新疆盐渍化土壤氮素矿化和硝化作用特征

为了探明新疆盐渍化土壤特性与土壤氮素矿化和硝化的关系,通过室内培养方法,研究了不同盐渍化类型和程度的新疆盐渍化土壤氮素的矿化和硝化特征。结果表明,盐渍化类型对土壤氮素矿化有重要影响。在培养过程中,碱化土壤矿质氮含量明显低于盐化土壤;在碱化土壤中,随着碱化度和pH值的升高,矿化量迅速降低;在盐化土壤中,盐化程度的增加对于土壤矿化特征影响不大,但是随着盐化程度的增加矿化率明显增加。在盐渍化土壤中,碱化土壤的氮素硝化作用较盐化土壤快;无论是碱化土壤还是盐化土壤,随着盐渍化程度的增加,氮肥硝化作用都受到不同程度的抑制;在碱化土壤中,氮素硝化率与pH、总盐含量、碱化度均呈极显著负相关,而在盐化土壤中,氮素硝化率与总盐含量呈极显著负相关。

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.