摘要
培育试验表明，磷在红壤中有效性的衰减可分为快反应（３小时）阶段和慢反应阶段，前者有效磷以直线关系下降，后者则为一渐减性曲线。快反应阶段磷有效性的衰减量和土壤活性铝含量呈显著相关，但与活性铁和交换铝相关不显著。用红壤、潮土、板浆白土三种性质不同的土壤进行的生物试验表明，产量也随着土－磷作用时间延长而下降，而且有一个终止时间。中性水稻土在８个月培育后产量即不再下降，石灰性潮土为１６个月，而酸性红壤在２８个月以上。影响产量衰减的可能和磷在土壤中的双核化（转化为环状双核结构）和吸收作用有关，它们在程度上和延续时间上不同土壤不同，在水稻土上最弱，延长时间最短，而在红壤上作用最强，延长时间最长，潮土处于两者之间。
Decline of available P (Olsen-P) in red earth with time may be devided into two stages: fast and slow stages. The former stage can be described with a straight line equation, y=a+bx, the second stage with a curve equation, y=a+blogx, where y= available P still remained, and x= incubation periods (month).Available P decline has a significant correlation with the amount of active Al content in soils but not with the amounts of active Fe and exchangeable Al. Pot experiment with three different types of soils: acidic red earth, neutral paddy soil, and calcareous fluvo-aquic soil, using wheat and rye grass as test plant, showed that the yield decline with soil and P reaction periods and ceased at different time with different soils. For the neutral paddy soil ,the decline in yield ceased after 8 months' incubation, for fluvo-aquic soil, after 16 months, but for red earth the decline ceased after more than 28 months. This may be due to different in extent of the formation reactions of P chelate ring structure and diffusing into the deeper layer under the surface of R2O3, and calcite in the soils. In neutral paddy soil this two reactions were weaker and led to higher available P remained after incubation period, while in acidic red soil and calcareous fulvo-acquic soil they were much more stronger especially in red soil, and lasting longer time.
出处
《土壤学报》
CAS
CSCD
北大核心
2000年第3期323-329,共7页
Acta Pedologica Sinica
基金
国家重点基金!49631010
关键词
红壤
养分退化
磷有效性
土壤磷素衰减
Phosphorus, Decline of phosphorus availability, Red earth
