Utilizing Conservation Tillage to Minimize Nutrient Losses from Poultry Litter Applied in Grain Production Systems

Most poultry litter is applied as fertilizer to cropland following nitrogen (N)-based nutrient management recommendations. Under N-based planning, rates for manure applications are typically based on the N requirement of the crops to be grown and the plant-available N content of the manure. A recent economic analysis confirmed that application of broiler litter as a fertilizer to cropland is the highest value use of the litter generated on the Delmarva Peninsula. The amount of phosphorous (P) applied with the manure usually has not been considered when determining recommended application rates. In these situations, soil P concentrations can increase rapidly. Recent research that examined phosphorous in manure-amended Atlantic Coastal Plain soils suggest that the Chesapeake Bay and its tributaries are more vulnerable to receiving excess P from surface runoff than from P leaching. This same research concluded that the primary focus of P management efforts should be minimizing loss through surface runoff pathways coupled with monitoring the degree of P saturation of surface soils. The purpose of this project is to demonstrate that currently existing conservation tillage technology can be successfully used to partially incorporate poultry litter in reduced tillage grain production systems, preserving surface residue and soil conservation conditions, while reducing N and P losses compared to no-till production systems. This nutrient management approach will be demonstrated and evaluated on 10-12 farms across the Delmarva Peninsula.