• Authors:
    • Guimaraes Junior, R.
    • Marchao, R.
    • Moraes Neto, S.
    • Vilela, L.
    • Pulrolnik, K.
  • Source: Boletim de Pesquisa e Desenvolvimento - Embrapa Cerrados
  • Issue: 276
  • Year: 2010
  • Summary: The trees may improve the productivity of an agroecosystem, influencing the characteristics of soil, microclimate, hydrology and biological components associated. However, there is little information on the tree species most suitable for use in the system of integration crop-livestock-forest (SiLPF). In this context, the objective of this work was to evaluate the initial growth and survival of tree species native and exotic in different space arrangements and plant density in SiLPF in Planaltina, DF. The planting of seedling trees was conducted between January and March 2009. O design of treatments was randomized blocks with three replications of five treatments: control (tillage/grazing), native (two rows of trees and spacing between alleys of 12 m), Eucalyptus cloeziana (7 rows of trees and spacing between alleys of 22 m), Eucalyptus urograndis (2 rows of trees and spacing between alleys of 12 m) and Eucalyptus urograndis (2 rows of trees and spacing between alleys of 22 m). Among the alleys of forest species was planted sorghum in March 2009 and soybeans in December 2009 in no-tillage system with recommended fertilizer for the crop. There was no significant difference in survival between the treatments. Among the species studied native cedar species was less growth in height, while the guapuruvu, angico red mahogany and had the highest growth. Guanandi registered the worst performance and is not recommended in areas with high water deficit.
  • Authors:
    • Bradford, S.
    • Crohn, D.
    • Poss, J.
    • Shouse, P.
    • Segal, E.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 137
  • Issue: 3/4
  • Year: 2010
  • Summary: A nutrient management plan (NMP) field experiment was conducted to investigate the fate of nitrogen (N), phosphorus (P), potassium (K) and salts in a semi-arid environment (San Jacinto, CA). Our mechanistic approach to study NMP performance was based on comprehensive measurements of water and N mass balance in the root zone. A cereal crop rotation (wheat-rye hybrid to sorghum, Triticum aestivum L.- Secale cereale L. to Sorghum bicolor L. Moench) that does not fix atmospheric N was employed during 2007, whereas a legume crop (alfalfa, Medicago sativa L.) that forms nodules to fix N was used in 2008. Blending (2007 and 2008) and cyclic (2007) dairy wastewater (DWW) application strategies (no statistical difference in 2007) were implemented to meet crop water and N uptake. The high content of salts in DWW and accurate application of water to meet evapotranspiration ( ET) yielded salt accumulation in the root zone. Leaching these salts after the fallow period resulted in the flushing of nitrate that had accumulated in the root zone due to continuous mineralization of soil organic N. This observation suggested that a conservative NMP should account for mineralization of organic N by (i) leaching salts following harvests rather than prior to planting and (ii) maintaining soils with low values of organic N. For the wheat-rye hybrid-sorghum rotation, losses of nitrate below the root zone were minimal and the soil organic N reservoir and P were depleted over time by applying only a fraction of the plant N uptake with DWW (28-48%) and using DWW that was treated to reduce the fraction of organic N (3-10%), whereas K accumulated similar to other salts. Conversely, with alfalfa approximately 15% of the applied N was leached below the root zone and the soil organic N increased during the growing season. These observations were attributed to fixation of atmospheric N, increased root density, and applying a higher fraction of plant N uptake with DWW (76%). Collectively, our results indicate that NMPs should accurately account for water and nutrient mass balances, and salt accumulation to be protective of the environment.
  • Authors:
    • Inomoto, M. M.
    • Asmus, G. L.
  • Source: Plant disease: an international journal of applied plant pathology
  • Volume: 94
  • Issue: 8
  • Year: 2010
  • Summary: Taking into account that information about the host status of cover crops for Pratylenchus brachyurus is scarce or contradictory, this study was undertaken to assess the host status of selected graminaceous cover crops by estimating nematode reproduction and their ability to decrease the nematode density in glasshouse conditions. Furthermore, the reproductive fitness of three P. brachyurus populations was assessed for Brachiaria grasses. Silage and forage sorghum proved to be good hosts for P. brachyurus; consequently, they should be avoided in fields infested with this lesion nematode, mainly before susceptible crop such as soybean, common bean, cowpea, and cotton. Dictyoneura grass, the pearl millet cv. ADR 300, and black oat were poor hosts for P. brachyurus but may increase densities of this nematode over time. Consequently, these cover crops might be used in infested fields for only short periods, because they could increase the P. brachyurus population density slowly but progressively.
  • Authors:
    • Kheira, A. A. A.
    • Lamm, F. R.
    • Trooien, T. P.
  • Source: Applied Engineering in Agriculture
  • Volume: 26
  • Issue: 5
  • Year: 2010
  • Summary: A 5-year field study (2004-2008) using irrigation water from an unlined surface reservoir was conducted to examine the effect of dripline depth (0.2, 0.3, 0.4, 0.5, or 0.6 m) on subsurface drip-irrigated rotational crop production of sunflower, soybean, and grain sorghum on a deep silt loam soil in western Kansas. Additional years (1999-2003) of data were included in the analysis of long-term dripline flowrates as affected by dripline depth. Crop seed germination and plant establishment with the subsurface drip irrigation system was not examined in this field study. There were no significant differences in crop yields or yield components in any year of the study with the exception of the number of soybean pods/plant in 2007. In that year, the number of pods/plant was significantly greater for the deeper dripline depths, but this improvement was not reflected in significantly greater soybean yield due to compensation from the other yield components. Measured crop water use and calculated water productivity (yield/water use) also were not significantly affected by dripline depth for any crop in any year. Crop water use varied less than 4% and water productivity varied less than 8% with dripline depth from the mean values for a given crop within a given year, but water productivity tended to be greater for the intermediate 0.4 m dripline depth. There was a tendency for the deeper dripline depths to have greater amounts of plant available soil water and this tendency was stronger as the crop season progressed and for deeper portions of the crop root zone. However, there were neither significant differences in plant available soil water in the upper (0 to 0.9 m) and lower root zones (0.9 to 2.4 m) at physiological maturity of the crop in any year, nor in the total 2.4 m soil profile. The lack of significant differences in crop yields, water use, water productivity and plant available soil water at physiological maturity suggests that dripline depths ranging from 0.2 to 0.6 m are acceptable for crop production of these three crops on the silt loam soils of the region. Measurements of plot dripline flowrates during the period 1999 through 2008 indicated a tendency for deeper disciplines to have reduced flowrates and these flowrate reductions were statistically significant in 2001, 2006, 2007, and 2008. Although the reason for these plot flowrate reductions cannot be fully ascertained, it seems likely they were caused by emitter clogging related to an interaction between dripline depth and irrigation water quality for which the rationale was not determined.
  • Authors:
    • Arriaga, F. J.
    • Rogers, H. H.
    • Runion, G. B.
    • Prior, S. A.
  • Source: Journal of Environmental Quality
  • Volume: 39
  • Issue: 2
  • Year: 2010
  • Summary: Increasing atmospheric CO(2) concentration has led to concerns about potential effects on production agriculture. In the fall of 1997, a study was initiated to compare the response of two crop management systems (conventional tillage and no-tillage) to elevated CO(2). The study used a split-plot design replicated three times with two management systems as main plots and two atmospheric CO(2) levels (ambient and twice ambient) as split plots using open-top chambers on a Decatur silt learn soil (clayey, kaolinitic, thermic Rhodic Paleudults). The conventional system was a grain sorghum [Sorghum bicolor (L.) Moench.] and soybean (Glycine max (L.) Merr.] rotation with winter fallow and spring tillage practices. In the no-tillage system, sorghum and soybean were rotated, and three cover crops were used [crimson clover (Trifolium incarnatum L.), sunn hemp (Crotalaria juncea L.), and wheat (Triticum aestivum L.)]. Over multiple growing seasons, the effect of management and CO(2) concentration on leaf-level gas exchange during row crop (soybean in 1999, 2001, and 2003; sorghum in 2000, 2002, and 2004) reproductive growth were evaluated. Treatment effects were fairly consistent across years. In general, higher photosynthetic races were observed under CO(2) enrichment (more so with soybean) regardless of residue management practice. Elevated CO(2) led to decreases in stomatal conductance and transpiration, which resulted in increased water use efficiency. The effects of management system on gas exchange measurements were infrequently significant, as were interactions of CO(2) and management. These results Suggest that better soil moisture conservation and high rates of photosynthesis can occur in both tillage systems in CO(2)-enriched environments during reproductive growth.
  • Authors:
    • Mandal, D. K.
    • Tiwary, P.
    • Venugopalan, M. V.
    • Challa, O.
  • Source: Agropedology
  • Volume: 20
  • Issue: 1
  • Year: 2010
  • Summary: The average productivity of cotton, sorghum and soybean in Maharashtra is considerably lower than their potential. There is also a large temporal and spatial variability in their productivity due to the spatial distribution of soils and its interaction with the rainfall pattern. WOFOST model-version 7.1 was validated and used for quantification of yield gaps under different rainfall patterns for cotton, sorghum and soybean on five soil series of Maharashtra. The validation results indicate that the model performed well with RMSE less than 20% and simulated the yields with Model efficiency (ME) values 0.73, 0.88 and 0.89 for cotton, sorghum and soybean, respectively. Between soil series, the variability in the mean simulated yield among years experiencing normal rainfall was higher for cotton (CV=53.9%) than for sorghum (CV=27.6%) or soybean (CY=20.1%) as soil parameters significantly affected the cotton yields. There was significant correlation between simulated yield with soil depth (r=0.91) and extractable soil moisture (r=0.96) for cotton; but not for sorghum and soybean. It is concluded that the WOFOST model could capture the effects of spatial distribution of soil and rainfall pattern on the yields of cotton, sorghum and soybean and can compliment other techniques in suggesting alternative crop options for aberrant rainfall situations.
  • Authors:
    • Chaudhari, P. V.
    • Vaidkar, R. D.
    • Vitonde, A. K.
    • Rangacharya, D. S.
  • Source: Agriculture Update
  • Volume: 5
  • Issue: 3/4
  • Year: 2010
  • Summary: This study was conducted in Amravati and Bhatkuli Tahsils of Amravati district and five villages from each tahsil which were adopting sorghum based cropping systems. The data was collected for the year 2008-2009 from 24 cultivators for each system randomly. The ratio return over the investment at cost 'A' were 2.34, 2.58, 2.47, 2.42, 2.64 and at cost 'B', the ratio were 1.64, 1.85, 1.71, 1.68, 1.83 respectively for sole sorghum, sorghum+tur, sorghum+soybean, sorghum+cotton, sorghum+green gram. In case of sorghum+tur, the ratio at cost 'C' showed higher ( i.e. 1.95) and lower in sole sorghum (i.e.1.39). Thus, the study indicated that the sorghum+tur was found to be most profitable cropping system followed by sorghum+cotton cropping system.
  • Authors:
    • Dahatonde, S.
    • Bunde, D.
    • Katkhede, S.
    • Pohare, J.
    • Khambalkar, V.
  • Source: Journal of Agricultural Science
  • Volume: 2
  • Issue: 4
  • Year: 2010
  • Summary: The present research work has been carried out at Central Research Station farm of Dr. PDKV, Akola and at Katkheda and Sutala village of the Akola and Bulbhana district respectively. The operations considered were land preparation, sowing, intercultural, harvesting and crop residue management etc. The inputs like human power, bullock power for traditional operation were studied in entire work of the research. Similarly, for the same crops these operations were carried out by the mechanized practice for the exact quantification of the operational energy input. The study reflects the energy use patterns in mechanized and traditional farming and optimized energy efficient cropping system through mechanized farming over traditional farming. The practices evaluated for the crop production which resulted in the high yielding of crop and the crop residues. On the basis of results obtained, it was observed that the traditional operational energy requirement increases from 2680.78 MJ/ha in traditional method to 3130.72 MJ/ha in mechanized method for green gram crop. While, there is decrease in cost of operation from Rs 8407.5/ha in traditional method to Rs 5147.0/ha in mechanized system. Similar trend was observed in cotton, soybean, sorghum and wheat crop. For all the crops seed bed preparation is done by tractors in traditional as well as mechanized method except in mechanized method land smoothening is done by self propelled tiller instead of bullock drawn blade harrow. In most of the crops the farm operations were mechanized with different implements except harvesting operation, due to unavailability of appropriate machine for harvesting of crops except wheat crop. Overall it seen that the application of modern implements and machineries for the crop production over the traditional practices reduces the cost of production which surely impact on the crop production and the net income of the farmers.
  • Authors:
    • Rosolem, C. A.
    • Calonego, J. C.
  • Source: European Journal of Agronomy
  • Volume: 33
  • Issue: 3
  • Year: 2010
  • Summary: Compacted subsoil layers result in shallow root systems hindering the absorption of water and nutrients by plants. Disruption of soil compacted layers can be promoted by mechanical and/or biological methods, using plants with strong root systems. The immediate and medium term effects of mechanical chiseling and crop rotations on soybean root growth and yield were evaluated during four years in Brazil. Triticale (X Triticosecale Wittmack) and sunflower (Helianthus annuus L) were grown in the autumn-winter (April-August). In the next spring (September-October/early November), designated plots were chiseled down to 0.25 m or planted to millet (Pennisetum glaucum L), sorghum (Sorghum bicolor (L.) Moench) and sunn hemp (Crotalaria juncea L.), grown as cover crops, preceding soybean (Glycine max (L.) Merrill). Chiseling was done only in the first year, and these plots were left fallow during the spring (September-October/early November) for the rest of the experiment. Chiseling resulted in lower soil penetration resistance and higher soybean yields in the first year. However, in the following years soybean root growth in depth was increased under rotation with triticale and pearl millet due to the presence of biopores and a decrease in soil penetration resistance. Soybean yields tended to decrease over the years in plots that were chiseled when compared with plots under crop rotation. Chiseling can be replaced by crop rotations involving species with aggressive root systems in order to alleviate deleterious effects of soil compaction on soybean yields in tropical soils. This effect is gradual, thus crop rotation will be fully effective in remediating soil compaction in a 3- to 4-year term. (C) 2010 Elsevier B.V. All rights reserved.
  • Authors:
    • Radmann, E. B.
    • Casagrande Junior, J. G.
    • Carpena Carvalho, F. L.
    • Gomes, C. B.
  • Source: Revista Brasileira de Fruticultura
  • Volume: 32
  • Issue: 1
  • Year: 2010
  • Summary: In a field naturally infested with ring nematode (Mesocriconema xenoplax), green covering were tested for their suppressing potential in winter and summer crops comparing to plots kept in fallow lands. Tree crop rotation system with the same plant species tested before (black oat/pig bean/millet/forage radish; forage radish/millet/white oat/corn; and white oat/dwarf velvet bean/wheat/sorghum) were evaluated for suppression potential to nematode M xenoplax for two years, using as control, plots that were kept in fallow lands. The experiments were conducted in the field in a randomized block design with six repetitions. Before and after the establishment of each plot, the nematode populations were evaluated on the number of M xenoplax/100cm3 of soil and the reproduction factor (RF=final population/initial population) of the ring nematode, where RF1,00, favoring of the reproduction. Most of the crops analyzed were unfavorable host (RF