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作 者 ：杨振明;王波;鲍士旦;史瑞和

期 刊 ：植物营养与肥料学报 1998年 4卷 1期 页码：43-49

关键词：耗竭；冬小麦；交换性钾；缓效性钾；1mol／L；HNO3不能提取的钾；

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。

Abstract: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.

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