生物可降解型自控缓释尿素养分释放规律的研究

以4种生物可降解型自控缓释尿素（CU1、CU2、CU3、CU4）为研究材料,通过静水释放试验模拟研究了4种肥料在常温条件下的养分释放规律,采用静水释放试验研究了不同温度对CU4养分释放的影响以及采用土壤培养的方法研究了不同土壤含水量对CU4养分释放的影响。结果表明,CU1和CU2养分累积释放曲线呈倒＂L＂形,CU3和CU4养分累积释放曲线呈＂S＂形,这与非生物可降解型聚合物包膜尿素养分累积释放曲线相同。4种肥料的初溶出率为0.07%-8.77%,微分溶出率除CU1外,均低于4%,其中CU4初溶出率最低,控释效果最好,约控释85天。升高温度将增大养分释放速率,缩短控释时间,降低土壤含水量能够降低养分释放速率和养分释放总量,但不管是升温还是降低土壤含水量均不改变肥料养分累积释放曲线类型。

Study on Nutrient Release Rule of Biodegradable Controlled-release Urea

Taking four kinds of biodegradable coated control-release urea(CU1,CU2,CU3,CU4) as testing materials,their nutrient releasing rules were studied by static water releasing test.The effects of different temperatures and soil moisture on the nutrient releasing of CU4 were also studied by static water release test and soil culture method respectively.The results showed that the nutrient releasing curve of CU1 and CU2 were in inverse "L" shape,while that of CU3 and CU4 were "S" shaped,which were in accordance with those of the non-biodegradable polymer-coated controlled-release urea.The early release ratios of the four kinds of controlled-release urea fertilizers were 0.07%~8.77%,while their differential release ratios were lower than 4% except CU1,in which,CU4 was the best with the lowest early release ratio and the best controlled-release effect,whose controlled release time was about 85 days.With the rising of the temperature,the nutrient release ratio could increase and the controlled release time could be shorted,while decreasing the soil moisture could decrease the nutrient release ratio and total rate.But increasing temperature and decreasing soil moisture could not change the type of nutrient release curve.