Abstract
An incubation experiment under aseptic and septic conditions using 15N-labelled NH4 +-N and NO3 –-N, was carried out to study the effect of N transformations after flooding on NH4 + fixation in a paddy soil from China. After flooding ammonification was favoured, providing NH4 + for fixation by clay minerals. NH4 + fixation was more pronounced under low redox potential (Eh) conditions. Close correlations existed between exchangeable NH4 +, Eh, and non-exchangeable NH4 +. Therefore, two major conditions for NH4 + fixation induced by flooding in paddy soil were found, namely flooding promoted net production of NH4 + due to the deamination of organic N and, in addition, decreased the Eh of the soil. A lower Eh was caused by reduction and dissolution of Fe oxide coating on the clay minerals' surfaces, eliminating the obstacles for NH4 + diffusing into or out of the interlayers of clay minerals. A higher concentration of exchangeable NH4 + from deamination of organic N would drive NH4 + diffusing from the soil solution into the interlayers of clay minerals. 15N-labelled NO3 – incorporated into the flooded soil was not reduced to NH3. The addition of NO3 – retarded the decrease in the soil Eh and, therefore, NH4 + fixation.
Article PDF
Similar content being viewed by others
Explore related subjects
Discover the latest articles, news and stories from top researchers in related subjects.Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 3 September 1999
Rights and permissions
About this article
Cite this article
Zhang, Y., Scherer, H. Mechanisms of fixation and release of ammonium in paddy soils after flooding II. Effect of transformation of nitrogen forms on ammonium fixation. Biol Fertil Soils 31, 517–521 (2000). https://doi.org/10.1007/s003740000202
Issue Date:
DOI: https://doi.org/10.1007/s003740000202