Application of precision nutrient tools for the optimization of fertilizer requirements and assessment of the growth and productivity of maize (Zea mays L.) in the northeastern Ghat of India

Cereals are vital food crops that provide dietary energy and food security. Among the different cereal crops, maize has its own importance in terms of area, production and productivity. However, it is a highly nutrient–draining crop, and its sustainable yield is dependent on proper nutrient management. The regional recommended dose of fertilizers and blanket application of nutrients cannot fulfil the requirements for improving maize productivity. Therefore, an experiment on precision nutrient management in maize was designed to optimize nutrient requirements and increase crop yield. The experiment was conducted for two consecutive years during two rabi seasons (November–March), 2021–2022 and 2022–2023, at the postgraduate research farms of the M.S. Swaminathan School of Agriculture, Centurion University of Technology and Management, Odisha, India. The treatments used were as follows: T1: recommended dose of fertilizer (RDF), T2: 125 % RDF, T3: 75 % RDF, T4: 150 % RDF, T5: RDF + nanourea, T6: 75 % RDF + nanourea, T7: leaf colour chart (LCC) 4–based nitrogen management, T8: LCC 5–based nitrogen management, T9: a chlorophyll content meter (CCM) (sufficiency index) (SI)–based nitrogen management at SI 85–90 %, T10: CCM SI–based N management at SI 90–95 % T11: nutrient expert (NE)–based nutrient recommendation for a targeted yield of 7 t/ha, T12: NE–based nutrient recommendation for a targeted yield of 9 t/ha and T13: unfertilized control. All the treatments were arranged in a randomized complete block design and replicated three times. The results revealed that during the harvesting stage, the highest plant height (239 and 242 cm), dry matter accumulation (2066 and 2149 g/m2), and leaf area (2985 and 2897 cm/m2) were obtained for both years with the T10 treatment: CCM SI–based N management at SI 90–95 %; however, they remained statistically significant at par with T4:150 % RDF during all the growth stages of maize. Higher values of most of the yield attributes were noted with CCM–SI-based N management at 90–95 % SI, which was on par with 150 % RDF. The impacts of growth and yield attributes were reflected in the grain (7.67 and 7.80 t/ha, respectively) and stover yields (12.72 and 12.60 t/ha, respectively) during both years. This study concluded that the precise application of nitrogen through a CCM–based sufficiency index by increasing the number of spits along with an optimum dose of phosphorous and potassium can improve the growth and productivity of maize.