籽粒苋根际土壤及根系分泌物对矿物态钾的活化作用

通过大田和模拟试验等方法 ,研究了籽粒苋根际土壤及根系分泌物对矿物态钾的活化作用 ,研究结果表明 :(1)籽粒苋根际土壤的速效钾含量较非根际土增加了 1.7倍 ,缓效钾 (K)的含量也提高了 5 5 .9% ;(2 )用籽粒苋根际土壤处理后的花岗岩粉末 ,其速效钾和缓效钾含量均较对照有所增加 ,增幅分别为 2 .8%～ 2 4.7%和 15 .7%～ 44 .7% ;用籽粒苋根际土壤处理后的紫色土 ,其速效钾和缓效钾含量较对照分别增加了 18.5 %和 11.1% ;(3 )通过对y值的综合贡献率计算可知 ,不同籽粒苋模拟根系分泌物对花岗岩粉末中矿物态钾的活化能力大小依次为 :草酸 >蔗糖 >核酸 >乳酸 >柠檬酸。

Mineral Potassium Activation in Rhizospere Soils and Root Exudates of Grain Amaranth

There was a correlation for the capability of potassium enrichment between root exudates of grain amaranth and activation of mineral potassium.The results of experiment showed: (1) There was a strong activation of mineral potassium in rhizosphere soils of grain amaranth.The available potassium contents in rhizosphere soils of grain amaranth were 1.7 times of those of none-rhizosphere soils and the exchangeable potassium was 55.9% higher than that of none-rhizosphere soils. (2)To be treated by root exudates,the available and exchangeable potassium were increased by 2.8% to 24.7% and 15.7% to 44.7% respectively in granite powder, and were increased 18.5% and 11.1% respectively in purple soil. (3)By analyzing experimental data with MSTATC software , the integration contribution ratio of y value showed that the ability of activation of mineral potassium in granite powder by the root exudates was in the order:oxalic acid>sucrose>nucleic acid >lactic acid>citric acid.