Assessment of precise nutrient management through nutrient expert on productivity and profitability of zero-till maize

An experiment was conducted during the rainy (kharif) season of 2017 and 2018 at the ICAR-Indian Agricultural Research Institute, New Delhi, to evaluate the effect of tillage and nutrient-management options on yield, nutrient uptake, residual soil-fertility status, and enzymatic activities in maize (Zea mays L.). The zero-tillage with crop residue at 3.5 t/ha (ZT + R) and conventional tillage with crop residue at 3.5 t/ha (CT + R) enhanced the grain yield (6.2–17.0%) of maize compared to CT without residue (4.40 t/ha). High cost of cultivation was recorded in CT + R (44.8 × 103 `/ha), while high net returns were found in ZT + R (37.6 × 103 `/ha). In ZT + R, the addition of wheat residue enhanced N, P, and K uptake in grain by 19.41, 12.81 and 13.92%, respectively over CT. Available N (182 kg/ha), available P (13.8 kg/ha), and exchangeable K (318 kg/ha) were found highest with ZT + R. Nutrient expert system (NES) enhanced the grain yield (5.30 t/ha) and net returns (43.0 × 103 `/ha) compared to no application of nutrients (control) (3.35 t/ha and 17.9 × 103 `/ha) and recommended dose of fertilizer (RDF) (4.70 t/ha and 34.8 × 103 `/ha). Higher activity of dehydrogenase (DHA) (25.9 TPF μg/g/h) and microbial biomass C (130 μg/g) were found with NES. An increase of 57.96–58.4% in N uptake was found with NES over RDF (80.0 kg/ha). The nutrient expert system (NES) and 125% of RDF left higher amount of residual N, P and K in soil than the control. Overall, nutrient expert system under zero-tillage with crop residue at 3.5 t/ha can increase the productivity and profitability in maize.