Used dynamics equation to express the relation between the accumulation amount of no 3 - n leaching and time : urea , ammonium - bicarbonate and composed fertilizer can be expressed as equation yt1 / 2 = a + bt , complex mixed fertilizer can be expressed as equation 1 / y = a + bl / t . the accumulation leaching quantity of no 3 - - n with urea , ammonium - bicarbonate , composed fertilizer and complex mixed 随时间t的变化用方程进行拟合，结果表明ck 、碳按和复混肥处理，以双曲线方程l / y二a + bl八拟合效果最好，而尿素和复合肥处理则以抛物线方程y ， ’ / 2 = a十bt拟合效果最好。
