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Singh R.J.,Indian Agricultural Research Institute | Singh R.J.,Central Soil and Water Conservation Research and Training Institute | Ahlawat I.P.S.,Indian Agricultural Research Institute | Singh S.,Indian Agricultural Research Institute
Environmental Monitoring and Assessment | Year: 2013

Although there is large-scale adoption of Bt cotton by the farmers because of immediate financial gain, there is concern that Bt crops release Bt toxins into the soil environment which reduces soil chemical and biological activities. However, the majorities of such studies were mainly performed under pot experiments, relatively little research has examined the direct and indirect effects of associated cover crop of peanut with fertilization by combined application of organic and inorganic sources of nitrogen under field conditions. We compared soil chemical and biological parameters of Bt cotton with pure crop of peanut to arrive on a valid conclusion. Significantly higher dehydrogenase enzyme activity and KMnO4-N content of soil were observed in Bt cotton with cover crop of peanut over pure Bt cotton followed by pure peanut at all the crop growth stages. However, higher microbial population was maintained by pure peanut over intercropped Bt cotton, but these differences were related to the presence of high amount of KMnO4-N content of soil. By growing cover crop of peanut between Bt cotton rows, bacteria, fungi, and actinomycetes population increased by 60%, 14%, and 10%, respectively, over Bt cotton alone. Bt cotton fertilized by combined application of urea and farm yard manure (FYM) maintained higher dehydrogenase enzyme activity, KMnO4-N content of soil and microbial population over urea alone. Significant positive correlations were observed for dry matter accumulation, dehydrogenase enzyme activity, KMnO4-N content, and microbial population of soil of Bt cotton, which indicates no harmful effects of Bt cotton on soil biological parameters and associated cover crop. Our results suggest that inclusion of cover crop of peanut and FYM in Bt cotton enhanced soil chemical and biological parameters which can mask any negative effect of the Bt toxin on microbial activity and thus on enzymatic activities. © 2012 Springer Science+Business Media B.V. Source

Singh R.J.,Indian Agricultural Research Institute | Singh R.J.,Central Soil and Water Conservation Research and Training Institute | Ahlawat I.P.S.,Indian Agricultural Research Institute
Communications in Soil Science and Plant Analysis | Year: 2012

A better understanding of the fate of nutrients in transgenic cotton (Gossypium hirsutum L.) fields will improve nutrient efficiencies, will optimize crop growth and development, and may help to enhance soil quality. A study was made to evaluate and quantify the effect of cropping system [sole cotton and groundnut (Arachis hypogaea) intercropping with transgenic cotton] and nitrogen (N) management [control (0N), 100% recommended dose of nitrogen (RDN) through urea, substitution of 25% RDN through farmyard manure (FYM), and substitution of 50% RDN through FYM] on dry matter (DM) and nutrient partitioning and accumulation by transgenic cotton and groundnut at New Delhi during 2006-2007. Soil and plant samples were collected and analyzed at 60, 90, and 120 days after sowing and at harvest. Results revealed that intercropping of groundnut with cotton did not significantly affect DM and nutrient partitioning in cotton, but residual soil fertility in terms of potassium permanganate (KMnO 4) N showed an improvement in contrast to Olsen's P and ammonium acetate (NH 4OAc)-exchangeable K over sole cotton. At harvest, of total DM assimilated, leaves constituted 10-20%, stem 50%, and reproductive parts of cotton accounted for the rest. For each kilogram of seed cotton produced, the crop assimilated 61 g of N, of which 23 g was partitioned to harvested seed cotton. Substitution of 25% RDN through FYM, being on par with 100% RDN through urea, recorded greater DM, nutrient uptake in different parts of cotton, agronomic N-use efficiency (9.5 kg seed cotton kg N -1), and apparent N recovery (83.3%) over 50% RDN substitution through FYM and control. The control, being on par with 50% RDN substitution through FYM, recorded significantly greater DM and nutrient uptake by intercropped groundnut over other treatments. Apparent N and potassium (K) balance at the end of study was negative in all treatments; however, the actual change in KMnO 4 N was positive in all the treatments except control. Our study suggests that intercropping of groundnut with transgenic cotton and substitution of 25% dose of N through FYM is sustainable in tropical countries. © 2012 Copyright Taylor and Francis Group, LLC. Source

Adamowski J.,McGill University | Chan H.F.,McGill University | Prasher S.O.,McGill University | Sharda V.N.,Central Soil and Water Conservation Research and Training Institute
Journal of Hydroinformatics | Year: 2012

Himalayan watersheds are characterized by mountainous topography and a lack of available data. Due to the complexity of rainfall-runoff relationships in mountainous watersheds and the lack of hydrological data in many of these watersheds, process-based models have limited applicability for runoff forecasting in these areas. In light of this, accurate forecasting methods that do not necessitate extensive data sets are required for runoff forecasting in mountainous watersheds. In this study, multivariate adaptive regression spline (MARS), wavelet transform artificial neural network (WA-ANN), and regular artificial neural network (ANN) models were developed and compared for runoff forecasting applications in the mountainous watershed of Sainji in the Himalayas, an area with limited data for runoff forecasting. To develop and test the models, three micro-watersheds were gauged in the Sainji watershed in Uttaranchal State in India and data were recorded from July 1 2001 to June 30 2003. It was determined that the best WA-ANN and MARS models were comparable in terms of forecasting accuracy, with both providing very accurate runoff forecasts compared to the best ANN model. The results indicate that the WA-ANN and MARS methods are promising new methods of short-term runoff forecasting in mountainous watersheds with limited data, and warrant additional study. © IWA Publishing 2012. Source

Singh R.J.,Vivekananda Parvatiya Krishi Anusandhan Sansthan | Singh R.J.,Central Soil and Water Conservation Research and Training Institute
Indian Journal of Agricultural Sciences | Year: 2012

An on-farm trial was conducted at five farmer fields of Bageshwar district of Uttrakhand to validate, refine and popularize the technology developed by VPKAS, Almora for managing Buttercup (Ranunculus spp) during 2007-10. The aim of the study was to find out the effectiveness of 2,4-D @ 1.0 kg ai/ha, isoproturon @ 1.0 kg ai/ha and tank mix application of 2,4-D @ 0.5 kg ai/ha with isoproturon @ 1.0 kg ai/ha over farmers practice of hand weeding twice at 30 and 60 DAS and unweeded control on the infestation of weeds and profitability of wheat (Triticum aestivum L. emend. Fiori and Paol.). Tank mix application of 2, 4-D+isoproturon (0.50+1.0 kg/ha) at 35-40 DAS reduced the density and dry weight of Ranunculus and other weeds and nutrient uptake by weeds (3.9 kg N, 0.9 kg P and 6.2 kg K/ha) compared to farmers practice. This combination also resulted in 12.5% higher grain yield, nutrients by wheat (73.5 kg N, 11.6 kg P and 60.0 kg K/ha) and net returns (r 19 030/ha) With this technology, drudgery reduction of about 475-man days/ha can be made possible, which could be used in other fruitful activities of hilly farmers, particularly women. Source

Madhu M.,Central Soil and Water Conservation Research and Training Institute | Hatfeld J.L.,Agriculture and the Environment NLAE
Agronomy Journal | Year: 2013

Plant growth is influenced by above- and belowground environmental conditions and increasing atmospheric carbon dioxide (CO2) concentrations enhances growth and yield of most agricultural crops. This review covers current knowledge on the impact of increasing CO2 concentration on root dynamics of plants in terms of growth, root/shoot (R/S) ratio, root biomass, root length, root longevity, root mortality, root distribution, root branching, root quality, and the response of these root parameters to management practices including soil water and nutrients. The effects of CO2 concentration on R/S ratio are contradictory due to complexity in accurate underground biomass estimation under diverse crops and conditions. Roots become more numerous, longer, thicker, and faster growing in crops exposed to high CO2 with increased root length in many plant species. Branching and extension of roots under elevated CO2 may lead to altered root architecture and ability of roots to acquire water and nutrients from the soil profile with exploration of the soil volume. Root turnover is important to the global C budget as well as to nutrient cycling in ecosystems and individual plants. Agricultural management practices have a greater impact on root growth than rising atmospheric CO2 since management practices influence soil physical, chemical, and biological properties of soil, consequently affects root growth dynamics in the belowground. Less understood are the interactive effects of elevated CO2 and management practices including drought on root dynamics, fine-root production, and water-nutrient use efficiency, and the contribution of these processes to plant growth in water and nutrients limited environments. © 2013 by the American Society of Agronomy., 5585 Guilford Road, Madison, WI 53711. All rights reserved. Source

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