土壤中无机氮的微生物同化和非生物固定作用研究进展

A RESEARCH PROGRESS ON BIOTIC AND ABIOTIC INORGANIC N IMMOBILIZATION IN SOILS

土壤中无机氮的迅速固持有利于土壤氮的持留,从而减少NO3-淋溶、NH3挥发以及N2O和NO排放损失。本文综述了土壤中无机氮的微生物同化和非生物固定作用,指出了无机氮微生物同化和非生物固定在氮循环中的重要意义,初步讨论了生物过程和非生物过程固定无机氮的机制和影响因素。但是对于非生物固定NO3--N,其机理目前还不清楚。从现有的文献报道来看,能够解释非生物固定NO3--N机制的仅有铁环假说。然而,铁环假说尚未得到完全证实,有待于深入的研究。

Inorganic nitrogen （N） immobilization in soils could enhance the capacity of soil N retention and thus re- duce the potential risk of NO3- leaching, NH3 volatilization as well as N20 and NO emissions losses. Biotic and abiotic in- organic N immobilization as well as their significance in soil N cycling is introduced in this paper. The paper discusses preliminarily the mechanisms and influence factors of both biotic and abiotic inorganic N immobilization and puts forward orientation of the future research. In particular, neither the mechanism nor the kinetics of abiotic immobilization of NO3- - N are known. So far, only the ferrous wheel hypothesis could explain abiotic immobilization of NO3--N in forest soils. However, the ferrous wheel hypothesis has not been fully demonstrated and therefore further studies about abiotic immobi- lization of NO3- -N are extremely needed.