Exploring optimal integrated nutrient management combinations in potato-fodder maize-maize rotation to improve agronomic parameters, productivity and nutrient uptakes under inceptisols of north-western, India

Integrated nutrient management (INM) plays a significant role in enhancing productivity in intensive cropping systems, and optimizing effective INM strategies for nutrient-exhaustive systems is essential for their successful adoption. This study evaluates INM strategies in diversified maize-based cropping system (potato-fodder maize-maize) under the north-western Indian sub-tropics. A two-year field experiment (2021–22 and 2022–23) was conducted at Punjab Agricultural University (PAU), Ludhiana, India, to assess the effects of different INM strategies on agronomic performance, system productivity, and nutrient uptake, along with their interrelationships, in this diversified cropping system. The results revealed that application of NM8 [Farmyard manure (FYM) @ 75 % of recommended dose (RD) + chemical fertilizer (CF) @ 100 % of RD in potato, FYM @ 75 % of RD + CF @ 75 % of RD + consortium in fodder maize and FYM @ 75 % of RD + CF @ 75 % of RD + cowpea biomass retention in maize] significantly improved the agronomic parameters of all three crops, and was statistically at par with the treatments of full recommended dose (NM11 and NM12) consequently resulted in higher tuber yield (302.90 q/ha), fodder yield (394.70 q/ha) and grain yield (56.45 q/ha). Furthermore, the treatment NM8 increased system productivity by 55.91 % over the control, thereby improving overall profitability. The correlation matrix and principal component analyses revealed strong (P ≤ 0.05 and P ≤ 0.01) associations among agronomic parameters and economic yield, while regression analysis showed that the nutrient uptake significantly (P ≤ 0.01) positively influenced economic yields. The treatment NM8 exhibited higher Benefit-cost (BC) ratios (1.44–1.48) across all three crops, with total net returns of Rs. 3,00,264/ha, indicating 2.10-fold increase over the control.