生物有机无机复混肥的养分释放特征研究

Research on nutrient-releasing characteristics of bio-organic-inorganic compound fertilizer

通过好气培养间歇淋洗法和室内培养法，研究了生物有机无机复混肥的养分释放和氮素在土壤中的矿化规律。结果表明，生物有机无机复混肥的氮磷钾淋洗累积量呈现“S”型曲线，氮素淋洗释放量在第21d达到最高峰，磷素在第28d养分释放量达到高峰，钾素在28～35d出现养分释放高峰，养分释放更加乎缓；氮素在土壤中矿化率2．8％～3．2％，0～18d表现为净固定过程，18d以后开始矿化释放无机氮，第35d达到高峰，硝化作用进行比较缓慢，硝化率表现为前期弱，后期强。

The results of the compound fertilizer＇s releasing law based on the intermissive pouring and washing showed： in the whole experiment period, a ＂S＂ curve was found in the accumulation of release of nitrogen, phosphor and kalium, with their peaks respectively in the 21^th, 28^th, and 28^th - 35^th day. The nutrients released steadily and permanently. The mineralization and nitration culture experiments in lab indicated that in the soil with 65% water content of outward fields and temperature of 30℃, the mineralization rate of nitrogen of the compound fertilizer was 2. 8%-3.2%. In the period of 0 - 18 day, only net stabilization progress was shown, and inorganic nitrogen had been released since the 18^th day, a peak of mineralization rate in the 35^th day, following that was a descending trend of nitrogen releasing. It was proved that nitration did not change largely from the start point to the end of culture experiments, the nitration rate was weak for the earlier period, was later period strong.