3种肥料品种的氮素养分静水释放试验

以3种不同肥料品种为试验材料，通过静水释放试验测定其氮素养分释放速率。结果表明，3种肥料的氮素养分释放曲线均呈“L”形；尿素在第3h的氮素累积释放率就达到了99．53％，而油茶专用肥（15-6-9）和掺混肥（15-6-9）在第23h的氮素累积释放率分别达到97．28％和99．36％。从长期累积释放情况来看，油茶专用肥缓释性优于掺混肥，更优于尿素。可见，添加有机质、经过造粒工艺处理，可在一定程度上减缓肥料养分的释放速率，有利于提高肥料利用率和降低肥料对环境尤其是对水的污染。

Hydrostatic Releasing Test on Nitrogen Nutrient in Three Fertilizers

Taking three different fertilizers as testing materials, releasing rates of nitrogen nutrient were measured by hydrostatic releasing test. The results showed that the releasing curves of nitrogen nutrient in three fertilizers were ＂L＂ shape. The accumulated releasing rate of nitrogen in urea at 3 h reached to 99. 53% , but the accumulated releasing rates of nitrogens in fertilizer for Camellia olifera （15-6-9） and bulk blending fertilizer （15-6-9） at 23 h were 97.28% and 99. 36% separately. According to the long- term accumulated releasing result, fertilizer for Camellia olifera （15-6-9） was prior to bulk blending fer- tilizer （15-6-9） and more prior to urea. It could slow down the nutrient releasing rate, improve the fer- tilizer＇ s utilization rate and reduce the environmental pollution especially the eutrophication of water body if the orgaric matter was added or the way of granulation process was used.