干旱区生态环境知识资源中心

On irrigated agricultural soils from semi-arid and arid regions, ammonia (NH3) volatilization and nitrous oxide (N2O) emission can be a considerable source of N losses. This study was designed to test the capture of N-15 loss as NH3 and N2O from previous and recent manure application using a sandy, calcareous soil from Oman amended one or two times with N-15 labeled manure to elucidate microbial turnover processes under laboratory conditions. The system allowed to detect N-15 enrichments in evolved N2O-N and NH3-N of up to 17% and 9%, respectively, and total N, K2SO4 extractable N and microbial N pools from previous and recent N-15 labeled manure applications of up to 7%, 8%, and 15%. One time manured soil had higher cumulative N2O-N emissions (141 mu g kg(-1)) than repeatedly manured soil with 43 mu g kg(-1) of which only 22% derived from recent manure application indicating a priming effect.