Nutrient Management in Conservation Agriculture-based Production Systems
Conservation agriculture (CA) based crop management practices enhance soil health that ultimately improves crop production with low environmental foot prints. Developments of the better nutrient management practices are important to successful implementation of CA On average, efficiency of fertilizer N in India is only 30-40% in rice and 50-60% in other cereals. Higher nutrient use efficiency (NUE) under CA can be achieved through fine-tuning of nutrient management practices based on local site-specific conditions developed for conventional till- based agriculture. In South Asia systematic research on nutrient dynamics in soils and crop nutrient management requirements in CA systems is limited. Opportunities exist to enhance the yield, profitability. and NUE through site-specific nutrient management (SSNM) in CA Various tools, techniques and decision support systems (nutrient expert, optical sensors and leaf colour chart) are available for soil- and plant- based precision nutrient management, which offer the potential to enhance NUE in cereals and to mitigate environmental quality risk by avoiding N losses via volatilization, leaching and denitrification. GreenSeeker (GS)-based SSNM saved-20-30 kg N ha without affecting the grain yield under CA-based cereal systems compared to general recommended dose of fertilizers Nutrient expert and GS-based nutrient management reduced GHG intensity of rice, wheat and maize production by 5-35 and 0-13%, respectively over farmers' fertilizer practice. There is a need to develop nutrient prescriptions and application strategies in line with the 4R-principles to increase the NUE under CA- based management practices Future studies should be focused on layering of CA with different novel nutrient management tools and subsurface fertigation for increasing both water and nutrient use efficiency In CA-based production systems, innovations in machinery are needed for precise band placement at seeding and during crop growth.
Nutrient management, Nutrient use efficiency, Environmental health