磷酸二氢钙和氯化钾对乌栅土氮素淋失的影响

利用土柱淋洗,研究了N、P、K共施对太湖乌栅土氮素(Urea-N、NH₄⁺-N和NO₃^--N)淋失的影响.结果表明,在不施尿素的条件下,N的淋失以NO₃^--N为主,占淋失总氮(Urea-N、NH₄⁺-N和NO₃^--N之和)的93.39%.施加尿素后,Urea-N、NH₄⁺-N和NO₃^--N的淋失量明显增加,三者占淋失N的比例分别为3.95%、15.25%和80.80%,占施入N的比例分别为0.26%、0.80%和2.54%.Ca(H₂PO₄)₂或KCl均可显著增加3种形态N的淋失,使3种形态N占淋失TN的比例分别为4.54%、24.11%、71.35%和3.45%、24.53%、72.02%,占施入N的比例分别为0.39%、1.86%、3.34%和0.32%、2.12%、4.06%.Ca(H2PO4)2和KCl共施对N素淋失存在着一定的交互作用,使3种形态N占淋失TN的比例分别达到4.10%、27.35%和68.55%,占施入N的比例分别为0.42%、2.60%和4.26%.不同形态N淋失的先后顺序为:Urea-N >NH₄⁺-N>NO₃^--N,而淋失总量的顺序为:Urea-N < NH₄⁺3^--N.

Effect of Monocalcium Phosphate and Potassium Chloride on Nitrogen Leaching in Paddy Soil

In this article, influence of monocalcium phosphate and potassium chloride application on nitrogen leaching in paddy soil of Taihu region was studied by soil column leaching. The results showed that nitrate nitrogen was the main component of nitrogen leaching without urea application which accounts for 93.39 percent of total nitrogen leaching(including urea, ammonium, and nitrate nitrogen). Amounts of urea, ammonium, and nitrate nitrogen in leachates increased significantly after urea application which account for 3.95, 15.25, and 80.80 percent of total nitrogen leaching respectively and for 0.26, 0.80, and 2.54 percent of applied nitrogen respectively. Amounts of urea, ammonium, and nitrate nitrogen in leachates were enhanced prominently by monocalcium phosphate or potassium chloride which are 4.54, 24.11, 71.34, and 3.45, 24.53, 72.02 percent of total nitrogen leaching respectively, and which are 0.39, 1.86, 3.34, and 0.32, 2.12, 4.06 percent of applied nitrogen separately. There is interactive influence on nitrogen leaching after application of monocalcium phosphate and potassium chloride together, and amounts of urea, ammonium, and nitrate nitrogen were 4.10, 27.35, and 68.55 percent of total nitrogen leaching, and 0.42, 2.60, and 4.26 percent of total applied nitrogen respectively. The leaching order of different form nitrogen followed as urea N>ammonium N>nitrate N, and leaching amounts of different form nitrogen followed as urea N