潜育性水稻土缺磷原因的分析

潜育性水稻土有效磷含量比非潜育性者低50～90％;有效磷占全磷的比例和植株吸磷量都比非潜育性水稻土低。水稻土中以Fe—P与有效磷的相关系数最大,依次为Al—P、O—P和Ca—P。潜育性水稻土上Fe—P、O—P(酸性土)、Al—P及有机磷量均低于非潜育性水稻土,与有效磷的趋势一致,是其缺磷的主要原因。潜育性水稻土对磷的吸附固定能力强,磷酸吸持容量高,无定形铁含量高。这是潜育性水稻土缺磷的又一重要原因。

THE REASONS OF THE DEFICIENCY OF PHOSPHORUS IN GLEY PADDY SOIL

Samples of gley paddy soil (GPS)and non-gleyed paddy soil (NGPS) derived from the same parent material were collected and analysed to ascertain the reasons of phosphorus deficiency in gley paddy soil. It was shown that the amount of the available P in GPS was 1-6 times less than that of NGPS, and available P/total P ratio in GPS was lower. P uptabe by plant grown in GPS at different growth stages was also lower than in NGPS. The coefficient of correlation between the available P and Fe-P, Al-P, O-P and Ca-P was 0.819, 0.689, 0.599 and 0.395, respectively.The contents of Fe-P, O-P and Al-P were all lower. The amount of organic P in GPS was also lower than that of NGPS, and related to the available P (r=0.486). Furthermore, phosphorus absorption capacity for GPS was high.