Impact of planting systems and nutrient management on growth and yield of maize and soybean in a maize + soybean cropping system

Abstract

A field experiment was conducted during Kharif 2023 at Lovely Professional University, Punjab, using a split-plot design (SPD) with five main plot treatments and five subplot treatments, replicated three times, to evaluate the effects of intercropping and nutrient management on maize growth and productivity. The main plot treatments consisted of cropping systems: Sole maize (M1), Sole soybean (M2), Maize + Soybean (1:1, M3), Maize + Soybean (1:2, M4) and Maize + Soybean (2:3, M5). Subplot treatments included nutrient management strategies: Absolute control (S1), 100% RDF through inorganic fertilizers (S2), 70% RDF + NPK nano fertilizer spray (S3), 70% RDF + homemade NPK spray (S4) and 70% RDF + plant extract NPK spray (S5). Results indicated that monocropped maize and soybean systems outperformed intercropping in terms of growth and grain yield, with similar trends observed for stover yield. Among nutrient management practices, foliar application of plant extract NPK showed the most significant improvement, enhancing growth attributes and crop growth rate (CGR) by 14.1% in maize and 43.4% in soybean and increasing productivity by 18% in maize and 30.6% in soybean compared to the control. The interaction of maize and soybean with foliar plant extract NPK spray led to grain yield increases of 36.6% in maize and 50.7% in soybean compared to untreated controls. Furthermore, the crop equivalent yield and land equivalent ratio were maximized in the maizesoybean intercropping system at a 1:1 ratio. This study underscores the role of strategic nutrient management and intercropping in optimizing maize and soybean productivity, with foliar NPK plant extract spray showing the most promising results for enhancing growth and yield.