用室内培养和~(19)N技术研究了土壤氮的矿化和固定,结果表明:无机氮添加不能引起土壤有机氮的加速分解;无机氮添加可显著增强添加氮的生物固定,但以减弱对土壤氮的固定为交换,因此培养期的总固定氮量并无显著增长。培养期间土壤净矿化氮因添加无机氮而有所增长,这一现象(时常被称为氮激发效应)看来主要是由于添加氮在土壤氮固定过程中替代了部分土壤氮之故。 The results showed that inorganic nitrogen could not accelerate the decomposition of soil organic nitrogen. Inorganic nitrogen addition could significantly enhance the biological fixation of added nitrogen, but weaken the soil nitrogen fixation. The fixation of soil nitrogen was exchanged, so there was no significant increase in the total fixed nitrogen during the cultivation period. The net net mineralization of soil N during cultivation increased with the addition of inorganic N, a phenomenon that is often referred to as the N-stimulus effect, and appears to be mainly due to the replacement of part of the soil N with the addition of N during soil N fixation.