脲酶／硝化抑制剂对土壤有效态氮、微生物量氮和小麦氮吸收的影响

研究了脲酶抑制剂(NBPT)、硝化抑制剂(DCD)及二者组合在草甸棕壤上施用对尿素态N转化及土壤总有效态N、微生物量N的影响．结果表明，尿素配施NBPT、DCD及抑制剂组合能够增加尿素水解后土壤NH4^+含量2％-53％。显著降低了氧化态N的浓度，抑制了土壤中铵态N的氧化，增加土壤总有效N34％-44％，小麦吸N量增加0．26％-6．79％。其中以脲酶抑制剂与硝化抑制剂组合的效果最明显．抑制剂施用增加了微生物在小麦生长初期对有效态N固持，有利于后期土壤有效态N的矿化．

Effects of urease/nitrification inhibitors on soil available N and microbial biomass N and on N uptake of wheat

With an aquic brown earth as test soil, this paper studied the effects of urease inhibitor (NBPT), nitrification inhibitor (DCD) and their combinations on the dynamics of soil available N and microbial biomass N. The results showed that the treatments of inhibitors, especially the combined application of NBPT and DCD, could increase soil NH4+-N by 2%-53%, inhibit NH4+ oxidation, decrease soil NO3(-)-N concentration, increase soil total available N by 34%-44%, and increase wheat N uptake by 0.26%-6.79%. The best treatment was urease inhibitor combined with nitrification inhibitor. The application of inhibitors increased soil microbial biomass N immobilization at the early growth stage of wheat, and promoted soil N mineralization at filling stage.