吉林省不同区域黑土供钾能力研究

Study on the Capability of Releasing Potassium in Several Phaeozem in Jilin Province

选取吉林省4个不同区域的黑土，设置施钾肥和不施钾肥2种处理，通过连续种植黑麦草（耗竭试验）来观察黑土的供钾能力。结果表明：供试土壤中速效钾的动态变化特征各异，其“最低值”的大小和出现的茬数也不相同。速效钾最低值的变幅为33-40 mg/kg，4号土壤速效钾含量降低的幅度最大，种植到第4茬时已经降低到原含量的8.96%，出现的茬数也较早。土壤中缓效钾下降幅度低于速效钾，“最低值”的变幅为527.87-824.28 mg/kg，出现的茬数最早在第4茬，最晚在第7茬。从植物的吸钾动态特征来看，速效钾对首茬植物的总吸钾量贡献最大，其次是缓效钾，但随着种植茬数的增加，缓效钾和矿物钾的贡献率逐渐升高。试验中在计算黑麦草的吸钾量时，将缓效钾和矿物钾区分开，并分析了速效性钾、缓效钾及矿物钾对植物的有效性。

Four phaeozem were selected at different areas from Jilin province and two treatments of using and non-using potassium were applied. The aim was to research the capability of supplying K in phaezem by successive planting Lolium perenne. The result showed that the change of available K was different in different soils. The minimum of available K and the time it appeared were also different, The range of minimum was 33-40 mg/kg. For No. 4 soil , its available K reduced rapidly and fell to 8.96 % when the plant harvested at the fourth times which was earlier than other soils. Non-exchangeable K decreased more slowly than available K and its minimum ranged from 527.87 mg/kg to 824.28 mg/kg. The earliest mini, mum appeared at the fourth harvest and the latest at the seventh harvest. For the content of K in the first harvest . the contribution of available K was the biggest and non-exchangeable K was bigger. But as the number of harvest increased, the contribution of non-exchangeable K and mineral K increased. The majority of K absorbed by plant originated from non-exchangeable K and mineral K. In addition, the experiment separated non-exchangeable K from mineral K and calculated the contribution of available K, non- exchangeable K and mineral K separately.