Animal manures and plant residue-based amendments for sustainable rice-wheat production and soil fertility improvement in eastern Uttar Pradesh, North India

Abstract

Agroecological interventions are imperative for boosting agricultural productivity and soil fertility while increasing profitability of subsistence farmers in low-income countries by replacing synthetic fertilizers. With this context, the present study was aimed to evaluate the impact of animal manures (sheep and poultry manure) and plant residue-based organic amendments (rice husk biochar and sugarcane pressmud) on soil quality, nutrient uptake and balance, yield, and sustainability of rice-wheat cropping in alluvial (rainfed) and red lateritic soil (dryland) of middle Gangetic plains (Narayanpur) and Vindhyan region (Rajgarh) of Mirzapur district in eastern UP. The field experiments were conducted for three years at the above two sites and amendments were done at a rate by replacing 30% standard recommended doses of fertilizer (RDF) for rice-wheat cropping system. Field trials were conducted with the 100% RDF as control, and 70% RDF with sheep manure, poultry manure, rice-husk biochar and sugarcane pressmud in a randomized block design. The organic amendments were done during the rice cultivation stage and the residual effect was observed during the subsequent wheat cultivation. Though soil organic carbon (SOC) was found to show significant (p ≥ 0.05) increase in biochar amended plots, animal manures followed by pressmud showed year wise increase in both SOC and microbial biomass carbon. In rainfed areas, plant growth and yield attributes for both rice and wheat were at par in amendments than control while in dryland, the 100% RDF showed better performance during the first year, after that amended plot showed better performance. All amendments resulted in higher benefit: cost ratio except biochar addition in Narayanpur, whereas in Rajgarh, the poultry manure resulted in significant improvement in benefit: cost ratio from second year onward. Our study advocates that validation of suitable amendment packages based on organic inputs are imperative for improving the yield, soil quality and nutrient balance of rice-wheat cropping system and thereby attaining the UN-SDGs at the village/local level.