论文部分内容阅读
为研究有机肥施入土壤后引起的土壤氮组分含量变化对农田氮流失的影响,采用小区试验,并结合田间原位模拟降雨试验,分析施用的有机肥中氮组分的量、土壤氮含量、农田氮素流失浓度及流失量三者间的关系。结果表明:有机肥中酸解氨基酸氮、酸解铵态氮含量占全氮比例分别为28.6%～40.6%,21.3%～33.2%,平均为35.4%、26.4%,是有机肥氮的主要组分;随着单位面积施入农田的有机肥中酸解氨基酸氮、酸解铵态氮(均为可矿化氮)的量增加,0～20 cm土层土壤可矿化氮含量也增加,二者呈极显著正相关;随着耕层土壤中可矿化氮含量增加,农田渗漏液中总氮、水溶性总氮、硝态氮浓度增高,二者呈显著或极显著正相关;随着施用有机肥中可矿化氮的量增多,径流液中总氮、水溶性总氮流失量增加,渗漏液中总氮、水溶性总氮、硝态氮浓度及流失量增高,分别呈显著和极显著正相关。因此,农田中高量施入有机肥,可造成土壤可矿化氮含量增加,农田氮素流失风险也随之增大。
In order to study the effect of the change of soil nitrogen content on the nitrogen loss in farmland caused by the change of soil nitrogen content after organic manure was applied to the soil, the plot experiment and field simulated rainfall experiment were used to analyze the amount of nitrogen component, Content, the concentration of farmland nitrogen loss and the relationship between the three losses. The results showed that the contents of acid-hydrolyzed amino acids and organic acids in total organic nitrogen accounted for 28.6% -40.6% and 21.3% -33.2%, respectively, with an average of 35.4% and 26.4% ; With the organic fertilizer applied to farmland per unit area of acid hydrolysis of amino acid nitrogen, ammonium acid hydrolysis of ammonium (both mineralizable nitrogen) the amount of 0 ~ 20 cm soil mineralizable nitrogen content also increased, There was a significant positive correlation between them. With the increase of mineralizable nitrogen in topsoil, total nitrogen, water-soluble total nitrogen and nitrate nitrogen in farmland leachate increased significantly, with significant or very significant positive correlation. With the increase of the amount of mineralizable nitrogen in organic manure, total nitrogen and water loss of total nitrogen in runoff increased, total nitrogen, water-soluble total nitrogen and nitrate nitrogen in runoff increased, Significant and very significant positive correlation. Therefore, high-level application of organic fertilizer in farmland may result in an increase of mineralizable nitrogen content in the soil and an increased risk of nitrogen loss from farmland.