Optimizing mineral nutrients for enhancing the yield, nutrient use efficiency and profitability of maize in India

Enhancing crop production and productivity to meet the needs of growing populations has emerged as a significant challenge. To explore this issue, a field experiment was conducted using optimal regimes of mineral fertilizers, either in combinations of three or two nutrients against no fertilization, to evaluate the effects on maize yield, nutrient uptake, and nitrogen (N) use efficiency in alluvial soils of India. In general, the results revealed that a significant increase in maize yield was achieved with 125% NPK application through mineral fertilizers. Nutrient uptake for P, and K was also significantly higher in the same treatment; however uptake of N was in 150% NPK. The highest agronomic efficiency of N and recovery efficiency of N was achieved with the treatment applied with 100% NPK, compared to the control. Economically, the 125% NPK treatment was found to be superior to all other treatments. Among the omissions of nutrients, N-omitted (100% PK) treatment produced the lowest yield, indicating N emerged as a critical element in crop production. The study also emphasized that the optimized yield of a combination of three nutrients is more effective than that of in a pair. The grain yield showed a positive and significant linear correlation with NPK-based treatments up to a maximum dose, indicating that higher levels of NPK could be beneficial for crop yield. The grain yield was found to be positively and significantly correlated with N and P at r=0.72 and 0.79, respectively. Overall, it could be recommended to increase the mineral NPK application by 25% from the current recommended dose of fertilizer, and a 125% NPK treatment is the optimal dosage for maize cultivation and profitability in India.