Evaluating Field Corn Yield and Plant and Soil Nutrient Concentrations Under Application of Synthetic Fertilizer and Dairy Manure

Application of manure in field corn has the potential to sustain corn yields and reduce nutrient leaching in soil profile. A field trial with randomized complete block design was conducted on Adkins fine sandy loam soil to evaluate the impact of application of manure and synthetic fertilizer on nutrient concentrations (N, P, K and S) in plant and soil and field corn yield. Experimental treatments included an application of synthetic fertilizer (NPK) and dairy manure application at 5-, 10- and 15-tons acre ^-1 in addition to a non-fertilized control. All the manure was applied before planting. Corn was manually harvested, and plants were separated into leaves, stems and cobs to determine dry weights. Post harvest soil sampling was performed at 0-30, 30-60 and 60-90 cm soil depths. Results indicated that in-season leaf nutrient concentration was significantly different among applied treatments. Application of synthetic fertilizer resulted in the highest plant height (116 in) and produced higher corn yield (45.5 tons acre ^-1 ) compared to control and application of dairy manure. Application of manure at 5 tons acre ^-1 produced higher corn yield (35.5 tons acre ^-1 ) compared to manure application at 10 (25.9 tons acre ^-1 ) and 15 tons acre ^-1 (26.1 tons acre ^-1 ). A similar trend was observed for leaf, stem and cobs fresh and dry weights. Nutrient recovery was higher under application of synthetic fertilizer followed by application of manure at 5 tons acre ^-1 . Soil nutrient analysis indicated no significant impact on N, P, K and S concentration among treatments except for NH ₄ ⁺ –N. However, nutrient concentration significantly varied under different soil depths. Results suggest that a combination of synthetic fertilizer application and manure might be a practical approach for balanced nutrient supply for field corn. Further investigations are necessary to explore the potential of manure application to ensure balanced nutrient supply, improved yields and reduced nutrient losses in field corn.