蓄水坑灌体系温度对土壤氮素运移转化影响

发布时间：2018-03-30 05:14

  本文选题：蓄水坑灌　切入点：体系温度　出处：《节水灌溉》2017年02期

【摘要】：通过研究体系温度对蓄水坑灌施条件下土壤水分及氮素运移转化的影响,明确蓄水坑灌土壤水氮时空分布特征,探究土壤水氮运移迁移转化机理,以期为水肥合理灌施提供理论基础。通过模拟构建蓄水坑灌模型,以大型控温箱精确控制土壤温度,采用克里克空间插值法分析了蓄水坑灌条件不同体系温度下的水分、硝态氮、铵态氮时空分布特征,结果显示7 h左右土壤水分、养分完成入渗进入再分布阶段,土壤水分随着时间的推移其垂向和径向迁移距离均逐渐增大,同一时刻,温度越高其横向与径向迁移距离越大,且靠近蓄水坑壁区域的土壤含水率相对越低;土壤中铵态氮含量在不同温度下随时间推移均呈现先增后减的现象,低温下第15 d时土壤养分再分布核心区出现下降趋势,中、高温第10 d时已出现下降趋势,且其迁移距离远低于水分、硝态氮的迁移距离;土壤中硝态氮含量在10℃下第10 d时出现增高现象,而20、25、35℃下第5 d时已出现增高现象,由蓄水坑周边至湿润体边缘呈现"低-高-低"的分布态势。表明再分布阶段温度升高能提高水分的再分布速率,提高脲酶活性加快尿素水解转化为铵态氮,同时促进硝化反应进程抑制铵态氮在土壤中的积累,当土壤含水量过高时,会抑制土壤中氮素的硝化作用。
[Abstract]:By studying the effect of system temperature on soil water and nitrogen transport and transformation under irrigation and application in water storage pit, the spatial and temporal distribution of soil water and nitrogen was determined, and the mechanism of soil water and nitrogen migration and transformation was explored. In order to provide the theoretical basis for rational irrigation of water and fertilizer, the irrigation model of water storage pit was constructed by simulation, the soil temperature was accurately controlled by a large temperature control box, and the moisture under different system temperature was analyzed by using Crick space interpolation method. The temporal and spatial distribution characteristics of nitrate and ammonium nitrogen showed that the soil moisture was about 7 h, the nutrient infiltration entered into the redistribution stage, and the vertical and radial migration distance of soil moisture gradually increased with time, at the same time. The higher the temperature, the larger the distance between lateral and radial migration, and the lower the soil moisture content near the water storage pit wall, and the more the content of ammonium nitrogen in the soil increases first and then decreases over time. At the 15th day of low temperature, the core area of soil nutrient redistribution showed a downward trend, and the migration distance of soil nutrient at the 10th day of high temperature was much lower than that of water and nitrate nitrogen. The nitrate nitrogen content in the soil increased at 10 鈩，

本文编号：1684501