长期定位施肥对灰漠土钾素形态的影响

灰漠土钾素含量较高,主要是以矿物钾和难交换性固定钾的形式存在 ,占土壤全钾的 98.6;,水溶性钾和交换性钾含量较低仅占土壤全钾的1.2;左右.土壤中各种形态钾素之间紧密相关,土壤水溶性钾、交换性钾和非特殊吸附钾与土壤速效钾之间达显著相关,是植物易吸收利用的有效性钾,特殊吸附钾与土壤速效钾之间呈负相关关系,是土壤交换性钾中植物不能直接吸收利用的钾.长期定位施肥改变了土壤钾素存在形态,配施有机肥使土壤有效性钾含量增加24;～56;,并促进土壤特殊吸附钾转化为其它形态的钾; 施化肥钾使土壤水溶性钾含量平均增加35;,提高了土壤钾素的供应水平,同时加速了土壤特殊吸附钾的积累.

Effects of Long - term Located Fertilization on the Grey Desert Soil Potassium Forms

The content of potassium was very high in the desert soil.Mineral K and Non-exchangeable was its main form,which was 98.6% of total K.The content of water soluble K and exchangeable K were low,which was 1.2% of total K.Potassium forms in the soil had close correlation.Water soluble K,exchangeable K,specific absorbed K and available K in the soil had significant correlation,and the plant was easy to make use of them.There was negative correlation between specific absorbed kand and the plant could not absorb it directly in exchangeable K of soil.The combined application of organic manure could make the conteut of available K in the soil increase by 24%-56%,transform specific absorbed K into other form potassium in the treatments of organic manure.The content of water soluble K in the soil increased by 35%,K supply level was improved,and specific K accumulation in the soil was increased in the treatments of potassium fertilizer.