中文摘要：

采用好气培养法，研究了双氰胺（DCD）、元素硫（S^0）和元素硫分解中间物（S2O^2-3）及其组合对蔬菜地土壤氮素硝化抑制作用。结果表明，在培养试验72d内，DCD＋S^0、DCD、DCD＋Na2S2O3处理土壤NH^＋4-N总量分别是N处理的5．8、5．1、5．9倍；S^0、Na2S2O3处理分别是N处理的1．8、1．4倍；而所有硝化抑制剂（DCD、S^0、S2O^2-3）处理土壤NOr^-3N含量显著低于N处理，表明DCD、S^0和S2O^2-3均能抑制菜地土壤铵态氮硝化。培养试验开始8d后，Na2S2O3和DCD对铵态氮硝化抑制产生协同效应，16d后S^0和DCD对铵态氮硝化抑制也产生协同效应，这可能是由于S^0氧化中间体S2O^2-3、S4O6^2-具有抑制DCD降解作用，延长了DCD硝化抑制作用时间。建议蔬菜生产上推荐使用DCD＋S^0组合，以提高氮素利用率。

英文摘要：

An incubation experiment was conducted to investigate the effect of three nitrification inhibitors[dicyandiamide （DCD）, elemental sulfur （S^0） and thoisulfate （S2O^2-3）] on nitrification of NH4^＋ -N in a typical vegetable soil. The resuits showed that within 72 day-incubation period, the soil NH^＋4 -N content at DCD ＋ S^0, DCD and DCD ＋ Na2S2O3 treatment was 5.8, 5.1 and 5.9 times of that at N treatment, respectively, and soil NH4^＋ -N content at So and Na2S2O3 treatment was 1.8 and 1.4 times of that at N treatment, respectively. Soil NO3^-N content was obviously lower in nitrification inhibitor treatments than in those without nitrification inhibitor treatments, implying that DCD, So and S2O^2-3 could inhibit nitrification of soil NH4^＋ -N in the vegetable soil. Synergistic effect of DCD ＋ So and DCD ＋ S2O^2-3 on nitrification inhibition of soil NH4^＋ -N was observed 16 and 8 days after the incubation experiment, respectively. This could be contributed to the effect of S2O^2-3 and S4O6^2- originated from So oxidation in soil on restraining decomposition of DCD, prolonging the time of DCD for nitrification inhibition. It is suggested that application of So combined with DCD could be used as a nitrification inhibitor in vegetable soils to increase fertilization nitrogen efficiency.