硝化抑制剂对苹果园酸性土壤尿素氨挥发的影响

大田条件下应用通气法,研究了双氰胺（DCD）和双氰胺与硫配合施用（DCD＋S）对苹果园酸性土壤尿素氨挥发的影响。结果表明：施肥后40天内,N＋DCD和N＋DCD＋S处理土壤NH4^＋-N含量均高于N处理,其中N＋DCD处理在第6～20天极显著高于N处理,而N＋DCD＋S处理直到第30天仍极显著高于N处理;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%。N处理氨挥发速率峰值最大,但持续时间最短;N＋DCD处理氨挥发持续时间为19天,N＋DCD＋S处理持续时间最长,分别比N和N＋DCD处理延长17天和7天。添加硝化抑制剂的处理氨挥发总量显著高于只施尿素处理,但各处理氨挥发总量占施氮量比例均处于较低水平。

Effect of Nitrification Inhibitor on Ammonia Volatilization in Acid Soil of Apple Orchard

The field experiment was conducted to investigate the effects of dicyandiamide(DCD) and combined application of dicyandiamide and sulphur(DCD+S) on ammonia volatilization in apple orchard acid soil by the venting method.The results showed that within 40 days after fertilization,the NH+4-N content in soil of N+DCD and N+DCD+S treatments were higher than that of the single nitrogen(N) treatment,among them,that of N+DCD treatment was very significantly(P<0.01) higher than that of N treatment within 6～20 days after fertilization,while that of N+DCD+S treatment was still very significantly(P<0.01) higher until 30 days after fertilization.The NO-3-N content in soil of the two nitrification inhibitor treatments obviously decreased by 18.72%～58.91% compared with that of N treatment.The peak value of ammonia volatilization rate was the largest under N treatment,but its duration was the shortest.The duration of N+DCD treatment was 19 days and that of N+DCD+S treatment was the longest,which was 17 and 7 days longer than that of N treatment and N+DCD treatment respectively.The gross of ammonia volatilization with nitrification inhibitor was significantly(P<0.05) higher than that of N treatment,but the ratio of gross rate of ammonia volatilization to N application rate was lower in all treatments.