Impacts of long-term rice-based organic farming on fractions and forms of soil organic carbon and nitrogen in the Indo-Gangetic Plain
Amrit Lal Meena, Renu Pandey, Dinesh Kumar, Vinod Sharma, M. D. Meena, Minakshi Karwal, Debashis Dutta, Lokesh Kumar Meena, Ekta Narwal, R. P. Mishra, A. S. Panwar, Avijit Ghosh
Abstract
The present study aimed to appraise the long-term effects of organics, crop residues, and biofertilisers on soil carbon (C) and nitrogen (N) pools for sustainable crop production and changes in soil quality under long-term organic farming practices. Hence, we studied the soil C and N pools and their sensitivity indices as influenced by a different combination of farmyard manure, vermicompost, biofertilisers, and crop residue of rice, wheat, and mungbean, under long-term rice–wheat–mungbean (RWMCS) and rice–wheat (RWCS) cropping systems in an Inceptisol of India. Total soil organic C increased by 78% and 104% for RWMCS and 94% and 123% for RWCS with FYM + crop residue + biofertilisers and vermicompost + crop residue + biofertilisers, respectively over unfertilised control plots of RWMCS. The highly labile C and microbial biomass C were highly sensitive to management practices compared to total organic C and less labile C fractions. Integrated application of manures and crop residues in FYM + crop residue and VC + crop residue resulted in significantly higher total N, labile N, and mineral N for both cropping systems. Higher values of C and N management indexes were observed with FYM + crop residue + biofertilisers and VC + crop residue + biofertiliser in both cropping systems than other treatments. Integrated use of organic sources had higher N fractions than the unfertilised control plots, indicating that long-term conjoint use of organics, crop residues, and biofertilisers could sustain crop production and soil quality.