Agronomic Performance of Maize (Zea mays l.) Fertilized with Siam Weed (Chromolaena odorata l.) Leaf Residues in Rainforest Zone of Nigeria

Abstract

Maize (Zea mays L.) is a staple crop in Nigeria, yet yields remain low due to declining soil fertility and dependence on inorganic fertilizers that are costly and environmentally unsustainable. This study investigated the use of Siam weed (Chromolaena odorata L) residues as an organic amendment under rainforest agroecological conditions in Benin City, Nigeria. Field trials were conducted at the Teaching and Research Farm, University of Benin, Benin City, across two seasons with leaf residues rates of 0, 10, 30, and 50 kg ha–1.Experimental design was Randomised Complete Block with four replications. Soil properties, plant growth, phenological traits, and yield components were measured. Results showed that Chromolaena leaf residues significantly improved soil nutrient status, reduced acidity, enhanced nitrogen uptake, and improved maize growth and yield. Application rates of 30 and 50 kg m–2 increased plant height (155.9, 160.3 cm, respectively), shortened anthesis-silking intervals (2.4,1.5 days) and enhanced nitrogen uptake (3.37, 4.35 g plant–1). These application rates also boosted grain yield (3.0, 3.8 t ha–1) by up to 192 and 268% compared to control plots and enhanced stover yield (2.7, 3.3 t ha–1), offering added value for livestock feeding. Grain yield showed strong negative and positive correlations with phenological traits and growth/yield attributes, respectively. Findings highlight Chromolaena leaf residues as a cost-effective, eco-friendly organic fertilizers, capable of improving maize productivity and supporting sustainable crop-livestock systems in Nigeria