3,4-dimethylpyrazol phosphate effect on nitrous oxide, nitric oxide, ammonia, and carbon dioxide emissions from grasslands

摘要

Intensively managed grasslands are potentially a large source of NH(3), N(2)O, and NO emissions because of the large input of nitrogen (N) in fertilizers. Addition of nitrification inhibitors (NI) to fertilizers maintains soil N in ammonium form. Consequently, N(2)O and NO losses are less likely to occur and the potential for N utilization is increased, and NH(3) volatilization may be increased. In the present study, we evaluated the effectiveness of the nitrification inhibitor 3,4-dimethylpyrazol phosphate (DMPP) on NH(3), N(2)O, NO, and CO(2) emissions following the application of 97 kg N ha(-1) as ammonium sulfate nitrate (ASN) and 97 kg NH(4)(+)-N ha(-1) as cattle slurry to a mixed clover-ryegrass sward in the Basque Country (northern Spain). After slurry application, 16.0 and 0.7% of the NH(4)(+)-N applied was lost in the form of N(2)O and NO, respectively. The application of DMPP induced a decrease of 29 and 25% in N(2)O and NO emissions, respectively. After ASN application 4.6 and 2.8% of the N applied was lost as N(2)O and NO, respectively. The application of DMPP with ASN (as ENTEC 26; COMPO, Munster, Germany) unexpectedly did not significantly reduce N(2)O emissions, but induced a decrease of 44% in NO emissions. The amount of NH(4)(+)-N lost in the form of NH(3) following slurry and slurry + DMPP applications was 7.8 and 11.0%, respectively, the increase induced by DMPP not being statistically significant. Levels of CO(2) emissions were unaffected in all cases by the use of DMPP. We conclude that DMPP is an efficient nitrification inhibitor to be used to reduce N(2)O and NO emissions from grasslands.