包膜尿素氮素的溶出特性研究

Study of the Characteristics of Nitrogen Solubility from Coated Urea

【目的】研究包膜尿素(LP30)氮素的溶出特性。【方法】采用土壤、纯水两种培养方式,在4种温度(10、15、20、25℃)条件下对不同培养时期氮素溶出率进行测定,利用具体的方法——The number of days transformed to standard temperature(DTS),对自然温度条件下氮素的溶出率进行预测。【结果】培养试验表明,土壤和纯水两种培养方式对包膜尿素氮素溶出率的影响很小,不同温度对氮素溶出率的影响显著。分析表明,一级反应动力学模型可很好地描述包膜尿素氮素的溶出过程。氮素溶出速率随温度升高而加快,在10～25℃内,每升高5℃,速率常数约提高1倍左右。包膜尿素埋藏土壤后实测的氮素溶出率值与采用DTS法预测的氮素溶出率值之间无明显差异。【结论】包膜尿素(LP30)氮素溶出率大小主要取决于温度的变化,DTS法能较准确地预测包膜尿素施入土壤后,自然温度条件下,任意天数的氮素溶出率。

[ Objective ] This paper studied the solubility characteristics of coated urea （LP 30）. [ Method] It adopted soil and purified water as two culture methods and measured the solubility rate with different times under 10, 15, 20, 25℃. It used DTS method to forecast the nitrogen solubility rate of nature temperature. [Result] Temperature had significant effect on the nitrogen solubility rate, but culture methods of soil and purified water had little effect on it. The first-order reaction model could describe well the solubility process of coated urea. The rate of nitrogen solubility increased with rising temperature. The reaction rate constant could increase about 1 time when the temperature rises 5℃ within 10-25℃. There was no obvious difference between the measured value of nitrogen solubility rate and the forecasted value using DTS method for coated urea. [ Conclusion] The value of nitrogen solubility rate of coated urea （LP 30） is mostly determined by temperature, DTS method can truly forecast the nitrogen solubility rate at any time at natural conditions after applying coated urea in soil.