• Authors:
    • Barbarick, K. A.
    • Ippolito, J. A.
    • McDaniel, J.
    • Hansen, N. C.
    • Peterson, G. A.
  • Source: Agriculture, Ecosystems & Environment
  • Volume: 150
  • Year: 2012
  • Summary: Dryland agroecosystems are generally ideal environments for recycling biosolids. However, what is the efficacy of biosolids addition to a no-till dryland management agroecosystem? From 2000 to 2010, we studied application of biosolids from the Littleton/Englewood, CO Wastewater Treatment Plant versus commercial N fertilizer in dryland no-till wheat ( Triticum aestivum, L.)-fallow (WF) and wheat-corn ( Zea mays, L.)-fallow (WCF) rotations at a site approximately 40 km east of Byers, CO. We tested if biosolids would produce the same yields and grain P, Zn, and Ba concentrations as an equivalent rate of N fertilizer, that biosolids-borne P, Zn, and Ba would not migrate below the 10 cm soil depth, and that biosolids application would result in the same quantity of residual NO 3-N as the equivalent N fertilizer rate. Biosolids and N fertilizer produced similar wheat and corn yields; but, biosolids application resulted in smaller wheat grain Ba due to the soil formation of BaSO 4. Biosolids application produced greater NO 3-N concentrations than N fertilizer in the 30-60 and 60-90 cm depths for the WF rotation and all but the 5-10 and 120-150 cm depths for the WCF rotation. We concluded that biosolids application in a no-till managed dryland agroecosystem is an efficacious method of recycling this nutrient source.
  • Authors:
    • de Oliveira, F. de A.
    • da S. Soares, L. C.
    • Soares, L. C. da S.
    • Freire, A. G.
    • Oliveira, F. R. A. de
    • Medeiros,J . F. de
    • Oliveira, F. de A. de
    • de Medeiros, J. F.
    • de Oliveira, F. R. A.
  • Source: Revista Ciencia Agronomica
  • Volume: 43
  • Issue: 2
  • Year: 2012
  • Summary: This study was conducted to evaluate the effect of different salinity levels of irrigation water and seed treated with growth regulator on the yield of cotton. It was used an entirely statistical randomized design, in a factorial scheme 5*2, with four replications. The treatments resulted from the combination of four salinity levels of irrigation water (S 1-0.5; S 2-2.0; S 3-3.5; S 4-5.0 and S 5-6.5 dS m -1) in treated and untreated seeds with growth regulator. The variables were: production of cotton, seed and fiber, 100 seed weight and percentage of fiber. There was not interaction between salinity levels and seed treated. The parameters of cotton production are reduced with the use of water salinity from 3.5 dS m -1, independent of seed treated or not with growth regulators. Agronomic traits 100 seed weight, percentage of fiber and seed cotton production are not influenced by mepiquat chloride. The seed treatment with growth regulator do not affects the adverse effect of salinity.
  • Authors:
    • de Oliveira, F. R. A.
    • de Medeiros, J. F.
    • de Oliveira, F. de A.
    • de A. de Oliveira, F.
    • Freire, A. G.
    • Oliveira, M. K. T. de
    • Oliveira, F. R. A. de
    • Medeiros, J. F. de
    • Oliveira, F. de A. de
    • de Oliveira, M. K. T.
  • Source: Revista Ciência Agronômica
  • Volume: 43
  • Issue: 3
  • Year: 2012
  • Summary: This work was carried out to evaluate the effect of irrigation water at different salinity levels, and of seed treatment with plant growth regulator, on the development of the cotton plant. The experimental design used was completely randomized, arranged in a 5*2 factorial scheme with four replications. The treatments resulted from the combinations of five levels of salinity of the irrigation water (S 1-0.5, S 2-2.0, S 3-3.5, S 4-5.0 and 6.5 dS m -1) on seeds, both treated and not treated with growth regulator. The evaluated characteristics were: number of leaves, leaf area, height, dry mass of stems, leaves and vegetative parts, specific leaf area and leaf area ratio. There was an interaction between salinity and seed treatments with mepiquat chloride, but only for leaf area and leaf area ratio. All other characteristics decreased with the increasing salinity of the irrigation water, with greater reductions in leaf area (mean of 65.8%) and dry mass of vegetative parts (64%). Seed treatment with mepiquat chloride affected plant development, independent of salinity.
  • Authors:
    • Alarcon, J. J.
    • Gil, M. I.
    • Allende, A.
    • Pedrero, F.
  • Source: Agricultural Water Management
  • Volume: 109
  • Year: 2012
  • Summary: The effects of applying different types of treated wastewater on citrus trees were studied in Murcia, in the south-east of Spain. Two treatments with wastewater effluents of different quality were applied for three consecutive years. In the first case, the wastewater received a secondary treatment (conventional activated sludge). In the second case, the irrigation water was a mix of well water and wastewater from a tertiary treatment plant (conventional activated sludge with ultraviolet tertiary treatment). The characteristics of the tertiary treated wastewater make it better for irrigation than the secondary treated wastewater. It was considered that high salinity, Cl and B concentration could be the main restrictions associated with treated wastewater irrigation in both cases, although leaf toxicity levels were not observed. The soil nitrate concentration increased over the experimental time period in both water irrigation treatments. The production was affected by the wastewater quality and the total crop yield was lower in the plots irrigated with secondary treated wastewater. However, in these plots, the fruit-quality indexes such as external colour, weight, peel thickness, firmness, soluble solids, pH, total acidity and maturity index were significantly better than those observed in the plots irrigated with tertiary treatment. The soil microbiological analysis revealed an absence of faecal coliforms, Escherichia coli and helminth eggs in the experimental plots irrigated with tertiary treated wastewater, but with secondary treated wastewater the soil accumulation of faecal coliforms exceeded health standards. In both cases, there was an absence of microbiological contamination on fruits.
  • Authors:
    • Ghahderijani, M.
    • Pishgar-Komleh, S. H.
    • Sefeedpari, P.
  • Source: Journal of Cleaner Production
  • Volume: 33
  • Year: 2012
  • Summary: The aim of this research was to examine the energy consumption and CO 2 emission of potato production in three different farm size sin Esfahan province of Iran. For this purpose, data were collected from 300 farmers by a face to face questionnaire. The results revealed total energy consumption and GHG emission of 47 GJ ha -1 and 992.88 kg CO 2eq ha -1, respectively. The most significant energy consumer was chemical fertilizers (49%), especially nitrogen (40%) and followed by seed with share of 24%. The energy use efficiency, specific energy and energy productivity were determined to be 1.71, 2.12 MJ kg -1 and 0.47 kg MJ -1. The different cultivated area levels analysis revealed that, large farms used the least amount of energy input significantly. It was found that the contribution of indirect energy was higher than that of direct energy and also the proportion of non-renewable energy was more than renewable resources. The results of econometric model estimation revealed that the impact of seed, water for irrigation, diesel fuel and chemical fertilizer energy inputs were significantly positive on potato yield. The sensitivity analysis illustrated that the marginal physical productivity (MPP) value of chemical fertilizer, diesel fuel and seed energy were -1.78 and -1.63 and 1.54, respectively.
  • Authors:
    • Pujari, B. T.
    • Halepyati, A. S.
    • Prabhu, G.
    • Desai, B. K.
  • Source: Karnataka Journal of Agricultural Sciences
  • Volume: 25
  • Issue: 2
  • Year: 2012
  • Summary: The field experiment was conducted at College of Agriculture Farm, Raichur on medium black soil during kharif, 2009 to study the weed management in Bt cotton ( Gossypium hirsutum L.) under irrigation. The results revealed that among the weed management treatments, weed free check recorded significantly higher uptake of nutrients (111.01, 31.21 and 129.11 NPK kg ha -1) and was followed by pendimethalin 38.7 CS (PRE)+quizalofop ethyl 5 EC (POE)+IC and HW at 60 DAS (T 12). With regards to yield and economics, pendimethalin 38.7 CS (PRE)+quizalofop ethyl 5 EC (POE)+IC and HW at 60 DAS (T 12) gave significantly higher seed cotton yield (14.06 q ha -1) and higher gross returns (Rs 35,150 ha -1), net returns (Rs 11,857 ha -1) and BC ratio (1.51).
  • Authors:
    • Qi, X. F.
  • Source: Research of Agricultural Modernization
  • Volume: 33
  • Issue: 2
  • Year: 2012
  • Summary: Based on the statistical data of crop yields, cropland areas and agricultural inputs in the period from 2001 to 2010, the amounts of carbon absorption and emission of the farmland ecosystems in Dezhou were calculated, and the spatial-temporal variations and impact factors of carbon absorption and emission were analyzed. Carbon absorption of farmland ecosystem in Dezhou showed a trend from 2001-2010 and the carbon absorption of wheat, corn as the main food crops was significantly higher than other crops. The carbon emission showed the change of the increases after first reduces in Dezhou from 2001 to 2010. As the different the direction of agricultural development and the development characteristics in different counties there were different carbon emission; the carbon emission of chemical fertilizer was a larger proportion and a decreasing trend in the five ways of carbon emissions; carbon absorption was far greater than the amount of carbon emissions in Dezhou from 2001 to 2010 and there were a strong carbon sink of the farmland ecosystem. The correlation analysis results showed that carbon absorption was significantly positive correlated with the yields of wheat, corn and cotton. Significant positive correlations were observed between carbon emission and agrochemical inputs, power and fuels consumption, and cultivation and irrigation management.
  • Authors:
    • Rajakumar
    • Kuchanur, P. K.
    • Nidagundi, J. M.
    • Konda, C. R.
  • Source: Electronic Journal of Plant Breeding
  • Volume: 3
  • Issue: 1
  • Year: 2012
  • Summary: Twenty two Bt cotton hybrids were evaluated for seed cotton yield and fibre quality parameters over three environments viz., Agricultural Research Station, Siruguppa (E-1), Main Agricultural Research Station, Raichur (E-2) and Agricultural Research Station, Bheemarayanagudi (E-3), during Kharif 2010-11. The seed cotton yield ranged from 1478 to 2203 kg/ha among the Bt cotton hybrids. Pooled data of seed cotton yield revealed that two hybrids viz., MRC 7347 BG II (2203 kg/ha) and ACH 177-2 BG II (2054 kg/ha) recorded numerically superior seed cotton yield over the check, MRC-7351 BG-II (2053 kg/ha). The data on 2.5 per cent span length ranged from 29.2 mm to 33.6 mm, while the fibre strength of the hybrids ranged from 21.7 g/tex to 23.9 g/tex. Fibre fineness or micronaire value ranged from 3.9 to 4.6 g/inch. None of the hybrids were found to be stable across all the test environments indicating the need to undertake extensive testing of Bt cotton hybrids for recommending region specific hybrids possessing high yielding potential coupled with desirable fibre quality parameters.
  • Authors:
    • Hekmat, M.
    • Sahebi, F. G.
    • Pourkhiz, E.
  • Source: International Journal of Agricultural Management and Development (IJAMAD)
  • Volume: 2
  • Issue: 2
  • Year: 2012
  • Summary: To evaluate the effect of water, tape drip and furrow irrigation methods on the performance components and features of Agria cultivar potato, an experiment was carried out in the agriculture faculty of Kermanshah. Repeated three times, this study was carried out in the form of full random blocks with the main factor of different amounts of irrigation water in three levels (50, 75, and100 percent of cumulative evaporation from an A-class evaporation pan) and the secondary factor of irrigation method (including drip and furrow irrigations). At 3 repetitions, results showed that the minimum performance (19.168 tons per hectare) was related to the drip irrigation method with 50 percent evaporation from the A-class pan and the maximum one (34.455 tons per hectare) was related to the drip irrigation method with 100 percent evaporation from the A-class pan. The rate of irrigation and effectiveness of method on the number of the main stem per square meter and number of the main stem in the bush were not significant. The minimum percent (number of tubers) of tubers smaller than 35 mm (26.47 percent) and the maximum tuber production (37.17 percent) in the size of food and market-friendly (tuber bigger than 55 mm) were attained by drip irrigation method with 100 percent evaporation from the A-class pan. The impact of Irrigation method on and the specific gravity of tubers and starch (dry matter) was and was not significant, respectively.
  • Authors:
    • Francis, F.
    • Liu, Y.
    • Sun, J.
    • Zhou, H.
    • Cheng, D.
    • Chen, J.
    • Xie, H.
  • Source: Journal of Economic Entomology
  • Volume: 105
  • Issue: 3
  • Year: 2012
  • Summary: The effects of intercropping wheat, Triticum aestivum L., with mung bean, Vigna radiate L., on the populations of English grain aphid, Sitobion avenae (F.) (Hemiptera: Aphididae), and its natural enemies were evaluated by field and laboratory experiments. The population densities of aphids and their natural enemies were evaluated in the intercropped field against different row ratio combinations of wheat-mung bean. Results showed that wheat-mung bean intercropping caused a drop in aphid densities, and the ratio 12 wheat:4 mung bean brought about the largest drop (>18%). In addition, the population densities of coccinellids (ladybirds) and parasitoids and the species diversity of all the natural enemies of aphid were higher in the intercropped field than in the field planted only with wheat. However, intercropping did not influence the community indices (evenness and index of dominance concentration) of the natural enemies. Y-tube olfactometer bioassays were carried out in the laboratory to test whether odor blends of host and nonhost plants affect the host selection of S. avenae. Bioassays indicated that both apterous and alate aphids significantly preferred host plant odor over odor blends of host and intercropped species. Hence, the olfactory-based host location of aphids in the field might be affected by intercropping. The intercropping experiment clearly showed that increased crop species diversity suppresses aphid population growth and preserves the population of natural enemies of aphids. Our results also provide support for the "resource concentration hypothesis" and the "enemies hypothesis".