土壤容重对涌泉根灌土壤水氮运移特性的影响

发布时间：2018-06-21 06:26

本文选题：涌泉根灌 + 土壤容重　；参考：《农业机械学报》2017年08期

【摘要】：在室内通过人工配置不同水平土壤容重(1.35、1.40、1.45、1.50 g/cm~3),用土箱进行水肥入渗模拟试验,研究土壤容重对累积入渗量、湿润锋运移、土壤水分以及铵态氮和硝态氮运移的影响,建立以土壤容重和入渗时间为自变量,累积入渗量和各向湿润锋运移距离为因变量的经验模型。结果表明:土壤容重对累积入渗量、各向湿润锋运移距离及湿润体内水分和氮素的分布、转化均具有较为显著的影响。随着土壤容重的减小,累积入渗量、湿润锋运移距离、湿润体内水分、铵态氮及硝态氮含量均呈增大趋势。入渗系数K随着土壤容重的增大而减小,入渗指数α随着土壤容重的增大而增大;在同一时刻,湿润体内铵态氮和硝态氮含量的平均值、变化量及转化率均随着土壤容重的增大而增大。距离灌水器越近,铵态氮、硝态氮含量越高;湿润体内铵态氮分布主要集中在灌水器附近,随着再分布进行,湿润体内铵态氮含量、转化率逐渐减小,转化量逐渐增加。灌水结束、再分布3、5、10、15、20 d条件下,以灌水结束时刻为基准,铵态氮含量降幅依次为2.34%、11.41%、34.22%、59.06%和73.75%。湿润体内硝态氮分布区域与水分分布相似,随着再分布进行,湿润体内硝态氮含量、转化量逐渐增大,再分布15 d达到最大值;而转化率呈现出先增大后减小的趋势,再分布10 d转化率达到最大值。灌水结束、再分布3、5、10、15、20 d条件下,以灌水结束时刻为基准,湿润体内硝态氮含量依次增加0.76%、60.12%、156.95%、204.68%和180.51%。土壤容重对涌泉根灌土壤水分和氮素运移、分布及其转化的影响均较为显著。
[Abstract]:In the laboratory, soil bulk density of 1.35 ~ 1.405g / cm ~ (-3) and 1.50 g / cm ~ (-3) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (50) g / cm ~ (3) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (-1) ~ (50) g / cm ~ (3) ~ (-1) ~ (-1) ~ (-1) ~ An empirical model with soil bulk density and infiltration time as independent variables, cumulative infiltration amount and migration distance of each wetting front as dependent variables was established. The results showed that the soil bulk density had a significant effect on the accumulation of infiltration, the migration distance to the wetting front, the distribution of water and nitrogen in the wetted body, and the transformation. With the decrease of soil bulk density, the cumulative infiltration amount, the migration distance of wetting front, the moisture in the wetted body, the contents of ammonium nitrogen and nitrate nitrogen all showed an increasing trend. The infiltration coefficient K decreases with the increase of soil bulk density, and the infiltration index 伪 increases with the increase of soil bulk density. The change and conversion rate increased with the increase of soil bulk density. The closer to the emitter, the higher the content of ammonium nitrogen and nitrate nitrogen, the more concentrated the distribution of ammonium nitrogen in wetting body is near the emitter, with the redistribution, the conversion rate of ammonium nitrogen decreases and the transformation amount increases gradually. At the end of irrigation and the redistribution of water at the end of irrigation for 20 days, the content of ammonium nitrogen decreased by 2.34% 11.41% and 34.22% and 73.75%, respectively, according to the end time of irrigation. The distribution of nitrate nitrogen in wetted body was similar to that of water. With the redistribution, the content of nitrate nitrogen and the amount of transformation increased gradually, and reached the maximum value at 15 days after redistribution, and the conversion rate increased first and then decreased. The conversion rate reached the maximum value for 10 days after redistribution. At the end of irrigation, the distribution of nitrate nitrogen in moist body was increased by 0.76%, 60.12% and 156.95%, 204.68% and 180.51%, respectively, on the basis of the end time of irrigation. The effect of soil bulk density on soil water and nitrogen migration, distribution and transformation in root irrigation of Yongquan was significant.
【作者单位】：西安理工大学水利水电学院;
【基金】：国家重点研发计划项目(2016YFC0400204) 国家自然科学基金项目(51279157、51479161) 公益性行业(农业)科研专项(201203003)
【分类号】：S152

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