超微细磷矿粉包膜缓释肥的缓释特征及其对大白菜生理特性的影响

以超微细磷矿粉为主要膜材料对普通复合肥(N-P2O5-K2O:15-15-15)进行包膜,制备了超微细磷矿粉分别占膜材料质量0%、40%、50%和60%比例的4种包膜缓释肥料,分别为CRF2、CRF3、CRF4、CRF5。通过室内养分缓释性能试验和大田试验研究了超微细磷矿粉包膜肥养分缓释特征及其对大白菜生理特性的影响。结果表明:1)用日产JEM-1200EX型电镜扫描观察膜形态结构,4种比例的超微细磷矿粉包膜复合肥随膜材中超细磷矿粉比例的增加其膜壳表面均匀度和致密度增强,对养分释放的缓释能力逐步增强,但缓释效果较树脂包膜肥略差。4种自制包膜肥的养分释放期较普通复合肥延长58～68d,但低于释放期为88天的树脂包膜肥。4种自制包膜肥在土壤培养试验中的土壤氮素表观释放率与树脂膜接近。2)与普通复合肥相比,4种自制包膜肥,能不同程度提高大白菜中后期叶绿素含量、净光合速率(Pn)、蒸腾速率(E)等,提高结球期根系活力及叶片的超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)等酶的活性。同时,大白菜单株的结球质量增加0.17～0.77㎏,产量提高6.66%～35.50%,提高了收获期大白菜的含糖量、糖酸比以及维生素C(VC)含量;3)与树脂包膜复合肥相比,各项生理指标均无显著差异。4种自制包膜肥的缓释性能及改善大白菜生理特性的顺序均为:CRF5≈CRF4>CRF3>CRF2。

Nutrient release characteristics of controlled release fertilizers coated with superfine phosphate rock powder and its effects on physiologic traits of Chinese cabbage

Four types of controlled release fertilizers,CRF2,CRF3,CRF4 and CRF5,were prepared out of a common compound fertilizer(N-P2O5-K2O: 15-15-15) by coating it with superfine phosphate rock powder(SPRP),which accounted for 0%,40%,50% and 60% of the total coating in mass,separately.Electronic microscope scanning,static water releasing,soil incubation and a field experiment were conduced to explore characteristics of their nutrient release and their effects on physiologic traits of Chinese cabbage.Results show that the use of superfine phosphate rock powder in coating markedly improved evenness and density of the surface of the coating and hence its capability of controlling nutrient release,and the effect increased with the proportion of the powder in coating.The four kinds of homemade SPRP-coated fertilizers had a nutrient releasing period,58～68 days longer than the common compound fertilizer had but still shorter than 88 days the resin coated fertilizers(CRF1) had.However,their apparent nitrogen release rates were approximate to that of CRF1.Besides,the four SPRP-coated fertilizers increased the chlorophyll content,photosynthetic rate,and transpiration rate in the leaves of the plant during its middle and late growth stages,the activities of SOD,CAT and POD during its balling period,the biomass per head by 0.17~0.77kg,the yield by 6.66%~35.50%,and sugar/acid ratio,soluble sugar content,and VC content of the head of the plant at the harvest stage.Comparison with CRF1 shows that they made no big differences in physiological traits of the plant.In terms of nutrient release and effects on physiological traits of the plant the four homemade fertilizers follow the order of CRF4≈CRF5>CRF3>CRF2.