Succession of Soil Acidity Quality and its Influence on Soil Phosphorus Types

Succession rules of soil acidity quality of larch plantations in first rotation at different development stages, succession rules of soil acidity quality of young stand of larch plantations in second rotation and the relationship between soil acidity and various forms of organic phosphorus and inorganic phosphorus were studied in mountainous area of eastern part of Northeastern China. The results showed that active acidity (pH value) inrhizosphere soil decreased continually with stand age increasing from young stand, half-mature stand, near mature stand to mature stand, but active acidity (pH value) in non-rhizosphere soil, exchange acidity, exchangeable aluminium, total hydrolytic acidity, and the ratio of exchange acidity and total hydrolytic acidity in rhizosphere soil and in non-rhizosphere soil increased apparently; total organic P, moderately resistant organic P, and highly resistant organic P in soil decreased at all age stages in larch plantations when soil acidity added. For rhizosphere soil of

Succession of Soil Acidity Quality and its Influence on Soil Phosphorus Types

Succession rules of soil acidity quality of larch plantations in first rotation at different development stages, succession rules of soil acidity quality of young stand of larch plantations in second rotation and the relationship between soil acidity and various forms of organic phosphorus and inorganic phosphorus were studied in mountainous area of eastern part of Northeastern China. The results showed that active acidity (pH value) inrhizosphere soil decreased continually with stand age increasing from young stand, half-mature stand, near mature stand to mature stand, but active acidity (pH value) in non-rhizosphere soil, exchange acidity, exchangeable aluminium, total hydrolytic acidity, and the ratio of exchange acidity and total hydrolytic acidity in rhizosphere soil and in non-rhizosphere soil increased apparently; total organic P, moderately resistant organic P, and highly resistant organic P in soil decreased at all age stages in larch plantations when soil acidity added. For rhizosphere soil of all stands of larch plantations at different development stages, there was positive correlation between Ca-P (except in young stand), Al-P(except in half-mature stand), Fe-P (except in near mature stand and mature stand), O-P (except in young stand), and soil active acidity, respectively; For rhizosphere soil, there was negative correlation between Ca-P (except in half-mature stand), Al-P(except in young stand), O-P, and exchange acidity, exchangeable aluminium, there was also negative correlation between Ca-P, Al-P(except in young stand and half-mature stand), Fe-P, O-P, and total hydrolytic acidity respectively. For rhizosphere soil, the correlation coefficient between Ca-P, O-P and total hydrolytic aciditydecreased, respectively, as stand ages up and that between Fe-P and exchange acidity, exchangeable aluminium increased, respectively, as stand ages grew. For non-rhizosphere soil, there was not significant correlation between soil acidity and various forms of inorganic phosphorus and organic phosphorus, respectively.