耗竭条件下冬小麦的吸钾特点及其对土壤不同形态钾的利用  

THE PROPERTY OF POTASSIUM UPTAKE BY WINTER WHEAT AND THE UTILITY OF DIFFERENT POTASSIUM FRACTIONS OF SOILS AFTER DEPLETION

作　　者：杨振明[1] 王波[1] 鲍士旦[1] 史瑞和[1] 

机构地区：[1]南京农业大学资源与环境学院

出　　处：《植物营养与肥料学报》1998年第1期43-49,共7页Journal of Plant Nutrition and Fertilizers

基　　金：国家自然科学基金!39470408

摘　　要：在耗竭条件下研究了冬小麦在我国11种主要土壤上的吸钾特点及其对不同形态钾利用。结果表明，冬小麦对钾的吸收具有明显的阶段性。拔节至齐穗期为吸钾高峰，成熟后出现“排钾”现象。耗竭条件下冬小麦各生育期土壤交换性钾含量变化不大，而缓效性钾从开穗后开始回升。冬小麦吸收的钾中，交换性钾占的比例较小，11种土壤平均为21.5％;1mol／LHNO3不能提取的钾占绝大部分，平均为78.5％。表明土壤经耗竭后，1mol／LHNO3不能提取的钟对作物钾营养的作用较大。耗竭后土壤交换性钾“最低值”出现的时期及数量大小是土壤重要的供钾特性之一。Pot experiment was carried out to sdudy the property of K uptake by winter wheat and the utillty of different K fractions after 5 cropping depletion on 11 main soils of China. The results showed that K uptake by wlnter wheat was obviously different at different growing stages. The peak of K uptake appeared at the Jointing full heading stage, while at the mature stage the wheat showed excretion of K. The exchangeable K of soils were low and stable at all growing stages, but the slowly availiable K increased after full heading of wheat. Most of the K absorbed by wheat was from the nonextractable K wlth 1mol/L HNO3, averaging 78. 5%, and only small proportion from the exchangeable K, averaging 21. 5%. This indicated that the contribution of nonextractable K with 1mol/L HNO3 to plant nutrlent has incresed after exhausted cropping. The date when the lowest value of exchangable K appeared and the lowest value was an important property of soil K supplying.

关 键 词：耗竭 冬小麦 交换性钾 缓效性钾 吸钾特性 

分 类 号：S512.101[农业科学—作物学]