Enhancing root growth dynamics of fodder cowpea (Vigna unguiculata) in the maize-based intercropping system: A comparative analysis of different management practices

A two-year field study (2022–2023) assessed the effects of nutrient and pest management practices on root growth, nodulation, green fodder yield, and maize grain equivalent yield (MEY) in a maize-cowpea intercropping system. The experiment employed a randomized block design with five treatments: control (sesbania alone), natural farming, organic farming, Integrated Crop Management (ICM) with botanical pesticides, and ICM with chemical pesticides. Integrated Crop Management with botanical pesticides consistently outperformed other treatments across both years. In 2023, this treatment achieved the highest lateral root length (10.49 cm) and main root length (20.25 cm), with increases of 44.7% and 42.1%, respectively, over the control. In 2022, lateral and main root lengths increased by 40.5% and 38.3%, respectively. Nodulation also improved significantly, with 30 nodules per plant and a nodule weight of 67.75 mg plant⁻¹ in 2023, compared to 16.75 nodules and 49.75 mg plant⁻¹ in the control. Green fodder yield was highest under ICM + botanical pesticides, reaching 36.25 t ha⁻¹ in 2023 and 34.75 t ha⁻¹ in 2022, representing increases of 65.8% and 62.3% over the control. Maize grain equivalent yield rose to 7.85 t ha⁻¹ in 2023 and 7.45 t ha⁻¹ in 2022, reflecting increases of 80.5% and 75.5% compared to the control. This study highlights the potential of integrating botanical pesticides with nutrient management to enhance root traits, nodulation, and productivity in maize-cowpea intercropping systems, offering a sustainable approach to improving resource-use efficiency.