• Authors:
    • Zhu, W. W.
  • Source: Guizhou Agricultural Sciences
  • Issue: 6
  • Year: 2009
  • Summary: The results from analyzing the comparative superiority of main agricultural products in Hunan province by using the comparative superiority index method show that the agricultural products with obvious comparative superiority are rice, cotton, soybean, tobacco and tea, which depend on their large-scale superiority, and the agricultural products with inferior position are maize, sorghum and wheat. The market competitive power is weak because the efficiency superiority of various agricultural products is not obvious essentially. The paper puts forward the measures including maintaining the market superiority of the agricultural products with obvious comparative superiority and improving the quality of the agricultural products with significant comparative inferiority to overall promote the market competitive power of Hunan province's agricultural products.
  • Authors:
    • Joshi, O. P.
    • Billore, S. D.
    • Dupare, B. U.
    • Verma, S. K.
  • Source: Soybean Research
  • Volume: 7
  • Year: 2009
  • Summary: A study was conducted to visualize the impact of soybean cultivation in the "Soya State", Madhya Pradesh. The data were collected using well-designed interview schedule containing relevant questions on how soybean has affected farmers lifestyle as well as overall farming scenario? Majority of the respondents perceived soybean cultivation as a major driving force for their socio-economic development. A steady increase in the farmers' inclination to grow soybean was observed during the last five decades, while, decreasing their area in traditionally grown crops like sorghum, pigeon pea, groundnut, cotton and black gram. During soybean introduction many changes in the overall farming scenario of Madhya Pradesh have occurred. The change was recorded in the land holding pattern of farmers which revealed that small and marginal farmers have further reduced their land holdings while larger farmers have not only managed their holdings but also added newer areas to their total farm size. The cost of cultivation as well as rates fetched by the soybean showed an upward trend with passage of time during these five decades. An inverse relationship between the labour availability and wages was also observed. The gathered opinion from farmers brought out that fertilizer consumption and insect-load appeared to have increased with time. It seems that in spite the irrigation facilities have increased during these 50 years, particularly that of canal, tube wells and ponds, soybean by and large, remained to be a rainfed crop. However, the farmers have shifted from bullock drawn implements to tractor drawn implements. This led to limiting number of animals with farmers, thereby progressive reduction in the use of manures. Subsequent to the introduction of soybean, the socio-economic status of the farmers has improved.
  • Authors:
    • Vicente, M. C. de
    • Andersson, M. S.
  • Source: book
  • Year: 2009
  • Summary: This comprehensive volume provides the scientific basis for assessing the likelihood of gene flow between twenty important crops and their wild relatives. The crops discussed include both major staples and minor crops that are nonetheless critical to food security, including bananas and plantain, barley, canola, cassava, chickpeas, common beans, cotton, cowpeas, finger millet, maize, oat, peanuts or groundnuts, pearl millet, pigeonpeas, potatoes, rice, sorghum, soyabeans, sweet potatoes, and wheat. Each chapter is devoted to one of the crops and details crop-specific information as well as relevant factors for assessing the probability of gene flow. The crop-specific reviews provide insights into the possible ecological implications of gene escape. For each crop, a full-colour world map shows the modelled distributions of crops and wild relatives. These maps offer readers, at a glance, a means of evaluating areas of possible gene flow. The authors classify the areas of overlap into three "gene-flow categories" with respect to the possibility of genetic exchange. The systematic, unbiased findings provided here will promote well-informed decision making and the conservation of wild relatives of crops. This book is particularly relevant to agriculture in developing countries, where most crop biodiversity is found and where current knowledge on biodiversity conservation is limited. Given the ecological concerns associated with genetically modified crops, this reference is an essential tool for everyone working to feed a growing world population while preserving crop biodiversity.
  • Authors:
    • Bhattarai, S. P.
    • Midmore, D. J.
  • Source: Journal of Integrative Plant Biology
  • Volume: 51
  • Issue: 7
  • Year: 2009
  • Summary: Impacts of salinity become severe when the soil is deficient in oxygen. Oxygation (using aerated water for subsurface drip irrigation of crop) could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation (12% air volume/volume of water) on vegetable soybean (moderately salt tolerant) and cotton (salt tolerant) in a salinized vertisol at 2, 8, 14, 20 dS/m EC e. In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency (WUE) by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na + and Cl - concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na + or Cl - concentration. Oxygation invariably increased, whereas salinity reduced the K +:Na + ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.
  • Authors:
    • Pringle, H.
    • Ebelhar, M.
    • Martin, S.
  • Source: Journal of Cotton Science
  • Volume: 12
  • Issue: 4
  • Year: 2008
  • Summary: Increasing available soil water for a crop can be accomplished with both deep tillage and irrigation. Both have the potential to replace or complement the other due to their common function. The addition of a crop rotation may also enhance or diminish the response from irrigation and/or deep tillage. The major objective of this study was to determine long-term effects of different levels of furrow irrigation and in-row subsoil tillage on lint yield and economic returns for cotton grown on alluvial silty clay loam soils in a cotton/corn cropping sequence. A secondary objective was to determine the ability and efficiency of deep tillage and irrigation to replace and/or complement each other in the cropping system. Field experiments were conducted at Tribbett, MS on silty clay loam soils from 1999 through 2004. In-row subsoil tillage was performed with a low-till parabolic subsoiler. A roll-out pipe system was used to furrow water the irrigated plots. Production costs were calculated and include direct costs plus total specified costs excluding land rent, general farm overhead, and returns to management. Growing non-irrigated cotton without deep tillage in this cotton/corn sequence on these silty clay loam soils that were prone to backwater flooding gave the highest average net returns. It appears producers should neither subsoil, nor furrow irrigate and the two should never be combined, based on this study. These results emphasize the need for drainage and support the need for further research on these type soils in the absence of drainage problems.
  • Authors:
    • Reddy, K. C.
    • Reddy, S. S.
    • Nyakatawa, E. Z.
    • Raper, R. L.
    • Reeves, D. W.
    • Lemunyon, J.
    • Roberson, T.
  • Source: Journal of Environmental Quality
  • Volume: 37
  • Issue: 2
  • Year: 2008
  • Summary: Increased CO2 release from soils resulting from agricultural practices such as tillage has generated concerns about contributions to global warming, Maintaining current levels of soil C and/or sequestering additional C in soils are important mechanisms to reduce CO2 in the atmosphere through production agriculture. We conducted a study in northern Alabama from 2003 to 2006 to measure CO2 efflux and C storage in long-term tilled and non-tilled cotton (Gossypium hirsutum L.) plots receiving poultry litter or ammonium nitrate (AN). Treatments were established in 1996 on a Decatur silt loam (clayey, kaolinitic thermic, Typic Paleudults) and consisted of conventional-tillage (CT), mulch-tillage (MT), and no-tillage (NT) systems with winter rye [Secale cereale (L.)] cover cropping and AN and poultry litter (PL) as nitrogen sources. Cotton was planted in 2003, 2004, and 2006. Corti was planted in 2005 as a rotation crop using a no-till planter in all plots, and no fertilizer was applied. Poultry litter application resulted in higher CO2 emission from soil compared with AN application regardless of tillage system. In 2003 and 2006, CT (4.39 and 3.40 mu mol m(-2) s(-1), respectively) and MT (4.17 and 3.39 mu mol m(-2) s(-1), respectively) with, PL at 100 kg N ha(-1) (100 PLN) recorded significantly higher CO2 efflux compared with NT with 100 PLN (2.84 and 2.47 mu mol m(-2) s(-1), respectively). Total soil C at 0- to 15-cm depth was not affected by tillage but significantly increased with PL application and winter rye cover cropping. In general, cotton, produced with NT conservation tillage in conjunction with PL and winter rye cover cropping reduced CO2 emissions and sequestered more soil C compared with control treatments.
  • Authors:
    • Cargnin, R.
    • Inomoto, M.
    • Asmus, G.
  • Source: Tropical Plant Pathology
  • Volume: 33
  • Issue: 2
  • Year: 2008
  • Summary: Two greenhouse and one field experiment were carried out to evaluate the reaction of cover crops to reniform nematode, Rotylenchulus reniformis, and their effect on nematode populations in a naturally infested soil (2,359 nematodes/200 cm 3) and on cotton yield. Oil radish ( Raphanus sativus), Mulato grass ( Brachiaria ruziziensis * B. brizantha), forage sorghum ( Sorghum bicolor), tef ( Eragrostis tef), foxtail millet ( Setaria italica), Algerian ( Avena byzantina) and black ( A. strigosa) oats, pearl millet ( Pennisetum glaucum), and finger millet ( Eleusine coracana) were determined to be poor hosts for R. reniformis in greenhouse experiments. Grain amaranth ( Amaranthus cruentus) and quinoa ( Chenopodium quinoa) were good hosts to R. reniformis. In the field, lower nematode densities were observed after Mulato grass, oil radish and forage sorghum. Higher cotton fiber yields were obtained from plots cultivated with Mulato grass or sorghum during the winter compared to clean fallow. Cotton yield was inversely correlated with both reproduction factor (p
  • Authors:
    • Balkcom, K. S.
    • Arriaga, F. J.
    • Bergtold, J. S.
    • Stoll, M. E.
    • Price, A. J.
    • Kornecki, T. S.
    • Rap, R. L.
  • Source: Communications in Biometry and Crop Science
  • Volume: 3
  • Issue: 1
  • Year: 2008
  • Summary: 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 (* 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.
  • Authors:
    • Kang, J.
    • Osmond, D. L.
  • Year: 2008
  • Authors:
    • Reddy, K. C.
    • Tazisong, I. A.
    • Nyakatawa, E. Z.
    • Senwo, Z. N.
    • Sainju, U. M.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 127
  • Issue: 3-4
  • Year: 2008
  • Summary: Disposal of poultry litter, a widely available organic manure in the southeastern USA because of a large-scale poultry industry, is a major concern because of its contamination in surface- and groundwater through N leaching and P runoff. Application of poultry litter in no-tilled intensive cropping system could increase soil C and N sequestration compared with the conventional-tilled system with inorganic N fertilization and reduce environmental contamination. We evaluated the 10-year effects of tillage, cropping systems, and N fertilizer sources on crop residue (stems + leaves) production and soil bulk density, organic C (SOC), and total N (STN) at the 0-20 cm depth in Decatur silt loam (clayey, kaolinitic, thermic, and Typic Paleudults) in northern AL, USA. Treatments were incomplete factorial combinations of three tillage practices [no-till (NT), mulch till (MT), and conventional till (CT)], two cropping systems [cotton (Gossypium hirsutum L.)-cotton-corn (Zea mays Q and rye (Secale cereale L.)/cotton-rye/cotton-corn], and two N fertilization sources and rates (0 and 100 kg N ha(-1) from NH4NO3, and 100 and 200 kg N ha(-1) from poultry litter) in randomized complete block with three replications. Rye was grown as winter cover crop and corn as residual crop without tillage and fertilization. Mean crop residue returned to the soil from 1997 to 2005 was greater in rye/cotton-rye/cotton-corn than in cotton-cotton-corn and greater with NH4NO3 than with poultry litter at 100 kg N ha(-1). While SOC and STN concentrations at 10-20 cm after 10 years were not influenced by treatments, SOC and STN contents at 0-20 cm were greater with poultry litter than with NH4NO3 in NT and CT. These resulted in a C sequestration rate of 510 kg C ha(-1) year(-1) and N sequestration rates of 41-49 kg N ha(-1) year(-1) with poultry litter compared with -120 to 147 kg C ha(-1) year(-1) and -23 to -3 kg N ha(-1) year(-1), respectively, with NH4NO3. Cropping and fertilization sequestered C at 730 kg C ha(-1) year(-1) and N at 67 kg N ha(-1) year(-1) compared with fallow and no-fertilization in NT. Tillage and cropping system did not influence SOC and STN. Long-term poultry litter application or continuous cropping can sequester C and N in the soil compared with inorganic N fertilization or fallow, thereby increasing soil quality and productivity and reducing the potentials for N leaching and greenhouse gas emission. Published by Elsevier B.V.