风化对土壤粒级中磷素形态转化及其有效性的影响

土壤风化程度经常与地带性土壤的磷素存在形态相关,这已为国内外的一些研究工作所证实,但对土壤不同粒级中磷形态的影响,迄今仍研究较少.在五十年代,Williams,E.G.和Saunders,W.M.H.曾测定了土壤不同粒级中的全磷、无机磷和有机磷含量,并指出在所有供试土壤中,无论是无机磷或有机磷,粘粒部分的相对含量都高于砂粒部分.

EFFECT OF WEATHERING ON THE TRANSFORMATION AND AVAILABILITY OF PHOSPHORUS IN DIFFERENT FRACTIONS OF PARTICLE SIZE OF MAIN SOILS OF CHINA

The present paper deals with the effect of intensity of weathering process during soil formation on the composition,distribution and transformation of phosphorus of various soil types fractions of soil particle sizes in soil types of China.Studies indicated that the higher the weathering degree of the soil,the greater the relative contents of total phosphorus,available phosphorus and organic phosphorus in clay.For example,the total phosphorus in clay fraction was five times as much as that in sand fraction of latosol,while this ratio fell below two in dark loessial soil which was more weakly weathered compared with the former.It was also showed that the forms and distribution of inorganic phosphate were also affected by the weathering process.In dark loessial soil the occluded phosphate might be up 47% of total inorganic phosphate in clay fraction,far higher than that in the original soil.