不同有机酸对黄褐土矿质元素活化作用的比较研究

为研究不同有机酸对黄褐土矿质元素的活化效应,采用同一浓度(10 mmol/L)的茶多酚(TP)和小分子有机酸(LMWOAs)进行土壤浸提试验,比较不同类型有机酸对黄褐土主要矿质元素活化效果的差异。结果表明：LMWOAs对黄褐土中Ca和Mg的活化能力均表现为：酒石酸>柠檬酸>乙酸>草酸。草酸对土壤Fe、Mn、Cu、Zn 4种元素均有较好的活化效果,且对Fe和Cu元素的活化能力显著高于其他LMWOAs;柠檬酸对土壤Mn元素的活化能力显著高于TP和其他LMWOAs;酒石酸对土壤Zn的活化能力显著高于TP和其他LMWOAs;乙酸对土壤Fe、Mn、Cu、Zn元素的活化能力显著低于TP和其他LMWOAs。TP对土壤Ca、Mg、Fe、Mn、Zn元素的活化能力显著低于LMWOAs（乙酸除外）,对K和Cu的活化效果显著优于LMWOAs。黄褐土种植茶树会加速K和Cu的活化和迁移（尤其是K）,提高矿质元素的生物有效性,同时可能造成土壤缺K和酸化。

The Effects of Different Organic Acids on Mobilizing Mineral Elements in Yellow Cinnamon Soil: A Comparative Study

To investigate the effects of different organic acids on mobilizing mineral elements in yellow cinnamon soil, tea polyphenol (TP) and low molecular weight organic acids (LMWOAs) with 10 mmol/L were used to study the difference of mobilization effects among mineral elements by soil extraction test. The results showed that the mobilization order of LMWOAs on Ca and Mg in yellow cinnamon soil was: tartaric acid > citric acid > acetic acid > oxalic acid. Oxalic acid showed strong mobilization ability on Fe, Mn, Cu and Zn, and the mobilization ability of oxalic acid on Fe and Cu were significantly stronger than that of other LMWOAs. The mobilization ability of citric acid on Mn was significantly higher than that of TP and other LMWOAs; the mobilization ability of tartaric acid on Zn was significantly higher than that of TP and other LMWOAs; the mobilization ability of acetic acid on Fe, Mn, Cu and Zn were significantly lower than that of TP and other LMWOAs. TP showed significantly lower mobilization ability on Ca, Mg, Fe, Mn and Zn compared with LMWOAs (except acetic acid), but the mobilization ability of TP on K and Cu were significantly higher than that of LMWOAs. Therefore, planting tea tree could accelerate the mobilization and migration of K and Cu (especially for K) in yellow cinnamon soil, improve the bioavailability of mineral elements while cause soil K deficiency and soil acidification.