Mitigation of nitrous oxide emission by controlled availability fertilizer and nitrification inhibitor

摘要

The effects of a controlled availability fertilizer and a nitrification inhibitor (AM: 2-amino-4-chloro-6-methyl pyrimidine) on the mitigation of nitrous oxide emission from soil were studied in a pot experiment. Urea coated with a polymer of olefin, a chemical fertilizer amended with AM, and urea were compared. The change of ammonium, nitrite and nitrate in the soil was monitored. Sweetcorn was cultivated in a 0.05 m2 pot. Nitrous oxide flux reached peaks at 25, 31 and 52 d after fertilizer application in the pots applied with urea, coated urea and chemical fertilizer amended with AM respectively. The order of total amount of emitted N2O through 80 d was: urea>coated urea (without sweetcorn)>coated urea>chemical fertilizer amended with AM>no N. The amounts were different with a 99% level of significance. In the laboratory, low-humic Andosol applied with urea, a controlled availability fertilizer or a fertilizer applied with nitrification inhibitor was incubated at a 80% field capacity moisture content. Nitrous oxide flux synchronized with nitrification activity. AM reduced N2O emission when compared with urea. It was concluded that AM reduced the ratio of nitrous oxide production through nitrification whether the plant grew or not. It is believed that the reduction of nitrous oxide emission was caused by the decrease of nitrite concentration in the soil. Controlled availability fertilizer decreased nitrous oxide emission from the sweetcorn soil. Without plants, the effects of the controlled availability fertilizer on reducing nitrous oxide are limited.