定位施钾对紫色土钾素形态在土层中分布的影响

EFFECTS OF K APPLICATION AT SET LOCATIONS ON THE DISTRIBUTION OF VARIOUS K FORMS IN DIFFERENT LAYERS OF PURPLE SOIL

采用化学形态分析方法 ,研究了稻麦水旱轮作制中 ,多年定位施钾对紫色土钾素形态土层分布的影响。结果表明 :经 8年 16季稻麦轮作后 ,土壤全钾含量 0cm～ 2 0cm土层与 2 0cm～ 40cm土层基本持平。土壤水溶性钾、非特殊吸附态钾、特殊吸附态钾、非交换性钾含量呈现 0cm～ 2 0cm土层高于 2 0cm～ 40cm土层的分布特点。

At the National Monitoring Center for Soil Fertility and Fertilizer Efficiency in Southwest Agricultural University,long-term application of K fertilizer at set locations was practised in a rice-wheat rotation system. It was shown that after 8 years' rice-wheat rotation (16 crops),total K in the top soil (0cm～20 cm layer) was almost equal to that in the subsoil(20cm～40cm layer),and the contents of water soluble K,non-specifically adsorbed K and specifically adsorbed K were higher in the surface soil than in the subsoil.Long-term top dressing of K fertilizer helped the formation of the characteristic distribution of K in the purple soil.