Poultry manure improves soil properties and grain mineral composition, maize productivity and economic profitability.

Research information on poultry manure's impact on soil characteristics, mineral composition and maize performance is scarce, despite the vital role nutrient levels play in supporting human health. The objective of this study was to examine the effects of poultry manure on soil properties, grain mineral content, growth, grain yield and economic benefit of maize. A two-year field experiment (2022-2023) was conducted at the Teaching and Research Farm of Adekunle Ajasin University, Akungba-Akoko, Ondo State using five poultry manure levels (0, 5, 10, 15, and 20 t ha⁻¹) in a randomized complete block design with three replications. Poultry manure significantly reduced soil bulk density and improved porosity, moisture content, chemical properties, and grain mineral composition. Maize growth and yield increased with higher manure levels, but the 10 t ha⁻¹ treatment produced the best outcomes, offering comparable nutritional quality and yield to the 15 and 20 t ha⁻¹ treatments. Relative to the control, grain yield increased by 54.6%, 94.6%, 93.5%, and 91.4% for 5, 10, 15, and 20 t ha⁻¹ treatments, respectively. The 10 t ha⁻¹ application rate was the most cost-effective and beneficial for improving soil properties and maize productivity, as indicated by the benefit-to-cost ratio. This study recommended the use of 10 t ha⁻¹ poultry manure for soil fertility management, sustainable nutrition, and enhanced maize performance in the study area. The findings highlight poultry manure's potential to improve soil properties, maize yield, and nutrient content, contributing to better human nutrition in areas with depleted soils.