自制缓释氮肥释放特征及其肥效研究

分别采用腐植酸和钙镁磷肥包裹颗粒尿素的方法自制了两种缓释氮肥，并通过室内土壤培养和盆栽实验研究了其氮素释放特征和肥效。结果表明，两种缓释氮肥较普通尿素均有明显的缓释效果，在室内培养24h后，尿素溶出率为56.78%，而两种自制缓释氮肥分别仅为15.28% 和11.58%；以玉米为供试作物，两种自制缓释氮肥与普通氮肥(尿素)相比，均具有明显的增产效果，并显著提高玉米吸氮量和氮素表观利用率，其中以腐植酸包裹尿素（SRF2）效果最佳，较普通氮肥增产13.62%，氮素表观利用率达66.2%。

Nitrogen Release Characteristics of Slow-release Fertilizer and Its Efficiency

Two slow-release nitrogen fertilizers (SRF) were self-produced by coating humic acid or fused calcium- magnesium phosphate on the surface of urea granule. Indoor soil culture and pot experiment were carried out to study the nitrogen release characteristic of SRF and its efficiency，respectively. The results of soil culture experiment showed that both two SRFs had significant effect of nitrogen slow release. After 24h’s incubation， the nitrogen release percentage of urea was 56.78%，however，which of SRFs was 15.28% and 11.58%， respectively. The results of pot experiment with corn showed that, compared with urea，SRFs significantly increased the yield and nitrogen uptake of corn as well as apparent nitrogen recovery, in which the SRF2 of coating urea with humid acid performed best.