• 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:
    • VandenBygaart, A. J.
    • Angers, D. A.
    • Rochette, P.
    • Gregorich, E. G.
  • Source: Soil & Tillage Research
  • Volume: 83
  • Issue: 1
  • Year: 2005
  • Summary: Agricultural soils can constitute either a net source or sink of the three principal greenhouse gases, carbon dioxide (CO2), nitrous oxide (N2O), and methane (CH4). We compiled the most up-to-date information available on the contribution of agricultural soils to atmospheric levels of these gases and evaluated the mitigation potential of various management practices in eastern Canada and northeastern USA. Conversion of native ecosystems to arable cropping resulted in a loss of ~22% of the original soil organic carbon (C)--a release of about 123 Tg C to the atmosphere; drainage and cultivation of organic soils resulted in an additional release of about 15 Tg C. Management practices that enhance C storage in soil include fertilization and legume- and forage-based rotations. Adopting no-till did not always increase soil C. This apparent absence of no-till effects on C storage was attributed to the type and depth of tillage, soil climatic conditions, the quantity and quality of residue C inputs, and soil fauna. Emission of N2O from soil increased linearly with the amount of mineral nitrogen (N) fertilizer applied (0.0119 kg N2O-N kg N-1). Application of solid manure resulted in substantially lower N2O emission (0.99 kg N2O-N ha-1 year-1) than application of liquid manure (2.83 kg N2O-N ha-1 year-1) or mineral fertilizer (2.82 kg N2O-N ha-1 year-1). Systems containing legumes produced lower annual N2O emission than fertilized annual crops, suggesting that alfalfa (Medicago sativa L.) and other legume forage crops be considered different from other crops when deriving national inventories of greenhouse gases from agricultural systems. Plowing manure or crop stubble into the soil in the autumn led to higher levels of N2O production (2.41 kg N2O-N ha-1 year-1) than if residues were left on the soil surface (1.19 kg N2O-N ha-1 year-1). Elevated N2O emission during freeze/thaw periods in winter and spring, suggests that annual N2O emission based only on growing-season measurements would be underestimated. Although measurements of CH4 fluxes are scant, it appears that agricultural soils in eastern Canada are a weak sink of CH4, and that this sink may be diminished through manuring. Although the influence of agricultural management on soil C storage and emission of greenhouse gases is significant, management practices often appear to involve offsets or tradeoffs, e.g., a particular practice may increase soil C storage but also increase emission of N2O. In addition, because of high variability, adequate spatial and temporal sampling are needed for accurate estimates of greenhouse gas flux and soil C stock. Therefore a full accounting of greenhouse gas contributions of agricultural soils is imperative for determining the true mitigation potential of management practices.
  • Authors:
    • Al-Kaisi, M. M.
    • Yin, X.
    • Licht, M. A.
  • Source: Applied Soil Ecology
  • Volume: 30
  • Issue: 3
  • Year: 2005
  • Summary: A wide range of tillage systems have been used by producers in the Corn-Belt in the United States during the past decade due to their economic and environmental benefits. However, changes in soil organic carbon (SOC) and nitrogen (SON) and crop responses to these tillage systems are not well documented in a corn-soybean rotation. Two experiments were conducted to evaluate the effects of different tillage systems on SOC and SON, residue C and N inputs, and corn and soybean yields across Iowa. The first experiment consisted of no-tillage (NT) and chisel plow (CP) treatments, established in 1994 in Clarion-Nicollet-Webster (CNW), Galva-Primghar-Sac (GPS), Kenyon-Floyd-Clyde (KFC), Marshall (M), and Otley-Mahaska-Taintor (OMT) soil associations. The second experiment consisted of NT, strip-tillage (ST), CP, deep rip (DR), and moldboard plow (MP) treatments, established in 1998 in the CNW soil association. Both corn and soybean yields of NT were statistically comparable to those of CP treatment for each soil association in a corn-soybean rotation during the 7 years of tillage practices. The NT, ST, CP, and DR treatments produced similar corn and soybean yields as MP treatment in a com-soybean rotation during the 3 years of tillage implementation of the second experiment. Significant increases in SOC of 17.3, 19.5, 6.1, and 19.3% with NT over CP treatment were observed at the top 15-cm soil depth in CNW, KFC, M, and OMT soil associations, respectively, except for the GPS soil association in a corn-soybean rotation at the end of 7 years. The NT and ST resulted in significant increases in SOC of 14.7 and 11.4%, respectively, compared with MP treatment after 3 years. Changes in SON due to tillage were similar to those observed with SOC in both experiments. The increases in SOC and SON in NT treatment were not attributed to the vertical stratification of organic C and N in the soil profile or annual C and N inputs from crop residue, but most likely due to the decrease in soil organic matter mineralization in wet and cold soil conditions. It was concluded that NT and ST are superior to CP and MP in increasing SOC and SON in the top 15 cm in the short-term. The adoption of NT or CP can be an effective strategy in increasing SOC and SON in the Corn-Belt soils without significant adverse impact on corn and soybean yields in a corn-soybean rotation.
  • Authors:
    • Al-Kaisi, M.
    • Yin, X.
  • Source: Journal of Environmental Quality
  • Volume: 34
  • Issue: 437
  • Year: 2005
  • Summary: Soil C change and CO2 emission due to different tillage systems need to be evaluated to encourage the adoption of conservation practices to sustain soil productivity and protect the environment. We hypothesize that soil C storage and CO2 emission respond to conservation tillage differently from conventional tillage because of their differential effects on soil properties. This study was conducted from 1998 through 2001 to evaluate tillage effects on soil C storage and CO2 emission in Clarion-Nicollet-Webster soil association in a corn [Zea mays L.]-soybean [Glycine max (L.) Merr.] rotation in Iowa. Treatments included no-tillage with and without residue, strip-tillage, deep rip, chisel plow, and moldboard plow. No-tillage with residue and strip-tillage significantly increased total soil organic C (TC) and mineral fraction C (MFC) at the 0 to 5 and 5 to 10cm soil depths compared with chisel plow after 3 yr of tillage practices. Soil CO2 emission was lower for less intensive tillage treatments compared with moldboard plow, with the greatest differences occurring immediately after tillage operations. Cumulative soil CO2 emission was 19 to 41% lower for less intensive tillage treatments than moldboard plow, and it was 24% less for no-tillage with residue than without residue during the 480-h measurement period. Estimated soil mineralizable C pool was reduced by 22 to 66% with less intensive tillage treatments compared with moldboard plow. Adopting less intensive tillage systems such as no-tillage, strip-tillage, deep rip, and chisel plow and better crop residue cover are effective in reducing CO2 emission and thus improving soil C sequestration in a corn-soybean rotation.
  • 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:
    • Spiridon, C.
    • Rotarescu, M.
    • Raranciuc, S.
    • Guran, M.
    • Popov, C.
    • Vasilescu, S.
    • Gogu, F.
  • Source: Probleme de Protectia Plantelor
  • Volume: 33
  • Issue: 1/2
  • Year: 2005
  • Summary: The paper presents the harmful organisms which attacked the field crops in 2004. It is emphasized the occurrence and spreading of the most important pathogens and harmful insects in cereals, grain legumes, industrial and fodder crops as well as their role on yield quality and quantity. In Romania, the most important issues of plant protection in 2004, by the economic impact and applied chemical measures were those determined by the following pathogens and harmful insects. The soil and seed pathogens were: Tilletia spp., Fusarium spp. in wheat; Ustilago nuda [ U. segetum var. nuda], Pyrenophora graminea in barley; Pythium spp., Fusarium spp. in maize; Sclerotinia sclerotiorum, Botrytis cinerea, Plasmopara helianthi [ Plasmopara halstedii], Orobanche cumana in sunflower; Fusarium spp., Pythium spp. in pea, beans and soyabean foliar and ear diseases were: Erysiphe spp., Septoria spp., Pyrenophora graminea, Puccinia spp., Fusarium spp. in wheat and barley; Ustilago maydis [ Ustilago zeae], Helminthosporium turcicum [ Setosphaeria turcica], Fusarium spp., Nigrospora oryzae [ Khuskia oryzae] in maize; Sclerotinia sclerotiorum, Botrytis cinerea, Alternaria spp., Phomopsis spp. in sunflower; Erysiphe spp., Septoria spp. in rape. The soil pests were: Zabrus tenebrioides, Agriotes spp. in spiked cereals; Tanymecus dilaticollis, Agriotes spp. in maize and sunflower; Delia platura in beans; Phyllotreta atra in rape and mustard; Aphthona euphorbiae in linseed; Sitona spp., Agriotes spp. in lucerne and clover. The pests which attack aerial part of plants and seeds were: Eurygaster integriceps, Lema melanopa [ Oulema melanopus], Anisoplia spp. in wheat, barley and oats; Ostrinia nubilalis, Diabrotica virgifera virgifera in maize; Thrips linarius in linseed; Athalia rosae, Meligethes aeneus, Brevicoryne brassicae in rape and mustard; Hypera variabilis [ Hypera postica], Semiothisa clathrata [ Chiasmia clathrata], Bruchophagus roddi, Subcoccinella 24- punctata in lucerne and clover. Based on evaluation of the attack potential of these harmful organisms in 2004, the potential for the future manifestation was also estimated.
  • Authors:
    • Price, A.
    • Saini, M.
    • van Santen, E.
  • Source: 2005 Southern Conservation Tillage Systems Conference, Oral Proceedings, Clemson University
  • Year: 2005
  • Summary: An integral component of a conservation-tillage system in corn (Zea mays L.) and cotton (Gossypium hirsutum L.) is the use of a winter cover crop. A field experiment was initiated in 2002 to evaluate winter weed dynamics following various winter cover crops in both continuous cotton and a corn and cotton rotation. Winter cover crops included black oats (Avena strigosa Schreb.); two crimson clover entries (Trifolium incarnatum L.); two cultivars of forage rape (Brassica napus L. var. napus), spring and winter; oil radish (Raphanus sativus var. oleiformis Pers.); three cultivars of turnip ( Brassica rapa L. subsp. rapa); white lupin ( Lupinus albus L.); and a mixture of black oat and lupin. Two-year conservation-tillage rotational sequences included conventionally tilled continuous corn and cotton winter fallow systems as controls. The 10 conservation-tillage, winter cover-crop systems investigated were three continuous cotton systems that alternated a winter legume (lupin or clover), six cotton-corn systems, where lupin preceded cotton and radish, rape, or turnip preceded corn, and a cotton-corn system that had a lupin-black oat mixture as a winter cover crop every year. Use of lupin or 'AU Robin' clover resulted in weed biomass reduction of up to 80% and 54%, respectively, in weed biomass compared to the fallow system. The highest yielding corn-cotton conservation tillage rotation with a winter cover yielded 200 lbs/acre more that the continuous cotton winter fallow system. Continuous conventional corn with winter fallow yielded 30 bu/acre less than the highest yielding 2-yr, conservation tillage winter crop system.
  • Authors:
    • Dhyani, S. K.
    • Singh, R.
    • Sharma, A. R.
  • Source: Indian journal of soil conservation
  • Volume: 33
  • Issue: 1
  • Year: 2005
  • Summary: Maize and wheat are the most important crop grown in sequence largely under rainfed conditions, with low inputs and traditional practices in the outer western Himalayan region of India. Deficiency of moisture and nutrients is primarily responsible for low productivity of these crops. The conventional practices for alleviating these stresses such as summer ploughing, use of organics, intercropping with legumes, mulching, haloding (interculturing), earthing-up and ploughing immediately after harvesting of maize are gradually being discontinued by the farmers due to various emerging problems. This article reviews the effects of tillage and mulching on moisture conservation and nutrient use in the maize-wheat cropping system. Field studies at different locations of this region have shown the beneficial effects of resource conserving technologies for improving productivity of maize and following wheat. The results have suggested that the conventional repetitive tillage operations including deep ploughing can be dispensed with, and equally good or even higher yields can be obtained with minimum or zero tillage along with mulching or residue management practices over a period due to improved soil environment. Live mulching with weeds, annual legumes or pruned biomass of perennial legumes in alley cropping systems are beneficial for efficient conservation of soil, moisture and nutrients for higher productivity in maize-wheat cropping system. There is a need for adopting diversified farming systems approach for improving productivity of crops as well as other enterprises for greater livelihood security of the farming community in this region.
  • Authors:
    • Rosenberg, N. J.
    • Brown, R. A.
    • Thomson, A. M.
    • Izaurralde, R. C.
    • Benson, V.
  • Source: Climatic Change
  • Volume: 69
  • Issue: 1
  • Year: 2005
  • Summary: Here we simulate dryland agriculture in the United States in order to assess potential future agricultural production under a set of general circulation model (GCM)-based climate change scenarios. The total national production of three major grain crops - corn, soybeans, and winter wheat - and two forage crops - alfalfa and clover hay - is calculated for the actual present day core production area (CPA) of each of these crops. In general, higher global mean temperature (GMT) reduces production and higher atmospheric carbon dioxide concentration ([CO 2]) increases production. Depending on the climatic change scenarios employed overall national production of the crops studied changes by up to plus or minus 25% from present-day levels. Impacts are more significant regionally, with crop production varying by greater than 50% from baseline levels. Analysis of currently possible production areas (CPPAs) for each crop indicates that the regions most likely to be affected by climate change are those on the margins of the areas in which they are currently grown. Crop yield variability was found to be primarily influenced by local weather and geographic features rather than by large-scale changes in climate patterns and atmospheric composition. Future US agronomic potential will be significantly affected by the changes in climate projected here. The nature of the crop response will depend primarily on to what extent precipitation patterns change and also on the degree of warming experienced.
  • Authors:
    • Hanna, W. W.
    • Timper, P.
  • Source: Journal of Nematology
  • Volume: 37
  • Issue: 2
  • Year: 2005
  • Summary: Pearl millet ( Pennisetum glaucum) has potential as a grain crop for dryland crop production in the southeastern United States. Whether or not pearl millet will be compatible in rotation with cotton ( Gossypium hirsutum), corn ( Zea mays), and peanut ( Arachis hypogaea) will depend, in part, on its host status for important plant-parasitic nematodes of these crops. The pearl millet hybrid 'TifGrain 102' is resistant to both Meloidogyne incognita race 3 and M. arenaria race 1; however, its host status for other plant-parasitic nematodes was unknown. In this study, the reproduction of Belonolaimus longicaudatus, Paratrichodorus minor, Pratylenchus brachyurus, and Meloidogyne javanica race 3 on pearl millet ('HGM-100' and TifGrain 102) was compared relative to cotton, corn, and peanut. Separate greenhouse experiments were conducted for each nematode species. Reproduction of B. longicaudatus was lower on peanut and the two millet hybrids than on cotton and corn. Reproduction of P. minor was lower on peanut and TifGrain 102 than on cotton, corn, and HGM-100. Reproduction of P. brachyurus was lower on both millet hybrids than on cotton, corn, and peanut. Reproduction of M. javanica race 3 was greater on peanut than on the two millet hybrids and corn. Cotton was a nonhost. TifGrain 102 was more resistant than HGM-100 to reproduction of B. longicaudatus, P. minor, and M. javanica. Our results demonstrated that TifGrain 102 was a poor host for B. longicaudatus and P. brachyurus (Rf