还田秸秆氮素转化及其对土壤氮素转化的影响

Nitrogen Transformation of Returned Straw in Soil and Its Effect on Soil Nitrogen Transformation

还田秸秆是农业生产重要的有机肥源,秸秆分解不仅是作物所需氮素的重要来源,而且能激发土壤微生物活性,提高土壤氮素的有效性。近年来,秸秆还田作为改善土壤养分状况的一项重要措施逐渐受到重视。因此,探明秸秆氮素在土壤中的释放和转化及外源秸秆氮对土壤氮素转移转化的影响对农田的氮素管理和合理进行秸秆还田具有重要指导意义。系统介绍了还田秸秆中氮素的存在形态及释放特征,探讨了秸秆氮在土壤中的去向及转化过程,综合分析了秸秆腐解对土壤氮素转化的影响,最后对秸秆还田条件下的土壤氮素研究进行了展望。

Crop straw is an important source of organic fertilizer for agricultural production. The decomposed straw not only provides an important source for nitrogen requirement of crop,but also stimulates the activity of soil microbes and improves the effectiveness of soil nitrogen. In recent years,returning straw to field as an important measure to improve soil nutrient status has been paid more and more attention. It is important to reveal the release and transformation of exogenous straw nitrogen and its effect on the turnover of native soil nitrogen,which is significant for nitrogen management and straw returning. In this paper,the present situation and the release characteristics of nitrogen in straw are systematically introduced. Then,the fate and transformation process of straw nitrogen in soil are discussed,and the effects of straw decomposition on soil nitrogen transformation are analyzed. Finally,the researches on soil nitrogen under the condition of straw returning are prospected.