硝化抑制剂与不同氮肥配施对土壤硝化过程的抑制效果

Inhibitory Effects of Nitrification Inhibitors Combined with Different Nitrogen Fertilizers on Soil Nitrification Process

为明确硝化抑制剂DMPP(3,4-二甲基吡唑磷酸盐)在不同土壤条件下与不同氮肥配施的作用效果,通过室内土壤培养试验,研究了DMPP分别与脲铵氮肥、复合肥、硫硝酸铵、草酰胺配施对不同酸碱性(pH 5.48和8.25)土壤中氮素转化及氨挥发的影响。结果表明:DMPP与不同类型氮肥配施,在不同pH土壤条件下均可抑制土壤NH_(4)^(+)-N向NO_(3)^(-)-N的转化,并且在碱性土中的效果优于酸性土。配施肥料不同对DMPP作用效果的影响也有不同,培养结束时,在酸性土壤条件下,DMPP与不同肥料配施的硝化抑制效果表现为复合肥>脲铵氮肥>草酰胺>硫硝酸铵,硝化抑制率分别为64.5%、54.1%、40.4%、13.2%;在碱性土壤条件下的硝化抑制效果表现为脲铵氮肥>复合肥>草酰胺>硫硝酸铵,硝化抑制率分别为69.6%、58.3%、49.9%、26.2%。不同肥料处理在碱性土壤条件下累积氨挥发量均显著高于酸性土壤,且在不同土壤条件下DMPP与复合肥配施均会显著增加土壤累积氨挥发量,但DMPP与脲铵氮肥、硫硝酸铵、草酰胺配施时对土壤累积氨挥发量影响不显著。总体来看,不同氮肥与DMPP配施均有抑制土壤硝化过程的作用,且在碱性土中的作用效果更好。然而,DMPP与普通平衡性复合肥配施会显著增加土壤氨挥发风险,这也与肥料类型和DMPP添加量以及土壤pH有关,使用时需注意土壤与肥料本身性质或适量降低DMPP添加浓度。综上,针对不同土壤条件选择不同含氮肥料与硝化抑制剂配施可以更好地发挥硝化抑制剂的作用,这对基于不同氮素形态的稳定性肥料生产具有重要指导意义。

To clarify the effects of DMPP(3,4-dimethylpyrazole phosphate)combined with different nitrogen fertilizers under different soil conditions,the effects of nitrification inhibitor DMPP combined with urea-ammonium nitrogen fertilizer,compound fertilizer,ammonium sulfate-nitrate and oxalamide on nitrogen conversion and ammonia volatilization in soils with pH 5.48(south paddy soil)and pH 8.25(north salinized fluvo-aquic soil)were studied via soil microcosm incubation in the laboratory.The results showed that the combined applications of DMPP with different types of nitrogen fertilizer could inhibit the conversion of soil NH_(4)^(+)-N to NO_(3)^(-)-N under different soil conditions,and the effects in alkaline soil were better than those in acidic soil.At the end of culture,in acidic soil,the nitrification inhibition effects of DMPP with different fertilizers were of compound fertilizer>urea-ammonium nitrogen fertilizer>oxalamide>ammonium sulfate-nitrate,with nitrification inhibition rates of 64.5%,54.1%,40.4%and 13.2%,respectively,while in alkaline soil were of urea-ammonium nitrogen fertilizer(69.6%)>compound fertilizer(58.3%)>oxalamidide(49.9%)>ammonium sulfate-nitrate(26.2%).The accumulated ammonia volatilization in alkaline soil was significantly higher than that in acidic soil under different fertilizer treatments,and the combined application of DMPP with compound fertilizer significantly increased the accumulated ammonia volatilization under different soil conditions,but the combined applications of DMPP with urea-ammonium nitrogen fertilizer,ammonium sulfur nitrate and oxalamide had no significant effect on soil accumulated ammonia volatilization.In general,the combined applications of different nitrogen fertilizers with DMPP can inhibit soil nitrification process,and the effects were better in alkaline soil,but the combined application of DMPP with conventional balanced compound fertilizer would significantly increase the risk of soil ammonia volatilization,which is also related to fertilizer type,DMPP added amount and soil pH.In conclusion,the combination applications of different fertilizers with nitrification inhibitors according to different soil conditions can better play the role of nitrification inhibitors,which has guiding significance for stabilized fertilizers production based on different nitrogen forms.