复合生化抑制剂对稻田氮素转化和水稻生长的影响

Effects of combined biochemical inhibitors on nitrogen transformation and rice growth in paddy fields

选择东南沿海种植单季水稻的典型青紫泥土壤稻田,研究含脲酶抑制剂正丁基硫代磷酰三胺[N-(n-butyl)thiophosphoric triamide,NBPT]和硝化抑制剂3,4-二甲基吡唑磷酸盐(3,4-dimethylpyrazole phosphate,DMPP)复合生化抑制剂的尿素在单施、分施及减施模式下,田面水和土壤氮素的动态变化特征以及对水稻生长的影响。结果表明:与常规尿素处理相比,添加NBPT和DMPP复合生化抑制剂的尿素按50%基肥和50%追肥2次施用,田面水铵态氮、硝态氮、亚硝态氮含量在水稻返青期和分蘖初期分别下降7.0%和13.2%、46.5%和50.5%、75.4%和58.2%;土壤铵态氮含量在返青期下降21.8%,在分蘖末期和拔节期增加27.5%和9.3%;水稻株高、分蘖数和叶绿素含量在分蘖期和拔节期分别增加4.8%和4.1%、4.9%和11.8%、17.8%和15.9%。与常规尿素处理相比,添加NBPT和DMPP复合生化抑制剂的尿素按一次性基施和分2次施用,成熟期水稻籽粒产量分别增加6.8%和12.5%,生物量分别增加9.2%和12.6%。综上所述,NBPT和DMPP复合生化抑制剂的施用可有效抑制田面水和土壤铵态氮和硝态氮含量的快速增加,延缓氮素形态转化,维持田面水和土壤中相对较低的硝态氮含量,有助于降低稻田氮素流失风险,同时,促进水稻的生长,提高其产量。

By selecting a typical blue clayey paddy soil with planting single-season rice in the southeast coast,we studied the effects of urea fertilizer containing N-(n-butyl)thiophosphoric triamide(NBPT,urease inhibitor)and 3,4-dimethylpyrazole phosphate(DMPP,nitrification inhibitors)biochemical inhibitors on the nitrogen transformation in the surface water and soil and rice growth under the different fertilization times and levels.The results showed that:compared with the conventional urea fertilizer treatment,when the urea added with NBPT and DMPP combined biochemical inhibitors was applied twice as 50%base fertilizer and 50%topdressing,the concentrations of ammonium,nitrate and nitrite in field surface water decreased by 7.0%and 13.2%,46.5%and 50.5%,75.4%and 58.2%at the regreening stage and early tillering stage of rice,respectively;the ammonium concentration in soil decreased by 21.8%at the regreening stage and increased by 27.5%and 9.3%at the later tillering stage and jointing stage of rice;besides,the plant height,tiller number and chlorophyll content of rice were increased by 4.8%and 4.1%,4.9%and 11.8%,17.8%and 15.9%at the tillering stage and jointing stage,respectively.Furthermore,the yield and biomass of rice increased by 6.8%and 12.5%,9.2%and 12.6%,respectively,at the mature stage,when the urea added with NBPT and DMPP combined biochemical inhibitors was applied once as base fertilizer or twice as 50%base fertilizer and 50%topdressing.In conclusion,the combined application of NBPT and DMPP biochemical inhibitors can effectively inhibit the rapid increase of ammonium and nitrate nitrogen in soil and field surface water,delay the transformation rate of nitrogen form,and maintain the relatively low nitrate nitrogen concentration in the surface water and soil in the rice fields,which can reduce the risk of nitrogen loss in paddy fields,promote rice growth and increase rice yield.