Release characteristics of a release-promoting calcined magnesium oxide and its effect on tomato growth

Chinese. 【目的】探讨促释型镁肥的养分释放特性、肥效及其作用机理。【方法】采用连续抽提、盆栽试验和X射线粉末衍射仪分别测定镁肥的水溶性镁释放量、番茄果实重量与生物量、镁肥的结构。【结果】连续抽提表明,促释型轻烧氧化镁水溶性镁每次的释放量高于轻烧氧化镁（第5次除外）,6次累积释放量是轻烧氧化镁的1.10倍。盆栽试验结果表明,促释型轻烧氧化镁处理的果实重量和生物量均高于轻烧氧化镁处理和硫酸镁处理;施镁肥处理的叶片镁、硫含量显著高于CK（无镁肥）,促释型轻烧氧化镁处理的番茄叶片镁含量显著高于轻烧氧化镁处理和硫酸镁处理;施镁处理的植株中的镁含量显著高于CK（无镁肥）,硫的含量没有显著性差异;番茄生物量与叶片、植株中的镁含量相关系数是0.8975、0.8715;X射线衍射分析结果显示,促释材料改变了轻烧氧化镁的结晶状态,促进了轻烧氧化镁中镁的释放。【结论】与轻烧氧化镁相比,促释型轻烧氧化镁的水溶性镁含量、生物量均提高。

English. [ Objective ] The objective of this experiment is to analyze the release characteristics, fertilizer effects and promoted mechanism of release-promoting calcined magnesium oxide （PRCMO）. [ Method ] Continuous water extraction, pot experiment and XRD spectroscopy were used to investigate the content of water-soluble Mg of magnesium fertilizer, the tomato yield and biomass, the structure of magnesium fertilizer. [Result] The result of continuous water extraction indicated that compared to calcined magnesium oxide, the content of water-soluble Mg of PRCMO was higher every time （except the fifth time）, and accumulative release rate of PRCMO was 1. 10 times higher. The result of the pot experiment indicated that tomato yield and biomass of PRCMO were higher than those of calcined magnesium oxide and MgSO4. The Mg and S contents in the leaf of all magnesium treatments were obviously higher than those of CK （no magnesium fertilizer）. Among Mg treatments, Mg content in the leaf of PRCMO was much higher than those of calcined magnesium oxide and MgSO4. Mg contents in the plant of all Mg treatments were also obviously higher than that of CK （no magnesium fertilizer）, while S contents in the plant were not significantly different. The correlation coefficients between biomass and Mg contents in the leaf and the plant were 0.8975 and 0.8715, respectively. The results of XRD spectroscopy showed that promoting material changed the crystal status of calcined magnesium oxide, and this promoted Mg release from calcined magnesium oxide. [Conclusion] Compared to calcined magnesium oxide, the content of water-soluble Mg and biomass of PRCMO were higher.