红壤磷素水平与油菜生长及根际土壤磷素组成变化

Effects of Residual Phosphorus on the Growth of Rapeseed and Inorganic Phosphate Fractionation of Rhizosphere Soil in Two Red Soils

盆栽试验研究江西鹰潭和湖北咸宁红壤上残留磷对油菜生长吸收磷素的影响及根际和本体土壤的无机磷组成 ,结果表明 :在 2种供试红壤上油菜产量均与土壤速效磷含量高低相关 ;油菜植株对P吸收增加最快的时期在 90～ 2 0 0d ,且土壤残留磷量影响其吸收动力学 ;鹰潭红壤的根际土pH低于本体土 ,咸宁棕红壤上趋势相反 ;NH4F和NaHCO3 提取土壤有效磷 ,鹰潭红壤上根际土壤有效磷亏缺 ,而咸宁棕红壤的根际土壤有效磷含量高于本体土壤 ;2种土壤的Ca2 P及Fe P含量与有效磷含量的变化趋势类似 ,而O

Two soils, sampled from Yingtan, Jiangxi Province and Xianning, Hubei Province, were employed to investigate the effects of residual soil phosphorus on the growth and P uptake of rapeseed, and inorganic phosphate fraction difference between rhizosphere and bulk soil were also studied through pot culture experiment and chemical dissolution. The results showed as tollows:The yield of rapeseed was corresponding to their P contents in the soils. The most P uptake occurred during 90～200 days, and they were also affected by P quantity.pH of rhizosphere soil was lower than that of bulk soil for Yingtan, whereas, the trend was reverse for Xianning soil.The available P in rhizosphere was lower than that in bulk for Yingtan red soil, but it was contrary for Xianning brown red soil. Moreover, there was distinct difference in the content of available P extracted with NH 4F or NaHCO 3. In both soils, Ca 2?P and Fe?P had similar variation trend as available P, where as O?P showed an opposite trend, which indicated that the former were available, but the latter was not.\;