广西土壤成土条件与铁铝土成土过程特征研究

选用1971~1980年广西气象、地质资料,从气候、生物、地形、母质和时间5个方面对广西土壤成土条件进行分析,并对铁铝土52个土壤剖面的B层52个土样进行土壤pH值和交换性铝、钾、钠、钙、镁、土壤全铁和全硅、游离氧化铁含量测定。结果表明:广西地处亚热带季雨林气候区,高温多雨,湿、热同步,化学风化、淋溶作用强烈,生物循环旺盛,母岩多样,地形复杂,由此形成了广西土壤类型以酸性富铝化土壤为主的多样性;广西铁铝土在成土过程中盐基被强烈淋溶,土壤多为酸性反应,盐基饱和度低,阳离子交换量很小,脱硅富铁铝化明显,游离氧化铁含量和交换性铝饱和度高。研究广西土壤成土条件与铁铝土成土过程特征,对于合理开发利用广西土壤资源有着重要的意义。

Soil-forming conditions and ferrallisols formation features in Guangxi

In order to explore the soil-forming conditions and ferrallisols formation features in Guangxi,the meteorological and geological data of Guangxi were applied to study the soil-forming conditions.And the soil pH values,the contents of free iron oxide,the exchangeable aluminum,potassium,sodium,calcium and magnesium,the total contents of iron and silicon in 52 soil samples of B horizon of 52 soil profiles collected from ferrallisols areas of Guangxi were determined.The results showed that the diversity of soil types which composed ferrallisols mainly in Guangxi resulted from that Guangxi was located in the subtropical rainforest region,with an abundant of rainfall and quantity of heat in the same period,strongly chemical weathering and leaching,quickly biological cycling,the diversity of parent rocky,and the complex terrain.The base in ferrallisols in Guangxi was leached during the soil-forming process;as a result,the soil was acid,lower base-saturation percentage and less cation exchange capacity,while the desilicification,allitization and ferritization in the soil was strong,and the content of free iron oxide and the exchangeable aluminum saturation percentage were high.