控释氮肥的氮素释放特征及其对水稻的增产效应

采用浸水释放试验和水稻田间试验方法研究了疏水性材料有机高分子聚合物包膜控释氮肥的释放特征,并以普通氮肥作对照研究了包膜控释氮肥对水稻的增产效应。研究结果表明,包膜控释氮肥养分释放达到了控释效果;与普通氮肥相比,施用控释氮肥有效提高了稻田土壤中碱解氮和铵态氮含量,促进了水稻植株和根系对氮素的吸收利用;两种处理的水稻总生物量差异不显著,但是在籽粒产量上,控释氮肥各处理两年的试验结果均比普通氮肥增产10%~40%,尤其是控释氮肥施用量为普通氮肥1/3时仍有增产效果,2003年高达15·1%;在当地稻田条件下,2002年控释氮肥氮素利用率最高达到了51·2%。采用疏水性包膜材料有机高分子聚合物包膜的控释氮肥比普通氮肥具有控制释放、促进水稻吸收氮素养分、提高籽粒产量和肥料的当季利用率与降低施肥量的优越性。

RELEASING CHARACTERISTICS OF CONTROLLED-RELEASE NITROGEN FERTILIZER AND ITS EFFECTS ON RICE YIELD

Nitrogen release experiments and field experiments were conducted to study release characteristics of the controlled release fertilizer(CRF) coated with hydrophobic material(organic macromolecule polymer) and its effect on rice yield as compared to common urea fertilizer(CUF).The results show that nutrient release of the CRF in water met the requirements for controlled-release.Compared with the CUF,the CRF significantly increased the contents of alkalytic N(ALR-N) and NH₄⁺-N in the paddy soil,facilitating N uptake by the roots of rice.There was no difference in total biomass of the rice plants between the different nitrogen treatments,but the results of two years' field experiments show that the grain yield of the rice in the CRF treatments was 10%~40% greater than that in the CUF treatments.Especially,the CRF,applied at a rate only 1/3 of the rate of the CUF,also increased the grain yield of rice by 15.1% in 2003.Under the local paddy field conditions,the results proved that the nitrogen use efficiency of CRF was up to 51.2% in 2002.The CRF showed its advantages of controlling release of N nutrient,promoting N uptake by the rice,increasing grain yield and nitrogen use efficiency,and reducing nitrogen application rate.