Temperature response of ammonia and greenhouse gas emission from manure amended silty clay soil

摘要

Soil temperature plays an important role in organic matter decomposition, thus likely to affect ammonia and gaseous emission from land application of manure. An incubation experiment was conducted to quantify ammonia and greenhouse gas (GHG) (N2O, CO2 and CH4) emissions from manure and urea applied at 215kg N ha(-1) to Fargo-Ryan silty clay soil. Soil (250g) amended with solid beef manure (SM), straw-bedded solid beef manure (BM), urea only (UO), and control (CT) were incubated at 5, 10, 15, and 25 degrees C for 31 days at constant 60% water holding capacity (WHC). The cumulative GHGs and NH3 emission generally increased with temperature and highest emission observed at 25 degrees C. Across temperature levels, 0.11-1.3% and 0.1-0.7% of the total N was lost as N2O and NH3, respectively. Cumulative CO2 emission from manure was higher than UO and CT at all temperatures (P&0.05). Methane accounted for &0.1% of the total C (CO2+CH4) emission across temperatures. The Q(10) values (temperature sensitivity coefficient) derived from Arrhenius and exponential models ranged 1.5-3.7 for N2O, 1.4-6.4 for CO2, 1.6-5.8 for CH4, and 1.4-5.0 for NH3. Our results demonstrated that temperature significantly influences NH3 and GHG emissions irrespective of soil amendment but the magnitude of emission varied with soil nutrient availability and substrate quality. Overall, the highest temperature resulted in the highest emission of NH3 and GHGs.