Technological watch

Conventional tillage practices coupled with irrational use of fertilizer in the rice-wheat cropping system (RWCS) often leads to poor productivity, low nutrient use efficiency, and cause environmental pollution. Conservation tillage with surface residue retention in combination with intelligent nutrient management might improve productivity and use efficiency of water as well as nutrients in zero-till direct-seeded rice (ZTDSR). Keeping this in mind, during the kharif season of 2018 and 2019, a trial was carried out at the ICAR-IARI in New Delhi to investigate the varying nutrient management approaches following a precise manner in DSR. The treatments consisted of soil-test-based NPK (STB-NPK) and Nutrient Expert® (+LCCN) based NPK (NE-NPK) applications, Fertilizer applied at the recommended dose (RDF) [120-60-40 kg/ha NPK], the state recommended NPK (110-50-40 kg/ha) and omission plot technique of NPK [i.e., STB (N0PK, NP0K & NPK0); SR (N0PK, NP0K & NPK0) and NE-(N0PK, NP0K & NPK0)]. The results indicated that STB NPK application led to a 12% higher grain yield over RDF. However, NE-NPK resulted in a 7% and 35% increase in N (AEN) agronomic efficiency and P (AEP) over the STB-NPK application respectively. In contrast, AEk was 24% higher in STB-NPK over NE-NPK treatment. The comparison of two years’ results that the first year performed better than the succeeding year in these respect (productivity and AE) except in the case of AEk. The N2O emission in NE-NPK treatment was also significantly reduced (49%) over the control (no N). STB-NPK treatment also improved profitability by 22% over RDF. Precision nutrient management (PNM) increased the crop yield, income, and use efficiency of nutrients and water and reduced greenhouse gas (GHG) emissions of DSR in Southeast Asia.