尿素氮在不同类型土壤中转化特征及其施用效果对生化抑制剂的响应

Transformation characteristics of urea nitrogen in different types of soil and the response of its application effect to biochemical inhibitors

通过盆栽试验,研究脲酶抑制剂正丙基硫代磷酰三胺(NPPT)、硝化抑制剂双氰胺(DCD)及其组合对黑土、棕壤、褐土中尿素氮素形态和玉米产量等因子的影响,为适宜黑土、棕壤、褐土的高效稳定性尿素肥料的研发提供理论依据。试验共设不施尿素(U0)、普通尿素(U)、尿素+脲酶抑制剂(UN)、尿素+硝化抑制剂(UD)、尿素+脲酶抑制剂+硝化抑制剂(UND)5个处理。在玉米苗期、大喇叭口期、灌浆期、成熟期采集土壤样品,测定尿素氮、铵态氮(NH_(4)^(+)-N)和硝态氮(NO_(3)^(-)-N)含量,计算氮素表观利用率等指标。在玉米灌浆初期,测定玉米棒三叶叶面积和叶绿素含量,收获后考种,采集植物样品测定玉米植株生物量和全氮含量。试验结果表明,黑土中抑制剂处理较U处理玉米能够增产,且UD处理增产幅度最大,为U处理的1.50倍,氮素表观利用率提高2.12倍,黑土中NH_(4)^(+)-N含量显著提高62.11%~121.21%;棕壤中UN、UD处理玉米增产显著,且UD处理增产幅度最大,为U处理的0.36倍,氮素表观利用率提高2.79倍,土壤中NH_(4)^(+)-N含量显著提高43.13%~131.31%;褐土中抑制剂处理明显增产,且UND处理增产最多,为U处理的1.51倍,氮素表观利用率提高4.08倍,土壤中NH_(4)^(+)-N含量提高19.08%~262.25%。黑土和棕壤种植玉米应选择添加DCD制成的高效稳定性尿素肥料,褐土种植玉米应选择添加NPPT和DCD配施制成的高效稳定性尿素。

A pot experiment was conducted to explore the effect of urease inhibitor n-propyl thiotriamine(NPPT),nitrification inhibitor dicyandiamide(DCD)and their combinations on nitrogen form and maize yield in black soil,brown soil and cinnamon soil.Five treatments were set up,including without urea fertilizer(U0),urea without inhibitors(U),urea+urease inhibitor(UN),urea+nitrification inhibitor(UD),and urea+urease inhibitor+nitrification inhibitor(UND).The contents of urea nitrogen,ammonium nitrogen(NH_(4)^(+)-N)and nitrate nitrogen(NO_(3)^(-)-N)in soil were measured at seedling stage,big trumpet stage,grouting stage and maturity stage of corn,and the nitrification inhibition rate,nitrogen apparent use efficiency were calculated correspondingly.The area and chlorophyll content of the three leaves of the rod were measured at the initial stage of corn filling,and the biomass and nitrogen content of the corn were measured after harvest.Compared with U treatment,maize yield in black soil could be increased by inhibitor treatment,and UD yield increased by 1.5 times as much as that in U treatment,nitrogen apparent use efficiency increased by 2.12 times,and NH_(4)^(+)-N content in black soil significantly increased by 62.11%~121.21%.In brown soil,the yield increased significantly under UN and UD treatment,and UD treatment had the largest yield increase,which was 0.36 times higher than that under U treatment.Nitrogen apparent use efficiency increased by 2.79 times,and NH_(4)^(+)-N content in soil increased significantly by 43.13%~131.31%.Inhibitor treatment significantly increased the yield in cinnamon soil,and UND treatment increased the yield by 1.51 times as much as U treatment,nitrogen apparent use efficiency increased by 4.08 times,and NH_(4)^(+)-N content in soil increased by 19.08%~262.25%.DCD had a significant effect on the nitrification inhibition of urea nitrogen in black soil and brown soil.The high efficiency and stability urea fertilizer added with DCD should be selected in the black soil and brown soil planting corn.The combined application of NPPT and DCD had a good synergistic effect on the conversion of urea nitrogen in the cinnamon soil.The high efficiency and stability urea fertilizer added with the combination of NPPT and DCD should be selected for the corn planting in the cinnamon soil.