沙柱淋溶法改进前后化肥氮素释放特性比较

Comparison on Release Characteristics of N in Chemical Fertilizer before and after Improvement of Leaching Method with Sand Column

[目的]实现对化肥养分释放特性的准确、可靠评价。[方法]以石英砂作为淋洗介质，以硫酸铵、普通复合肥和控失肥为供试肥料，改变沙柱长度、化肥形状和加水方式，测定淋溶法改进前后淋洗液中的铵氮浓度。[结果]淋溶法改进前硫酸铵、复合肥和控失肥的铵氮溶出分别为（0．6253±0．2187）、（O．0544±0．0233）、（0．0400±0．0154）g，离散系数分别为35％、43％、39％；淋溶法改进后硫酸铵、复合肥和控失肥的铵氮溶出分别为（0．5658±0．0672）、（0．0397±0．0051）、（0．0312±0．0233）g，离散系数分别为12％、13％、9％；硫酸铵铵氮溶出3次重复间的试验误差由36．7％降至3．3％。[结论]以石英砂为介质，改进后模拟淋溶试验的稳定性和可重复性得到显著改善．试验误差从35％～45％降低到10％左右。

[ Objective ] The aim was to implement the accurate and reliable evaluation on release characteristic of fertilizer nutrient. [ Method] With quartz sand as the leaching medium and ammonium sulfate, compound fertilizer, controlled release fertilizer as the tested fertilizer, the ammonium nitrogen cohen, of the eluent pre and post improvement of leaching method was detected by changing sand eolumn length, fertilizer type and water adding methods. [ Result ] The ammonium nitrogen dissolution of ammonium sulfate, compound fertilizer and controlled release fertilizer pre improvement of leaching method were （0. 625 3 ± 0.218 7 ）, （0.054 4 ± 0. 023 3 ） and （ 0.040 0 ±0.015 4 ） g resp. with dispersion coefficient of 35% , 43% and 39% resp. The ammonium nitrogen of ammonium sulfate, compound fertilizer and controlled release fertilizer post improvement of leaching method were （0. 565 8 ± 0. 067 2）, （0. 039 7 ±0. 005 1 ） and （0.031 2 ± 0.023 3 ） g resp. with dispersion coefficient of 12%, 13% and 9% resp. The test error of ammonium nitrogen dissolution of ammonium sulfate between 3 repeated tests was decreased from 36.7% to 3.3%. [ Conclusion] With quartz sand as the leaching medium, the stability and repeatability of simulation leaching test were improved significantly, and the test error was decreased from 35% -45% to about 10%.