氮肥品种对砖红壤中钾素淋溶特征的影响

Effects of Different Nitrogen Fertilizers on Leaching Characteristics of Potassium in Latosol

通过室内盆载试验研究不同氮肥品种对砖红壤中钾素淋溶特征的影响,结果表明,不同氮肥品种处理的渗漏液中,K+浓度大小顺序为复混肥b>碳铵≈尿素>复混肥a;对各处理渗漏液中K+淋溶量Yt随时间t的变化用7种方程进行拟合,其中对照、碳铵和复混肥b处理中,K+淋溶量可以用二级动力学方程1/Y=a+b/t来描述,尿素和复混肥a处理,以抛物线方程Yt1/2=a+bt拟合效果较好;从渗漏液中K+累计淋溶量来看,复混肥b>碳铵≈尿素>复混肥a,且各处理中种植玉米均能显著减少K+累计淋溶量;最后对土壤剖面中速效钾含量进行分析,结果显示,种植玉米处理中在25 cm处有累积效应,且稍高于对应的休闲处理。

Effects of different nitrogen fertilizers on leaching characteristics of potassium in latosol were studied with a pot experiment. Results are as follows： The sequence of concentration of K^＋ in the leachate ranked as： complex mixed fertilizer b〉ammonium-bicarbonate≈urea〉complex mixed fertilizer a; Seven equation models were used to describe the relationship between accumulated amounts of K^＋ leaching and time with different nitrogen fertilizers. It was discovered that the second order kinetic equation 1/Y = a ＋ b/t can be well expressed the real situation with the check, ammonium-bicarbonate and complex mixed fertilizer b treatment and the parabola equation Yt^1/2 = a ＋ bt can be well expressed with urea and complex mixed fertilizer a treatment. In this study, the sequence of accumulated amounts of K^＋ leaching was in an order： complex mixed fertilizer b〉ammonium-bicarbonate≈urea〉complex mixed fertilizer a. Planting corn can significantly decrease the leaching amount of K^＋. Analyzed the contend of available K in the soil, there are accumulation of potassium in the 25 cm soil layer with planting corn treatment and the contends of potassium were higher than the corresponding bare treatments.