• Authors:
    • Dellow, J. J.
    • Schipp, A.
    • Haskins, B.
    • Brooke, G.
  • Source: Weed control in winter crops 2006
  • Year: 2006
  • Summary: This publication provides a guide to chemical weed control during different growth stages of fallow, wheat, barley, oats, rye, triticale, rape, safflower, lentil, linseed, lupin, chickpea, faba bean and field pea in New South Wales, Australia. Recommended timing of herbicide application is given. Sensitivity of winter crop cultivars to herbicides is outlined. Information is also included on crop rotation, use of surfactants and oils, water quality for herbicide application, spray equipment clean-up, herbicide spray drift, compatibility of winter crop herbicides and insecticides, and common retail prices of chemicals used on winter crops.
  • Authors:
    • Age Pedersen, C.
  • Source: Review of agricultural experiments 2006. Trials and research in the agronomy sector. Oversigt over Landsfors<o>gene 2006. Fors<o>g og unders<o>gelser i de land<o>konomiske foreninger.
  • Year: 2006
  • Summary: The organization and aims of the 'Landsforsgene', the collective name for the body that coordinates agricultural experiments in Denmark, are described. The growing season 2005-2006 in Denmark was characterized by long periods of severe drought in summer that resulted in lower crop yields, although the economic effect was mitigated to some extent by higher prices. Separate sections of the review deal with winter barley, winter rye, triticale, winter wheat, spring barley, oats, spring wheat, various seed crops, field seeds, winter rape, manures and calcium treatments, growing techniques, organic farming, potatoes, sugar beet, grass and green fodder crops, maize, plant breeding, general information on experimental design and aims, and a list of authors.
  • Authors:
    • Mallarino, A. P.
    • Parkin, T. B.
    • Laird, D. A.
    • Russell, A. E.
  • Source: Soil Science Society of America Journal
  • Volume: 69
  • Issue: 2
  • Year: 2005
  • Summary: Growing interest in the potential for agricultural soils to provide a sink for atmospheric C has prompted studies of effects of management on soil organic carbon (SOC) sequestration. We analyzed the impact on SOC of four N fertilization rates (0-270 kg N ha-1) and four cropping systems: continuous corn (CC) (Zea mays L.); corn-soybean [Glycine max (L.) Merr.] (CS); corn-corn-oat-alfalfa (oat, Avena sativa L.; alfalfa, Medicago sativa L.) (CCOA), and corn-oat-alfalfa-alfalfa (COAA). Soils were sampled in 2002, Years 23 and 48 of the experiments located in northeast and north-central Iowa, respectively. The experiments were conducted using a replicated split-plot design under conventional tillage. A native prairie was sampled to provide a reference (for one site only). Cropping systems that contained alfalfa had the highest SOC stocks, whereas the CS system generally had the lowest SOC stocks. Concentrations of SOC increased significantly between 1990 and 2002 in only two of the nine systems for which historical data were available, the fertilized CC and COAA systems at one site. Soil quality indices such as particulate organic carbon (POC) were influenced by cropping system, with CS < CC < CCOA. In the native prairie, SOC, POC, and resistant C concentrations were 2.8, 2.6, and 3.9 times, respectively, the highest values in cropped soil, indicating that cultivated soils had not recovered to precultivation conditions. Although corn yields increased with N additions, N fertilization increased SOC stocks only in the CC system at one site. Considering the C cost for N fertilizer production, N fertilization generally had a net negative effect on C sequestration.
  • Authors:
    • Dell, C. J.
    • Venterea, R. T.
    • Sauer, T. J.
    • Allmaras, R. R.
    • Reicosky, D. C.
    • Johnson, J. M. F
  • Source: Soil & Tillage Research
  • Volume: 83
  • Issue: 1
  • Year: 2005
  • Summary: The central USA contains some of the most productive agricultural land of the world. Due to the high proportion of land area committed to crops and pasture in this region, the carbon (C) stored and greenhouse gas (GHG) emission due to agriculture represent a large percentage of the total for the USA. Our objective was to summarize potential soil organic C (SOC) sequestration and GHG emission from this region and identify how tillage and cropping system interact to modify these processes. Conservation tillage (CST), including no-tillage (NT), has become more widespread in the region abating erosion and loss of organic rich topsoil and sequestering SOC. The rate of SOC storage in NT compared to conventional tillage (CT) has been significant, but variable, averaging 0.40 ± 0.61 Mg C ha-1 year-1 (44 treatment pairs). Conversion of previous cropland to grass with the conservation reserve program increased SOC sequestration by 0.56 ± 0.60 Mg C ha-1 year-1 (five treatment pairs). The relatively few data on GHG emission from cropland and managed grazing land in the central USA suggests a need for more research to better understand the interactions of tillage, cropping system and fertilization on SOC sequestration and GHG emission.
  • Authors:
    • Lal, R.
  • Source: Environment International
  • Volume: 31
  • Issue: 4
  • Year: 2005
  • Summary: Reducing and off-setting anthropogenic emissions of CO, and other greenhouse gases (GHGs) are important strategies of mitigating the greenhouse effect. Thus, the need for developing carbon (C) neutral and renewable sources of energy is more than ever before. Use of crop residue as a possible source of feedstock for bioenergy production must be critically and objectively assessed because of its positive impact on soil C sequestration.. soil quality maintenance and ecosystem functions. The amount of crop residue produced in the US is estimated at 367x10(6) Mg/year for 9 cereal crops, 450x10(6) Mg/year for 14 cereals and legumes, and 488x10(6) Mg/year for 21 crops. The amount of crop residue produced in the world is estimated at 2802x10(6) Mg/year for cereal crops, 3107x10(6) Mg/year for 17 cereals and legumes, and 3758x10(6) Mg/year for 27 food crops. The fuel value of the total annual residue produced is estimated at 1.5x10(15) kcal, about 1 billion barrels (bbl) of diesel equivalent, or about 8 quads for the US; and 11.3x10(15) kcal, about 7.5 billion bbl of diesel or 60 quads for the world. However, even a partial removal (30-40%) of crop residue from land can exacerbate soil erosion hazard, deplete the SOC pool, accentuate emission of CO, and other GHGs from soil to the atmosphere, and exacerbate the risks of global climate change. Therefore, establishing bioenergy plantations of site-specific species with potential of producing 10-15 Mg biomass/year is an option that needs to be considered. This option will require 40-60 million hectares of land in the US and about 250 million hectares worldwide to establish bioenergy plantations. (c) 2004 Elsevier Ltd. All rights reserved.
  • Authors:
    • Arshad, M.
    • Klein-Gebbinck, H.
    • Soon, Y.
  • Source: Canadian Journal of Plant Science
  • Volume: 85
  • Issue: 1
  • Year: 2005
  • Summary: Brown girdling root rot (BGRR) is a serious and widespread disease of canola ( Brassica rapa L.) in the Peace River region of northwestern Canada. There is no chemical control treatment for the pathogen, and farmers have observed that the disease is more severe when canola follows red fescue ( Festuca rubra L.) or clover ( Trifolium spp.) compared to summer fallow. A field study was conducted to determine how crop sequences following red fescue termination can be combined with residue and tillage management to reduce BGRR infection and increase canola yield. The five treatments consisted of rotations of: continuous canola (CCC) and oat ( Avena sativa L.)-oat-canola (OOC), both managed using reduced tillage (RT), and wheat ( Triticum aestivum L.)-wheat-canola (WWC), managed using RT, conventional tillage (CT) or no-till (NT). Canola yield followed the trend: OOC(RT)=WWC(RT) > WWC(CT) > CCC(RT)=WWC(NT). BGRR infection increased with tillage intensity: WWC(CT) > CCC(RT)=WWC(RT)=OOC(RT) > WWC(NT), and was reduced when canola followed two cereal break crops. Yield was highest when canola was preceded by a cereal crop and lowest without a break crop. The low yield with NT was attributed to poor crop emergence from a hard seed bed with unbroken turf and to competition from re-emerged fescue in the third year after fescue breaking. This study demonstrated that the cropping sequence and tillage system used influenced canola yield to a greater extent than did BGRR infection.
  • Authors:
    • Jamiokowska, A.
  • Source: Ochrona Roślin
  • Volume: 50
  • Issue: 1
  • Year: 2005
  • Summary: The importance of cover crops for protection of soil from water and aerial erosion, as well as leaching of nutrients from soil is emphasized. Use of green manures as a mechanical barrier against weeds, and beneficial effects of exudates of green manures on control of weeds, pests and diseases of vegetables are discussed. Recommendations are included for autumn and spring sowing of cover crops (e.g. rye, wheat, oat, barley, sorghum, vetch, rape and mustard), which are cut or desiccated in the spring and are left in the field as mulch. Negative effects of mulching are considered, i.e. a decrease of soil temperature in the spring resulting in a slower growth rate and later ripening of tomato. It is also stated that yield of some vegetables, including tomato, can be lower in the no-tillage cultivation compared with traditional cultivation. However, the dry matter content is higher in tomato grown with no-tillage. Field trials were conducted in Lublin, Poland, to study the effect of cover crops, such as rye, white and red clover, and field pea on health of tomato. Data are tabulated on fungi isolated from soil under tomato grown with rye and field pea as mulch crops compared with the traditional cultivation system during 1998-2000. The results showed that use of cover crops resulted in a good control of plant pathogens, especially Fusarium oxysporum f.sp. lycopersici, and an increase in the number of antagonistic fungi, e.g. Trichoderma spp. It is concluded that use of cover crops allows decrease of the number of mechanical cultivations, as well as decrease of the use of fertilizers, fungicides, insecticides and herbicides.
  • Authors:
    • Shimi, P.
    • Kazemi, H.
  • Source: Iranian Journal of Weed Science
  • Volume: 1
  • Issue: 1
  • Year: 2005
  • Summary: An isolate of F. moniliforme [Gibberella moniliformis], a pathogen of winter wild oat (A. ludoviciana [A. sterilis var. ludoviciana]), was obtained from Tehran Province, Iran, in 1994. A host range test performed on wheat, barley, maize, rye, millet, crested wheatgrass, faba bean, red bean, green bean, sunflower, soyabean, oilseed rape, cotton, safflower, cucumber, water melon, berseem clover, and sainfoin, resulted in no symptom induction by the pathogen. However, winter wild oat, crested wheatgrass, johnsongrass and tomato showed susceptibility to the pathogen with 78, 24, 19 and 17% mortality, respectively. The results indicate that this pathogen could be considered as a potential biological agent for the control of winter wild oat.
  • Authors:
    • Kim,J. G.
    • Chung,E. S.
    • Seo,S.
    • Kim,M. J.
    • Chang,Y. S.
    • Chung,B. C.
  • Source: Han'gug coji hag'hoeji
  • Volume: 25
  • Issue: 3
  • Year: 2005
  • Summary: This study was conducted to determine the effect of nitrogen fertilizer levels and mixture of small grains on the productivity and quality of spring forage rape (Brassica napus) in the south region of Korea (Mokpo). The experiment was arranged in a split plot design with three replications. The main plots consisted of three different levels of nitrogen fertilizer (100, 150 and 200 kg/ha). The sub-plots consisted of five kinds of mixed small grain species (rye (Secale cereale), oat (Avena sativa), barley (Hordeum vulgare), italian ryegrass (Lolium multiflorum), and rape (B. napus) monoculture). The results were summarized as follows: (1) dry matter (DM) content of rye+rape and barley+rape mixtures increased by 2-3% compared to rape monoculture. The high level of nitrogen application increased the fresh matter yield and yield of rye+rape monoculture were higher than that of others; (2) dry matter yield of rye+rape mixture and rape monoculture with 200 kg/ha of nitrogen application were higher by 9449 and 9227 kg/ha, respectively; (3) the crude protein (CP) content of rape was high as 18.6% while average CP content was 16%. (4) The average total digestible nutrient (TDN) content showed high as 70%. It is suggested that the rye+rape mixture or rape monoculture would recommended for spring use of rape in the southern region of Korea.
  • Authors:
    • Clayton, G. W.
    • Harker, K. N.
    • Blackshaw, R. E.
    • O'Donovan, J.
    • Maurice, D. C.
  • Source: Canadian Journal of Plant Science
  • Volume: 85
  • Issue: 4
  • Year: 2005
  • Summary: Various regression equations based on weed density alone, or relative time of weed and crop emergence or crop density in addition to weed density have been developed in western Canada to estimate the effects of wild oat (Avena fatua L.) and volunteer cereals on yield loss of field crops, and to advise farmers on the economics of weed control with herbicides. In 1997, 1998, and 1999, several of these equations were evaluated in 9 barley (Hordeum vulgare L.), 9 wheat (Triticum aestivum L.) and 11 canola (Brassica napus L.) fields in Alberta. Wild oat was the dominant weed in the barley and wheat fields, and wild oat or volunteer cereals in the canola fields. In barley and wheat, more complex equations based on both weed density and either crop density or relative time of weed and crop emergence were more reliable in estimating yield losses due to wild oat than those based on weed density alone. In canola, an equation based on volunteer barley and canola density provided the most reliable estimates. Under the assumed crop prices and herbicide costs, these equations also resulted in the best estimates of whether or not a herbicide application resulted in a net profit or loss. Herbicide application was rarely economical in barley, but usually economical in wheat and canola reflecting the different market value of the crops. The implementation of the weed economic threshold concept is likely to be more feasible in low-value crops such as feed barley than in higher-value crops such as canola.