

    Khalid Ali Al-Gaadi

    2014-01-01

    Full Text Available An experiment on a 50 ha center pivot field was conducted to determine the Vegetation Indices (VI’s that were helpful in assessing the in-season performance of wheat crop treated with graded levels of irrigation water and fertilizers. The irrigation levels were at 100, 90, 80 and 70% evapotranspiration (ETc; however, the fertilizer levels of N: P: K kg-1ha included 300:150:200 (low; 400:250:300 (medium and 500:300:300 (High. The crop was sown on January 1st and harvested on May 9th, 2012. Temporal data on biophysical parameters and reflectance of the crop in hyper spectral bands (350-2500 nm were collected at booting and ripening growth stages (February 17th and April 5th, 2012. Results of the study revealed that many of the tested spectral indices showed significant response to irrigation levels. Out of those, only two spectral indices (Plant Senescence Reflectance Index ‘PSRI’ and Photochemical Reflectance Index ‘PRI’ also exhibited significant response to fertilizer levels. The Middle Infrared-Based Vegetation Index (MIVI showed a significant response to the irrigation levels for both sampling dates. Among the tested spectral indices, Normalized Difference Infrared Index (NDII and Normalized Difference Nitrogen Index (NDNI exhibited the highest correlation to crop Leaf Area Index (LAI. Five indices showed the most response to wheat grain yield. These indices included Near Infrared band (NIR, Water Band Index (WBI, Normalized Water Index-1 (NWI-1, Normalized Water Index-3 (NWI-3 and Normalized Water Index-4 (NWI-4.

  5. Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines, and ground cover plants.

    Science.gov (United States)

    Childers, Carl C; Ueckermann, Eduard A

    2014-10-01

    Seven citrus orchards on reduced- to no-pesticide spray programs were sampled for predacious mites in the families Eupalopsellidae and Stigmaeidae (Acari: Prostigmata) in central and south central Florida. Inner and outer canopy leaves, fruit, twigs, and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. Two species of eupalopsellid mites (Exothorhis caudata Summers and Saniosulus harteni (van-Dis and Ueckermann)) were identified from 252 specimens collected within citrus tree canopies within the seven citrus orchards of which 249 were E. caudata. Only two E. caudata were collected from ground cover plants within five of the seven orchards. Eight species of Stigmaeidae were identified from 5,637 specimens: Agistemus floridanus Gonzalez, A. terminalis Gonzalez, Eustigmaeus arcuata (Chandhri), E. sp. near arcuata, E. segnis (Koch), Mediostigmaeus citri (Rakha and McCoy), Stigmaeus seminudus Wood, and Zetzellia languida Gonzalez were collected from within citrus tree canopies from seven orchard sites. Agistemus floridanus was the only species in either family that was abundant with 5,483 collected from within citrus tree canopies compared with only 39 from vine or ground cover plants. A total of 431 samples from one or more of 82 vines and ground cover plants were sampled monthly between September 1994 and January 1996 in five of these orchards and one or more eupalopsellids or stigmaeids were collected from 19 of these plants. Richardia brasiliensis (Meg.) Gomez had nine A. floridanus from 5 of 25 samples collected from this plant. Solanum sp. had five A. floridanus from three samples taken. Both eupalopsellid and stigmaeid species numbers represented orchards were on full herbicide programs and ground cover plants were absent. Agistemus floridanus was more abundant in the citrus orchards with on-going or recent herbicide programs compared with orchards having well-developed ground

  6. Effects of surface applications of biosolids on soil, crops, ground water, and streambed sediment near Deer Trail, Colorado, 1999-2003

    Science.gov (United States)

    Yager, Tracy J.B.; Smith, David B.; Crock, James G.

    2004-01-01

    The U.S. Geological Survey, in cooperation with Metro Wastewater Reclamation District and North Kiowa Bijou Groundwater Management District, studied natural geochemical effects and the effects of biosolids applications to the Metro Wastewater Reclamation District properties near Deer Trail, Colorado, during 1999 through 2003 because of public concern about potential contamination of soil, crops, ground water, and surface water from biosolids applications. Parameters analyzed for each monitoring component included arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc (the nine trace elements regulated by Colorado for biosolids), gross alpha and gross beta radioactivity, and plutonium, as well as other parameters. Concentrations of the nine regulated trace elements in biosolids were relatively uniform and did not exceed applicable regulatory standards. All plutonium concentrations in biosolids were below the minimum detectable level and were near zero. The most soluble elements in biosolids were arsenic, molybdenum, nickel, phosphorus, and selenium. Elevated concentrations of bismuth, mercury, phosphorus, and silver would be the most likely inorganic biosolids signature to indicate that soil or streambed sediment has been affected by biosolids. Molybdenum and tungsten, and to a lesser degree antimony, cadmium, cobalt, copper, mercury, nickel, phosphorus, and selenium, would be the most likely inorganic 'biosolids signature' to indicate ground water or surface water has been affected by biosolids. Soil data indicate that biosolids have had no measurable effect on the concentration of the constituents monitored. Arsenic concentrations in soil of both Arapahoe and Elbert County monitoring sites (like soil from all parts of Colorado) exceed the Colorado soil remediation objectives and soil cleanup standards, which were determined by back-calculating a soil concentration equivalent to a one-in-a-million cumulative cancer risk. Lead concentrations

  7. Effect of Polythene-covering on Above-ground tuberization and storage roots yield in Cassava (Manihot esculenta Crantz

    Directory of Open Access Journals (Sweden)

    Abdullahi N

    2014-02-01

    Full Text Available Present study aimed to investigate the effectiveness of polythene-covering on activation of dormant auxiliary buds on the stem for lateral tuber formation and the resultant effect on total storage roots yield. Three time intervals i.e. 1 day after planting, 30 days after planting and 60 days after planting used as treatment, and uncovered stem used as control. Treatments were tested in randomized complete block design with three replications. Regardless of the variety, stem polythene-covering at day 1 after planting showed the highest effect with respect to storage roots production and yield components tested. However, the effect of stem polythene-covering at day 1 after planting in terms of dry mass partitioning to storage roots was the lowest across all the treatments (25.50 to 27.37% of the biomass compared to that of stem covering at day 60 after planting (33.10 to 37.20%. This study opens new perspectives in cassava yield improvement which hitherto has not been exploited.

  8. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    KAUST Repository

    Jadoon, Khan

    2015-09-18

    We tested an off-ground ground-penetrating radar (GPR) system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  9. Temporal Monitoring of the Soil Freeze-Thaw Cycles over a Snow-Covered Surface by Using Air-Launched Ground-Penetrating Radar

    Directory of Open Access Journals (Sweden)

    Khan Zaib Jadoon

    2015-09-01

    Full Text Available We tested an off-ground ground-penetrating radar (GPR system at a fixed location over a bare agricultural field to monitor the soil freeze-thaw cycles over a snow-covered surface. The GPR system consisted of a monostatic horn antenna combined with a vector network analyzer, providing an ultra-wideband stepped-frequency continuous-wave radar. An antenna calibration experiment was performed to filter antenna and back scattered effects from the raw GPR data. Near the GPR setup, sensors were installed in the soil to monitor the dynamics of soil temperature and dielectric permittivity at different depths. The soil permittivity was retrieved via inversion of time domain GPR data focused on the surface reflection. Significant effects of soil dynamics were observed in the time-lapse GPR, temperature and dielectric permittivity measurements. In particular, five freeze and thaw events were clearly detectable, indicating that the GPR signals respond to the contrast between the dielectric permittivity of frozen and thawed soil. The GPR-derived permittivity was in good agreement with sensor observations. Overall, the off-ground nature of the GPR system permits non-invasive time-lapse observation of the soil freeze-thaw dynamics without disturbing the structure of the snow cover. The proposed method shows promise for the real-time mapping and monitoring of the shallow frozen layer at the field scale.

  10. Growth and yield of two grain crops on sites former covered with euca-lypt plantations in Koga Watershed, northwestern Ethiopia

    Institute of Scientific and Technical Information of China (English)

    Desalegn Tadele; Demel Teketay

    2014-01-01

    Farmers in the highlands of Ethiopia often plant Eucalyptus on their farmlands. However, growing Eucalyptus, especially on farm-lands suitable for crop production has become a great concern due to its alleged long-term site effects. Our study was conducted at Koga water-shed, Mecha District, northwestern Ethiopia to investigate whether crop-lands afforested with Eucalyptus camaldulensis Dehnh. can be restored for annual crop production after tree harvest. We compared growth and yield of two agricultural crops, barley (Hordeum vulgare L.) and finger millet (Eleusine coracana (L.) Gaertn.), grown in clear-felled stands of E. camaldulensis and continuously cultivated croplands at twelve paired farmlands under a conventional farming system. Plant height and dry matter production were evaluated as indices of crop growth, while grain weight was evaluated as an index of crop yield. Crop growth and yield measurements averaged over all farmlands differed between land-use types. For both crops, plants grown on clear-felled stands were taller than on croplands. Dry matter production and yield were also significantly greater in crops cultivated on clear-felled stands. Cropland aboveground and belowground dry matter productions were lower by 31.8 and 25.4%for barley and 32.8%and 37%for finger millet, respectively. Clear-felled stands gave an average yield of 2.91 t⋅ha-1 for barley and 3.27 t⋅ha-1 for finger millet while cropland gave a yield of 1.97 and 2.31 t⋅ha-1 for barley and finger millet, respectively. Farmers also responded that farm plots on former eucalypt plantations showed greater crop growth and yield than did continuously cultivated croplands. Farmers perceived that Eucalyptus plantations improved soil fertility and they preferred clear-felled stands for crop production and wished to plant Eucalyptus on their farmlands. Our results suggest that conversion of agricultural lands to Eucalyptus plantations can increase post-felling yields of cereal crops.

  11. Cover crops growth under water deficitCrescimento de plantas de cobertura sob déficit hídrico

    Directory of Open Access Journals (Sweden)

    Edison Ulisses Ramos Junior

    2013-03-01

    Full Text Available One of the challenges to be overcome in no till deploying in tropical regions is the production of straw in the offseason, a period commonly with low water availability. To help in the choice of species to be used as cover crop in dry winter regions, the aim of this work was to evaluate the effect of soil water potential on growth of black oat (Avena strigosa Sckreb, pearl millet (Pennisetum glaucum (L. R. Brown, grain sorghum (Sorghum bicolor L. Moench. e guinea sorghum (Sorghum bicolor subespécie bicolor raça guinea. Pearl millet is a good option to be cropped during offseason by show high yield potencial, even been more sensitive to water deficit. Grain sorghum and guinea sorghum are also good options, particularly by showed abundant root system, which possibly gives them a certain tolerance to low water availability conditions. The black oat, even with high tolerance to water stress (tolerance conferred by highest percentage of fine roots, seems to be much affected by higher temperatures, common to these regions. Um dos desafios a serem vencidos na implantação do sistema de semeadura direta em regiões tropicais é a produção de palhada na entressafra, período comumente com baixa disponibilidade hídrica. Visando auxiliar a escolha das espéciesa serem empregadas como planta de cobertura em regiões de inverno seco, objetivou-se com este trabalho avaliar o efeito de potenciais de água no solo no crescimento de aveia preta (Avena strigosa Sckreb, milheto (Pennisetum glaucum (L. R. Brown, sorgogranífero (Sorghum bicolor L. Moench. esorgo-de-guiné(Sorghum bicolor subespécie bicolor raça guinea, bem como detectar possíveis estratégias destas espécies para contornarem condições de baixa disponibilidade hídrica. O milheto, mesmo sendo mais sensível ao déficit hídrico, é uma boa opção a ser cultivado na entressafra pelo seu elevado potencial produtivo. O sorgo granífero e o sorgo-de-guiné também são boas opções, em

  12. Atributos químicos e estabilidade de agregados sob diferentes culturas de cobertura em Latossolo do cerrado Chemical properties and aggregate stability under different cover crops in cerrado Oxisol

    Directory of Open Access Journals (Sweden)

    Glenio G. Santos

    2012-11-01

    Full Text Available Objetivou-se, com este trabalho, avaliar o efeito de diferentes culturas de cobertura sobre os atributos químicos e a estabilidade de agregados de um Latossolo do cerrado, sob plantio direto. O estudo foi conduzido em área experimental na Embrapa Arroz e Feijão, em Santo Antônio de Goiás, GO. As culturas de cobertura avaliadas foram: braquiária, milho em consórcio com braquiária (integração lavoura-pecuária, guandu anão, milheto, capim mombaça, sorgo granífero, estilosantes e crotalária. As amostras foram coletadas em abril de 2005 e 2006. O delineamento experimental foi o de blocos completos ao acaso com quatro repetições e os tratamentos arranjados em esquema fatorial 8 x 2, sendo oito culturas de cobertura e duas profundidades de amostragem do solo: 0-0,10 e 0,10-0,20 m. As culturas de cobertura influenciam, de forma diferenciada, os valores de pH e os teores de cálcio, magnésio, alumínio, fósforo, potássio, cobre, zinco e ferro do solo. O tratamento estilosantes tem maior poder em acidificar o solo. A agregação do solo varia com as culturas de cobertura e com a profundidade.The objective of this study was to evaluate the effect of different cover crops on chemical properties and aggregate stability in a cerrado Oxisol under no-tillage. The study was carried out in Embrapa Rice and Beans, in Santo Antônio de Goiás, GO, Brazil. The cover crops evaluated were: Urochloa brizantha, Urochloa brizantha and corn in association (crop-livestock integrated, Cajanus cajan, Pennisetum glaucum, Panicum maximum, Sorghum bicolor, Stylosanthes guianensis and Crotalaria juncea. The soil samples were collected in April and September 2005 and April 2006. The experimental design was in completely randomized blocks with four replications and treatments arranged in factorial scheme 8 x 2, eight cover crops and two soil sampling depths, 0-0.10 and 0.10-0.20 m. The different cover crops affect pH values and calcium, magnesium, aluminum

  13. The Crop Journal Calls for Papers

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    We would like to invite you to submit your latest research accomplishments to The Crop Journal,an international,peer‐reviewed research publication covering all aspects of crop sciences including crop genetics,breeding,agronomy,crop physiology,germplasm resources,grain chemistry,grain storage and processing,crop management practices,crop biotechnology,and biomathematics on a bimonthly basis.

  14. The Crop Journal Calls for Papers

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    We would like to invite you to submit your latest research accomplishments to The Crop Journal,an international,peer-reviewed research publication covering all aspects of crop sciences including crop genetics,breeding,agronomy,crop physiology,germplasm resources,grain chemistry,grain storage and processing,crop management practices,crop biotechnology,and biomathematics on a bimonthly basis.

  15. The Crop Journal Calls for Papers

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    We would like to invite you to submit your latest research accomplishments to The Crop Journal,an international,peer‐reviewed research publication covering all aspects of crop sciences including crop genetics,breeding,agronomy,crop physiology,germplasm resources,grain chemistry,grain storage and processing,crop management practices,crop biotechnology,and biomathematics on a bimonthly basis.

  16. Desempenho operacional de semeadura-adubadora em diferentes manejos da cobertura e da velocidade Operational performance of seeder in different forward speed and winter cover crop management

    Directory of Open Access Journals (Sweden)

    Carlos E. A. Furlani

    2007-08-01

    Full Text Available O presente trabalho teve como objetivo avaliar o desempenho de uma semeadora-adubadora no sistema plantio direto. Os fatores estudados foram três manejos das culturas de cobertura, selecionados em função do tamanho de fragmentos da vegetação, triturador de palhas (palha totalmente triturada, roçadora (palha parcialmente picada e rolo-facas (palha acamada, combinados com três velocidades do conjunto trator-semeadora-adubadora, sendo 4,0; 5,0 e 6,0 km h-1. O delineamento experimental foi em blocos casualizados, em esquema fatorial 3 x 3, com nove tratamentos e oito repetições, totalizando 72 observações. Para comparar os tratamentos, avaliaram-se a capacidade de campo operacional, a força de tração e a potência na barra, o consumo horário e por área, e a patinagem dos rodados do trator. O desempenho da semeadora-adubadora não foi influenciado pelos três manejos na cultura de cobertura vegetal. O aumento da velocidade provocou diminuição da força de tração, sendo o inverso para a capacidade de campo operacional e a potência na barra. O consumo horário de combustível aumentou com a velocidade, enquanto o operacional diminuiu.The present work aimed to evaluate the seeder performance in the direct sowing system. The studied factors were three cover crop managements, chosen according to the size of the vegetation fragment, such as straw (straw totally triturated, weeder (straw partially chopped and knife-rolls (straw practically entire, combined with three speeds of the seeder, being 4.0; 5.0 and 6.0 km h-1. The experimental outlining was carried out in casual blocks in factorial scheme 3 x 3, with nine treatments and eight repetitions, totalizing 72 observations. In the course of the experiment the following variants were evaluated: effective field capacity, force and power in the bar, hourly and area consumption of fuel and tractor’s pulleys sliding. The data reached were tabulated and submitted to factorial variant

  17. Soil bulk electrical resistivity and forage ground cover: nonlinear models in an alfalfa (Medicago sativa L. case study

    Directory of Open Access Journals (Sweden)

    Roberta Rossi

    2015-12-01

    Full Text Available Alfalfa is a highly productive and fertility-building forage crop; its performance, can be highly variable as influenced by within-field soil spatial variability. Characterising the relations between soil and forage- variation is important for optimal management. The aim of this work was to model the relationship between soil electrical resistivity (ER and plant productivity in an alfalfa (Medicago sativa L. field in Southern Italy. ER mapping was accomplished by a multi-depth automatic resistivity profiler. Plant productivity was assessed through normalised difference vegetation index (NDVI at 2 dates. A non-linear relationship between NDVI and deep soil ER was modelled within the framework of generalised additive models. The best model explained 70% of the total variability. Soil profiles at six locations selected along a gradient of ER showed differences related to texture (ranging from clay to sandy-clay loam, gravel content (0 to 55% and to the presence of a petrocalcic horizon. Our results prove that multi-depth ER can be used to localise permanent soil features that drive plant productivity.

  18. Biotechnology: herbicide-resistant crops

    Science.gov (United States)

    Transgenic, herbicide-resistant (HR) crops are planted on about 80% of the land covered by transgenic crops. More than 90% of HR crios are glyphosate-resistant (GR) crops, the others being resistant to glufosinate. The wide-scale adoption of HR crops, largely for economic reasons, has been the mos...

  19. The effect of cover crop and crop rotation on soil water storage and on sorghum yield Efeito de cultura de cobertura e de rotação de cultura no armazenamento de água do solo e no rendimento de sorgo

    Directory of Open Access Journals (Sweden)

    Demóstenes Marcos Pedrosa de Azevedo

    1999-03-01

    Full Text Available Crop rotation and cover crop can be important means for enhancing crop yield in rainfed areas such as the lower Coastal Bend Region of Texas, USA. A trial was conducted in 1995 as part of a long-term cropping experiment (7 years to investigate the effect of oat (Avena sativa L. cover and rotation on soil water storage and yield of sorghum (Sorghum bicolor L.. The trial design was a RCB in a split-plot arrangement with four replicates. Rotation sequences were the main plots and oat cover crop the subplots. Cover crop reduced sorghum grain yield. This effect was attributed to a reduced concentration of available soil N and less soil water storage under this treatment. By delaying cover termination, the residue with a high C/N acted as an N sink through competition and/or immobilization instead of an N source to sorghum plants. Crop rotation had a significantly positive effect on sorghum yield and this effect was attributed to a significantly larger amount of N concentration under these rotation sequences.Rotação de cultura e cultura de cobertura constituem importantes meios para melhoria do rendimento de culturas em áreas de sequeiro como a região "Coastal Bend" do Estado do Texas. Um ensaio foi conduzido em 1995, como parte de um experimento de longa duração (7 anos, com o objetivo de investigar o efeito da aveia (Avena sativa L. como cultura de cobertura, e da rotação de cultura, no armazenamento da água do solo e no rendimento do sorgo (Sorghum bicolor L.. O delineamento experimental adotado foi o de blocos ao acaso, em parcelas subdivididas, com quatro repetições. As rotações foram alocadas nas parcelas, e a cultura de cobertura, nas subparcelas. A cultura de cobertura reduziu o rendimento do sorgo. Este efeito foi atribuído à reduzida concentração de N disponível do solo. Por atraso no extermínio e incorporação da aveia, seu resíduo, com elevada relação C/N, atuou como dreno, pela imobilização, em lugar de ser fonte

  20. Using Moderate-Resolution Temporal NDVI Profiles for High-Resolution Crop Mapping in Years of Absent Ground Reference Data: A Case Study of Bole and Manas Counties in Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Pengyu Hao

    2016-05-01

    Full Text Available Most methods used for crop classification rely on the ground-reference data of the same year, which leads to considerable financial and labor cost. In this study, we presented a method that can avoid the requirements of a large number of ground-reference data in the classification year. Firstly, we extracted the Normalized Difference Vegetation Index (NDVI time series profiles of the dominant crops from MODIS data using the historical ground-reference data in multiple years (2006, 2007, 2009 and 2010. Artificial Antibody Network (ABNet was then employed to build reference NDVI time series for each crop based on the historical NDVI profiles. Afterwards, images of Landsat and HJ were combined to obtain 30 m image time series with 15-day acquisition frequency in 2011. Next, the reference NDVI time series were transformed to Landsat/HJ NDVI time series using their linear model. Finally, the transformed reference NDVI profiles were used to identify the crop types in 2011 at 30 m spatial resolution. The result showed that the dominant crops could be identified with overall accuracy of 87.13% and 83.48% in Bole and Manas, respectively. In addition, the reference NDVI profiles generated from multiple years could achieve better classification accuracy than that from single year (such as only 2007. This is mainly because the reference knowledge from multiple years contains more growing conditions of the same crop. Generally, this approach showed potential to identify crops without using large number of ground-reference data at 30 m resolution.

  1. Study of growth and development features of ten ground cover plants in Kish Island green space in warm season

    Directory of Open Access Journals (Sweden)

    S. Shooshtarian

    2016-05-01

    Full Text Available Having special ecological condition, Kish Island has a restricted range of native species of ornamental plants. Expansion of urban green space in this Island is great of importance due to its outstanding touristy position in the South of Iran. The purpose of this study was to investigate the growth and development of groundcover plants planted in four different regions of Kish Island and to recommend the most suitable and adaptable species for each region. Ten groundcover species included Festuca ovina L., Glaucium flavum Crantz., Frankenia thymifolia Desf., Sedum spurium Bieb., Sedum acre L., .Potentilla verna L., Carpobrotus acinaciformis (L. L. Bolus., Achillea millefolium L., Alternanthera dentata Moench. and Lampranthus spectabilis Haw. Evaluation of growth and development had been made by measurement of morphological characteristics such as height, covering area, leaf number and area, dry and fresh total weights and visual scoring. Physiological traits included proline and chlorophyll contents evaluated. This study was designed in factorial layout based on completely randomized blocks design with six replicates. Results showed that in terms of indices such as covering area, visual quality, height, total weight, and chlorophyll content, Pavioon and Sadaf plants had the most and the worst performances, respectively in comparison to other regions’ plants. Based on evaluated characteristics, C. acinaciformis, L. spectabilis and F. thymifolia had the most expansion and growth in all quadruplet regions and are recommend for planting in Kish Island and similar climates.

  2. Estimation of Carbon Budgets for Croplands by Combining High Resolution Remote Sensing Data with a Crop Model and Validation Ground Data

    Science.gov (United States)

    Mangiarotti, S.; Veloso, A.; Ceschia, E.; Tallec, T.; Dejoux, J. F.

    2015-12-01

    Croplands occupy large areas of Earth's land surface playing a key role in the terrestrial carbon cycle. Hence, it is essential to quantify and analyze the carbon fluxes from those agro-ecosystems, since they contribute to climate change and are impacted by the environmental conditions. In this study we propose a regional modeling approach that combines high spatial and temporal resolutions (HSTR) optical remote sensing data with a crop model and a large set of in-situ measurements for model calibration and validation. The study area is located in southwest France and the model that we evaluate, called SAFY-CO2, is a semi-empirical one based on the Monteith's light-use efficiency theory and adapted for simulating the components of the net ecosystem CO2 fluxes (NEE) and of the annual net ecosystem carbon budgets (NECB) at a daily time step. The approach is based on the assimilation of satellite-derived green area index (GAI) maps for calibrating a number of the SAFY-CO2 parameters linked to crop phenology. HSTR data from the Formosat-2 and SPOT satellites were used to produce the GAI maps. The experimental data set includes eddy covariance measurements of net CO2 fluxes from two experimental sites and partitioned into gross primary production (GPP) and ecosystem respiration (Reco). It also includes measurements of GAI, biomass and yield between 2005 and 2011, focusing on the winter wheat crop. The results showed that the SAFY-CO2 model correctly reproduced the biomass production, its dynamic and the yield (relative errors about 24%) in contrasted climatic, environmental and management conditions. The net CO2 flux components estimated with the model were overall in agreement with the ground data, presenting good correlations (R² about 0.93 for GPP, 0.77 for Reco and 0.86 for NEE). The evaluation of the modelled NECB for the different site-years highlighted the importance of having accurate estimates of each component of the NECB. Future works aim at considering

  3. Investigating Hydrogeologic Controls on Sandhill Wetlands in Covered Karst with 2D Resistivity and Ground Penetrating Radar

    Science.gov (United States)

    Downs, C. M.; Nowicki, R. S.; Rains, M. C.; Kruse, S.

    2015-12-01

    In west-central Florida, wetland and lake distribution is strongly controlled by karst landforms. Sandhill wetlands and lakes are sand-filled upland basins whose water levels are groundwater driven. Lake dimensions only reach wetland edges during extreme precipitation events. Current wetland classification schemes are inappropriate for identifying sandhill wetlands due to their unique hydrologic regime and ecologic expression. As a result, it is difficult to determine whether or not a wetland is impacted by groundwater pumping, development, and climate change. A better understanding of subsurface structures and how they control the hydrologic regime is necessary for development of an identification and monitoring protocol. Long-term studies record vegetation diversity and distribution, shallow ground water levels and surface water levels. The overall goals are to determine the hydrologic controls (groundwater, seepage, surface water inputs). Most recently a series of geophysical surveys was conducted at select sites in Hernando and Pasco County, Florida. Electrical resistivity and ground penetrating radar were employed to image sand-filled basins and the top of the limestone bedrock and stratigraphy of wetland slopes, respectively. The deepest extent of these sand-filled basins is generally reflected in topography as shallow depressions. Resistivity along inundated wetlands suggests the pools are surface expressions of the surficial aquifer. However, possible breaches in confining clay layers beneath topographic highs between depressions are seen in resistivity profiles as conductive anomalies and in GPR as interruptions in otherwise continuous horizons. These data occur at sites where unconfined and confined water levels are in agreement, suggesting communication between shallow and deep groundwater. Wetland plants are observed outside the historic wetland boundary at many sites, GPR profiles show near-surface layers dipping towards the wetlands at a shallower

  4. Land Use and Land Cover, Existing land use derived from orthoimagery. Ground-truthing from discussion with local plan commission members., Published in 2000, 1:12000 (1in=1000ft) scale, Portage County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Land Use and Land Cover dataset current as of 2000. Existing land use derived from orthoimagery. Ground-truthing from discussion with local plan commission members..

  5. [Pediatric cases in preclinical emergency medicine: critical aspects in the range of missions covered by ground ambulance and air rescue services].

    Science.gov (United States)

    Schlechtriemen, T; Masson, R; Burghofer, K; Lackner, C K; Altemeyer, K H

    2006-03-01

    The aim of this study was to demonstrate differences in structure and severity of pediatric emergencies treated by aeromedical (air rescue) or ground ambulances services. Conclusions for the training of emergency physicians are discussed. In a 3-year study period, a total of 9,274 pediatric emergencies covered by the ADAC air rescue service are compared to 4,344 pediatric patients of ground ambulance services in Saarland. In aeromedical services pediatric emergencies are more frequent (12.9% vs. 6.4%), trauma predominates (59.9% vs. 35.6%) and severe injuries or diseases occur more frequently (30.5% vs. 15.0%). In both groups pediatric emergency cases are concentrated into very few diagnostic groups: more than one third of the cases involving pre-school children is due to convulsions. Respiratory diseases and intoxication are the next most frequent causes and are more common in ground ambulance patients. Head trauma is the most common diagnosis in cases of pediatric trauma, followed by musculoskeletal and thoracoabdominal trauma. All types of severe trauma are more frequent in pediatric patients of the aeromedical services. Training of emergency physicians should include pediatric life support and specific information about frequent pediatric emergency situations. For emergency physicians in aeromedical services, an intensive training in pediatric trauma life support is also necessary.

  6. Sistema radicular de plantas de cobertura sob compactação do solo Root system of cover crops under soil compaction

    Directory of Open Access Journals (Sweden)

    Wainer G. Gonçalves

    2006-04-01

    Full Text Available Com o objetivo de avaliar a capacidade de crescimento de raízes em camadas de solo compactadas, quatro espécies de plantas de cobertura (amaranto, milheto ADR 500, capim pé-de-galinha e kenaf foram cultivadas em anéis de PVC, com níveis de compactação em subsuperfície (densidade do solo: 1,18; 1,34; 1,51 e 1,60 Mg m-3, sendo o experimento conduzido em casa de vegetação, utilizando-se de um Latossolo Vermelho distroférrico. A camada compactada em subsuperfície foi restritiva ao crescimento de raízes das espécies estudadas, ocasionando a concentração de raízes na camada superficial. O milheto ADR 500 e o amaranto foram as espécies que se destacaram na produção de massa seca da parte aérea e conseguiram desenvolver-se nas camadas compactadas e abaixo delas. O milheto ADR500 apresentou maior densidade de comprimento radicular em todas as camadas. O capim pé-de-galinha e o amaranto tiveram comportamento semelhante quanto à densidade de comprimento radicular. O capim pé-de-galinha e o kenaf apresentaram menor massa seca de raízes em relação às demais espécies. O kenaf apresentou menores valores de massa seca da parte aérea, mas não foi afetado pela presença de camadas compactadas.With the objective of evaluate the root growth capacity in the compacted soil layer, four vegetal species of the cover crops (amaranth, pearl millet ADR500, finger millet and kenaf were cultivated in columns of PVC with increasing levels of subsurface compaction (soil bulk densities: 1.18; 1.34; 1.51 and 1.60 Mg m-3. The experiment was carried out in a greenhouse conditions, using a Dusky Red Latosol. The subsurface compacted layer was restrictive to the roots growth of the studied species, causing the root concentrating to the surface. Pearl millet ADR500 and the amaranth were the species that had detached in the production of dry matter weight and developed itself in the compacted layers and below of them. Pearl of millet ADR500 presented the

  7. Efeito de coberturas de inverno e sua época de manejo sobre a infestação de plantas daninhas na cultura de milho Effect of winter cover crops and their management timing on weed infestation in maize crop

    Directory of Open Access Journals (Sweden)

    A.A. Balbinot Jr.

    2007-09-01

    Full Text Available No sistema de plantio direto, a presença de palha sobre o solo proporciona significativa supressão de plantas daninhas. O objetivo deste trabalho foi avaliar o potencial de coberturas de inverno e sua época de manejo em reduzir a infestação de plantas daninhas na cultura de milho quando semeada em sucessão. Dois experimentos foram realizados em Canoinhas, SC, nas safras 2003/04 e 2004/05. No primeiro experimento, avaliaram-se seis coberturas de solo no inverno: nabo forrageiro, aveia-preta, centeio, azevém, consórcio entre aveia-preta e ervilhaca e o consórcio entre nabo forrageiro, aveia-preta, centeio, azevém e ervilhaca. Essas coberturas foram roçadas em três épocas antes da semeadura do milho: 1, 10 e 25 dias. Já no segundo experimento, foram avaliados os efeitos de supressão de plantas daninhas pela palha das seis coberturas citadas anteriormente, mais a ervilhaca. As palhas de azevém e do consórcio das cinco espécies utilizadas no experimento apresentaram alta capacidade em suprimir a emergência e o acúmulo de massa seca das plantas daninhas, enquanto a palha de nabo forrageiro apresentou baixo potencial de supressão. O manejo das coberturas próximo à semeadura da cultura de milho reduziu a infestação de plantas daninhas.Straw on the soil significantly reduces weed infestation under the no-tillage system. The aim of this research was to evaluate the potential of winter cover crops and their management timing in reducing weed infestation in maize crop. Two experiments were carried out in Canoinhas, SC, Brazil, in 2003/2004 and 2004/2005. In the first experiment, six winter cover crops were investigated: oilseed radish, black oat, rye, rye grass, intercropped among black oat and common vetch and among oilseed radish, black oat, rye, ryegrass and common vetch. These cover crops were slashed down at three different times before maize seeding (1, 10 and 25 days. In the second experiment, the potential to reduce weed

  8. High residue cover crops alone or with strategic tillage to manage glyphosate-resistant palmer amaranth (amaranthus palmeri) in Southeastern cotton (gossypium hirsutum)

    Science.gov (United States)

    Glyphosate-resistant (GR) Palmer amaranth (Amaranthus palmeri S. Wats) is redefining row crop weed management in the Southeast due to its widespread distribution, high competitive ability, copious seed production, and resilience to standard weed management programs. Herbicides alone are failing to p...

  9. Effects of cover crops on mite communities in tea plantations%间作牧草对茶园螨类群落多样性的影响

    Institute of Scientific and Technical Information of China (English)

    陈李林; 林胜; 尤民生; 陈少波; Liette Vasseur; 叶树纯

    2011-01-01

    diversity index (eHi), number of individuals (N), and absolute abundance (n) of predatory mites than in control tea plantations with natural vegetation. Plantations intercropped with P notatum or C. rotundifolia displayed a significantly higher number of individuals (N) ofAnystis baccarum,a common predatory species, for both canopy and litter samples versus the tea plantation with natural groundcover and on bare ground. Species richness, number of individuals, and diversity indices of both phytophagous and saprophagous mite communities collected from tea canopies and of saprophagous mite communities in litter were not different among the various intercropping treatments. Seasonal dynamics in mite species richness (S) and number of individuals (N) were apparent for all treatments. Czekanowski similarity indices suggested that these communities were highly similar to each other. For the tea plantation intercropped with P notatum or C. rotundifolia, or with natural ground cover, the total number of mites in tea canopies was positively associated with the total number of mites in the liner. We suggest that diversifying tea agroecosystems by using intercrops can bolster predatory mite densities, thus providing a viable strategy for pest management and promoting the environmentally benign production of tea products.

  10. Efeito do intervalo de dessecação antecedendo a semeadura do milho e do uso de diferentes espécies de plantas de cobertura Timing of desiccation of distinct cover crops before corn sowing

    Directory of Open Access Journals (Sweden)

    Juliano Corulli Corrêa

    2008-04-01

    Full Text Available O intervalo entre a dessecação e a semeadura da cultura de interesse comercial pode favorecer o crescimento e desenvolvimento dessas plantas e, conseqüentemente, aumentar sua produtividade. O objetivo deste trabalho foi avaliar os efeitos de diferentes intervalos de dessecação e uso de diferentes tipos de plantas de cobertura na fertilidade do solo, no teor nutricional e no crescimento inicial da cultura do milho. O experimento foi realizado em condições controladas de casa de vegetação, sendo constituído dos seguintes tratamentos: quatro intervalos de dessecação antecedendo a cultura comercial, que corresponderam a 21, 14, 7 e 0 dias, em interação com três espécies de cobertura vegetal; Crotalaria juncea (crotalária; Pennisetum americanum (milheto e Brachiaria brizantha cv. marandu (braquiária. O maior intervalo entre a dessecação e a semeadura do milho aumentou o teor de MO, P e K no solo; o teor desses dois nutrientes no solo depende da planta de cobertura em questão. O milho apresentou maior absorção de N, P e K, em razão do maior intervalo de dessecação das plantas de cobertura. O crescimento do milho foi favorecido em razão dos maiores intervalos de dessecação das espécies de cobertura, devendo ser respeitado o intervalo superior a 14 dias para maior disponibilidade de nutrientes às plantas.The timing of desiccation of the cover crop before crop sowing can favor the development of the plants and, consequently, increase yields. The purpose of this study was to evaluate the effects of intervals after desiccation of distinct cover crops and corn sowing on soil fertility, nutritional content and the initial development of corn. The experiment was carried out under controlled conditions in a greenhouse, and consisted of the following treatments: four desiccation periods preceding the corn crop (21, 14, 7 and 0 days, combined with three cover crop species; Crotalaria juncea (Indian hemp, Pennisetum americanum

  11. Land cover detection with SAR images of Delta del Llobregat

    Science.gov (United States)

    Godinho, R.; Borges, P. A. V.; Calado, H.; Broquetas, A.

    2016-08-01

    This work presents a study of a multitemporal set of C-band images collected by ERS-2, aiming to understand the differentiations of the backscatter intensity and the phase coherence of different land covers to find possible synergies that could improve land cover detection. The land cover analysis allowed to observe the perfect differentiation of urban areas from intensity images. The observation of multitemporal RGB compositions combining key dates of the different points of crops growth make possible to differentiate this land cover and also to observe fluctuations inside the class itself. This fluctuations present a pattern that correspond to the crop field structure, which suggests that more information can be obtained. The shrubs are difficult to detect from the intensity images, but once the observation is combined with coherence images the detection is possible. However, the coherence image must be generated from pairs of images with a temporal interval lower than three months, independently from the year of registration of each image due to the general decrease of coherence when larger intervals are used. The analysis allowed to observe the potential of this data to perfect distinguish urban, crops and shrubs. The study of the seasonal fluctuations of intensity for the crops land cover with precise ground truth for crops type and points of growth is proposed as a future line of research.

  12. Effects of legume cover crop and sub-soiling on soil properties and Maize (Zea mays L) growth in semi arid area of Machakos district, Kenya = Efecto del cultivo de cobertua y el subsolado sobre las propiedades del suelo y crecimiento de maiz (Zea mays L.) en la region semi arida de Machakos, Kenia

    NARCIS (Netherlands)

    Karuma, A.; Gachene, C.K.K.; Gicheru, P.; Mwangombe, A.W.; Mwangi, H.W.; Clavel, D.; Verhagen, A.; Kaufmann, Von R.; Francis, J.; Ekaya, W.

    2011-01-01

    Low crop yields in the semi arid areas of Kenya have been attributed to, among other factors, low soil fertility, low farm inputs, labour constraints and inappropriate tillage practices that lead to pulverized soils. The aim of this study was to determine the effects of legume cover crops (LCC) on s

  13. Effects of legume cover crop and sub-soiling on soil properties and Maize (Zea mays L) growth in semi arid area of Machakos district, Kenya = Efecto del cultivo de cobertua y el subsolado sobre las propiedades del suelo y crecimiento de maiz (Zea mays L.) en la region semi arida de Machakos, Kenia

    NARCIS (Netherlands)

    Karuma, A.; Gachene, C.K.K.; Gicheru, P.; Mwangombe, A.W.; Mwangi, H.W.; Clavel, D.; Verhagen, A.; Kaufmann, Von R.; Francis, J.; Ekaya, W.

    2011-01-01

    Low crop yields in the semi arid areas of Kenya have been attributed to, among other factors, low soil fertility, low farm inputs, labour constraints and inappropriate tillage practices that lead to pulverized soils. The aim of this study was to determine the effects of legume cover crops (LCC) on s

  14. Effects of spatially variable snow cover on thermal regime and hydrology of an Arctic ice wedge polygon landscape identified using ground penetrating radar and LIDAR datasets

    Science.gov (United States)

    Gusmeroli, A.; Liljedahl, A. K.; Peterson, J. E.; Hubbard, S. S.; Hinzman, L. D.

    2012-12-01

    Ice wedge polygons are common in Arctic terrains underlain by permafrost. Permafrost degradation could transform low- into high centered polygons, causing profound changes in the hydrologic regime of Arctic lands, which in turn, could affect the energy balance and subsurface biodegradation of organic carbon responsible for greenhouse gas production. Understanding the linkages between microtopography, snow cover, thermal properties, and thaw depth is critical for developing a predictive understanding of terrestrial ecosystems and their feedbacks to climate. In this study, we use high frequency (500-1000 MHz) ground penetrating radar (GPR) data acquired in spring 2012 within the Next Generation Ecosystem Experiment (NGEE) study site in Barrow, AK to characterize the spatial variability of snow distribution. We compare it's distribution to microtopography, estimated using LIDAR data, and thaw depth, also estimated using ground penetrating radar collected at different times during the year and simulated over time using mechanistic thermal-hydrologic modeling. The high spatial resolution offered by LIDAR and ground penetrating radar permit detailed investigations of the control of microtopography on snow and thaw layer depth. Results suggest that microtopographical variations are responsible for substantial differences in snow accumulation. In low centered polygons, snow depth can be up to four times greater in the troughs than on the rims. Both modeling and observations suggest that the microtopography-governed snow thickness affects the thermal properties of the subsurface and thus the thaw layer thickness; regions with thicker snowpack generally correspond to regions of greater thaw depth. We conclude that a transition from low- to high centered polygons will not only impact watershed runoff but, since snow accumulation is sensitive to the microtopography, it will also impact snow distribution. In turn, snow distribution affects thaw depth thickness, and the

  15. Suitability of peanut residue as a nitrogen source for a rye cover crop Resíduos da cultura de amendoim como fonte de nitrogênio para uma cultura de cobertura de centeio

    Directory of Open Access Journals (Sweden)

    Kipling Shane Balkcom

    2007-01-01

    Full Text Available Leguminous winter cover crops have been utilized in conservation systems to partially meet nitrogen (N requirements of succeeding summer cash crops, but the potential of summer legumes to reduce N requirements of a winter annual grass, used as a cover crop, has not been extensively examined. This study assessed the N contribution of peanut (Arachis hypogaea L. residues to a subsequent rye (Secale cereale L. cover crop grown in a conservation system on a Dothan sandy loam (fine-loamy, kaolinitic, thermic Plinthic Kandiudults at Headland, AL USA during the 2003-2005 growing seasons. Treatments were arranged in a split plot design, with main plots of peanut residue retained or removed from the soil surface, and subplots as N application rates (0, 34, 67 and 101 kg ha-1 applied in the fall. Peanut residue had minimal to no effect on rye biomass yields, N content, carbon (C /N ratio, or N, P, K, Ca and Zn uptake. Additional N increased rye biomass yield, and N, P, K, Ca, and Zn uptakes. Peanut residue does not contribute significant amounts of N to a rye cover crop grown as part of a conservation system, but retaining peanut residue on the soil surface could protect the soil from erosion early in the fall and winter before a rye cover crop grows sufficiently to protect the typically degraded southeastern USA soils.Culturas leguminosas de inverno tem sido utilizadas em sistemas conservacionistas para suprimento parcial das necessidades de nitrogênio (N de culturas subseqüentes de verão, mas o potencial destas culturas leguminosas de verão no sentido de reduzir as necessidades de N de gramíneas anuais de inverno, utilizadas como culturas de cobertura, ainda não foi extensivamente estudado. Este trabalho avaliou a contribuição dos resíduos de uma cultura de amendoim (Arachis hypogaea L. sobre as necessidades de N de uma cultura subsequente de centeio (Secale cereale L. como cobertura desenvolvida dentro de um sistema conservacionista, em um

  16. Fitomassa e decomposição de resíduos de plantas de cobertura puras e consorciadas Biomass and decomposition of cover crop residues in monoculture and intercropping

    Directory of Open Access Journals (Sweden)

    Alexandre Doneda

    2012-12-01

    Full Text Available O cultivo de plantas de cobertura, no outono/inverno, na região do Planalto do Rio Grande Sul contribui para o sucesso do sistema plantio direto. No entanto, informações relativas à produção de fitomassa e decomposição de resíduos dessas espécies ainda são escassas para a região, sobretudo para espécies consorciadas. O experimento foi conduzido em Não-Me-Toque, RS, em um Latossolo Vermelho distrófico típico, avaliando-se nove tratamentos, sendo quatro constituídos por plantas de cobertura em culturas puras [centeio (Secale cereale L., aveia-preta (Avena strigosa Schreb, ervilha forrageira (Pisum sativum subesp. arvense e nabo forrageiro (Raphanus sativus L. var. oleiferus Metzg] e cinco por consórcios [(centeio + ervilha forrageira, centeio + nabo forrageiro, aveia + nabo forrageiro, centeio + ervilhaca (Vicia sativa L. e aveia + ervilhaca]. A dinâmica de decomposição dos resíduos culturais das plantas de cobertura foi avaliada em bolsas de decomposição, as quais foram distribuídas na superfície do solo e coletadas aos sete, 14, 21, 28, 57, 117 e 164 dias. O consórcio entre leguminosas e crucífera com gramíneas resultou em maior produção de fitomassa em relação ao cultivo destas em culturas puras. O nitrogênio (N acumulado na parte aérea dos consórcios formados por ervilha forrageira e nabo com centeio e aveia foi semelhante ao da leguminosa e da crucífera em culturas puras e superou em 220,4 % os valores de N observados para as gramíneas em culturas puras. Por meio do consórcio entre as espécies de cobertura foi possível reduzir a taxa de decomposição dos resíduos culturais, em comparação com as culturas puras da leguminosa e da crucífera.The use of cover crops in autumn/winter, in the Planalto region of Rio Grande do Sul, contributes to the success of the no-tillage system. However, information about the biomass production and decomposition of such species in the region is still scarce, especially

  17. Produtividade e composição de uva e de vinho de videiras consorciadas com plantas de cobertura Productivity and composition of grapes and wine of vines intercropped with cover crops

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    Jovani Zalamena

    2013-02-01

    Full Text Available O objetivo deste trabalho foi avaliar a influência de plantas de cobertura verde sobre a produtividade das videiras e sobre a composição da uva e do vinho. Durante duas safras, foram feitas avaliações de três tipos de consórcio, dois manejos das coberturas e de um tratamento controle, com plantas espontâneas controladas por herbicidas e roçagem. Utilizou-se vinhedo de uvas 'Cabernet Sauvignon', localizado a 1.130 m de altitude, em um Cambissolo Húmico distrófico, em São Joaquim, SC. Os consórcios foram realizados com a sucessão de cultivos anuais de moha (Setaria italica com azevém (Lolium multiflorum e de trigo mourisco (Fagopyrum esculentum com aveia‑branca (Avena sativa, bem como com a planta perene festuca (Fetusca sp.. Os manejos consistiram da transferência ou não do resíduo cultural da linha para a entrelinha. As videiras apresentaram maior produtividade de uva no consórcio com as plantas anuais, em comparação ao tratamento controle, ou com a planta perene festuca. O manejo da cobertura verde não teve influência sobre as variáveis avaliadas. Os consórcios não influenciaram de forma consistente os teores de N da uva nem a composição do mosto, embora, na última safra, o teor de sólidos solúveis totais do mosto tenha sido maior nos tratamentos com consórcio, em comparação ao controle. Além disso, as videiras consorciadas com festuca podem proporcionar vinho com maior teor de antocianinas e polifenóis totais.The objective of this work was to evaluate the influence of green cover crops on vine productivity and on grape and wine composition. For two growing seasons, evaluations were done for three intercrops, two managements of the cover crops, and for a control treatment with weeds controlled by herbicides and mowing. A vineyard of 'Cabernet Sauvignon', located at 1,130 m altitude in a Haplumbrept soil, in São Joaquim, SC, Brazil was used. Intercropping was done with a succession of the cover crops moha

  18. Adubação nitrogenada para milho com o uso de plantas de cobertura e modos de aplicação de calcário Forms of lime application, cover crops and nitrogen rates in maize

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    Aguinaldo José Freitas Leal

    2013-04-01

    Full Text Available O sistema plantio direto (SPD é uma realidade na região dos Cerrados, mas alguns questionamentos persistem nesse tipo de manejo como o modo de realização da calagem e a dose de nitrogênio (N a ser adotada em cultura comercial, em relação às culturas precedentes. Desse modo, objetivou-se avaliar modos de aplicar o calcário na implantação do SPD e o efeito de culturas de cobertura precedentes sobre a necessidade de adubação nitrogenada da cultura do milho, durante diferentes anos agrícolas. O delineamento experimental utilizado foi de blocos casualizados, em esquema fatorial 5 x 2 (modos de aplicação do calcário x culturas de cobertura e posterior divisão em três subparcelas, referentes às doses de N (0, 90 e 180 kg ha-1. Foram avaliados quatro modos de aplicação de calcário: incorporado a 0-0,2 m, em out./2001; dose total em superfície aplicada, em out./2001; aplicação de 1/2 da dose, em out./2001, e 1/2, em ago./2002, na superfície; e aplicação de 1/3 da dose recomendada, em mar./2001, + 1/3, em out./2001, e 1/3, em ago./2002, também em superfície. Além de um tratamento testemunha (sem calcário e duas culturas de cobertura, crotalária e milheto. Os diferentes modos de calagem não alteraram a produtividade de grãos de milho. O cultivo de milho após crotalária apresentou melhor desempenho e menor demanda de adubação nitrogenada, quando comparado ao cultivado após milheto.The no-tillage (NT management is widely used in the Cerrado region, but some questions remain unanswered, for example about the need of liming and adequate nitrogen rates for commercial crops when preceded by cover crops. Our objective was to evaluate the effect of precedent cover crops on the maize demand for nitrogen fertilization and forms of liming preceding the adoption of no-tillage management (NT in different growing seasons. The experiment was arranged in a randomized block factorial design 5 x 2 (liming forms x cover crops and

  19. Ground measurements of the hemispherical-directional reflectance of Arctic snow covered tundra for the validation of satellite remote sensing products

    Science.gov (United States)

    Ball, C. P.; Marks, A. A.; Green, P.; Mac Arthur, A.; Fox, N.; King, M. D.

    2013-12-01

    Surface albedo is the hemispherical and wavelength integrated reflectance over the visible, near infrared and shortwave infrared regions of the solar spectrum. The albedo of Arctic snow can be in excess of 0.8 and it is a critical component in the global radiation budget because it determines the proportion of solar radiation absorbed, and reflected, over a large part of the Earth's surface. We present here our first results of the angularly resolved surface reflectance of Arctic snow at high solar zenith angles (~80°) suitable for the validation of satellite remote sensing products. The hemispherical directional reflectance factor (HDRF) of Arctic snow covered tundra was measured using the GonioRAdiometric Spectrometer System (GRASS) during a three-week field campaign in Ny-Ålesund, Svalbard, in March/April 2013. The measurements provide one of few existing HDRF datasets at high solar zenith angles for wind-blown Arctic snow covered tundra (conditions typical of the Arctic region), and the first ground-based measure of HDRF at Ny-Ålesund. The HDRF was recorded under clear sky conditions with 10° intervals in view zenith, and 30° intervals in view azimuth, for several typical sites over a wavelength range of 400-1500 nm at 1 nm resolution. Satellite sensors such as MODIS, AVHRR and VIIRS offer a method to monitor the surface albedo with high spatial and temporal resolution. However, snow reflectance is anisotropic and is dependent on view and illumination angle and the wavelength of the incident light. Spaceborne sensors subtend a discrete angle to the target surface and measure radiance over a limited number of narrow spectral bands. Therefore, the derivation of the surface albedo requires accurate knowledge of the surfaces bidirectional reflectance as a function of wavelength. The ultimate accuracy to which satellite sensors are able to measure snow surface properties such as albedo is dependant on the accuracy of the BRDF model, which can only be assessed

  20. 冬季覆盖作物对双季稻光合特性的影响%Effects of Different Winter Cover Plants on Photosynthetic Characteristics of Double-cropping Rice

    Institute of Scientific and Technical Information of China (English)

    唐海明; 肖小平; 汤文光; 杨光立; 汤海涛

    2011-01-01

    The effects of four different winter cover plants, ryegrass, Chinese milk vetch, rape and potato, on photosynthetic characteristics of double-cropping rice in southern China were studied in experimental field from 2008 to 2009. The results showed that compared with the CK (fallow in winter), the treatments of ryegrass, Chinese milk vetch and potato increased obviously the LAI, chlorophyll content and net photosynthetic rate in leaves of the double-cropping rice during the whole growth stages, raised the grain yield and increased total bio-energy and the solar energy utilization ratio of stem, leaf and grain of double-cropping rice.%以冬闲为对照,研究了黑麦草、紫云英、油菜和马铃薯4种冬季覆盖作物对双季稻的光合特性的影响.结果表明:黑麦草、紫云英和马铃薯3种冬季覆盖作物处理能明显提高双季稻各个生长发育时期叶片的叶面积指数、叶绿素含量和净光合速率,增加稻谷产量,提高生物能及植株茎叶光能利用率、籽粒光能利用率和总光能利用率.

  1. Temperatura do solo em função do preparo do solo e do manejo da cobertura de inverno Soil temperature as affected by soil tillage and management of winter cover crops

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    Carlos Eduardo Angeli Furlani

    2008-02-01

    Full Text Available Com o objetivo de avaliar o efeito do preparo do solo e do manejo da cobertura de inverno (consórcio aveia-preta + nabo forrageiro sobre a temperatura do solo, realizou-se um experimento em um Nitossolo em Botucatu-SP no outono/inverno de 2000. Utilizou-se um delineamento em blocos casualizados em esquema fatorial 3 x 3 (três preparos e três manejos. O preparo do solo constou de: preparo convencional, preparo conservacionista com escarificação e plantio direto, e o manejo da cobertura: consórcio dessecado, rolado e triturado. Foram avaliados a temperatura do solo (termopares a 5 cm de profundidade, de hora em hora, aos 7, 14, 30, 45 e 60 dias após a emergência das plantas do consórcio; o teor de água do solo na profundidade de 10 cm, nas mesmas épocas; e a cobertura do solo (massa seca e índice de cobertura, imediatamente após aplicação dos tratamentos. O sistema plantio direto apresentou temperaturas do solo menores que as do preparo convencional, até o 14º dia após emergência (DAE das plantas. A partir do 30° DAE das plantas, a temperatura não foi mais influenciada pelos tratamentos, devido à cobertura do consórcio e ocorrência de boa disponibilidade de água no solo. Os manejos da cobertura com rolo-faca, triturador e herbicida não influenciaram a temperatura do solo. A temperatura do solo não interferiu no crescimento e desenvolvimento das culturas de cobertura.To evaluate the effect of soil tillage and management of winter cover crops (black oat + radish intercrop on the soil temperature, an experiment was conducted in a Nitossol (Alfisol in Botucatu, state of São Paulo, Brazil, in the 2000 fall/winter season. A design in randomized blocks was used in a 3 x 3 factorial scheme (three tillage and three cover crop managements. Soil tillage consisted of: conventional tillage, conservation tillage with chiseling, and no-tillage. The cover crops managements included plant killing with post-emergence herbicide, rolling

  2. Atributos biológicos do solo sob influência da cobertura vegetal e do sistema de manejo Soil biological attributes influenced by cover crops and management systems

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    Mozaniel Batista da Silva

    2007-12-01

    Full Text Available O objetivo deste trabalho foi avaliar os efeitos de culturas de cobertura e dos sistemas plantio direto (PD e convencional (PC sobre indicadores biológicos do solo, cultivado com feijoeiro-comum, no inverno, sob irrigação. O experimento foi conduzido em Santo Antônio de Goiás, GO, em Latossolo Vermelho distrófico textura argilosa. Culturas de cobertura foram implantadas anualmente no verão, desde 2001, sendo utilizadas a braquiária, guandu, milheto, capim-mombaça, sorgo, estilosantes, braquiária consorciada com milho, e mata nativa, como tratamento referência. Em 2005, 60 dias após o corte das culturas de cobertura foi implantada a cultura do feijoeiro, cultivar BRS Valente, sob irrigação, com semeadura realizada em 16/6/2005 e colheita efetuada em 19/9/2005. Coletaram-se amostras de solo, na profundidade de 0-10 cm, em três épocas: novembro de 2004 (pré-plantio das culturas de coberturas, junho (pré-plantio do feijoeiro e julho (florescimento do feijoeiro de 2005. Avaliaram-se a respiração basal, o carbono e o nitrogênio da biomassa microbiana, a razão carbono da biomassa microbiana/carbono orgânico, a razão nitrogênio da biomassa microbiana/nitrogênio total e o quociente metabólico do solo. Esses atributos biológicos do solo são influenciados pelas culturas de cobertura, manejo do solo e épocas de amostragem.The objective of this work was to evaluate the effects of cover crops and direct and conventional tillage systems on soil biological attributes when cultivated with dry bean in winter under sprinkle irrigation. The experiment was conducted in Santo Antônio de Goiás, GO, Brazil, in a clayey Rhodic Haplustox. Cover crops were cultivated annually in the summer since 2001, using Brachiaria brizantha, Cajanus cajan, Pennisetum glaucum, Panicum maximum, sorghum, Stylosanthes guianensis, brachiaria in association with corn, and native vegetation as reference. In 2005, 60 days after cutting the cover crops, BRS

  3. Upland rice yield as affected by previous summer crop rotation (soybean or upland rice and glyphosate management on cover crops Produtividade do arroz de terras altas afetada pela rotação de cultura e pelo manejo de glifosato nas plantas de cobertura do solo

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    A.S Nascente

    2013-03-01

    Full Text Available The appropriate chemical management of cover crops in no-tillage aims to obtain greater benefits with its employment in agricultural systems. The objective of this study was to assess upland rice yield as affected by the previous summer crop, species and desiccation timing of cover crops by glyphosate. Sown cover crops were sown (November 2007, followed by rice in half of the experimental area and soybean in the other half (November 2008. After the harvesting of these crops, the same cover crops were sown again (March 2009 and followed by upland rice in the total area (November 2009. The experiment consisted of the combination of five cover crops (fallow, Panicum maximum, Brachiaria ruziziensis, B. brizantha and Pennisetum glaucum, four desiccation timings (30, 20, 10 and 0 days before rice sowing, and two antecedents of the summer crop (rice or soybean under no-tillage system (NTS, plus two control treatments at conventional tillage system (CTS. Cover crops significantly affect rice grain yield and its components. There is a significant tendency to highest yield when cover crop desiccation is conducted farther from the rice sowing date (from 2,577.1 kg ha-1 - desiccation at rice sowing to 3,115.30 kg ha-1 - desiccation 30 days before rice sowing. Soybean as an antecedent of summer crop allows better upland rice yield (3,754 kg ha-1 than rice as an antecedent of summer crop (2,635 kg ha-1; fallow/soybean/fallow (4,507 kg ha-1 and millet/soybean/millet (4,765 kg ha-1 rotation at no-tillage system, and incorporated fallow /soybean/ incorporated fallow (4,427 kg ha-1 at conventional tillage system allow the highest rice yield; upland rice yield is similar at no-till (3,194 kg ha-1 and till system (2,878 kg ha-1.O correto manejo químico das plantas de cobertura visa obter maiores benefícios com a sua introdução nos sistemas agrícolas. O objetivo deste estudo foi avaliar como a produção do arroz de terras altas é afetada pela safra de ver

  4. Soil erosion and runoff response in almond orchards under two shrub cover-crops strips in a high slope in semi-arid environment

    Energy Technology Data Exchange (ETDEWEB)

    Carceles-Rodriguez, B.; Francia-Martinez, J. R.; Martinez-Raya, A.; Duran-Zuazo, V. H.; Rodriguez-Pleguezuelo, C. R.; Casado-Mateos, J. P.

    2009-07-01

    Soil erosion is one of the main physical processes of land degradation in Spain. Several studies in the Mediterranean environment have demonstrated the positive effect of vegetation covers on the reduction of water erosion and their indirect improvement of the soil physical and chemical properties, essentially by the incorporation of organic matter. (Author)

  5. EFEITO DA COBERTURA VEGETAL DO SOLO SOBRE A ABUNDÂNCIA E DIVERSIDADE DE INIMIGOS NATURAIS DE PRAGAS EM VINHEDOS EFFECTS OF COVER CROPS ON THE ABUNDANCE AND DIVERSITY OF NATURAL ENEMIES OF GRAPEVINE PEST

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    MARCOS ANTÔNIO MATIELLO FADINI

    2001-12-01

    Full Text Available O controle de pragas da videira no Brasil restringe-se basicamente ao uso de inseticidas, devido à inexistência de trabalhos que visem a complementar o manejo de pragas através de controle biológico. Neste trabalho, objetivou-se verificar o efeito de diferentes coberturas vegetais nas entrelinhas de plantio de videira sobre a abundância e diversidade de potenciais inimigos naturais de pragas da videira no município de Caldas, região Sul do Estado de Minas Gerais. Foram testadas sete diferentes coberturas de solo (aveia-preta, aveia-preta e ervilhaca, ervilhaca, cobertura morta, uso de herbicida, capina mecânica e mato roçado. A cobertura vegetal do solo influenciou tanto a diversidade quanto a abundância de inimigos naturais, sendo o consórcio de aveia-preta e ervilhaca, cultivadas simultaneamente, o tratamento que proporcionou maior diversidade e abundância de inimigos naturais. Assim, a cobertura vegetal do solo pode, potencialmente, ser um componente importante em programas de manejo integrado de pragas na cultura da videira.The control of grapevine pests in Brazil is only based in the use of chemical products. It is due to the whole absence of experimental works developed to test and evaluate alternative control systems, like the biological control. The objective of this work was to evaluate the effect of different types of cover crops, placed between the cultivation lines of grapevine, in the abundance and diversity of natural control arthropods of grapevine pests. The experiment was conduced in the EPAMIG, Caldas Research Farm, located in the Minas Gerais State, Brazil. They Were tested seven different systems of soil covering. The presence of vegetal covering was beneficial to improve the diversity as well as the abundance of biological control agents present on the grapevine crop. The cultivation of black oat and pea together, was the treatment that showed the better result to diversity and abundance. Therefore, the cover

  6. Phytosociological aspects and weed management using cover crops on organic conilon coffee plantations / Aspectos fitossociológicos e manejo de plantas espontâneas utilizando espécies de cobertura em cafeeiro Conilon orgânico

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    José Antonio Azevedo Espindola

    2010-09-01

    Full Text Available Weeds can bring benefits to agriculture, but when incorrectly managed they can compete with commercial crops for resources. The objective of this work was to evaluate the effect that cover crops, associated with Coffea canephora cv. Conilon, imposes to the weed community. Cover crops were planted between the rows of a 6.5 years old organic coffee plantation spaced 2.0 x 1.5 m. The experiment was arranged in a complete randomized block design, with four replications, in a factorial scheme with the following treatments: control, Pennisetum glaucum and the legume plants: Canavalia ensiformis, Mucuna deeringiana and Cajanus cajan, with and without Rizobium inoculation. Cover crops dry weight and nutrient contents on coffee trees were determined. Weeds density, frequency, relative abundance, importance value index and plant similarity index were also determined. Twenty seven weed species were identified, with special emphasis on Bidens subalternans and Commelina benghalensis. Cover crops promote modifications on the succession dynamics of weeds and do not interfere with the development of the coffee trees. Canavalia ensiformis, Mucuna deeringiana and Pennisetum glaucum help on weed control.As plantas espontâneas competem com as culturas por recursos escassos, quando mal manejadas. No entanto, podem trazer benefícios à agricultura. O objetivo desse trabalho foi avaliar o efeito que plantas de cobertura, consorciadas com Coffea canephora cv. Conilon, impõem à comunidade de plantas espontâneas. Plantas de cobertura foram semeadas nas entrelinhas de um cafezal de 6,5 anos conduzido sob manejo orgânico, com espaçamento de 2,0 x 1,5 m. O delineamento experimental foi de blocos ao acaso, com quatro repetições, num arranjo fatorial com tratamentos adicionais: testemunha, milheto – Pennisetum glaucum, e as leguminosas feijão-de-porco – Canavalia ensiformis, mucuna-anã – Mucuna deeringiana, e feijão-guandu – Cajanus cajan, com e sem

  7. Expression profile analysis of genes involved in horizontal gravitropism bending growth in the creeping shoots of ground-cover chrysanthemum by suppression subtractive hybridization.

    Science.gov (United States)

    Xia, Shengjun; Chen, Yu; Jiang, Jiafu; Chen, Sumei; Guan, Zhiyong; Fang, Weimin; Chen, Fadi

    2013-01-01

    The molecular mechanisms underlying gravitropic bending of shoots are poorly understood and how genes related with this growing progress is still unclear. To identify genes related to asymmetric growth in the creeping shoots of chrysanthemum, suppression subtractive hybridization was used to visualize differential gene expression in the upper and lower halves of creeping shoots of ground-cover chrysanthemum under gravistimulation. Sequencing of 43 selected clones produced 41 unigenes (40 singletons and 1 unigenes), which were classifiable into 9 functional categories. A notable frequency of genes involve in cell wall biosynthesis up-regulated during gravistimulation in the upper side or lower side were found, such as beta tubulin (TUB), subtilisin-like protease (SBT), Glutathione S-transferase (GST), and expensing-like protein (EXP), lipid transfer proteins (LTPs), glycine-rich protein (GRP) and membrane proteins. Our findings also highlighted the function of some metal transporter during asymmetric growth, including the boron transporter (BT) and ZIP transporter (ZT), which were thought primarily for maintaining the integrity of cell walls and played important roles in cellulose biosynthesis. CmTUB (beta tubulin) was cloned, and the expression profile and phylogeny was examined, because the cytoskeleton of plant cells involved in the plant gravitropic bending growth is well known.

  8. Manejo da cobertura de ambientes protegidos: radiação solar e seus efeitos na produção da gérbera Greenhouse cover management: solar radiation effects on production and quality of a gerbera crop

    Directory of Open Access Journals (Sweden)

    Cristiane Guiselini

    2010-01-01

    Full Text Available Este trabalho propôs avaliar a influência das malhas de sombreamento (termorrefletora instaladas externa e internamente em ambiente protegido coberto com polietileno de baixa densidade (PEBD, cultivado com gérbera, na radiação solar global (Qg e nos parâmetros da planta: crescimento, desenvolvimento e qualidade da gérbera. O experimento foi conduzido em dois ciclos no ano de 2004, na ESALQ/USP, em Piracicaba, SP, em ambiente protegido, dividido em dois módulos de produção. Os ambientes foram diferenciados um do outro pela instalação da malha termorrefletora (50%: malha externa (ambiente 1 - A1 e malha interna (ambiente 2 - A2. Nesses ambientes, os resultados dos dois ciclos mostraram alteração na Qg; nos ambientes A1 e A2 as Qg foram respectivamente 33,6 e 21,7 (1º ciclo e 27,2 e 17,9% (2º ciclo em relação à observada externamente. Considerando-se os dois ciclos conclui-se que os resultados indicaram que não houve diferenças na qualidade das plantas nos dois ambientes, mas, analisando-se separadamente os dois ciclos da cultura, o A1 (malha externa foi o que mais favoreceu a qualidade das plantas de gérbera e somente as gérberas presentes no A1 (malha externa atenderam às exigências mercadológicas, quanto aos números de botões florais.The objective of this study was to evaluate the influence of low density polyethylene (PEBD as a greenhouse cover in association with thermal shading screen installed in two different positions (outside and inside, cultivated with gerbera, on solar radiation (Qg, as well as on the growth and quality of gerbera plants. The experiment was carried out during two crop cycles in 2004, at ESALQ/USP, in Piracicaba, State of São Paulo, Brasil. A greenhouse was sub-divided into two parts and covered with PEBD differing from each other by the position of the thermal shading screen (50%, witch was installed inside (at 3 m height and outside (covering the plastic cover. The environment with the

  9. De novo assembly of the pennycress (Thlaspi arvense) transcriptome provides tools for the development of a winter cover crop and biodiesel feedstock.

    Science.gov (United States)

    Dorn, Kevin M; Fankhauser, Johnathon D; Wyse, Donald L; Marks, M David

    2013-09-01

    Field pennycress (Thlaspi arvense L.) has potential as an oilseed crop that may be grown during fall (autumn) and winter months in the Midwestern United States and harvested in the early spring as a biodiesel feedstock. There has been little agronomic improvement in pennycress through traditional breeding. Recent advances in genomic technologies allow for the development of genomic tools to enable rapid improvements to be made through genomic assisted breeding. Here we report an annotated transcriptome assembly for pennycress. RNA was isolated from representative plant tissues, and 203 million unique Illumina RNA-seq reads were produced and used in the transcriptome assembly. The draft transcriptome assembly consists of 33 873 contigs with a mean length of 1242 bp. A global comparison of homology between the pennycress and Arabidopsis transcriptomes, along with four other Brassicaceae species, revealed a high level of global sequence conservation within the family. The final assembly was functionally annotated, allowing for the identification of putative genes controlling important agronomic traits such as flowering and glucosinolate metabolism. Identification of these genes leads to testable hypotheses concerning their conserved function and to rational strategies to improve agronomic properties in pennycress. Future work to characterize isoform variation between diverse pennycress lines and develop a draft genome sequence for pennycress will further direct trait improvement.

  10. SUSTENTABILIDADE DE SISTEMAS ORGÂNICOS COM PLANTAS DE COBERTURA NA CULTURA DO ARROZ, POR MEIO DE ALTERAÇÕES FÍSICAS DO SOLO ORGANIC SYSTEMS SUSTAINABILITY USING COVER CROPS IN RICE CULTIVATION THROUGH SOIL PHYSICAL ATTRIBUTES CHANGES

    Directory of Open Access Journals (Sweden)

    Roberta Paula de Jesus

    2010-05-01

    ísica intermediária. A porcentagem de agregados com diâmetro maior que 2 mm e o diâmetro médio ponderado dos agregados foram maiores, independentemente de cobertura de solo, na camada 0,10-0,20 m de profundidade. Também, independentemente da cobertura de solo, o conteúdo de matéria orgânica decresceu com a profundidade do solo.

    PALAVRAS-CHAVE: Plantas de cobertura; preparo do solo; porosidade; estabilidade de agregados.

    To evaluate the influence of cover crops on Oxisol physical attributes, in an organic production system with conventional tillage, a study was conducted at Embrapa Arroz e Feijão, Santo Antônio de Goiás, Goiás State, Brazil, for two years, in a succession cover crops-rice, in which cover crops were sown in the autumn/winter and the subsequent crop, rice cultivar Aimoré, was sown in the summer. Five cover crops were used: Velvet bean (Mucuna aterrima, Sunn hemp (Crotalaria juncea, Pigeon pea (Cajanus cajan, Broom sorghum (Sorghum technicum, and spontaneous vegetation fallowing. A randomized blocks design with four replications was used. In the second year of

  11. Diversity and stability of arthropod community in peach orchard under effects of ground cover vegetation%桃园生草对桃树节肢动物群落多样性与稳定性的影响

    Institute of Scientific and Technical Information of China (English)

    蒋杰贤; 万年峰; 季香云; 淡家贵

    2011-01-01

    A comparative study was conducted on the arthropod community in peach orchards with and without ground cover vegetation. In the orchard with ground cover vegetation, the individuals of beneficial, neutral, and phytophagous arthropods were 1. 48, 1. 84 and 0. 64 times of those in the orchard without ground cover vegetation, respectively, but the total number of arthropods had no significant difference with that in the orchard without ground cover vegetation. The species richness, Shannon' s diversity, and Pielou' s evenness index of the arthropods in the orchard with ground cov-er vegetation were 83. 733±4. 932, 4. 966±0. 110, and 0. 795±0. 014, respectively, being signifi-cantly higher than those in the orchard without ground cover vegetation, whereas the Berger-Parker' s dominance index was 0. 135±0. 012, being significantly lower than that (0. 184±0. 018) in the orchard without ground cover vegetation. There were no significant differences in the stability indices S/N and Sd/Sp between the two orchards, but the Nn/Np, Nd/Np, and Sn/Sp in the orchard with ground cover vegetation were 0. 883±0. 123. 1714±0. 683, and 0. 781 ±0. 040, respectively, being significantly higher than those in the orchard without ground cover vegetation. Pearson' s cor-relation analysis indicated that in the orchard with ground cover vegetation, the Shannon' s diversity index was significantly negatively correlated with Nd/Np, Sd/Sp, and S/N but had no significant correlations with Nn/Np and Sn/Sp, whereas in the orchard without ground cover vegetation, the di-versity index was significantly positively correlated with Nn/Np and Nd/Np and had no significant correlations with Sd/Sp ,Sn/Sp, and S/N.%对种植白三叶草的桃园(生草桃园)和非生草桃园的桃树节肢动物群落进行分析比较.结果表明:生草桃园桃树天敌、中性类群和植食类群数量分别是非生草桃园的1.48、1.84和0.64倍,而节肢动物群落个体总数无显著差异;与非

  12. The Crop Journal Call for Papers

    Institute of Scientific and Technical Information of China (English)

    2016-01-01

    We would like to invite you to submit your latest research accomplishments to The Crop Journal,an international,peer-reviewed research publication covering all aspects of crop sciences including crop genetics,breeding,agronomy,crop physiology,germplasm resources,grain chemistry,grain storage and processing,crop management practices,crop biotechnology,and biomathematics on a bimonthly basis.Article types considered include Original Research,Reviews,and Short Communications.The readership of

  13. COVER CROPS EFFECTS ON THE DEVELOPMENT OF UPLAND RICE UNDER ORGANIC FARMING SYSTEM PLANTAS DE COBERTURA DE SOLO E SEUS EFEITOS NO DESENVOLVIMENTO DA CULTURA DO ARROZ DE TERRAS ALTAS EM CULTIVO ORGÂNICO

    Directory of Open Access Journals (Sweden)

    Roberta Paula de Jesus

    2007-12-01

    Full Text Available

    This research was conducted in an experimental area in Santo Antônio de Goiás (16º28'S, 49º17'W and altitude 823 m, Brazil, during the months of June, 2004, and March, 2005. The upland rice variety Aimoré was used along with several cover crops aiming to evaluate leaf area, number of tillers, dry matter, and nitrogen content in the phytomass during the rice crop cycle. The experimental design was the randomized blocks one, with five treatments and four replications. The treatments consisted of different cover crops, such as velvet bean (Mucuna aterrima, sunn hemp (Crotalaria juncea, dwarf pigeon pea (Cajanus cajan, broom sorghum (Sorghun bicolor, and a check treatment with spontaneous vegetation growing among the rice plants. The leguminous plants, specially C. juncea, presented better results in tillering production, leaf area index, dry matter yield, and accumulated nitrogen content, if compared to the treatments where grasses were used as soil cover crop. It was concluded that rice presented a satisfactory development in the different soil cover treatments, specially after leguminous cultivation.

    KEY-WORDS: Rice, green manure, leaf area index, dry matter.

    O experimento foi conduzido numa área experimental em Santo Antônio de Goiás (16º28'S, 49º17'W e altitude de 823 m, no período de junho de 2004 a março de 2005. Utilizou-se a cultivar Aimoré de arroz de terras altas, em seqüência a diferentes plantas de cobertura de solo, com o objetivo de avaliar o índice de área foliar (IAF, número de afilhos, acúmulo de massa de matéria seca (MMS e o teor de nitrogênio acumulado na fitomassa durante o ciclo da cultura do arroz. O delineamento experimental foi o de blocos ao acaso, com cinco

  14. Soybean production and carpogenic germination of Sclerotinia sclerotiorum under different cover cropsProdução de soja e germinação carpogênica de Sclerotinia sclerotiorum sob diferentes coberturas de solo

    Directory of Open Access Journals (Sweden)

    Luciano Reis Venturoso

    2013-05-01

    Full Text Available The aim of this work was to evaluate the influence of different soil cover crops on the carpogenic germination of Sclerotinia sclerotiorum and the development and yield of soybean. The treatments consisted of mulches of brachiaria, canola, safflower, crambe, sunflower and forage radish mulch, and a control with no cover mulch. The crops were sown in pots containing 4.4 dm³ of soil type Rhodic Acrustox. After 45 days the plant material was cut into pieces in order to standardize the amount of straw to 2800 kg ha-1. Soybean seeds were sown and seven days after seedling emergence two sclerotia were allocated in each pot. With regard to carpogenic germination, we analyzed the time to germination of sclerotia and formation of apothecia, number of stipes and apothecia per sclerotia and the percentage apothecia formed. In the soybean crop was determined plant height at flowering and harvest, relative chlorophyll index, dry matter mass and root, number of pods per plant, number of seeds per pod, grain yield, number of nodules per plant and dry mass of nodules. With the exception of safflower mulch, the use of cover crops reduced the formation of stipes and apothecia of S. sclerotiorum. The covers with brachiaria, sunflower and forage radish mulch increased by 16, 10 and 6 days respectively the overall period of apothecium formation, but only brachiaria reduced the percentage of apothecia formed. The sunflower mulch hindered soybean development and yield. O trabalho teve por objetivo avaliar a influência de diferentes coberturas vegetais de solo sobre a germinação carpogênica de Sclerotinia sclerotiorum e sobre o desenvolvimento e rendimento da cultura da soja. Os tratamentos constaram da palhada de braquiária, canola, cártamo, crambe, girassol e nabo forrageiro, mais um controle sem cobertura. As culturas de cobertura foram semeadas em vasos contendo 4,4 dm³ de solo do tipo Latossolo Vermelho Distroférrico. Após 45 dias o material vegetal foi

  15. Monitoring of a debris-covered and avalanche-fed glacier in the Eastern Italian Alps using ground-based SfM-MVS

    Science.gov (United States)

    Piermattei, Livia; Carturan, Luca; Cazorzi, Federico; Colucci, Renato R.; Dalla Fontana, Giancarlo; Forte, Emanuele

    2015-04-01

    The Montasio Occidentale glacier is a 0.07 km2 wide, avalanche-fed glacier located at very low-altitude (1860-2050 m a.s.l.) in the Eastern Italian Alps. The glacier is still active and shows a detectable mass transfer from the accumulation area to the lower ablation area, which is covered by a thick debris mantle. Geometric changes and mass balance have been monitored starting in 2010, combining glaciological methods and high-resolution geodetic surveying with a terrestrial laser scanner (TLS). The TLS technique has proved to be very effective in determining the volume change of this glacier, but presents several limitations as high costs, high level of specialized training and low portability. On the other hand, the recent improvements in close-range photogrammetric techniques like the Structure from Motion (SfM), combined with dense image matching algorithms as Multi View Stereo (MVS), make them competitive for high quality 3D models production. The purpose of this work was to apply ground-based photogrammetric surveys for the monitoring of the annual mass balance and surface processes of Montasio Occidentale glacier. A consumer-grade SLR camera and the SfM-MVS software PhotoScan were used to detect the changes in the surface topography of the glacier from 2012 to 2014. Different data acquisition settings were tested, in order to optimize the quality and the spatial coverage of the 3D glacier model. The accuracy of the image-based 3D models was estimated in stable areas outside the glacier, using the TLS 3D model as reference. A ground penetrating radar (GPR) survey was carried out in 2014, simultaneously to the photogrammetric survey, that was used to compare the snow height estimations obtained by photogrammetry with those obtained by geophysics. The achieved results indicate that the resolution and accuracy of the 3D models generated by the SfM-MVS technique are comparable with those obtained from TLS surveys. Consequently, almost identical volumetric changes

  16. Cover crops and their effects on the biomass yield of Serjania marginata plants Culturas de cobertura e seus efeitos na produção de biomassa de plantas de Serjania marginata

    Directory of Open Access Journals (Sweden)

    Luciane Almeri Tabaldi

    2012-04-01

    Full Text Available The use of cover crops can reduce or even eliminate the use of nitrogenous fertilizers, contributing to a more sustainable agriculture and ensuring the conservation of natural resources. Thus, the aim of this research was to evaluate the use of cover crops to improve the biomass yield of Serjania marginata plants. The experiment was carried out at the Federal University of Grande Dourados, in Dourados-MS, from December 2009 to February 2011. A split plot design was used in a randomized block design with four replications, being evaluated in plots three species of tropical legumes (Stizolobium aterrimum, Crotalaria spectabilis and Canavalia ensiformes, and one control plot (without cover crops, and in subplots the addition or not of nitrogen (N (at 150 days after transplant (DAT. Plants of S. marginata in each subplot were harvested at 240 and 350 DAT. S. aterrimum and C. ensiformes showed higher accumulation of fresh (average of 37.61t ha-1 and dry (average of 6.39t ha-1 biomass of shoot in flowering, compared with the C. spectabilis (21.92 and 4.63t ha-1, respectively. The contribution of cover crops as a likely source of N only was observed for S. aterrimum and C. ensiforme, which promoted an increase in chlorophyll index, leaf area, fresh and dry weight of leaves and stem of S. marginata plants, in absence of N. In leaves of S. marginata, only C. ensiformes contributed significantly to an increase in N levels, while an increase in K levels was observed with all cover crop treatments, when compared to control. Pre-cultivation with S. aterrimum and C. ensiformes provided an increase in P levels in leaves of S. marginata. Therefore, S. aterrimum and C. ensiformes were the most promising cover crops for growing of S. marginata, improving the biomass yield and probably the N economy.O uso de culturas de cobertura pode reduzir ou até mesmo eliminar o uso de fertilizantes nitrogenados, contribuindo para uma agricultura mais sustentável e

  17. Non-phytoseiid Mesostigmata within citrus orchards in Florida: species distribution, relative and seasonal abundance within trees, associated vines and ground cover plants and additional collection records of mites in citrus orchards.

    Science.gov (United States)

    Childers, Carl C; Ueckermann, Eduard A

    2015-03-01

    Seven citrus orchards on reduced- to no-pesticide spray programs in central and south central Florida were sampled for non-phytoseiid mesostigmatid mites. Inner and outer canopy leaves, fruits, twigs and trunk scrapings were sampled monthly between August 1994 and January 1996. Open flowers were sampled in March from five of the sites. A total of 431 samples from one or more of 82 vine or ground cover plants were sampled monthly in five of the seven orchards. Two of the seven orchards (Mixon I and II) were on full herbicide programs and vines and ground cover plants were absent. A total of 2,655 mites (26 species) within the families: Ascidae, Blattisociidae, Laelapidae, Macrochelidae, Melicharidae, Pachylaelapidae and Parasitidae were identified. A total of 685 mites in the genus Asca (nine species: family Ascidae) were collected from within tree samples, 79 from vine or ground cover plants. Six species of Blattisociidae were collected: Aceodromus convolvuli, Blattisocius dentriticus, B. keegani, Cheiroseius sp. near jamaicensis, Lasioseius athiashenriotae and L. dentatus. A total of 485 Blattisociidae were collected from within tree samples compared with 167 from vine or ground cover plants. Low numbers of Laelapidae and Macrochelidae were collected from within tree samples. One Zygoseius furciger (Pachylaelapidae) was collected from Eleusine indica. Four species of Melicharidae were identified from 34 mites collected from within tree samples and 1,190 from vine or ground cover plants: Proctolaelaps lobatus was the most abundant species with 1,177 specimens collected from seven ground cover plants. One Phorytocarpais fimetorum (Parasitidae) was collected from inner leaves and four from twigs. Species of Ascidae, Blattisociidae, Melicharidae, Laelapidae and Pachylaelapidae were collected from 31 of the 82 vine or ground cover plants sampled, representing only a small fraction of the total number of Phytoseiidae collected from the same plants. Including the

  18. The Investigation of Species and Application of Ground Cover Plants in Jiaozuo%焦作市地被植物种类及应用调查

    Institute of Scientific and Technical Information of China (English)

    韩红军; 张桂芝; 马君丽; 孔德政

    2012-01-01

    根据对焦作市建成区地被植物进行实地调查,统计得出焦作市作为地被植物应用的灌木,藤本,一、二年生花卉,宿根、球根花卉、草类共有192种65科151属.灌木应用较多,宿根、球根花卉,一、二年生花卉应用较少;提出了应用频率最高的地被植物有:马棘、月季、剑麻、铺地柏、迎春等;焦作地被植物应用形式主要有以下几种;模纹花坛和绿篱,旷地造景,路缘造景等.最后提出优化灌草比例,引进新优品种的建议.%Based on the investigation of ground cover plants, which be divided into Bush, Fujimoto, one or two annual flower, Perennial and bulbs flowers and grasses, which we proposes 192 species in the Building area in the city of Jiaozuo belong to 65 families and 151 genera. Bush is widely used, on the contrary, one or two annual flowers and Perennial and bulbs flowers used very seldom. And we discover these plants as indigofera and rose and jasmine and sisal and winter juniper etc are used the most frequently. There are these kinds of application forms as follows: mode pattern flower and hedgerow, open areas landscaping, road edge landscaping. At the last, we proposed that Optimization the Proportion of bush and grass and introduction new and excellent variety.

  19. Optimizing placements of ground-based snow sensors for areal snow cover estimation using a machine-learning algorithm and melt-season snow-LiDAR data

    Science.gov (United States)

    Oroza, C.; Zheng, Z.; Glaser, S. D.; Bales, R. C.; Conklin, M. H.

    2016-12-01

    We present a structured, analytical approach to optimize ground-sensor placements based on time-series remotely sensed (LiDAR) data and machine-learning algorithms. We focused on catchments within the Merced and Tuolumne river basins, covered by the JPL Airborne Snow Observatory LiDAR program. First, we used a Gaussian mixture model to identify representative sensor locations in the space of independent variables for each catchment. Multiple independent variables that govern the distribution of snow depth were used, including elevation, slope, and aspect. Second, we used a Gaussian process to estimate the areal distribution of snow depth from the initial set of measurements. This is a covariance-based model that also estimates the areal distribution of model uncertainty based on the independent variable weights and autocorrelation. The uncertainty raster was used to strategically add sensors to minimize model uncertainty. We assessed the temporal accuracy of the method using LiDAR-derived snow-depth rasters collected in water-year 2014. In each area, optimal sensor placements were determined using the first available snow raster for the year. The accuracy in the remaining LiDAR surveys was compared to 100 configurations of sensors selected at random. We found the accuracy of the model from the proposed placements to be higher and more consistent in each remaining survey than the average random configuration. We found that a relatively small number of sensors can be used to accurately reproduce the spatial patterns of snow depth across the basins, when placed using spatial snow data. Our approach also simplifies sensor placement. At present, field surveys are required to identify representative locations for such networks, a process that is labor intensive and provides limited guarantees on the networks' representation of catchment independent variables.

  20. Cultivos de cobertura,¿una alternativa viable para la región semirárida pampeana? Cover crops: a viable alternative for the semiarid Pampa region?

    Directory of Open Access Journals (Sweden)

    Romina Fernández

    2012-12-01

    N disponible en el suelo para el cultivo de maíz y sorgo. El rendimiento de maíz fue dependiente de la disponibilidad hídrica en el suelo a la siembra, ya que en B fue de 1015 kg ha-1, mientras que el rendimiento promedio con antecesor CC fue de 4044 kg ha-1. Para el caso del cultivo de sorgo, el manejo previo (con o sin CC no condicionó los rendimientos del mismo, debido a su ciclo fenológico más largo que facilitó que el cultivo aprovechara mayores precipitaciones específicamente durante el período entre siembra y floración.The effect of cover crops (CC on the provision of soil cover, N sequestration, accumulation of available water and the yield of a subsequent summer crop was evaluated. A field experiment with the following treatments was established: fallow without cover crop (B and rye as CC, control (CT, and fertilized (CF in a randomized complete block design with plots divided in two moments of drying of CC: July (CTJ and CFJ respectively and August (CTA and CFA respectively. On all treatments, two summer crops (CV, corn and sorghum were planted after fallowing at the end of November. Soil moisture and nitrate-N were determined at seeding of the CC, during their growing season, and at planting and flowering of corn and sorghum. Consumptive water use (UC and water use efficiency (EUA of CC, corn and sorghum were calculated. The standing biomass of CC was determined at the two dates of drying (J and A, and at planting of the summer crops and during their growing period the CC biomass litter was measured. The carbon (C, nitrogen (N and phosphorus (P contents of the dry matter were determined for all sampling dates. At planting of the summer crops, B treatment had less available water stored in the soil than CC, and J stored more water than A treatment. Total dry matter production of CC was higher in F and when dried in A. The CC sequestered important amounts of C, N and P, preventing potential leaching losses of N during the fallow, and CC litter

  1. Comportamento de atributos relacionados com a forma da estrutura de Latossolo Vermelho sob sistemas de preparo e plantas de cobertura Structural attributes of a clayey Hapludox cultivated under distinct tillage methods and cover crops

    Directory of Open Access Journals (Sweden)

    Jeferson Argenton

    2005-06-01

    Full Text Available Os sistemas de preparo de solo e de culturas têm influência significativa na estrutura do solo e nos fluxos de água e ar. Este trabalho objetivou avaliar os efeitos do manejo do solo sobre as propriedades relacionadas com estrutura de um Latossolo Vermelho cultivado com milho intercalado com plantas de cobertura de verão. Dois experimentos foram realizados em Chapecó (SC, em preparo reduzido (PR, de 1993 a 1998, e preparo convencional (PC, de 1994 a 1998, nos quais foram avaliados três sistemas de cultura: milho + guandu anão, milho + mucuna cinza e milho isolado. Adjacente aos experimentos, foi avaliada uma mata nativa. Em comparação com a mata nativa, os sistemas de preparo modificaram a estrutura do solo, com aumento da densidade e da resistência do solo à penetração e redução da macroporosidade e da porosidade total. Após cinco anos de uso, o PR com milho isolado não recuperou as propriedades relacionadas com a forma da estrutura; entretanto, no sistema milho intercalado com mucuna cinza, notou-se aumento da macroporosidade, porosidade total e condutividade hidráulica saturada, bem como a redução da densidade do solo. Estas melhorias, advindas do uso de plantas de cobertura, não foram observadas no sistema de preparo convencional. O uso de culturas intercalares foi adequado para melhorar a qualidade física desse Latossolo Vermelho argiloso, especialmente pelo maior aporte de resíduos de culturas.Soil tillage and crop systems have significant influence on the soil structure, affecting water and air flow. The objective of this study was to evaluate the effects the management has on the soil properties of a Hapludox cultivated with maize intercropped with summer cover crops. Two experiments were carried out in Chapecó, State of Santa Catarina, Brazil under reduced tillage (RT from 1993 to 1998 and conventional tillage (CT from 1994 to 1998. Three cropping systems were evaluated under each tillage system: maize + Cajanus

  2. Impact of seasonal forecast use on agricultural income in a system with varying crop costs and returns: an empirically-grounded simulation

    Science.gov (United States)

    Gunda, T.; Bazuin, J. T.; Nay, J.; Yeung, K. L.

    2017-03-01

    Access to seasonal climate forecasts can benefit farmers by allowing them to make more informed decisions about their farming practices. However, it is unclear whether farmers realize these benefits when crop choices available to farmers have different and variable costs and returns; multiple countries have programs that incentivize production of certain crops while other crops are subject to market fluctuations. We hypothesize that the benefits of forecasts on farmer livelihoods will be moderated by the combined impact of differing crop economics and changing climate. Drawing upon methods and insights from both physical and social sciences, we develop a model of farmer decision-making to evaluate this hypothesis. The model dynamics are explored using empirical data from Sri Lanka; primary sources include survey and interview information as well as game-based experiments conducted with farmers in the field. Our simulations show that a farmer using seasonal forecasts has more diversified crop selections, which drive increases in average agricultural income. Increases in income are particularly notable under a drier climate scenario, when a farmer using seasonal forecasts is more likely to plant onions, a crop with higher possible returns. Our results indicate that, when water resources are scarce (i.e. drier climate scenario), farmer incomes could become stratified, potentially compounding existing disparities in farmers’ financial and technical abilities to use forecasts to inform their crop selections. This analysis highlights that while programs that promote production of certain crops may ensure food security in the short-term, the long-term implications of these dynamics need careful evaluation.

  3. Manejo de Conyza bonariensis resistente ao glyphosate: coberturas de inverno e herbicidas em pré-semeadura da soja Management of glyphosate resistant Conyza bonariensis: winter cover crops and herbicides in soybean pre-seeding

    Directory of Open Access Journals (Sweden)

    F.P. Lamego

    2013-06-01

    Full Text Available Conyza bonariensis tornou-se a principal planta daninha da cultura da soja no Sul do Brasil, em decorrência da evolução para resistência ao herbicida glyphosate. O objetivo deste trabalho foi avaliar o efeito de diferentes coberturas de inverno e da associação de manejo de dessecação pré-semeadura da soja, visando ao controle de C. bonariensis resistente ao glyphosate. Um experimento foi conduzido em campo, na safra 2010/2011. Os tratamentos foram conduzidos em esquema de parcelas subdivididas, em que as coberturas de inverno foram alocadas nas parcelas principais: aveia-preta, nabo, ervilhaca, azevém, trigo e pousio. Nas subparcelas, foram alocados os tratamentos de manejo de dessecação pré-semeadura da soja: glyphosate (720 g e.a ha-1, glyphosate (720 g e.a ha-1 + 2,4-D (1.050 g e.a ha-1, glyphosate (720 g e.a ha-1 + 2,4-D (1.050 g e.a ha-1/paraquat (200 g i.a ha-1 + diuron (100 g i.a ha-1, glyphosate (720 g e.a ha-1 + chlorimuron-ethyl (80 g i.a ha-1, glyphosate (720 g e.a ha-1 + chlorimuron-ethyl (80 g i.a ha-1/paraquat (200 g i.a ha-1 + diuron (100 g i.a ha‑1 e roçada. O nabo foi a espécie de cobertura que produziu o maior volume de massa seca durante o inverno, enquanto a ervilhaca foi a que apresentou maior efeito supressor sobre a germinação e o desenvolvimento inicial de C. bonariensis. Associações de glyphosate com 2,4-D ou chlorimuron-ethyl, seguidas da aplicação sequencial de paraquat + diuron, causaram maior redução na infestação de C. bonariensis.Conyza bonariensis became the main weed in soybean crop in Southern Brazil, as a consequence of the evolution of resistance to the herbicide glyphosate. The objective of this work was to evaluate the effect of different winter cover crops and the association of burn-down herbicides on the control of glyphosate-resistant C. bonariensis. A field experiment was conducted in the 2010/2011 season. The treatments were arranged in a split-plot scheme, with the winter

  4. Soil quality evaluation following the implementation of permanent cover crops in semi-arid vineyards. Organic matter, physical and biological soil properties

    Energy Technology Data Exchange (ETDEWEB)

    Virto, I.; Imaz, M. J.; Fernandez-Ugalde, O.; Urrutia, I.; Enrique, A.; Bescansa, P.

    2012-07-01

    Changing from conventional vineyard soil management, which includes keeping bare soil through intense tilling and herbicides, to permanent grass cover (PGC) is controversial in semi-arid land because it has agronomic and environmental advantages but it can also induce negative changes in the soil physical status. The objectives of this work were (i) gaining knowledge on the effect of PGC on the soil physical and biological quality, and (ii) identifying the most suitable soil quality indicators for vineyard calcareous soils in semi-arid land. Key soil physical, organic and biological characteristics were determined in a Cambic Calcisol with different time under PGC (1 and 5 years), and in a conventionally managed control. Correlation analysis showed a direct positive relationship between greater aggregate stability (WSA), soil-available water capacity (AWC), microbial biomass and enzymatic activity in the topsoil under PGC. Total and labile organic C concentrations (SOC and POM-C) were also correlated to microbial parameters. Factor analysis of the studied soil attributes using principal component analysis (PCA) was done to identify the most sensitive soil quality indicators. Earthworm activity, AWC, WSA, SOC and POM-C were the soil attributes with greater loadings in the two factors determined by PCA, which means that these properties can be considered adequate soil quality indicators in this agrosystem. These results indicate that both soil physical and biological attributes are different under PGC than in conventionally-managed soils, and need therefore to be evaluated when assessing the consequences of PGC on vineyard soil quality. (Author) 65 refs.

  5. Tomato yield and soil chemical attributes depending on previous cover crops Produtividade do tomateiro e atributos químicos do solo em função do uso de plantas de cobertura antecedendo o cultivo

    Directory of Open Access Journals (Sweden)

    Alexandre G Galvão

    2013-03-01

    Full Text Available The influence of different cover crops was evaluated over the agronomic performance of tomato hybrids for industrial processing, as well as its effect over soil chemical attributes. The experimental design was completely randomized, in a split plot scheme, with four replications. Main treatments (plots were composed of winter cover crops (oat, hairy vetch, clover and radish and of a fallow area (spontaneous vegetation. Subplots were composed of four processing tomato hybrids (AP529, AP533, Kátia and Sicílio. We evaluated the total production (TP, marketable production (CP, average mass of marketable fruits (AMCF and number of marketable fruits (NCF. Chemical analysis of soil was done in two stages: one week preceding implantation of cover crops and in the phase of tomato implantation. Highest TPs were obtained in treatments in which cover crops were composed by hairy vetch and radish. However, although hairy vetch has caused an increase in TP, no difference between covers was obtained in relation to CP. Sicílio hybrid presented the greatest AMCF, however, its TP was lower than expected. This fact is related to lower NCF, which was half of the observed in AP529 and AP533 hybrids. Radish cover increased phosphorus, calcium and potassium in soil and this could be one of the factors responsible for the increase of TP provided by radish. On the other hand, oat has caused inverse effect, reducing availability of Ca and K. All covers have increased organic matter in soil, the major increment being presented by oat. Based on these results we conclude that hairy vetch and radish are the most indicated plants for cover preceding tomato cultivation.Foram avaliadas diferentes coberturas de solo sobre o desempenho agronômico de híbridos de tomate para processamento industrial, bem como seus efeitos sobre atributos químicos do solo. O delineamento experimental foi em blocos casualizados, com quatro repetições, no esquema de parcelas subdivididas. Os

  6. Environmental impact of almond crop in strong slope with two vegetable covers: bush and leguminous; Impacto en el medio ambiente del cultivo de almendros en fuertes pendientes con dos cubiertas vegetales: Matorral y Leguminosa

    Energy Technology Data Exchange (ETDEWEB)

    Carceles Rodriguez, B.; Francia Martinez, J. R.; Martinez Raya, A.

    2009-07-01

    Soil erosion is one of the main physical processes of land degradation in Spain. Several studies in the Mediterranean environment have demonstrated the positive effect of vegetation covers on the reduction of water erosion and their indirect improvement of the soil physical and chemical properties, essentially by the incorporation of organic matter. Sol loss and surface runoff patterns over a four-year period were monitors in erosion plots from hill slope with two different cover-crop strips: (1) non-tillage with leguminous (Lens esculenta Moench) and (2) non-tillage with and a mixture of autochthonous thymes (Thymus baeticus Boiss. ex Lacaita, Thymus capitatus (L) Hoffmanns and Link., Thymus vulgaris L.) of 3 m with, in Lanjaron (Granada) on the south flank of the Sierra Nevada of southeast Spain. The erosion plots were located on the hill slope at 35% incline, at 580 m in altitude and with 144 m{sup 2} (24 m x 6 m) in area. the area selected for the experiment is the part of the rainfed orchard given entirely with almond (Prunus amygdalus Basch cv. Desmayo Largueta) trees, the planting gird were 6 x 7 m. (Author) 10 refs.

  7. Calagem em latossolo sob influência de coberturas vegetais: neutralização da acidez Liming in a latosol under influence of cover crops: acidity neutralization

    Directory of Open Access Journals (Sweden)

    Tullio Raphael Pereira de Pádua

    2006-10-01

    Full Text Available A movimentação dos produtos da dissolução do calcário e a correção da acidez podem ser influenciadas pelo manejo da calagem e pela quantidade e qualidade da matéria orgânica presente no solo. Avaliou-se a correção da acidez de acordo com a aplicação de calcário superficial ou incorporado nas profundidades de 0-10, 0-20 cm, em um Latossolo Vermelho distroférrico (LVdf sob diferentes coberturas vegetais anteriores (mata, eucalipto, pinus e pastagem. O estudo foi realizado de novembro de 2002 a janeiro de 2003 no Departamento de Ciência do Solo da UFLA, sendo avaliados, depois de 30 dias de reação do calcário, e antes do cultivo do algodão, os teores trocáveis de Ca2+ e Al3+, o pH e os níveis de saturação por bases (V em amostras de solo coletadas nas profundidades de 0-5, 5-10, 10-20 e 20-40 cm. A calagem superficial causou, na camada de 0-5 cm, uma elevação do pH e V para níveis acima dos considerados adequados para o cultivo do algodoeiro, caracterizando uma calagem excessiva. Foram verificados acréscimos, em relação à área sem calagem, do pH, Ca2+ e saturação por bases em camadas de solo além das camadas de incorporação do corretivo, principalmente nas amostras de solo com maior teor de matéria orgânica, mas esses efeitos não se estenderam à camada de subsolo (20-40 cm.Lime mobility and soil acidity correction can be influenced by liming management and the quantity and quality of soil organic matter. Acidity neutralization in function of the lime incoporation and surface liming was evaluated in a red Latosol (Oxisol under different antecedent vegetation covers (eucalyptus, forest, pasture and pine. The study was carried out from November 2002 to January 2003 at the Soil Science Department of the Lavras Federal University. After 30 days of incubation of soils with lime, the contents of Ca2+ e Al3+, pH and base saturation levels were quantified at the 0-5, 5-10, 10-20 and 20-40 cm sample depths. At the

  8. Dinâmica do potássio nos resíduos vegetais de plantas de cobertura no Cerrado Potassium dynamics in crop residues of cover plants in Cerrado

    Directory of Open Access Journals (Sweden)

    José Luiz Rodrigues Torres

    2008-08-01

    Full Text Available A produção de biomassa, a manutenção dos resíduos vegetais sobre o solo e sua posterior decomposição são fatores de grande importância no estudo da ciclagem de nutrientes. Este estudo foi desenvolvido na área experimental do CEFET-Uberaba-MG, onde foram avaliados oito tipos de coberturas vegetais: milheto (Pennisetum americanum sin. tiphoydes, braquiária (Brachiaria brizantha, sorgo-forrageiro (Sorghum bicolor L. Moench, guandu (Cajanus cajan (L. Mill sp., crotalária (Crotalarea juncea, aveia-preta (Avena strigosa Schreb, pousio e área em preparo convencional de solo (testemunha em área de Cerrado, na região do Triângulo Mineiro. Avaliaram-se a fitomassa seca (FS, a decomposição dos resíduos em bolsas de decomposição, e a liberação de K. Utilizou-se um modelo matemático para descrever a decomposição dos resíduos e a liberação de K, e calcularam-se a constante de decomposição (k e o tempo de meia-vida (T½. O milheto, o sorgo e a crotalária foram as coberturas que apresentaram maiores produções de matéria seca. O maior acúmulo de K ocorreu em gramíneas e a maior liberação de K ocorreu no milheto, aveia, braquiária e crotalária nos primeiros 42 dias após manejo, nos dois períodos avaliados. A braquiária apresentou o menor T½ vida e a maior taxa de liberação de K.Crop residue production, plant residue maintenance and their decomposition are important factors in the understanding of nutrient recycling process. To evaluate K accumulation and release a study with eight cover crops types was developed: pearl millet (Pennisetum americanum sin. tiphoydes, brachiaria grass (Brachiaria brizantha, sorghum (Sorghum bicolor L. Moench, pigeonpea (Cajanus cajan (L. Millsp, sunn hemp (Crotalarea juncea and black oats (Avena strigosa Schreb, fallow land and conventional culture (control in the experimental area of CEFET-Uberaba-MG, in a Cerrado area. The dry mass production, crop residue decomposition in litter bags

  9. Profiling crop pollinators: life history traits predict habitat use and crop visitation by Mediterranean wild bees.

    Science.gov (United States)

    Pisanty, Gideon; Mandelik, Yael

    2015-04-01

    Wild pollinators, bees in particular, may greatly contribute to crop pollination and provide a safety net against declines in commercial pollinators. However, the identity, life history traits, and environmental sensitivities of main crop pollinator species.have received limited attention. These are crucial for predicting pollination services of different communities and for developing management practices that enhance crop pollinators. We sampled wild bees in three crop systems (almond, confection sunflower, and seed watermelon) in a mosaic Israeli Mediterranean landscape. Bees were sampled in field/orchard edges and interiors, and in seminatural scrub surrounding the fields/orchards. We also analyzed land cover at 50-2500 m radii around fields/orchards. We used this data to distinguish crop from non-crop pollinators based on a set of life history traits (nesting, lecty, sociality, body size) linked to habitat preference and crop visitation. Bee abundance and species richness decreased from the surrounding seminatural habitat to the field/orchard interior, especially across the seminatural habitat-field edge ecotone. Thus, although rich bee communities were found near fields, only small fractions crossed the ecotone and visited crop flowers in substantial numbers. The bee assemblage in agricultural fields/orchards and on crop flowers was dominated by ground-nesting bees of the tribe Halictini, which tend to nest within fields. Bees' habitat preferences were determined mainly by nesting guild, whereas crop visitation was determined mainly by sociality. Lecty and body size also affected both measures. The percentage of surrounding seminatural habitat at 250-2500 m radii had a positive effect on wild bee diversity in field edges, for all bee guilds, while at 50-100 m radii, only aboveground nesters were positively affected. In sum, we found that crop and non-crop pollinators are distinguished by behavioral and morphological traits. Hence, analysis of life

  10. How effective are slurry storage, cover or catch crops, woodland creation, controlled trafficking or break-up of compacted layers, and buffer strips as on-farm mitigation measures for delivering an improved water environment?

    Directory of Open Access Journals (Sweden)

    Randall Nicola P

    2012-10-01

    Full Text Available Abstract Background Agriculture has intensified over the last 50 years resulting in increased usage of fertilizers and agrochemicals, changes in cropping practices, land drainage and increased stocking rates. In Europe, this has resulted in declines in the quality of soils and waters due to increased run off and water pollution. Fifty percent of nitrates in European rivers are derived from agricultural sources in the UK this value is as high as 70%, where agriculture also contributes to approximately 28% of phosphates and 76% of sediments recorded in rivers. Catchments dominated by agricultural land use have increased levels of pesticides and bacterial pathogens. European member states have a policy commitment to tackle water pollution through the Water Framework Directive. An analysis of the effectiveness of water pollution mitigation measures should enable decision makers and delivery agencies to better facilitate catchment planning. The aim of this systematic review is to assess the effectiveness of slurry storage, cover/catch crops, woodland creation, controlled trafficking/break-up of compacted layers and buffer strips, as on farm mitigation measures, for delivering an improved water environment. Methods The systematic review will consist of a searchable systematic map database for all the named interventions. Where possible, quantitative analysis will be used to assess the effectiveness of interventions. Electronic databases, the internet, and organisational websites will be searched, and stakeholders will be contacted for studies that investigate the impact of the on-farm mitigation measures on water quality. All studies found will be assessed for suitability for inclusion in the next stage. Inclusion criteria will be based on subject, intervention, comparator and outcome. The details of included studies will be incorporated into the systematic map database, and studies scored for effectiveness of intervention and study design. Where

  11. Path Analysis Between Soil Microbial Biomass and Soil Nutrient Contents in Cover Cropping System of Vineyard%行间生草葡萄园土壤微生物量与土壤养分的通径分析

    Institute of Scientific and Technical Information of China (English)

    惠竹梅; 岳泰新; 张振文

    2011-01-01

    Two perennial legumes (white clover and alfalfa) and a perennial grass (tall fescue) were sown in inter-rows of Cabernet sauvignon vineyard. The effects of inter-row cover cropping on soil microbial bio-mass, respiration strengths, microbial quotient, soil nutrient contents and their relationships were studied with clean tillage as control. Results showed that white clover and alfalfa increased the contents of soil organic matter and soil total N significantly, and decreased available P contents; tall fescue significantly decreased soil organic matter and available K contents. The soil microbial biomass carbon contents of white clover, alfalfa and tall fescue increased 65. 2% , 61. 6% ,6. 7% , respectively, and soil microbial biomass nitrogen contents increased 53. 6% , 52. 4% , 15. 0% , respectively, compared with control. The soil microbial quotients in cover cropping treatments were increased significantly, but the soil respirations had no significant differences between cover crop treatments and control. The soil microbial indicators showed significant positive correlations with soil organic matter, total N, hydrolyzable N and available K, and significant negative correlations with total P and available P. Path analysis indicated that in the vineyard intercropping system, soil hydrolyzable N and total N were direct factors affecting the accumulation of soil microbial biomass, respiration strengths and microbial quotient.%在酿酒葡萄(Vitis vini era)园行间播种白三叶草(Tri folium repens L.)、紫花苜蓿(Medicago sativa L.)和高羊茅(Festuca arundinacea Schreb),以清耕为对照,研究了土壤微生物量、土壤微生物呼吸强度和土壤微生物熵的变化及其与土壤养分的关系.结果表明:与清耕(对照)相比,白三叶草和紫花苜蓿处理显著提高了土壤有机质、全氮含量,显著降低了速效磷含量;而高羊茅处理土壤有机质和速效钾含量显著低于清耕.白三叶草、紫花苜蓿和高羊

  12. Cultivos de cobertura: efectos sobre la macroporosidad y la estabilidad estructural de un suelo franco-limoso Cover crops: effects on soil macroporosity and soil structural stability in a silt loam soil

    Directory of Open Access Journals (Sweden)

    María Florencia Varela

    2011-07-01

    Full Text Available Los suelos franco-limosos manejados con siembra directa a menudo poseen porosidad estructural baja e inestable. Con el objetivo de determinar la capacidad de los cultivos de cobertura (CC de mejorar la porosidad y estabilidad estructural de estos suelos se llevaron a cabo experimentos de campo y de invernáculo. Ambos tuvieron tratamientos con y sin CC (avena, Avena sativa L., en rotación con soja (Glicine max L. Merr.. Luego de los CC se midieron densidad aparente (DA, el índice de inestabilidad estructural (IE y en el ensayo de invernáculo además, se midió la evolución de la distribución de tamaño de poros (DTP. En ambos ensayos la introducción de CC no disminuyó la DA, aunque incrementó la estabilidad del suelo (PNo- till (NT silt loam topsoils have often a low and unstable structural porosity. The objective of this study was to determine the capability of cover crops (CC of improving the structural porosity and stability of silt loam soils under NT. Greenhouse and field experiments were carried out on a silt loam soil (Typic Argiudoll with and without CC (oat, Avena sativa L. in crop sequences with soybean (Glicine max L. Merr.. Soil bulk density (DA and aggregate instability index (IE were measured after the CC in both experiments. In the greenhouse experiment, soil pore size distribution (DTP was measured. The use of CC did not change DA, but soil IE was significantly lower in crop sequences with CC (P < 0.05 both under field and greenhouse conditions. Stability increases were likely due to the effect of CC residues and root mass. No differences in DTP were found between treatments, although a significant effect of sampling date was observed (P<0.05. Changes in DTP were due to significant increases in mesopore (517.5% and macropore (52.7% volumes. Such changes occurred in all the treatments, probably due to the soil wetting-drying cycles. The results found in this study agree with other studies carried out on silt loams in the

  13. Ground flora, small mammal and bird species diversity in miscanthus (Miscanthusxgiganteus) and reed canary-grass (Phalaris arundinacea) fields

    Energy Technology Data Exchange (ETDEWEB)

    Semere, T.; Slater, F.M. [Cardiff University, School of Biosciences, Llysdinam Field Centre, Newbridge-on-Wye, Llandrindod Wells, Powys LD1 6NB (United Kingdom)

    2007-01-15

    Wildlife monitoring of two miscanthus and two reed canary-grass fields in Herefordshire, England was carried out in 2002, 2003 and 2004 to investigate the ecological impact of perennial biomass grass crops on ground flora, small mammals and birds. Quadrats were used to record percentage ground vegetation cover within and around the periphery of each crop. Small mammals were sampled by live trapping using Longworth traps. The common bird census technique was used to monitor populations of birds. Miscanthus fields were richer in weed vegetation than reed canary-grass or arable fields. Bird use of the biomass crop fields varied depending on species. There were considerably more open-ground bird species such as skylarks (Alauda arvensis), lapwings (Vanellus vanellus) and meadow pipits (Anthus pratensis) within miscanthus than within reed canary-grass fields. There was no particular crop-type preference by the small mammal species, but rather a preference for good ground cover and little land disturbance, which was provided by both biomass crops. Ground flora, small mammals and most of the bird species (except open-ground birds) were found more abundantly within field margins and boundaries than in crop fields indicating the importance of retaining field structure when planting biomass crops. The miscanthus work relates entirely to young crops, which may be representative of part of the national crop if large areas are cultivated for rhizomes. The findings from the current project indicate that perennial biomass grass crops can provide substantially improved habitat for many forms of native wildlife, due to the low intensity of the agricultural management system and the untreated headlands. (author)

  14. Caracterização das perdas e distribuição de cobertura vegetal em colheita mecanizada de soja Characterization of losses and crop residue cover distribution in soybean mechanized harvest

    Directory of Open Access Journals (Sweden)

    Anderson de Toledo

    2008-12-01

    Full Text Available O conceito de controle de qualidade nas operações inserido na agricultura é viabilizado por incidir diretamente nos principais objetivos do processo produtivo: retorno econômico e aumento da produtividade. A colheita mecanizada normalmente é realizada sem que haja controle efetivo para que a variabilidade das perdas fique dentro de padrões aceitáveis. Esta pesquisa teve o objetivo de determinar e caracterizar as perdas e a distribuição da cobertura vegetal após a colheita mecanizada da soja, por meio de ferramenta de controle estatístico de processo (cartas de controle. A média da perda de grãos total foi próxima do limite superior aceitável para a cultura da soja, apresentando alta variabilidade entre os pontos, tornando o processo fora de controle. A distribuição de cobertura vegetal manteve-se em processo controlado, com maior variabilidade onde o relevo foi mais inclinado. A utilização das cartas de controle foi eficiente na identificação dos pontos fora de controle e na avaliação da qualidade do processo de colheita.The concept of operation control inserted in agriculture is made possible by making a directly influence in the main objectives of productive process, economic return and increase of productivity. The mechanized harvest normally is carried out without an effective control of the variability of losses so that it maintains acceptable standards. This research aimed to determinate and characterize the losses and crop residue cover distribution after soybean mechanized harvest, using the tool of statistical process control (control charts. The average of total grain losses was near the upper limit specified for losses in soybean, showing high variation between points, and putting the process out of control. The residue crop cover distribution stayed under control process, with greater variability where the terrain was more sloping. The use of control charts was efficient to identify the points out of control

  15. Cover crop management in the weed control and productive performance in cornManejo de plantas de cobertura no controle de plantas daninhas e desempenho produtivo da cultura do milho

    Directory of Open Access Journals (Sweden)

    Pedro Valério Dutra de Moraes

    2013-05-01

    Full Text Available Objetivou-se avaliar espécies vegetais com potencial alelopático, associados às práticas de manejo e ao uso de herbicida nicosulfuron, no controle de plantas daninhas e nos componentes de produtividade da cultura do milho. O delineamento experimental utilizado foi em blocos ao acaso, com quatro repetições. O experimento foi composto por três fatores: espécies de cobertura, manejo das coberturas e aplicação ou não de herbicida nicosulfuron em pós-emergência. As variáveis avaliadas foram: número de plantas daninhas, número de fileiras de grãos, número de grãos por fileira, número de grãos por espiga e produtividade de grãos de milho. A cobertura de azevém, em geral, reduz o número de plantas daninhas emergidas e favorece o desempenho produtivo do milho. O manejo das plantas de cobertura com roçada e retirada da palha reduz a produtividade do milho. A maior produtividade do milho, foi observada com a aplicação de nicosulfuron em pós-emergência, independente da cultura de cobertura ou do manejo adotado. The objective of the study was evaluate the allelopathy of cover species, associated to management practices and use of nicosulfuron herbicide on the productive performance of corn. The experimental design consisted of complete randomized block with four replications. The treatments were: cover species, cover management and application or not of post-emergence herbicide. The variables evaluated were: number of weeds, number of rows kernels, number of kernels rows, number of kernels ear and grain yield of corn. Lolium multiflorum, reduced the number of emerged weeds and provides the best results in productive performance. The management simulated grazing, does not favor the yield of corn. The application of nicosulfuron in post-emergence, along with the allelopathic activity increases the productive performance of corn, regardless of cover crop or soil management.

  16. Revegetação com plantas de cobertura em solos arenizados sob erosão eólica no Rio Grande do Sul Revegetation with cover crops for soils under arenization and wind erosion in Rio Grande do Sul state, Brazil

    Directory of Open Access Journals (Sweden)

    Ana Paula Moreira Rovedder

    2008-02-01

    revegetation with cover crops such as Avena strigosa Schieb. and Lupinus albescens H. et Arn., was developed to reduce the soil particle movement by eolic erosion. The experiment was carried out on a Quartzipsament soil, from September to December 2001 and from January to December 2002, in a completely randomizased design and nine replications, on a degraded area and on a degraded area under cover crops. Galvanized metal boxes of 0.5 x 0.5 m, in a pyramid base shape, were buried in the center of the plots, with the upper opening at the ground level. The sand volume deposited in the boxes by the wind was measured every fortnight, and the water content determined. In 2001, the amount of transported sand was 365 Mg ha-1 from the area with cover crops and 5.053 Mg ha-1 from the degraded area, expressing a reduction of 93 % in sand transport by eolic erosion. In 2002, 775 Mg ha-1 of sand was transported from the area with cover crops, whereas 11080 Mg ha-1 was moved from the degraded area, with the same reduction of 93 % in sediment transport due to soil covering. These results indicate that the technique of revegetation with cover plants may be used to detain the sand in degraded areas.

  17. Impact of GM crops on biodiversity.

    Science.gov (United States)

    Carpenter, Janet E

    2011-01-01

    The potential impact of GM crops on biodiversity has been a topic of interest both in general as well as specifically in the context of the Convention on Biological Diversity. Agricultural biodiversity has been defined at levels from genes to ecosystems that are involved or impacted by agricultural production (www.cbd.int/agro/whatis.shtml). After fifteen years of commercial cultivation, a substantial body of literature now exists addressing the potential impacts of GM crops on the environment. This review takes a biodiversity lens to this literature, considering the impacts at three levels: the crop, farm and landscape scales. Within that framework, this review covers potential impacts of the introduction of genetically engineered crops on: crop diversity, biodiversity of wild relatives, non-target soil organisms, weeds, land use, non-target above-ground organisms, and area-wide pest suppression. The emphasis of the review is peer-reviewed literature that presents direct measures of impacts on biodiversity. In addition, possible impacts of changes in management practises such as tillage and pesticide use are also discussed to complement the literature on direct measures. The focus of the review is on technologies that have been commercialized somewhere in the world, while results may emanate from non-adopting countries and regions. Overall, the review finds that currently commercialized GM crops have reduced the impacts of agriculture on biodiversity, through enhanced adoption of conservation tillage practices, reduction of insecticide use and use of more environmentally benign herbicides and increasing yields to alleviate pressure to convert additional land into agricultural use.

  18. Spatial Variability Mapping of Crop Residue Using Hyperion (EO-1 Hyperspectral Data

    Directory of Open Access Journals (Sweden)

    Abderrazak Bannari

    2015-06-01

    Full Text Available Soil management practices that maintain crop residue cover and reduce tillage improve soil structure, increase organic matter content in the soil, positively influence water infiltration, evaporation and soil temperature, and play an important role in fixing CO2 in the soil. Consequently, good residue management practices on agricultural land have many positive impacts on soil quality, crop production quality and decrease the rate of soil erosion. Several studies have been undertaken to develop and test methods to derive information on crop residue cover and soil tillage using empirical and semi-empirical methods in combination with remote sensing data. However, these methods are generally not sufficiently rigorous and accurate for characterizing the spatial variability of crop residue cover in agricultural fields. The goal of this research is to investigate the potential of hyperspectral Hyperion (Earth Observing-1, EO-1 data and constrained linear spectral mixture analysis (CLSMA for percent crop residue cover estimation and mapping. Hyperion data were acquired together with ground-reference measurements for validation purposes at the beginning of the agricultural season (prior to spring crop planting in Saskatchewan (Canada. At this time, only bare soil and crop residue were present with no crop cover development. In order to extract the crop residue fraction, the images were preprocessed, and then unmixed considering the entire spectral range (427 nm–2355 nm and the pure spectra (endmember. The results showed that the correlation between ground-reference measurements and extracted fractions from the Hyperion data using CLMSA showed that the model was overall a very good predictor for crop residue percent cover (index of agreement (D of 0.94, coefficient of determination (R2 of 0.73 and root mean square error (RMSE of 8.7% and soil percent cover (D of 0.91, R2 of 0.68 and RMSE of 10.3%. This performance of Hyperion is mainly due to the

  19. Trade-offs around the use of biomass for livestock feed and soil cover in dairy farms in the Alaotra lake region of Madagascar. Special Issue: Biomass use trade-offs in cereal cropping systems: Lessons and implications from the developing world

    NARCIS (Netherlands)

    Naudin, K.; Bruelle, G.; Salgado, P.; Penot, E.; Lubbers, M.T.M.H.; Ridder, de N.; Giller, K.E.

    2015-01-01

    Conservation agriculture (CA) is promoted as a promising technology to stabilize or improve crop yields in Africa and Madagascar. However, small-scale farmers face difficulties to retain soil cover, mainly because of competing uses for the biomass produced, especially to feed cattle. To explore the

  20. Trade-offs around the use of biomass for livestock feed and soil cover in dairy farms in the Alaotra lake region of Madagascar. Special Issue: Biomass use trade-offs in cereal cropping systems: Lessons and implications from the developing world

    NARCIS (Netherlands)

    Naudin, K.; Bruelle, G.; Salgado, P.; Penot, E.; Lubbers, M.T.M.H.; Ridder, de N.; Giller, K.E.

    2015-01-01

    Conservation agriculture (CA) is promoted as a promising technology to stabilize or improve crop yields in Africa and Madagascar. However, small-scale farmers face difficulties to retain soil cover, mainly because of competing uses for the biomass produced, especially to feed cattle. To explore the

  1. Capacidade de suporte e compressibilidade de um argissolo, influenciadas pelo tráfego e por plantas de cobertura de inverno Bearing capacity and compressibility of argisol (paleudult as affected by traffic and winter cover crops

    Directory of Open Access Journals (Sweden)

    Henrique Debiasi

    2008-12-01

    Full Text Available Uma das medidas mais efetivas na prevenção da compactação do solo é a aplicação de pressões inferiores à sua capacidade de suporte de carga, estimada pela tensão de pré-consolidação (σp. Visando a quantificar o efeito de plantas de cobertura de inverno e do tráfego de rodados de trator sobre a σp e sobre o índice de compressibilidade (IC, vem sendo realizado, desde 2002, um experimento em Eldorado do Sul (RS, em Argissolo Vermelho distrófico franco-argilo-arenoso. Os tratamentos, sob semeadura direta, abrangem três coberturas de inverno (pousio, aveia preta e aveia preta + ervilhaca, substituída em 2006 por nabo forrageiro e duas condições de tráfego (com ou sem tráfego de rodados de trator. No verão, foram semeados milho e soja, em rotação anual. Amostras de solo indeformadas, visando à determinação de algumas propriedades físicas e da σp e do IC, foram coletadas, em junho e novembro de 2006, nas camadas de 0,03-0,06 e 0,12-0,15 m, e equilibradas a diferentes tensões de água. Independentemente da época de avaliação e do tráfego, o pousio resultou nos maiores valores de σp e menores de IC na camada de 0,03-0,06 m. Com menor teor de água no solo, as diferenças na σp entre o pousio e as plantas de cobertura tenderam a diminuir. A realização de sete tráfegos em cinco anos aumentou a σp apenas na superfície do solo, mas não afetou o IC. O uso de plantas de cobertura de inverno, aliado à ausência de tráfego, ao reduzir a densidade do solo e aumentar a macroporosidade, diminuiu a capacidade de suporte de carga e aumentou a susceptibilidade da superfície do solo à compactação.One of the most effective practices in preventing soil compaction is to apply stresses below the bearing capacity of the soil, often estimated by the pre-compression stress (σp. To evaluate the effects of cover crops and tractor traffic on σp and compression index (CI, a field experiment was initiated in 2002 on sandy clay

  2. Even the smallest non-crop habitat islands could be beneficial: distribution of carabid beetles and spiders in agricultural landscape.

    Science.gov (United States)

    Knapp, Michal; Řezáč, Milan

    2015-01-01

    Carabid beetles and ground-dwelling spiders inhabiting agroecosystems are beneficial organisms with a potential to control pest species. Intensification of agricultural management and reduction of areas covered by non-crop vegetation during recent decades in some areas has led to many potentially serious environmental problems including a decline in the diversity and abundance of beneficial arthropods in agricultural landscapes. This study investigated carabid beetle and spider assemblages in non-crop habitat islands of various sizes (50 to 18,000 square metres) within one large field, as well as the arable land within the field, using pitfall traps in two consecutive sampling periods (spring to early summer and peak summer). The non-crop habitat islands situated inside arable land hosted many unique ground-dwelling arthropod species that were not present within the surrounding arable land. Even the smallest non-crop habitat islands with areas of tens of square metres were inhabited by assemblages substantially different from these inhabiting arable land and thus enhanced the biodiversity of agricultural landscapes. The non-crop habitat area substantially affected the activity density, recorded species richness and recorded species composition of carabid and ground-dwelling spider assemblages; however, the effects were weakened when species specialised to non-crop habitats species were analysed separately. Interestingly, recorded species richness of spiders increased with non-crop habitat area, whereas recorded species richness of carabid beetles exhibited an opposite trend. There was substantial temporal variation in the spatial distribution of ground-dwelling arthropods, and contrasting patterns were observed for particular taxa (carabid beetles and spiders). In general, local environmental conditions (i.e., non-crop habitat island tree cover, shrub cover, grass cover and litter depth) were better determinants of arthropod assemblages than non-crop habitat island

  3. 行间生草对葡萄园土壤水分含量及贮水量变化的影响%Effects of cover cropping system on soil moisture content and water storage in a vineyard

    Institute of Scientific and Technical Information of China (English)

    惠竹梅; 李华; 周攀; 岳泰新

    2011-01-01

    研究葡萄园生草对土壤水分影响,可为葡萄园生草在半干旱地区的应用和推广提供理论依据.在葡萄园种植多年生白三叶草、紫花苜蓿和高羊茅.采用TRIME-FM时域反射仪对生草葡萄园O~80 cm土层进行土壤水分定位观测,采用环刀法对O~60 cm土层土壤物理性状进行测定.结果表明,生草可改善葡萄园土壤物理性状,使0~60 cm土壤容重平均降低8.5%~9.8%,总孔隙度提高11.5%~13.9%.在不同降水年份,葡萄园行间生草均使土壤含水量降低,在2006及2007年,生草使0~80 cm土层土壤含水量平均降低幅度分别为2.3%~7.5%及10.7%~15.9%,在冬季贮水量不足、春季干旱的年份土壤含水量降低幅度较大.生草种类不同,对土壤贮水量及增减量的影响存在差异,紫花苜蓿区土壤贮水最较低.%Soil water content was closely correlated with application and extent of vineyard cover crop in a semiarid area. A permanent inter-row cover crop of Trifolium repens, Medicago sativa, and Festuca arundinacea in a vineyard was compared with clean tillage. Localized observation of soil moisture content in the 0-80 cmlayer with TRIME-FM TDR was carried out in the vineyard, and soil physical characteristics of the 0-60 cm layer were investigated using the cutting ring method. After planting grasses, the soil physical characteristics improved, soil bulk density of the 0-60 cm soil layer decreased by 8.5%-9.8%, and total soil porosity increased by 11.5 %-13.9 %. The soil moisture content of a grass-covered vineyard was considerably reduced in 2006 and 2007 compared with clean tillage and the average soil water content of the 0-80 cm depth was reduced by 2.3%-7.5% and 10.7%-15.9% respectively. The soil water content was severely reduced in a year with spring drought and shortage of soil moisture storage from the previous winter. Soil moisture storage and variation of water storage differed between sward treatments, and

  4. Macrofauna edáfica associada a plantas de cobertura em plantio direto em um Latossolo Vermelho do Cerrado Soil macrofauna communities and cover crops in a Cerrado Oxisol under no tillage

    Directory of Open Access Journals (Sweden)

    Glenio Guimarães Santos

    2008-01-01

    Full Text Available O objetivo deste trabalho foi caracterizar a macrofauna edáfica e avaliar o efeito de plantas de cobertura em plantio direto, nos principais grupos da macrofauna do solo, em duas épocas de avaliação em um Latossolo Vermelho distroférrico. O delineamento experimental foi o de blocos ao acaso, com oito tratamentos (plantas de cobertura e quatro repetições. As plantas de cobertura: Crotalaria juncea, guandu-anão (Cajanus cajan, Stylosanthes guianensis, Brachiaria brizantha, B. brizantha consorciada com milho (Zea mays, milheto (Pennisetum glaucum, mombaça (Panicum maximum e Sorghum bicolor foram cultivadas de novembro a abril. Em setembro de cada ano, foi realizado o plantio de feijão, em cultivo irrigado por pivô central. A área útil em cada parcela foi de 60 m². Amostras de solo na forma de monólitos (25x25 cm foram retiradas aleatoriamente em cada parcela, para contagem da macrofauna, às profundidades de 0-10 cm e 10-20 cm, em abril e em setembro de 2005. Os grupos taxonômicos, identificados em ordem decrescente de densidade relativa, são: Formicidae, Oligochaeta, Dermaptera, Coleoptera, Hemiptera, Miriapoda, Isoptera, Araneae, Lepidoptera, Blattodea e larvas de Diptera. Crotalaria juncea apresentou maior densidade de macrofauna, seguida por B. Brizantha, B. Brizantha consorciada com milho, Sorghum bicolor, Stylosanthes guianensis, Cajanus Cajans, Pennisetum Glaucum e Panicum maximum. O uso das plantas de cobertura, associado à irrigação na avaliação de setembro, favorece a colonização do solo pela macrofauna.The objective of this work was to characterize soil fauna groups and to evaluate the effects of cover crops under no-tillage system, in a Cerrado Oxisol, in two evaluation periods. The cover crops: Crotalaria juncea, Cajanus cajan, Stylosanthes guianensis, Brachiaria brizantha, Brachiaria brizantha/ Zea mays association, Pennisetum glaucum, Panicum maximum and Sorghum bicolor were cultivated from November to April

  5. Crescimento aéreo e radicular da soja e de plantas de cobertura em camadas compactadas de solo Shoot and root growth of soybean and