• Authors:
    • Machado, V.
    • Lopes, J.
    • Souza, R.
    • Souza, C.
    • Teixeira, C.
  • Source: Informe Agropecuario
  • Volume: 32
  • Issue: 260
  • Year: 2011
  • Summary: The successful implementation and establishment of the no-tillage (NT) system is directly related to the maintenance of straw on the soil surface. The system of crop rotation also contributes to the success of NT. In the Cerrado (Minas Gerais, Brazil), the high temperature and rainfall mainly during the first six months accelerate straw decomposition and hinder the cultivation of crops during the winter. This paper presents various crop management options to promote the success of NT in the Cerrado region. Most notable is the oversowing of millet in soyabean and Santa Fe system, which involves a mixture of grasses and perennial crops, such as sorghum, millet and maize.
  • Authors:
    • Lehane, K.
    • Orange, D.
    • Holmes, C.
    • King, A.
    • Weston, E.
    • Dalal, R.
    • Thomas, G.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 1
  • Year: 2011
  • Summary: Rainfed grain production in semi-arid, subtropical south-west Queensland in north-east Australia is marginal, because of low and variable rainfall and low soil fertility. Current cropping systems are based around winter cereals, with a summer fallow period essential for storing soil water to reduce risk. Increasing the soil water storage and the efficiency of water and nitrogen use is essential for sustainable crop production in this region. The effects on crop production and economic returns of various crop rotations involving winter crops - wheat ( Triticum aestivum), chickpea ( Cicer arietinum), faba bean ( Vicia faba) and canola ( Brassica napus); summer crops - grain sorghum ( Sorghum bicolor) and mung bean ( Phaseolus mungo); and fertilizer N application to wheat, canola and grain sorghum were studied from 1996 to 2005 on a grey Vertisol. Annual rainfall was above the long-term average in 6 of these 10 years and below average in 4 years. Crops were either not sown or failed due to drought in 3 years during this period. Under the seasonal conditions and grain prices that occurred during this experiment, mean annual gross margin was $100/ha greater for a 2-year chickpea-wheat rotation, $20/ha greater for a faba bean-canola-wheat rotation and $45/ha greater for an alternate cereal-grain legume rotation involving grain sorghum, mung bean, wheat and chickpea than for continuous wheat ($40/ha), where no nitrogen fertilizer was applied to wheat, canola or grain sorghum. Where nitrogen fertilizer was applied to target prime hard grain protein in wheat and maximize yield in canola and grain sorghum, chickpea-wheat ($170/ha) was the only rotation to result in greater gross margin than continuous wheat ($110/ha). Chickpea generally yielded well and resulted in a mean yield increase of 22% in the following wheat crop compared with continuous wheat, where no nitrogen fertilizer was applied in wheat and of 11% where N fertilizer was applied in wheat to target prime hard grain protein. On average, the grain legumes, chickpea and faba bean, provided soil nitrogen benefits of 20 and 40 kg N/ha, respectively, thereby reducing nitrogen fertilizer requirements for following cereal crops and canola. Therefore, the profitability and sustainability of crop production in this semi-arid, subtropical environment can be improved, compared with continuous winter cereal cropping, by appropriate crop rotations and nutrient management.
  • Authors:
    • Fahed, S.
    • Rana, G.
    • Katerji, N.
  • Source: Hydrological Processes
  • Volume: 25
  • Issue: 1
  • Year: 2011
  • Summary: In this paper two models are presented for calculating the hourly evapotranspiration lambda E (W m -2) using the Penman-Monteith equation. These models were tested on four irrigated crops (grass, soya bean, sweet sorghum and vineyard), with heights between 0.1 and 2.2 m at the adult growth stage. In the first model (Katerji N, Perrier A. 1983. Modelisation de l'evapotranspiration reelle ETR d'une parcelle de luzerne: role d'un coefficient cultural. Agronomie 3(6): 513-521, KP model), the canopy resistance rc is parameterized by a semi-empirical approach. In the second model (Todorovic M. 1999. Single-layer evapotranspiration model with variable canopy resistance. Journal of Irrigation and Drainage Engineering-ASCE 125: 235-245, TD model), the resistance rc is parameterized by a mechanistic model. These two approaches are critically analysed with respect to the underlying hypotheses and the limitations of their practical application. In the case of the KP model, the mean slope between measured and calculated values of lambda E was 1.010.6 and the relative correlation coefficients r2 ranged between 0.8 and 0.93. The observed differences in slopes, between 0.96 and 1.07, were not associated with the crop height. This model seemed to be applicable to all the crops examined. In the case of the TD model, the observed slope between measured and calculated values of lambda E for the grass canopy was 0.79. For the other crops, it varied between 1.24 and 1.34. In all the situations examined, the values of r2 ranged between 0.73 and 0.92. The TD model underestimated lambda E in the case of grass and overestimated it in the cases of the other three crops. The under- or overestimation of lambda E in the TD model were due: (i) to some inaccuracies in the theory of this model, (ii) to not taking into account the effect of aerodynamic resistance ra in the canopy resistance modelling. Therefore, the values of rc were under- or overestimated in consequence of mismatching the crop height. The high value of air vapour pressure deficit also contributed to the overestimation of lambda E, mainly for the tallest crop. The results clarify aspects of the scientific controversy in the literature about the mechanistic and semi-empirical approaches for estimating lambda E. From the practical point of view the results also present ways for identifying the most appropriate approach for the experimental situations encountered.
  • Authors:
    • Galusha, T. D.
    • Jackson, D. S.
    • Mason, S. C.
    • Griess, J. K.
    • Pedersen, J. F.
    • Yaseen, M.
  • Source: Crop Science
  • Volume: 51
  • Issue: 4
  • Year: 2011
  • Summary: Grain processors would benefit from information about the production environment and the influences of the sorghum [ Sorghum bicolor (L.) Moench] hybrid on food-grade flour properties. The objective of this study was to determine the effects of environment and hybrid on rapid-visco-analysis (RVA) flour properties of commercially available food-grade sorghum. A randomized complete block experiment was planted in 12 environments, which included the 2004 and 2005 growing seasons and irrigated and dryland water regimes in eastern, central, and west central Nebraska, and a dryland, low-N environment in eastern Nebraska. The environment accounted for 71-85% of the total variation in RVA parameters, while the hybrid accounted for 11-23% and the environment-by-hybrid interaction, 1-3%. Unfortunately, the results of this experiment suggest that it is difficult to predict the effect that environment will have on resulting sorghum-flour parameters. Although of secondary importance in terms of total variation in sorghum-flour RVA properties, the choice of hybrid predictably and significantly contributes to sorghum-starch viscosity properties. Food-grade hybrids were grouped based on viscosity properties into those best suited for dry-mill and alkaline-cooked products (Asgrow Orbit; Sorghum Partners NK1486) and those best suited for porridge, consumable alcohol, and ethanol production (Kelly Green Seeds KG6902; NC+ Hybrids 7W92; Asgrow Eclipse; and Fontanelle W-1000). These results were consistent with those previously reported for grain density.
  • Authors:
    • Joshi, A. K.
    • Dixon, J.
    • Waddington, S. R.
    • Li, X.Y.
    • Vicente, M. C. de
  • Source: Food Security
  • Volume: 3
  • Issue: 1
  • Year: 2011
  • Summary: Variation in water availability is a major source of risk for agricultural productivity and food security in South Asia. Three hundred and thirty expert informants were surveyed during 2008-09 to determine the relative importance of drought and water-related constraints compared with other constraints limiting the production of four major food crops (wheat, rice, sorghum, chickpea) in five broad-based South Asian farming systems. Respondents considered drought an important constraint to crop yield in those farming systems that are predominantly rainfed, but associated it with low yield losses (well below 10% of all reported losses) for crops in farming systems with well-developed irrigation. In these systems, other water-related constraints (including difficult access to sufficient irrigation water, the high cost of irrigation, poor water management, waterlogging and flooding of low-lying fields) were more important. While confirming the importance of drought and water constraints for major food crops and farming systems in South Asia, this study also indicated they may contribute to no more than 20-30% of current yield gaps. Other types of constraint, particularly soil infertility and the poor management of fertilizer and weeds for the cereals, and pests and diseases for chickpea, contributed most yield losses in the systems. Respondents proposed a wide range of interventions to address these constraints. Continued investments in crop-based genetic solutions to alleviate drought may be justified for food crops grown in those South Asian farming systems that are predominantly rainfed. However, to provide the substantial production, sustainability and food security benefits that the region will need in coming decades, the study proposed that these be complemented by other water interventions, and by improvements to soil fertility for the cereals and plant protection with chickpea.
  • Authors:
    • McSorley, R.
  • Source: Nematropica
  • Volume: 41
  • Issue: 2
  • Year: 2011
  • Summary: Studies that utilized rotation crops for management of root-knot nematodes in the southeastern United States were examined to evaluate the overall performance of rotation crops. In general, nematode-susceptible crops that followed effective rotation crops produced yields and supported nematode numbers similar to those obtained on crops treated with most standard nematicides. Fumigation with methyl bromide was an exception, and resulted in low nematode numbers up to the end of the susceptible target crop, whereas nematode numbers recovered following rotation crops. Performance of rotation crops was similar to clean fallow in most studies, and there was little evidence that rotation crops could suppress nematode numbers below levels obtained after clean fallow. Large reductions in nematode numbers often were achieved following rotation crops. In sites with relatively low initial population levels before rotation crops were used, effective rotation crops sometimes maintained relatively low nematode numbers through the following susceptible target crop, and nematode recovery was not observed until the second year of the rotation sequences. Where practical, very long rotations such as bahiagrass pastures were often effective in preventing increase in nematode numbers on subsequent susceptible crops. Rehabilitation of heavily infested sites is difficult, could require several years of rotation crops, and the benefit gained may last only through one susceptible crop.
  • Authors:
    • Ball, L. O.
    • Vandever, M. W.
    • Milchunas, D. G.
    • Hyberg, S.
  • Source: Rangeland Ecology & Management
  • Volume: 64
  • Issue: 3
  • Year: 2011
  • Summary: The effects of grazing, mowing, and type of cover crop were evaluated in a previous winter wheat fallow cropland seeded to grassland under the Conservation Reserve Program in eastern Colorado. Prior to seeding, the fallow strips were planted to forage sorghum or wheat in alternating strips (cover crops), with no grazing, moderate to heavy grazing, and mowing (grazing treatments) superimposed 4 yr after planting and studied for 3 yr. Plots previously in wheat had more annual and exotic species than sorghum plots. Concomitantly, there were much greater abundances of perennial native grass and all native species in sorghum than wheat cropped areas. The competitive advantage gained by seeded species in sorghum plots resulted in large increases in rhizomatous western wheatgrass. Sorghum is known to be allelopathic and is used in crop agriculture rotations to suppress weeds and increase crop yields, consistent with the responses of weed and desired native species in this study. Grazing treatment had relatively minor effects on basal and canopy cover composition of annual or exotic species versus perennial native grass or native species. Although grazing treatment never was a significant main effect, it occasionally modified cover crop or year effects. Opportunistic grazing reduced exotic cheatgrass by year 3 but also decreased the native palatable western wheatgrass. Mowing was a less effective weed control practice than grazing. Vegetative basal cover and aboveground primary production varied primarily with year. Common management practices for revegetation/restoration currently use herbicides and mowing as weed control practices and restrict grazing in all stages of development. Results suggest that allelopathic cover crop selection and opportunistic grazing can be effective alternative grass establishment and weed control practices. Susceptibility, resistance, and interactions of weed and seeded species to allelopathic cover species/cultivars may be a fruitful area of research.
  • Authors:
    • Gill, M. S.
    • Bhale, V. M.
    • Deshmukh, M. S.
    • Narkhede, W. N.
    • Gadade, G. D.
    • More, S. S.
  • Source: Indian Journal of Agronomy
  • Volume: 56
  • Issue: 2
  • Year: 2011
  • Summary: A field experiment was conducted for three consecutive years (2005-2007) at Parbhani to find out most productive and profitable cropping system. Among the different cropping systems, highest wheat [( Triticum aestivum L.) emend. Fiori & Paol] equivalent yield (19.9 t/ha) and net monetary returns (Rs 107.8*10 3/ha) were obtained from soybean [ Glycine max (L. Merr.)]-onion ( Allium capa L.) cropping system, followed by turmeric ( Curcuma domestica L.)+castor ( Ricinus communis L.) (WEY-14.0 t/ha, and NMR Rs 89.8*10 3/ha). The soybean-onion system also recorded maximum net monetary advantage per unit time (Rs 573/ha/day), employment (374 mandays) and water use efficiency (221 kg/ha-cm), followed by turmeric+castor intercropping system. The highest nutrient uptake was recorded in sorghum [ Sorghum bicolor (L.) Moench]-wheat followed by maize ( Zea mays L.)+cow-pea ( Vigna sinensis L.)-wheat and maize-wheat cropping systems. The highest soil nutrient status was observed in cotton ( Gossypium sp.)-summer groundnut ( Arachis hypogaea L.) followed by soybean-onion cropping systems.
  • Authors:
    • Nelson, S. O.
    • Trabelsi, S.
  • Source: Transactions of the American Society of Agricultural and Biological Engineers
  • Volume: 54
  • Issue: 2
  • Year: 2011
  • Summary: Based on microwave dielectric properties of wheat, corn, barley, oats, grain sorghum, soybeans, canola, shelled peanuts and pod peanuts measured over ranges of frequency and moisture content, models for predicting the dielectric constant and loss factor of these commodities are described. Nearly linear relationships between dielectric properties and log of frequency or frequency and moisture content permitted multiple linear regression models to be developed for predicting dielectric constants and loss factors for each type of grain and seed at 23degreesC. Models predicted dielectric constants with s.e. of 1 to 2% with some up to approx. 4% for grain and seed at frequencies in the range 5 to 15 GHz over given moisture ranges. Loss factors are predicted with s.e. of a few percent, but much larger errors can naturally result when loss factors are very small.
  • Authors:
    • Thakare, S. S.
    • Shende, N. V.
  • Source: The Asian economic review: journal of the Indian Institute of Economics
  • Volume: 53
  • Issue: 3
  • Year: 2011
  • Summary: In this study an attempt has been made to study the structural changes in cost of cultivation of selected crops in Vidarbha. The study is based on estimates of cost of cultivation of four selected crops viz. Cotton, Soybean, Sorghum and Paddy of Vidarbha region of Maharashtra. The study used cross sectional cum time series data of Vidarbha region for selected crops for ten years from 1999-00 to 2008-09. The total cost of cultivation of cotton, soybean, sorghum and paddy has been depicting an increase by 1.82,1.86, 1.17 and 1.42 times during the period of study respectively. It was revealed that the share of operational cost to total change in cost of cultivation has been almost same for cotton, soybean and paddy crops indicating that the operational cost and fixed cost increased over time in a commensurate manner for these crops except sorghum crop. For all selected crops, the cost of cultivation has increased at a faster rate as compared to increase in prices of their output. The study also revealed that, during 1999-00, the return over cost A was highest for paddy crop followed by sorghum and cotton and lowest for soybean. The return over cost C was highest for paddy followed by sorghum but the return over cost C for soybean and cotton found negative. There for paddy crop had comparative economic advantage as compared to other selected crops of Vidarbha in 1999-00. During 2008-09, return over cost A was highest for cotton crop followed by paddy, soybean and sorghum. The return over cost C was highest for cotton followed by soybean and paddy crop. There for cotton crop had comparative economic advantage among the selected crops of Vidarbha in 2008-09. Cotton and paddy are the important crops of Vidarbha. These crops are more profitable as compared to other crops of Vidarbha, but now the area under cotton was replaced by soybean due to high cost of cultivation of cotton. Hence cotton area is likely to dominate day by day.