丹江口库区覆膜耕作土壤净氮矿化随夏玉米生长期的变化

发布时间：2018-11-27 14:24

【摘要】：农田土壤净氮矿化对土壤氮素流失和农业非点源污染有重要影响.以丹江口库区五龙池小流域夏玉米黄棕壤为例,进行原位矿化试验,通过与无覆膜耕作土壤相比较,研究覆膜耕作条件下土壤净氮矿化在夏玉米生长期内的变化.结果表明:夏玉米整个生长期内,覆膜耕作土壤净氨化量、净硝化量和净氮矿化量均明显高于无覆膜土壤,分别高6.63、12.96和19.59mg·kg~(-1);覆膜耕作土壤净氨化速率表现为在苗期较高、抽穗期最低、成熟期增至最高的变化特征,而土壤净硝化和净氮矿化速率均呈现苗期较高、拔节期最低、成熟期升至最高的变化过程;覆膜耕作土壤净氮矿化速率均与土壤全氮和NO_3~--N含量、土壤含水量之间呈显著线性关系.覆膜可有效调节土壤水热条件,促进土壤净氮矿化.
[Abstract]:Net nitrogen mineralization in farmland has an important effect on soil nitrogen loss and agricultural non-point source pollution. Taking yellow brown soil of summer maize in Wulongchi small watershed of Danjiangkou reservoir area as an example, the in situ mineralization experiment was carried out. The changes of net nitrogen mineralization in summer maize during the growth period of summer maize under film mulching were studied by comparing with the soil without mulching film tillage. The results showed that during the whole growth period of summer maize, the net ammoniation, nitrification and mineralization of mulching tillage soil were significantly higher than that of non-mulching soil, which were 6.63 ~ (12. 96) and 19.59mg kg~ (-1), respectively. The net ammoniation rate of mulching tillage soil was higher at seedling stage, lowest at heading stage, and increased to the highest at maturity stage, while the rate of net nitrification and net nitrogen mineralization was higher at seedling stage and lowest at jointing stage. The process of rising to the highest at maturity; There was a significant linear relationship between net nitrogen mineralization rate and soil total nitrogen and NO_3~--N content and soil water content. Film mulching can effectively regulate soil hydrothermal conditions and promote soil net nitrogen mineralization.
【作者单位】：湖北大学资源环境学院/区域开发与环境响应湖北省重点实验室;
【基金】：国家自然科学基金项目(41471227)资助~~
【分类号】：S513;S153

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