Characteristics of nitrogen mineralization and nitrification in salinized soils of Xinjiang

Characteristics of nitrogen(N) mineralization and nitrification of different salinization types and degrees in Xinjiang soils were studied by using laboratory incubation in order to investigate the relationships between properties of salinized soil and nitrogen mineralization and nitrification in salinized soils.The results showed that salinization type affected nitrogen mineralization in soils.The amount of mineralized N in the alkali soils was significantly lower than that in the saline soils.In the alkali soil,the amount of N mineralized rapidly decreased with the increasing of alkalinity and pH.In saline soil,the increase of salinity had a minimal influence on N mineralization.Mineralization rate of N increased with the increase in soil salinity.Regardless of alkali or saline soil,nitrification was inhibited to certain degrees with the increasing of salinization degree.In alkali soil,nitrification rate was negatively related to pH,total salt content and alkalinity,whereas in saline soil,nitrification rate was negatively related to total salt content.