Enhancing nutrient-use efficiency in crop production – A review

The nutrient-use efficiency of all the major, secondary and micronutrients continuous to be low despite increasing consumption of fertilizers in India. Improvement in nutrient-use efficiency is necessary to reduce the cost of production as well as to prevent environmental pollution. Adoption of best management practices is essential to get higher input-use efficiency and profitability. Among all the major nutrients, nitrogen is most vulnerable, and increasing its use efficiency through physical manipulation of the size of granules, coating of granules with films, amendments or chemicals to prevent their fast dissolution or prevent bacterial-mediated denitrification did not prove economically viable. Split application is effective but costly. Reliance on biological N₂ fixation through inclusion of legumes in cropping system and maintenance of higher soil organic matter will help to build-up soil fertility and better soil physical and microbial environment with good buffering capacity. The recent developments in the field of biological nitrification inhibition offer good opportunity in effective nitrate management. Identification of efficient genotypes for low nutrient situations or higher response to applied nutrients through better acquisition and assimilation are encouraging. Phosphorus management should consider proper source and the cumulative effects that can be exploited through biological processes for nutrient availability and root acquisition. Adoption of conservation tillage, site-specific nutrient management and best fertilizer management practices will go a long way in increasing nutrient-use efficiency. Adoption of new technology through the gadgets such as leaf colour charts, sensor-based technology, laser land leveling etc. can reduce the dependence on laboratory assistance and manual labour.