砖红壤中氨挥发特征研究初报

Volatilization of Ammonia from Latosol Soil After Application of Fertilizers

应用室内土柱模拟,以砖红壤为供试土壤,研究了肥料投入量、氮肥品种、种植模式与氨挥发特征的变化关系。结果表明,尿素在砖红壤中氨挥发过程可分为快速挥发和慢速挥发2个阶段;不同尿素投入量下,氨累计挥发量并不总是随尿素施用量的增加而增加,在本试验条件下,当尿素用量超过375Nkg·hm-2后,其累计挥发量并无明显增加。不同种植模式下,休闲处理氨挥发速率均相对高于对应的种植玉米处理;从休闲处理各氮肥品种氨挥发最大速率来看,碳铵>复混肥a>尿素>复混肥b;从各氮肥品种氨累计挥发量来看,复混肥a>碳铵>尿素>复混肥b;各种氮肥品种的氨累计挥发量随时间的变化关系均可用动力学方程Yt=a+blnt来表示。

To evaluate volatilization of ammonia in tropical area from latosol soil, the changes of ammonia volatilization with different application dosagesof urea were studied in laboratory by soil column containing disturbed latosol.Effects on fertilizer sorts and planting model were also researched simultaneously. The results showed that ammonia volatilization of urea in latosol was divided into two stages, namely, quick stage in early time and slow stage in late. Inthis study, no significant increase of ammonia was observed, while urea quantity increased when the dose of urea applied was beyond the level of 375 N kg·hm-2. The relationship between accumulated amount of ammonia volatilization and urea quantity applied exhibited a regression model y=-1.7027+0.0384x-3×10-5x2. For different planting model, the ammonia volatilization velocity was always higher in bare treatment than that in the planting corn. In this study, the sequence of ammonia volatilization velocity was in an order: ammonium-bicarbonate>complex mixed fertilizer a >urea>complex mixed fertilizer b in the bare treatment. In addition, the sequence of accumulated amounts of ammonia volatilization ranked as: complex mixed fertilizer a>ammonium-bicarbonate>urea>complex mixed fertilizer b. It has been also discovered that 14.02%ratio of ammonia volatilization of complex mixed fertilizer a was obtained in the bare treatment. Seven equation models were used to describe the relationship between accumulated amounts of ammonia volatilization and time with different nitrogen fertilizer sorts. It was discovered that the equation Yt=a+blnt could be well expressed the real situation.