施钾对两种土壤钾素动态变化影响的研究

采用盆栽试验 ,研究黄土和红土母质发育的褐土中和其上种植的谷子中钾的含量变化 .结果表明 :苗期谷子吸钾很少 ,土壤钾变化也较小 ,对照处理的速效钾和缓效钾均有所增加 ,施钾处理的速效钾有所减少 ,但缓效钾大幅度增加 .拔节期至抽穗期谷子吸钾能力大为增强 ,土壤中缓效钾和速效钾急剧下降 ,达到“最低值” .成熟期谷子根系吸钾能力减弱 ,土壤缓效钾和速效钾开始回升 .

Effect of applying K fertilizer on the dynamics of soil potassium

A pot experiment was conducted on red and white soils by using millet (Setaric L. Beauv) as an indicator. The soils and plants were sampled at different stages of growth. The dynamic characteristics of K in the soils and its relationship with K uptake by millet plant were studied in terms of direct observation and chemical analysis. (1)The amount of K uptake by root was insignificant and the soil readily available K content did vary greatly at the seeding stage, while the slowly available K content increased instead. (2)At the elongation and sprouting stages, the ability of K uptake by plant increased with the rapid decrease in soil readily available and slowly available K, which reached the "minimum".(3)At the later stage, the K amount taken up by root reduced, while the content of the two kinds of K in the soil gradually raised up in the red soil.