应用BaPS技术研究双氰胺及硫对苹果园土壤尿素的硝化抑制效应

 在大田条件下应用气压过程分离法（BaPS）研究了双氰胺（DCD）和双氰胺与硫配合施用（DCD + S）对苹果园土壤氮素的硝化抑制效应。结果表明：施肥后40 d内，N + DCD和N + DCD + S处理的土壤NH₄⁺-N含量均高于N处理（对照）。N + DCD处理在6 ~ 20 d显著高于N处理；N + DCD + S处理直到30 d时仍显著高于N处理，比只施DCD的处理硝化抑制作用延长了10 d。两个添加硝化抑制剂处理土壤NO₃^--N含量显著低于N处理，降幅达18.72% ~ 58.91%。与N处理（对照）相比，N + DCD和N + DCD + S处理明显降低了土壤总硝化速率和反硝化速率，试验前期差异最大，进一步证实了硝化抑制剂可以有效地抑制NH4+-N向NO₃^--N的转化。

Nitrification-inhibiting Effect of Dicyandiamide and Sulfur on Apple Orchard Soil Using Barometric Process Separation

A natural field experiment was conducted to investigate the effect of dicyandiamide（DCD）and DCD + S on nitrification-inhibiting on apple orchard soil. The results were as follows：soil NH4+-N contents in N + DCD and N + DCD + S treatments were higher than that of N treatment within 40 days after fertilization，while the NH4+-N content in soil with N + DCD treatment was significantly higher than that of N treatment within 6–20 days after fertilization，yet the NH₄⁺-N content in soil with N + DCD + S treatment was still significantly higher until 30 days after fertilization，prolonging 10 days than DCD for nitrification inhibition；Soil NO₃^--N content was obviously lower in the two nitrification inhibitor treatments than that of N treatment, decreasing by 18.72%–58.91%. Compared with N treatment，gross nitrification and denitrification rates in soil were low in N + DCD and N + DCD + S treatments，and the biggest difference appeared at early times，this confirmed that nitrification inhibitor could inhibit the transformation of soil NH4+-N to NO₃^--Neffectively.