• Authors:
    • Humburg, D. S.
    • Schumacher, T. E.
    • Osborne, S. L.
  • Source: Agricultural Journal
  • Volume: 3
  • Issue: 5
  • Year: 2008
  • Summary: Although no-till soil management has many benefits, including protecting the soil from erosion, improving soil organic matter and improving soil moisture storage, depending on environmental conditions there could be a number of potential problems. Implementation of no-till soil management in eastern South Dakota can lead to wet and cold soils at the time of planting. Cover crops have the potential to utilize excess soil moisture and improve soil conditions at planting. A field experiment was established to evaluate the impact of 14 different cover crop species as well as no cover crop and conventional tillage on soil conditions prior to corn planting and the impact on corn yield and quality. The experimental design was a randomized complete block design with 4 replications. Cover crops evaluated include a mixture of grass, legumes, cool and warm season crops. All cover crops were planted in early August (following spring wheat harvest) at recommended seeding rates. The following spring all plots were planted to corn ( Zea mays L.). The experiment was conducted in a 3 year crop rotation (soybean [ Glycine max (L.) Merrill]/spring wheat ( Triticum aestivum L.)-cover crop/corn). Cover crop species that survived the winter included hairy vetch, red clover, sweet clover, Alsike clover, slender wheatgrass and winter ryegrass. The presence of these species increased soil strength and reduced soil moisture. Corn grown following hairy vetch was the only treatment that exhibited a significant reduction in plant population. Corn yield for plots grown under red clover, winter ryegrass and no cover crop had yield significantly higher than corn grown after conventional tillage, hairy vetch and slender wheatgrass. This experiment illustrated the ability of cover crops to utilize excess soil moisture and increase soil strength compared to conventional tillage or no cover crop.
  • Authors:
    • Suzuki, L. G. A. S.
    • Alves, M. C.
    • Suzuki, L. E. A. S.
    • Rodrigues, R. A. F.
  • Source: Científica, Jaboticabal
  • Volume: 36
  • Issue: 2
  • Year: 2008
  • Summary: The objective of this study was to verify the biomass yield potential of different cover crops in a Cerrado region, in Selviria, Mato Grosso do Sul, Brazil. The work was conducted in the Experimental University Farm of the Paulista State University (UNESP). The experimental design was the randomized complete blocks in strips with splitsplit plot: the plots were the cover crops Mucuna aterrima, Pennisetum americanum, Crotalaria juncea, Cajanus cajan and a fallow area; the split plots were the no-tillage and the conventional tillage, and the splitsplit plots were corn ( Zea mays L.), soybean ( Glycine max (L.) Merrill), and cotton ( Gossypium hirsutum L.) crops. In the winter irrigated Phaseolus vulgaris L. was the crop. In the spring/summer season the cover crop with the greatest biomass yield was Pennisetum americanum. Crotalaria juncea and the fallow area showed medium results while Mucuna aterrima and Cajanus cajan were those with the least yields. Pennisetum americanum was the crop cover with the biggest production potential of dry biomass. The cultivation systems did not influence the dry biomass of the cover crops. Only Pennisetum americanum production was influenced by crop sequence.
  • Authors:
    • Santini, J. B.
    • Vyn, T. J.
    • Faghihi, J.
    • Ferris, V. R.
    • Westphal, A.
    • Creech, J. E.
    • Johnson, W. G.
  • Source: Weed Science
  • Volume: 56
  • Issue: 1
  • Year: 2008
  • Summary: Certain winter annual weeds have been documented as alternative hosts to soybean cyst nematode (SCN), and infestations of such species have become common in no-till production fields in the Midwest. This research was conducted to determine the influence of herbicide- and cover-crop-based winter annual weed management systems and crop rotation on winter annual weed growth and seed production, SCN population density, and crop yield. Two crop rotations (continuous soyabean and soyabean-maize) and six winter annual weed management systems (a nontreated control, autumn and spring herbicide applications, spring-applied herbicide, autumn-applied herbicide, autumn-sown annual ryegrass, and autumn-sown winter wheat) were evaluated in no-tillage systems from autumn 2003 to 2006 at West Lafayette and Vincennes, Indiana. Autumn or spring herbicide treatments generally resulted in lower winter annual weed densities than cover crops. Densities of henbit and purple deadnettle increased over years in the cover crop systems but remained constant in the herbicide systems. Averaged over sites and years, winter annual weed densities were nearly 45% lower in the spring than the autumn due to winter mortality. Maize yield was reduced by the cover crops at West Lafayette but not Vincennes. Winter annual weed management system had no influence on soyabean yield. SCN population density was reduced by including maize in the crop sequence but was not influenced by winter annual weed management. The density of weedy host species of SCN in the experimental area was relatively low (less than 75 plants m -2) compared to densities that can be observed in production fields. The results suggest that inclusion of maize into a cropping sequence is a much more valuable SCN management tool than winter annual weed management. In addition, control of winter annual weeds, specifically for SCN management, may not be warranted in fields with low weed density.
  • Authors:
    • Anderson, R. L.
  • Source: Weed Technology
  • Volume: 22
  • Issue: 1
  • Year: 2008
  • Summary: Producers are interested in tactics for managing crop residues when growing maize after spring wheat. We compared five systems of managing spring wheat residues: conventional tillage, no-till, strip-till, cover crop (hairy vetch) with no-till, and cover crop with strip-till following spring wheat. Conventional tillage consisted of chisel ploughing and discing, whereas strip-till consisted of tilling a 15-cm band centred on maize rows, which were spaced 76 cm apart. Plots were split into weed-free and weed-infested subplots. Grain yield in weed-free conditions did not differ among treatments. However, weed-free yield was nearly 40% greater than weed-infested maize in conventional tillage. In contrast, weeds reduced yield only 15% with strip-till. Weed density and biomass was two-fold greater with conventional tillage compared with the no-till and strip-till treatments. Weed seedlings also emerged earlier with conventional tillage. Increased weed tolerance with strip-till may be related to fertilizer placement. Maize growth and tolerance to weeds in no-till systems may be improved if a starter fertilizer is placed in the seed furrow.
  • Authors:
    • Correia, M. E. F.
    • Mercante, F. M.
    • Silva, R. F. da
    • Aquino, A. M. de
    • Guimaraes, M. de F.
    • Lavelle, P.
  • Source: European Journal of Soil Biology
  • Volume: 44
  • Issue: 2
  • Year: 2008
  • Summary: This work was aimed at evaluating the invertebrate macrofauna community in the soil, by means of its abundance and richness of groups under different plant covers in the no-till system. Evaluations were performed at the experimental field of Embrapa Agropecuaria Oeste, in the municipal district of Dourados-MS, on a Typic Hapludox under conventional, no-till, and natural systems. Samplings were performed in December 2000, June 2001, January 2002, and June 2002. Five soil monoliths measuring 0.25*0.25 m width and 0.30 m depth were sampled along a transect. Turnip residues before a corn crop (turnip/corn) and soybean residues before wheat and turnip crops (soybean/wheat and soybean/turnip) provided positive effects on the density and diversity of the edaphic macrofauna community.
  • Authors:
    • Moraes, A.
    • Balbinot Junior, A.
    • Backes, R.
  • Source: PLANTA DANINHA
  • Volume: 25
  • Issue: 3
  • Year: 2007
  • Summary: Straw on the soil significantly reduces weed infestation under no-tillage system. The potential of winter cover crops and their management timing in reducing weed infestation in maize crop were studied in Canoinhas, Santa Catarina, Brazil, in 2003/04 and 2004/05. In the first experiment, 6 winter cover crops were investigated: oilseed radish, black oat [ Avena nuda], rye, ryegrass [ Lolium sp.], intercropped among black oat and common vetch [ Vicia sativa] and among oilseed radish, black oat, rye, ryegrass and common vetch. These cover crops were slashed down at three different times before maize sowing (1, 10 and 25 days). In the second experiment, the potential to reduce weed infestation was investigated in the 6 cover crops previously mentioned, plus the common vetch. The straw of ryegrass and from intercropping among the 5 species used had a high capacity to suppress weed emergence and dry matter production, while oilseed radish straw showed low weed suppression potential. The winter cover crops slashed down next to maize sowing decreased the weed infestation.
  • Authors:
    • Backes, R.
    • Moraes, A.
    • Balbinot Junior, A.
    • Souza, A.
  • Source: Scientia Agraria
  • Volume: 8
  • Issue: 2
  • Year: 2007
  • Summary: A study was undertaken in Canoinhas, Santa Catarina, Brazil, during 2004/05 season to evaluate the effect of cover crop desiccation time in relation to maize sowing on the weed infestation and maize yield. Ryegrass ( Lolium multiflorum) as a single crop and in an intercropping system (rye grass+black oat ( Avena strigosa [ A. nuda])+rye+common vetch ( Vicia sativa)+oilseed radish) were desiccated 5 times at 1, 10 20 and 30 days before maize sowing. Cover crop management near maize sowing decreased the density and mass accumulation of weeds and improved the maize grain yield.
  • Authors:
    • Piza, R.
    • Camargo, R.
  • Source: Bioscience Journal
  • Volume: 23
  • Issue: 3
  • Year: 2007
  • Summary: The effect of different cover crops on maize yield was investigated in the second no-till year, in Passos, Minas Gerais, Brazil. White oats ( Avena sativa), black oats [ Avena nuda], Brachiaria decumbens [ Urochloa decumbens] and forage turnips were cultivated in the same plots as in the previous winter, and were subsequently sown with maize. The forage crops were sown in lines in May 2004 and desiccated in October 2004, after the determination of dry matter yield. Maize was sown in each plot and the soil organic matter and grain yield were determined at the end of the cropping season. The black oats yielded the greatest amount of mulch; however, this increase did not affect the soil organic matter, in relation to all other treatments, and maize yield in the no-till system.
  • Authors:
    • Dimitrova, T.
  • Source: Herbologia
  • Volume: 8
  • Issue: 1
  • Year: 2007
  • Summary: Field experiments were conducted in Pleven, Bulgaria, from 2003 to 2005, on slightly leached chernozem and a natural background of weed infestation, to determine the effect of weeds and their control by using the herbicide imazamox alone or combined with an adjuvant (Desh) and with oat as a cover crop, on the grain productivity of spring forage pea. It was found that at a high weed infestation degree and under the conditions of the study, the reduction of spring forage pea yield reached approximately 33%, imazamox 40 a.i./litre at 24 ml a.i./ha + 500 ml Desh/ha could be applied to spring forage pea at the 3-5 leaf stage to control the annual mono- and dicotyledonous weeds. The treatment with the herbicide at the mentioned rate resulted in a decrease of weed infestation degree by 96% and an increase of grain yield by 43% (on average for a 3-year period). Oat, sown as a cover crop for pea, decreased the weed infestation degree by 55% and the grain yield was 17% higher than that from the pure untreated stand.
  • Authors:
    • Libardi, P. L.
    • Fernandes, F. C. S.
    • Silva, M. M. da
  • Source: Acta Scientiarum Agronomy
  • Volume: 29
  • Issue: Suplemento Espec
  • Year: 2007
  • Summary: The present study evaluated the effect of nitrogen levels and splittings on the chemical characteristics of a soil cropped with maize in succession to black oats at the establishment of the no tillage system. The experiment was carried out in a Red-Yellow Latosol (typic Hapludox), with 14% of clay in the 0-0.20 m soil layer. The work consisted of two maize crops (2003/04 and 2004/05) and a black oats one in between, as cover crop. The experimental design was randomized blocks in an incomplete factorial scheme, with four replications. Treatments consisted of nitrogen levels (60, 120 and 180 kg ha -1) and one control without nitrogen, besides the splittings (30 or 60 kg ha -1 at sowing, the balance in cover and 60 kg ha -1 at sowing, remaining top dressed). The following soil variables were evaluated: Ca, Mg, K, organic matter, P, H+Al, Al, sum of bases, CEC, pH and base saturation V(%). Ammonium sulfate fertilization top dressed promoted a pH decrease in all treatments after the second maize crop and the increase in the level of N decreased the contents of soil Ca, Mg and K.