【摘要】 采用水中溶出法、饱和盐溶液蒸汽压法和土壤培养法,研究了包膜尿素氮素释放的机理,并通过油菜盆栽试验评价了包膜尿素与油菜需肥规律的吻合性。结果表明:(1)包膜尿素的氮素释放速率随温度的升高而增大,温度每提高15~20℃,氮素释放速率提高约3~8倍,并且氮素释放率与时间的关系可用一级动力学方程Nt=No(1-e-kt)、叶诺维奇方程Nt=a+blnt和抛物线方程Nt=a+bt0.5表征。(2)包膜尿素的氮素释放率随着水蒸气压差的增大而增加,并随土壤水分含量增加而增加。(3)包膜控释肥料膜内外水蒸气压差是控制养分释放的主要因素。(4)盆栽试验证明,包膜尿素处理的油菜吸氮量和生物量最高,并且包膜尿素的氮素释放特征更接近油菜的需肥规律。更多还原

【Abstract】 This paper was to explore the mechanism of thermoplastic coated urea by water dissolution experiment,vapor pressure experiment in saturated salt solution and soil extraction experiment.Pot experiment was conducted to evaluate the relationship between nitrogen release characteristics of coated urea and the nitrogen absorbing model of cole.The results indicated that:(1) Nitrogen release rate increased with increasing incubation temperature and the nitrogen release rate enhanced approximately 3 times to 8 times when the temperature enhanced every 15℃ to 20℃.The dynamics of nitrogen release rate could be quantitatively described by three equations: the first-order kinetics equation(Nt=No(1-e-kt),Elovich equation(Nt=a+blnt) and parabola equation(Nt=a+bt0.5).(2) The nitrogen release rate of coated urea increased with the increasing of water vapor pressures and soil water contents increase.(3) The differences of inside and outside water vapor pressures were the direct reason for the nitrogen release.(4) Pot experiment testified that the nitrogen absorbing and output of cole in coated urea treatment was the highest,and the nitrogen release characteristic of coated urea was in accordance with the nitrogen uptake model of cole.更多还原