After acid treatment,the chemical and physical properties of red yellow soil significantly changed.The pH decreased,and numerous Al ions,which are harmful to plant growth,were leached.The structure of soil aggregates was damaged,followed by an increase of soil stickiness and water maintainability,and a decrease of air penetrability.The germination of Chinese Pine ( Pinus tabulacformic Carr).seeds decreased after sowed in red yellow soil acidified by H 2SO 4 solution.The direct cause w...