| 引用本文: | 杨 瑞,童菊秀,李佳韵,等.稻田地表径流氮素流失量数值模拟及淋失规律[J].灌溉排水学报,2018,37(1):63-69. |
| YANG Rui,TONG Juxiu,LI Jiayun,et al.稻田地表径流氮素流失量数值模拟及淋失规律[J].灌溉排水学报,2018,37(1):63-69. |
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| 摘要: |
| 【目的】研究稻田氮素径流流失和淋失规律。【方法】在连续淹水条件下开展稻田野外试验，对氮素径流流失过程进行了数值模拟，同时分析了施肥前后土壤剖面氮素质量浓度分布。【结果】 施肥当天径流试验中总氮、氨态氮和硝态氮以及施肥后第18天硝态氮的径流流失质量浓度随时间的下降过程可以用幂函数拟合，而施肥后第18天总氮和氨态氮用指数函数拟合。氮素径流流失过程前期，累积流失量与累积径流量的关系曲线可用抛物线函数拟合，径流后期用抛物线函数拟合效果略好于对数函数。在连续淹水下稻田中硝态氮量很低，主要以氨态氮形式流失。上层土壤（0~30 cm）氮素量大于下层，且上层的氮素量随时间的变化幅度高于下层。【结论】 稻田氮素径流流失过程可通过初等函数拟合进行定量描述，提高根系对上层土壤氮素利用率有利于减小氮素淋失，且氮素量呈现高离散程度的上层土壤区是淋失过程定量描述的重点和难点。 |
| 关键词: 氮； 水稻田； 径流流失； 土壤剖面； 数值模拟 |
| DOI：10.13522/j.cnki.ggps.2017.0172 |
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| Numerical Simulation of Nitrogen Loss in Surface Runoff and Leaching from Paddy Field |
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YANG Rui, TONG Juxiu, LI Jiayun, WEI Wenshuo
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Key Laboratory of Groundwater Cycle and Environment Evolution(China University of Geosciences), Ministry of Education, Beijing 100083, China; Collage of Water Resources and Environment Sciences, China University of Geosciences, Beijing 100083, China
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| Abstract: |
| 【Objective】 Field experiments were conducted in a paddy field under traditional continuously flooded irrigation (CFI) to study nitrogen (N) loss by runoff and leaching from soil profile. 【Method】 The numerical simulation of runoff N loss was carried out, and the distributions of N concentration in soil profile before and after fertilization were also analyzed. 【Result】 The reaults showed that, the total N, ammonium and nitrate concentrations in runoff during the decline stage on the day of fertilization were fitted well by power function. The nitrate concentration in runoff on the 18th day after fertilization was also well fitted by power function. While the total N and ammonium concentrations in runoff on the 18th day after fertilization were fitted well by exponential function. During the early half runoff N loss processes, the relationship between cumulative surface runoff and accumulation of N loss was fitted well by parabolic function. In the late half process, the parabolic function was slightly better than the logarithmic function. NO3--N content was low and NH4+-N was the main N loss under CFI in the paddy field. The N concentration in upper soil (0~30 cm) was usually greater than that in lower soil. And the change amplitude in upper soil was much higher than that in subsoil. 【Conclusion】 The process of runoff N loss in paddy field can be quantitatively described by elementary function fitting. Increasing the utilization rate of N in the upper soil by root is beneficial to reduce the leaching, and the upper soil area with high degree of N content is the key and difficult point of the leaching process quantitative description. |
| Key words: nitrogen; paddy field; runoff loss; soil profile; numerical simulation |
