降雨条件下农田氮素地表径流流失特征研究

发布时间：2018-03-22 02:17

本文选题：土壤　切入点：农田氮素　出处：《灌溉排水学报》2016年07期 　论文类型：期刊论文

【摘要】：为探究沟施氮肥后,氮素随地表径流的流失规律,在野外降雨模拟试验条件下,研究了农田裸地氮素随地表径流流失规律。结果表明,在一定雨强范围内,土壤前期含水率对产流特征影响显著;在该裸地试验场地条件下,硝态氮质量浓度输出变化过程和总氮表现出良好的相关性,是氮素输出的主要形态;且硝态氮质量浓度随时间的变化曲线下降部分的下降速率具有一定规律性,用幂函数曲线拟合的结果最好,R2均在0.90以上;3次事件的地表径流累积量与累积氮素流失量成良好的正相关关系,可对观测值用幂函数和线性函数进行分段拟合。合理施肥,并尽量避免在强降雨来临前施肥,可以减缓施肥不当所造成的农业面源污染。
[Abstract]:In order to investigate the regularity of nitrogen loss with surface runoff after applying nitrogen fertilizer in ditch, under the condition of field rainfall simulation experiment, the regularity of nitrogen loss with surface runoff in bare farmland was studied. The results showed that in a certain range of rain intensity, Under the condition of the bare soil test site, the variation process of mass concentration of nitrate and total nitrogen showed a good correlation with the total nitrogen, which was the main form of nitrogen output. And the decreasing rate of the decreasing part of the curve of the mass concentration of nitrate with time has a certain regularity. The fitting result of power function curve is best that the cumulative amount of surface runoff with R2 above 0.90 is positively correlated with the accumulated nitrogen loss. The observed values can be fitted by power function and linear function. And avoid fertilization before heavy rainfall, which can reduce agricultural non-point source pollution caused by improper fertilization.
【作者单位】：中国地质大学(北京)地下水循环与环境演化教育部重点实验室;中国地质大学(北京)水资源与环境学院;上海市青浦区水利技术推广站;
【基金】：国家自然科学基金项目(51209187) 北京高等学校青年英才计划项目(YETP0653) 水资源与水电工程科学国家重点实验室开放基金项目(2013B108) 中央高校基本科研业务费资助项目(2652015116)
【分类号】：S157.1

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