Growth and Productivity Performance of Maize under Different Row Ratios in Maize + Cowpea Intercropping System

Abstract

The present study aimed to evaluate the growth and productivity performance of maize under different row ratios and nitrogen management practices in a maize + cowpea intercropping system. A field experiment was conducted during kharif 2023 and 2024 at the Students’ Instructional Farm, Chandra Shekhar Azad University of Agriculture and Technology, Kanpur (U.P.). The experiment was laid out in a Split Plot Design with three replications, consisting of four intercropping arrangements sole maize, sole cowpea, maize + cowpea (1:1), and maize + cowpea (2:1) and five nitrogen management practices combining different levels of the recommended nitrogen dose (RDN) and foliar-applied nano urea. Results indicated that sole maize recorded the maximum plant height on pooled basis (221.01 cm), dry matter accumulation (2854.74 g m⁻²) at harvest and leaf area index (3.16 at 60 DAS). Among intercropping treatments, maize + cowpea (1:1) achieved the highest maize equivalent yield (8.66 t ha⁻¹) with a land equivalent ratio (LER) 1.37, demonstrating efficient resource use and productivity advantage over sole cropping. Among nitrogen management practices, 100% RDN produced the tallest plants (214.90 cm) and maximum dry matter (2096.50 g m⁻²), while 75% RDN with two foliar sprays of nano urea at 30 and 50 DAS recorded comparable plant height (214.48 cm) and dry matter (1945.78 g m⁻²), demonstrating 25% nitrogen saving without yield reduction. The study concludes that maize + cowpea intercropping in a 1:1 row ratio, coupled with 75% RDN and two nano urea sprays, enhances maize growth, nitrogen use efficiency, and total system productivity, thereby promoting a sustainable and resource-efficient cereal–legume production system in the Central Plain Zone of Uttar Pradesh.