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.
出处
《植物营养与肥料学报》
CAS
CSCD
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
关键词
耗竭
冬小麦
交换性钾
缓效性钾
吸钾特性
Depletion Winter wheat Exchangeable K Slowly available K Nonextractable K with 1mol/L HNO_3