Nayak A.K.,Project Directorate of Farming Systems Research |
Nayak A.K.,Indian Central Rice Research Institute |
Gangwar B.,Project Directorate of Farming Systems Research |
Gangwar B.,Indian Institute of Science |
And 8 more authors.
Field Crops Research | Year: 2012
Rice-wheat rotation is the most important cropping system of the Indo-Gangetic Plains (IGP) and is responsible for the food security of the region. The effect of different integrated nutrient management practices on soil organic carbon (SOC) stocks and its fractions, SOC sequestration potential as well as the sustainability of the rice-wheat system were evaluated in long term experiments at different agro-climatic zones of IGP. Application of NPK either through inorganic fertilizers or through combination of inorganic fertilizer and organics such as farm yard manure (FYM) or crop residue or green manure improved the SOC, particulate organic carbon (POC), microbial biomass carbon (MBC) concentration and their sequestration rate. Application of 50% NPK+50%N through FYM in rice and 100% NPK in wheat, sequestered 0.39 , 0.50, 0.51 and 0.62MgCha -1yr -1 over control (no N-P-K fertilizers or organics), respectively at Ludhiana, Kanpur, Sabour and Kalyani using the mass of SOC in the control treatment as reference point. Soil carbon sequestration with response to application of fertilizer partially substituted (50% on N basis) with organics were higher in Kalyani and Sabour lying in humid climate than Ludhiana and Kanpur lying in semiarid climate. The rice yield recorded a significant declining trend in Ludhiana and Kanpur where as the yield trend was stable at Sabour and Kalyani under unfertilized control. The system productivity in N-P-K fertilized plots and NPK along with organics showed either an increasing trend or remained stable at all locations during last two and half decades of the experiment. © 2011 Elsevier B.V.
Chakraborty D.,Indian Agricultural Research Institute |
Mazumdar S.P.,Indian Agricultural Research Institute |
Mazumdar S.P.,Project Directorate of Farming Systems Research |
Garg R.N.,Indian Agricultural Research Institute |
And 5 more authors.
Indian Journal of Agricultural Sciences | Year: 2011
Limited numbers of pedotransfer functions (PTFs) for predicting the soil moisture transmission parameters are available for the Indian soils. These PTFs have been developed from limited datasets and are area specific, limiting their applicability elsewhere. Secondary data from various sources often have non-systematic errors and lacking in uniformity. The present study makes an attempt to explore the possibility of developing PTFs from wide textural range of Indian soils for four points on the moisture retention curve, -33, -100, -500 and -1 500 kPa. Moisture content at these four matric potentials was significantly related to clay and sand but little or no correlation was observed with bulk density and organic C content in soils. For each potential, six sets of regression equations were used to predict the moisture content from textural composition, bulk density and organic C content. The predictive potential is better by considering only clay and silt at -33 and -500 kPa while clay, silt and bulk density gave good moisture predictability at -100 and -1 500 kPa potential values. The developed PTFs for moisture contents at -33 and -1 500 kPa were evaluated with existing PTFs and were found to perform satisfactorily.