酸性土壤上肥田萝卜和小麦对低品位磷矿粉的吸收差异

根据对肥田萝卜和小麦生长于不同P处理下的网膜分隔三室及二室模拟栽培系统的试验,分析了肥田萝卜和小麦对酸性土壤上低品位磷矿粉不同处理的吸收效果。结果表明,肥田萝卜对磷矿粉的吸收受到根系活动范围的限制,它可以有效利用施在根室区的低品位磷矿粉,干物重增加幅度达233%,比对照有极显着的提高;不论根室区是否施磷矿粉,肥田萝卜对于施在外室区(与根室区用网膜相隔)的低品位磷矿粉都具有微弱的利用能力,认为这是少量渗入到外室的根分泌的有机酸的活化作用。不过肥田萝卜对这一部分P的利用量不足以显着提高植株的干物重;小麦对于施在根室或外室区的低品位磷矿粉均不能有效利用.

Difference in P uptake from low-grade rock phosphate by radish and wheat on acid soil

Based on the simulating cultivation experiments with three and two seperated compartments, the uptake effect of low grade rock phosphate by radish ( Raphanus sativus ) and wheat ( Triticum aestivum ) was analyzed. The P uptake by radish was restricted by the range of its root action. Radish could efficiently utilize rock phosphate in root compartment, and its dry weight was increased by 23.3%. Whether the rock phosphate was applied in root compartment or not, radish could only slightly utilize the rock phosphate applied in outer compartment, suggesting that it was activated by the small amount of organic acids infiltrating into outer compartment. This small part of phosphate utilized by radish could not obviously increase its dry weight. Wheat could not efficiently utilize low grade rock phosphate, whether it was applied to root compartment or outer compartment.