• Authors:
    • Smith, H. J.
    • Trytsman, G.
    • Bloem, J. F.
  • Source: Biological Nitrogen Fixation: Towards Poverty Alleviation through Sustainable Agriculture
  • Volume: 48
  • Issue: 1-3
  • Year: 2009
  • Summary: Farm lands of resource-poor communities in South Africa are depleted of nutrients due to continuous mono-cropping, limited use of fertilisers, and sometimes leaching caused by high rainfall. Despite the well-known advantages of biological nitrogen fixation (BNF) in cropping systems, less than 10% of the grain crops planted annually in these areas are legumes. Using a participatory research and development approach, resource-poor farmers were introduced to conservation agriculture (CA) practices, including BNF, that promoted zero (or reduced) tillage, increased retention of soil cover, as well as crop diversification. Because crop rotation and intercropping of legumes with cereals are known to contribute to soil fertility while enhancing food security, resource-poor fanners from various Provinces in South Africa were trained on the benefits of legume culture for eight years. As a result, these resource-poor farmers did not only get training in inoculation techniques, but were also supplied with inoculants for use on their farms. Data collected from Farmers Demonstration Trials at Belvedere, Dumbarton and Lusikisiki, showed that the grain and fodder yield of maize planted after legumes, and maize intercropped with legumes, were comparable to those of maize receiving high N fertilizer dose (i.e. 54 kg N at planting and 54 kg N as top-dressing). The same data further showed that Rhizobium inoculation, when combined with application of low levels of P and K. significantly increased crop yields within farmers' trial plots. BNF therefore offers a great opportunity for resource-poor farmers in South Africa to increase their crop yields and thus improve the quality of their livelihoods through the adoption of affordable and sustainable biological technologies that enhance soil fertility.
  • Authors:
    • Bolotova, N. S.
  • Source: Kormoproizvodstvo
  • Issue: 12
  • Year: 2009
  • Summary: Techniques and standards for production of haylage and silage from high-protein fodder mixtures of pea, oat, rape, vetch, barley, beans, rye, wheat and maize are discussed. Plants should be cut into 15-20 mm pieces when the protein content of fodder mixture is over 30%, and into 40-50 mm pieces when the protein content of fodder mixture is less than 20%. Bales of silage mass are wrapped in film and roll size is 1.2 m wide and 0.8-1.6 m in diameter. The high yield of maize, vetch, and oat-rape mixture achievable in the conditions of European Russia is 10.8 t/ha of dry mass and 1.2 t/ha of protein.
  • Authors:
    • Blackshaw, R. E.
  • Source: Crop Protection
  • Volume: 27
  • Issue: 2
  • Year: 2008
  • Summary: Cover crops may have a valuable role to play in developing improved dry bean production systems. A field experiment was conducted to determine the agronomic benefits of including various fall-seeded and spring-seeded cereal cover crops with and without in-crop herbicides in dry bean. Main plot treatments included fall-seeded winter rye, barley, oat, and spring rye; spring-seeded barley, oat, and spring rye; and a no-cover crop control. Subplot treatments consisted of in-crop sethoxydim/bentazon and an untreated control. Fall-seeded cover crops were often superior to spring-seeded cover crops in terms of providing sufficient ground cover to reduce the risk of soil erosion and reducing weed emergence and growth. Among the fall-seeded cover crops, winter rye provided the greatest ground cover and often resulted in the greatest weed suppression. Dry bean density was not affected by any of the cover crops, but fall-seeded cover crops delayed emergence by up to 5 days and delayed maturity by up to 4 days. Cover crop effects on dry bean yield were most evident in the absence of in-crop herbicides, where fall-seeded cover crops increased dry bean yield by 20-90%. Cover crops also increased dry bean yield in 2 of 3 years when in-crop herbicides were used but yield increases were much smaller, ranging from 5% to 13%. These yield increases occurred with fall-seed cover crops that aided in weed management but also with spring-seeded cover crops where weed suppression was not evident, suggesting that cover crops provided additional benefits beyond weed management. Information gained in this study will be utilized to advise farmers on the most suitable use of cover crops in sustainable dry bean production systems.
  • Authors:
    • Bellinder, R. R.
    • Brainard, D. C.
    • Hahn, R. R.
    • Shah, D. A.
  • Source: WEED SCIENCE
  • Volume: 56
  • Issue: 3
  • Year: 2008
  • Summary: Three major hypotheses were examined in this study: (1) the density of summer annual weeds is reduced in crop rotation systems that include winter wheat compared to those with strictly summer annual crops, (2) the integration of a red clover in cropping systems reduces weed seedbank densities, and (3) changes in weed seedbanks due to crop rotation system have greater impact on future crops that are managed with cultivation alone, compared to those managed with herbicides. To test these hypotheses, five 3-year rotation sequences were examined in central New York state, USA: continuous field maize (FC); field maize with red clover (FC+CL); field maize-oats-wheat (FC/O/W); sweetcorn-peas-wheat (SC/P/W), and SC/P/W with red clover (SC/P/W+CL). In the fourth year, sweetcorn, snap beans, and cabbage were planted in subplots with three levels of weed management as sub-subplots: cultivation alone, reduced-rate herbicides (1/2*), and full-rate herbicides (1*). The trial was carried out in two separate cycles, from 1997 to 2000 (cycle 1) and from 1998 to 2001 (cycle 2). Crop rotations with strictly summer annual crops (FC) did not result in consistently higher weed seedbank densities of summer annual weeds compared to rotations involving winter wheat (FC/O/W; SC/P/W; SC/P/W+CL). Integration of red clover in continuous field maize resulted in higher weed seedbanks (cycle 1) or emergence (cycle 2) of several summer annual weeds compared to field maize alone. In contrast, integration of red clover in the SC/P/W rotation led to a 96% reduction in seedbank density of winter annuals in cycle 1, although this effect was not detected in cycle 2. Observed changes in weed seedbank density and emergence due to crop rotation resulted in increased weed biomass in the final year in only one case (sweetcorn, cycle 2), and did not result in detectable differences in crop yields. In contrast, final year weed management had a strong effect on weed biomass and yield; cultivation alone resulted in yield losses for sweetcorn (32 to 34%) and cabbage (0 to 7%), but not snap beans compared to either 1/2* or 1* herbicides.
  • Authors:
    • Blecharczyk, A.
    • Maecka, I.
  • Source: Agronomy Research
  • Volume: 6
  • Issue: 2
  • Year: 2008
  • Summary: Yield, N uptake, weeds and diseases of spring barley were examined under five mulching practices (white mustard, phacelia, oat-pea mixture, straw mulch, and no mulch), three tillage systems (conventional, reduced and no-tillage) and three doses of nitrogen fertilization (0, 50 and 100 kg N ha -1). In general the grain yield of spring barley for cover crops was 10-31% higher compared with the no-mulch treatment. A mulch of straw provided a smaller barley grain yield than the no-mulch treatment. Compared to conventional tillage, grain yield under reduced tillage and no-tillage were 7 and 12% less, respectively. Spring barley sowing after a mixture of oat-pea led to decreased a negative response of reduced and no-tillage. Grain yield after treatment with legume cover crops and without N fertilization was similar compared as the rates 50 kg N ha -1 after white mustard or phacelia and as the rate 100 kg N ha -1 without mulches. There was no evidence of tillage * N fertilization interaction on grain yield, dry matter production and plant-N uptake. Cover crops and straw mulch significantly decreased total weed populations compared with the treatment without mulch. Total weed density increased from 108 plants per m 2 in the no-tillage to 322 plants per m 2 for reduced tillage, and to 416 plants per m 2 for the conventional tillage over mulch. Higher infestation of spring barley with stem base and root diseases was observed in reduced and no-tillage in comparison with the conventional soil tillage and after straw mulch and no-mulch than after cover crops.
  • Authors:
    • Starkova, D. L.
    • Platunov, A. A.
  • Source: Kormoproizvodstvo
  • Issue: 8
  • Year: 2008
  • Summary: The effect of soil moisture level on development of perennial leguminous grasses in conditions of the Kirov region, Russia, is considered. The results of previous field trials revealed that the soil moisture content was higher under winter rye compared with spring crops or the absence of crops. Growing of a vetch-oat mixture for green fodder resulted in the driest soil conditions compared with oat, barley and wheat. Advantages of growing birdsfoot trefoil under the cover of cereal crops are discussed as a way of weed control, also resulting in better soil water conditions. However, birdsfoot trefoil had more light and soil moisture content and showed more intensive above-ground growth in the absence of a crop cover. Field trials were conducted to study the complex relationship between the growth and yield of spring and winter crops, availability of water and light, and weed control and production of high yield of green fodder. Data are tabulated on development and green fodder yield of birdsfoot trefoil during the 1st and 2nd years of growth without plant cover compared with growth under the cover of winter rye, barley, wheat, oat and vetch + oat in 2005 and 2006. Overall results confirmed advantages of growing birdsfoot trefoil under spring crops, especially oat, a vetch-oat mixture and wheat for higher yield of green fodder.
  • Authors:
    • Pridham, J. C.
    • Entz, M. H.
  • Source: Agronomy Journal
  • Volume: 100
  • Issue: 5
  • Year: 2008
  • Summary: The success of organic wheat ( Triticum aestivum L.) production can be severely inhibited by weed and disease pressures. This study sought to determine the effectiveness of wheat intercrop mixtures in suppressing weeds and diseases and increasing grain yield and net return. Field experiments were conducted on organically managed land in 2004 and 2005 and three representative intercrop systems were tested: wheat with other cereals [oats ( Avena sativa L.), barley ( Hordeum vulgare L.), and spring rye ( Secale cereale L.)]; wheat and noncereal seed crops (flax [ Linum usitatissimum L.], field pea [ Pisum sativum L.], oriental mustard [ Brassica juncea L.]); and wheat and cover crops (red clover [ Trifolium pratense L.], hairy vetch [ Vicia villosa L.], annual ryegrass [ Lolium multiflorum Lam.]). The cereal intercrop systems provided no consistent yield benefit over wheat monocultures. Results from noncereal-wheat intercrops were variable. Wheat-flax reduced the wheat crop to unacceptable levels but was capable of reducing wheat flag leaf disease levels. Wheat-field pea resulted in the lowest disease levels, yet had inconsistent yields, and more weeds than wheat monoculture. Wheat-mustard did not reduce weeds or diseases, but it was capable of high grain yields and net returns, though usually hampered by flea beetle ( Phyllotreta cruciferae) attack. The effect of cover crops on wheat was affected by environment. Wheat-red clover and wheat-hairy vetch did demonstrate the ability to maintain high wheat grain yield in certain site-years. In conclusion, wheat intercrop mixtures provided little short-term benefit over monoculture wheat in this study.
  • Authors:
    • Singer, J.
  • Source: Agronomy Journal
  • Volume: 100
  • Issue: 6
  • Year: 2008
  • Summary: Surveying end-users about their use of technologies and preferences provides information for researchers and educators to develop relevant research and educational programs. A mail survey was sent to Corn Belt farmers during 2006 to quantify cover crop management and preferences. Results indicated that the dominant cereal cover crops in Indiana and Illinois are winter wheat ( Triticum aestivum L.) and cereal rye ( Secale cereale L.), cereal rye and oat ( Avena sativa L.) in Iowa, and oat in Minnesota. Legumes were used more frequently in Indiana and Illinois, and red clover ( Trifolium pratense L.) was the dominant choice across the region. Farmers relied solely on herbicides 54% of the time to kill cover crops. Ninety-three percent of respondents indicated that they received no cost sharing for using cover crops and 14% indicated that they would plant cover crops on rented land. Corn Belt farmers prefer cover crops that overwinter (68%) and fix N (64%). The information provided in this survey supplements existing knowledge that can be used to develop relevant research and educational programs to address agronomic production systems that include cover crops.
  • Authors:
    • Jones, C. A.
    • Buschena, D. E.
    • Miller, P. R.
    • Holmes, J. A.
  • Source: Agronomy Journal
  • Volume: 100
  • Issue: 3
  • Year: 2008
  • Summary: Transition to no-till (NT) and organic (ORG) farming systems may enhance sustainability. Our objectives were to compare transitional crop productivity and soil nutrient status among diversified NT and ORG cropping systems in Montana. Three NT systems were designed as 4-yr rotations, including a pulse (lentil [ Lens culinaris Medik.] or pea [ Pisum sativum L.]), an oilseed (canola [ Brassica napus L.] or sunflower [ Helianthus annuus L.]) and two cereal crops (corn [ Zea mays L.], proso millet [ Panicum miliaceum L.], or wheat [ Triticum aestivum L.]). No-till continuous wheat was also included. The ORG system included a green manure (pea), wheat, lentil, and barley ( Hordeum vulgare L.) and received no inputs. Winter wheat in the ORG system yielded equal or greater than in the NT systems, and had superior grain quality, even though 117 kg N ha -1 was applied to the NT winter wheat. After 4 yr, soil nitrate-N and Olsen-P were 41 and 14% lower in the ORG system, whereas potentially mineralizable N was 23% higher in the ORG system. After 4 yr, total economic net returns were equal between NT and ORG systems on a per-ha basis. Studying simultaneous transition to diversified NT and ORG cropping systems was instructive for increased sustainability.
  • Authors:
    • Kang, J.
    • Osmond, D. L.
  • Year: 2008