不同养分释放期控释尿素掺混后的养分释放特征

Nutrient Release Characteristics of Controlled Release Urea with Different Blending Proportions at Different Nutrient Release Period

以3种养分释放期不同的控释尿素为供试肥料,采用化工行业标准《控释肥料》(HG/T 4215—2011)中规定的25℃静水浸提凯氏定氮法和100℃快速浸提凯氏定氮法,试验研究了不同养分释放期控释尿素的不同掺混比例对养分释放特征的影响。试验结果表明:几种控释尿素掺混后养分释放率的实测值与按比例加权值计算的释放率相当,通过100℃静水浸提法也可快速预测掺混控释尿素在25℃静水中的养分释放期;不同养分释放期的控释尿素掺混后,其养分释放期仍与养分释放期较长的那种控释尿素相同,养分释放高峰点出现时间与不同养分释放期控释尿素掺混比例有关;根据不同养分释放期控释尿素时段溶出的养分加权值计算不同时段的养分释放率,所得预测值与实测释放率基本一致;对于掺混控释尿素,养分释放期较长的控释尿素掺混一定比例的养分释放期相对较短的控释尿素,可在作物前期或在作物快速生长期出现养分释放高峰,更好地满足作物养分最大效率期对养分的需求,弥补单一长效控释尿素前期养分供应不足的缺点,使控释肥养分释放与作物各生育期对养分的需求相同步。

t Three kinds of controlled release urea with different nutrient release period are used as experimental fertilizers, with 25 ℃ static water extraction Kjeldahl determination, and 100℃ water fast extraetion Kjeldahl method stipulated by chemical industry standard ＂ Controlled Release Fertilizer＂ （HG/T 4215-2011）, the study of effects of different blending ratio of different nutrient release period of controlled release urea on nutrient release characteristics is carried out. Experimental results show that measured nutrient release rate values of several bulk blending controlled release urea are almost the same as the calculated release rate values by proportional weight method, through 100 ℃ static water extraction, the nutrient release period of bulk blending controlled release urea in 25 ℃ static water can be quickly predicted ; the release period of bulk blending controlled release urea with different release period are the same as that of longer release period controlled release urea, theemergence time of nutrient release peak point is associated with the blending ratio of controlled release urea with different release period; based on dissolved nutrient weighted value at different time period, the nutrient release rate at different time period can be calculated, the calculated predicted value and the actual measured release rate value is basically the same; a longer release period controlled release urea blended with a shorter release period controlled release urea can make nutrient releasing peak period bring about at early growth stage of crop or at crop rapid growth stage, to satisfy the nutrient requirement of crops when they have the highest utilization efficiency of fertilizer and to avoid the disadvantages of nutrient deficiency in crop early stage caused by the use of single long release period controlled release urea, keeping the nutrient release of controlled release fertilizer in line with the nutrient requirement at different crop growth period.