Effect of nitrification inhibitor DMPP on nitrogen leaching, nitrifying organisms, and enzyme activities in a rice-oilseed rape cropping system

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• 作者：Hua LI ; Xinqiang LIANG ; Yingxu CHEN ; Yanfeng LIAN ; Guangming TIAN ; Wuzhong NI
• 关键词：DMPP (3 ; 4-dimethylpyrazole phosphate) ; nitrification inhibitor ; nitrifying organisms ; nitrogen leaching ; soil enzymes
• 刊名：Journal of Environmental Sciences
• 出版年：2008
• 出版时间：February 2008
• 年：2008
• 卷：20
• 期：2
• 页码：149-155
• 全文大小：631 K

文摘

DMPP (3,4-dimethylpyrazole phosphate) has been used to reduce nitrogen (N) loss from leaching or denitrification and to improve N supply in agricultural land. However, its impact on soil nitrifying organisms and enzyme activities involved in N cycling is largely unknown. Therefore, an on-farm experiment, for two years, has been conducted, to elucidate the effects of DMPP on mineral N (NH₄⁺- N and NO₃⁻-N) leaching, nitrifying organisms, and denitrifying enzymes in a rice-oilseed rape cropping system. Three treatments including urea alone (UA), urea + 1 % DMPP (DP), and no fertilizer (CK), have been carried out. The results showed that DP enhanced the mean NH₄⁺-N concentrations by 19.1 % –24.3 % , but reduced the mean NO₃⁻-N concentrations by 44.9 % –56.6 % in the leachate, under a two-year rice-rape rotation, compared to the UA treatment. The population of ammonia oxidizing bacteria, the activity of nitrate reductase, and nitrite reductase in the DP treatment decreased about 24.5 % –30.9 % , 14.9 % –43.5 % , and 14.7 % –31.6 % , respectively, as compared to the UA treatment. However, nitrite oxidizing bacteria and hydroxylamine reductase remained almost unaffected by DMPP. It is proposed that DMPP has the potential to either reduce NO₃⁻-N leaching by inhibiting ammonia oxidization or N losses from denitrification, which is in favor of the N conversations in the rice-oilseed rape cropping system.