Nitrous oxide loss from poultry manure-amended soil after rain

Land application of poultry wastes in Kentucky will increase as the broiler industry grows. If poultry manure stimulates N₂O loss from soil it will reduce the fertilizer N value of this waste. In contrast, stimulated N₂O loss in grass filter strips receiving the runoff from manured fields could help reduce contamination of surface water by NO₃/^-. Our objectives were to determine (i) if poultry manure stimulated N₂O loss in soil after rainfall and (ii) if there was an edge-of-field effect on N₂O loss in grass filters intercepting runoff from amended soil. Soil covers were used to measure N₂O loss from a well-drained, poultry manure-amended, silt loam soil immediately after simulated rainfall and were also used to measure N₂O loss from grass filters intercepting their surface runoff. Nitrous oxide loss from manure-amended soil was greater than from unamended controls and ranged from 5 to 13 mg N₂O-N m^-2 h^-1. The maximum N₂O loss was equivalent to 3.2 kg N₂O-N ha^-1 d^-1. Nitrous oxide loss from grass filters intercepting runoff ranged from 0.1 to 1.4 mg N₂O-N m^-2 h^-1 and was significantly greater than portions of the grass filters that did not intercept runoff. Nitrous oxide loss from poultry manure-amended soils was greater than N₂O loss typically measured from waste-amended agricultural soils. However, it only represented up to 0.7% of the total N in the applied manure.