脲酶抑制剂/硝化抑制剂对土壤中尿素氮转化及形态分布的影响

运用^15N尿素示踪技术，以壤质草甸棕壤和春小分别作供试土壤和作物进行盆栽试验，结果表明，与单^15N尿素或^15N尿素＋氢素＋氢醌（HQ）相比，配施双氰胺（DCD）尤其与HQ组合可使土壤保持较高的^15N回收率，其中有^15N占相当大的比例，在小麦孕穗期前，上述两处理可有效地保持尿素解后土壤中NH^ 4 -^15N含量，并显著降低（NO^ 3 NO^-2)-^15N的富集；促进肥料^15N固持－矿化的周转，HQ与DCD配合施用对尿素施用后土壤中残留^15N量及有机^15N的再矿化和NH^ 4-^15N含量具有一定的协同作用。

EFFECT OF UREASE/NITRIFICATION INHIBITORS ON THE DISTRIBUTION OF TRANSFORMED UREA-N FORMS IN SOIL

By applying labeled urea into a loamy meadow brown soil,a pot experiment with spring wheat as test crop was carried out. The results showed that in comparison with applying urea alone and urea+hydroquinone(HQ),an application of dicyandiamide(DCD),and especially of its combination with HQ, gave a much higher recovery of soil urea ¹⁵N, among which organic ¹⁵N occupied a great portion.These two treatments played an active role in the conservation of urea-deleased NH₄⁺-¹⁵N in soil and in the decrease of the accumulation of urea-derived (NO₃^-+NO₂^-)-¹⁵N. They could markedly promote the mineralization-immobilization turnover of fertilizer ¹⁵N following the hydrolysis of applied urea Synergistic effects of HQ and DCD on the contents of fertilizer-¹⁵N and NH₄⁺-¹⁵N in soil as well as the mineralization of soil organic-¹⁵N will appear after the application of labeled urea.