一种氮缓释复混肥料的制备及其氮素缓释性评价

用化学方法制备了氮素不同程度缓释的复混肥(氮缓释肥),在实验室条件下肥料的淋洗实验表明,相比对照复混肥,这种复混肥的氮素具有一定程度的缓释性,且随着复混肥制备过程中所加入的缓释剂甲醛的增加,氮素的缓释性得到增强。用双曲线方程Xt=b-a/t对氮缓释肥的氮素累计溶出率进行拟合,采用拟合方程中b值和a值计算得到的缓释指数SRI来定性和定量评价氮缓释肥的氮缓释特性。结果表明:氮缓释肥的氮素缓释指数SRI与制肥中加入的缓释剂相对含量X具有较好的正相关,其直线相关系数达0.9905(P<0.01)。这种对相关养分淋洗数据用双曲线按淋洗时间段分段拟合,并引入缓释指数SRI评价缓释肥料缓释特性的方法,为缓释肥料缓释特性的快速定性和定量评价提供了依据。

Manufacture of a kind of N slow-release compound fertilizer and evaluation of its N slow-release characteristics

Chemical method is used in the preparation of partial nitrogen slowrelease compound fertilizer (NSF). It is proved that the nitrogen of NSF can be released slowly compared with compound fertilizer (CK) in leaching experiments. Slowrelease properties of the fertilizer is enhanced when the content of additive formaldehyde increases in the procedure of preparation. Hyperbolic curve equation X_t=b-a/t is selected to fit the accumulated N dissolving percentage according to different leaching stage, slowrelease index(SRI), which is calculated from the b value and a value in the equation, is used to evaluate slow release properties of the nitrogen in NSF quantitatively. The results show that the SRI is positive relationship to the additive content in the NSF and the liner correlation coefficient 0.9905(P<0.01). The hyperbolic curve fitting method according to different leaching stages and the subsequent SRI are useful in quick evaluation on the slowrelease properties of the fertilizer in quality and quantity, respectively.