添加NBPT/DMPP/CP的高效稳定性尿素在黑土和褐土中的施用效应

  【目的】  研究添加脲酶/硝化抑制剂的高效稳定性尿素在黑土和褐土中的作用效果，为科学合理选择抑制剂提供科学依据。  【方法】  以春玉米为试材，采用东北典型的黑土和褐土进行盆栽试验。供试抑制剂包括N-丁基硫代磷酰三胺 (NBPT)、3, 4-二甲基吡唑磷酸盐 (DMPP)、2-氯-6 (三氯甲基)-吡啶 (CP)。试验设不施氮肥 (U0)、施普通尿素 (U)，和在尿素中添加NBPT、DMPP、CP、NBPT+DMPP、NBPT+CP、DMPP+CP，共8个处理。在玉米苗期、大喇叭口期、灌浆期、成熟期取样，测定土壤尿素态氮、NH₄+-N和NO₃–-N含量，计算硝化抑制率，玉米抽雄吐丝后测定棒三叶叶面积和叶绿素含量，收获后测定玉米生物量、氮素含量等指标。  【结果】  1) 与普通尿素 (U) 相比，黑土上添加NBPT+DMPP、NBPT+CP处理玉米苗期土壤中NH₄+-N含量分别提高1.32、0.96倍，NO₃–-N含量分别降低1.35、1.04倍，玉米叶面积增加，叶片叶绿素含量增高。褐土中，添加DMPP+CP处理在玉米苗期土壤NH₄+-N含量提高3.09倍，NO₃–-N含量降低1.49倍，玉米叶绿素含量提高1.61倍，显著高于对照和单一抑制剂处理。2) 在黑土中，与普通尿素相比，添加NBPT+DMPP、NBPT+CP处理的玉米籽粒产量分别增加1.64和2.18倍；氮素表观利用率分别提高3.02和3.34倍，高于其他处理。褐土添加DMPP+CP处理的籽粒产量增加1.41倍，氮素表观利用率提高4.98倍，高于其他处理。  【结论】  在黑土中，尿素配施NBPT+DMPP、NBPT+CP可以有效抑制NH₄+-N向NO₃–-N的转化，增加玉米氮素吸收量，提高氮肥利用率，从而获得较高的产量，是黑土栽培玉米施用氮肥的最佳选择。褐土中，DMPP+CP的硝化抑制率显著高于添加单一抑制剂，有效抑制铵态氮的硝化作用，减少氮素损失，增加玉米氮素吸收量，从而使玉米高产，因此，添加DMPP+CP是制备褐土玉米专用高效稳定性尿素的最好选择。

Effects of stabilized urea containing NBPT/DMPP/CP on nitrogen use efficiency and maize yield in black and cinnamon soil

  【Objectives】  The effect of commonly used N fertilizer synergistic agents were studied in black soil and cinnamon soil, aiming to identify the suitable type of urease and nitrification inhibitors for the two soils.  【Methods】  The tested synergistic agents included N-butyl thiophosphate-triamine (NBPT), 3, 4-dimethyl-pyrazole phosphate(DMPP), and 2-chloro-6 (trichloromethyl)-pyridine (CP). A pot experiment was conducted using maize as test materials. Besides no N control, seven treatments were set up, they were urea (U), and U plus NBPT, DMPP, CP, NBPT+DMPP, NBPT+CP, and DMPP+CP. The contents of urea N, NH₄+-N and NO₃–-N in soil were measured at seedling, big trumpet, grouting and maturity stage of maize, and the nitrification inhibition rate was calculated correspondingly. The maize leaf area and chlorophyll content were measured after tassel spinning, and the biomass and N content of the plant were measured after harvest.  【Results】  1) Compared with common urea treatment, adding NBPT+DMPP and NBPT+CP treatments increased the content of NH₄+-N in black soil by 1.32 and 0.96 times, and decreased the content of NO₃–-N by 1.35 and 1.04 times in the seedling stage of maize. The leaf area of corn and the content of chlorophyll were increased because the sufficient soil NH₄+ supply. In cinnamon soil, DMPP+CP increased the content of NH₄+-N by 3.09 times compared with U treatment, and decreased the content of NO₃–-N by 1.49 times. Meanwhile, the content of chlorophyll increased by 1.61 times, higher than that in control and single inhibitor treatment significantly. 2) In black soil, the grain yield of NBPT+DMPP and NBPT+CP was increased by 1.64 and 2.18 times, respectively, compared with U treatment. The N apparent use efficiency increased by 3.02 and 3.34 times, which were higher than those in other treatments (P < 0.05). DMPP+CP increased the grain yield and the N apparent use efficiency in cinnamon soil by 1.41 times and 4.98 times, respectively, which were higher than those in other treatments.  【Conclusions】  In black soil, NBPT+DMPP and NBPT+CP exhibited highest yield, inhibited nitrification and increased N absorption by maize and the N apparent use efficiency. In cinnamon soil, the combining addition of DMPP+CP significantly decreased nitrification rate than any single inhibitor application, reduced N loss and increased N uptake of maize, leading to a high yield of corn. Therefore, adding DMPP+CP is the best choice for stabilized urea for corn plantation system in the cinnamon soil.