Inmobilization-remineralization of NO3-N and total N balance during the decomposition of glucose, sucrose and cellulose in soil incubated at different moisture regimes

Abstract

A laboratory incubation experiment was conducted to study the effect of organic amendment and moisture regimes on the immobilization-remineralization of NO3-N and total N balance in soil fertilized with KNO3. Immobilization of NO3-N was very rapid in soil amended with glucose and sucrose followed by a remineralization of organic N and accumulation of mineral N. Cellulose caused a slow but continued immobilization and did not show net accumulation of mineral N during 8 weeks of incubation. At the end of incubation, a significant increase in total N and organic N content of the soil was observed which is perhaps attributable to the activity of free living N2 fixers. Although N losses seemed to have occurred at 100% WHC through denitrification in soil amended with glucose and sucrose, main cause of NO3 elimination was microbial immobilization.