Abstract: A laboratory experiment was conducted to explore changes in total amount of soluble Al and form of soluble Al in two types of acid soils,tea garden yellow brown soil and tea garden red soil,incorporated with various plant materials: canola straw,wheat straw,rice straw,corn straw,soybean straw,peanut straw,faba bean straw,Chinese milk vetch shoot and pea straw.Except for the treatments of yellow brown soil incorporated with canola straw,wheat straw and rice straw,all the treatments decreased in total soluble Al,total monomeric Al and three inorganic monomeric Al′s,i.e.Al3+,Al-OH and Al-F complexes in two soils to a varying extent as was compared with that in control,because these plant materials increased soil pH.In the yellow brown soil the effect of the legume plant materials on soil pH was higher than that of the non-legume plant materials,thus reducing the amount of Al3+,AlOH and Al-F complexes to a greater extent.All of the nine plant materials increased pH of red soil and decreased soil soluble Al to a varying extent,which followed the order of peanut straw > canola straw > faba bean straw > rice straw > corn straw > wheat straw > Chinese milk vetch shoot > soybean straw and pea straw.Therefore,the incorporation of plant materials can ameliorate soil acidity and reduce toxicity of soluble Al to plants in the soils.Peanut straw is the best choice for increasing soil pH and decreasing toxic aluminum in acid soils.

Key words: plant material, acid tea garden soil, soluble Al, aluminum form