枸溶性钾肥对作物生物量及作物–土壤系统钾素平衡的影响

Effects of Citrate-soluble Potassium Fertilizer on Crop Biomass and Potassium Balance in Crop-Soil System

通过盆栽试验研究了不同形态钾肥的施用对连续3季作物(油菜、油菜、水稻)生物量、钾素(K2O)吸收量、作物-土壤系统钾素平衡以及土壤速效钾和缓效钾含量的影响。研究结果表明,不同形态钾肥施用后,枸溶性钾硅肥(K枸)与水溶性钾肥(K水)效果一致,与不施钾相比,3季作物生物量都显著增加,钾素总吸收量增加155%,钾素平衡系数为0.79,钾素的供应缓解了土壤钾素亏缺,利于维持土壤钾素平衡;而粉碎性钾矿粉(K矿)钾素不能被作物充分吸收利用,增产效果不显著。第一季油菜收获后K枸、K水处理土壤速效钾、缓效钾含量显著高于K0、K矿,但随着作物的收获各处理间差异逐渐变小,最终趋于一致。枸溶性钾硅肥和水溶性钾肥均能补充土壤的有效钾素,缓解土壤钾素的消耗,维持土壤钾素肥力水平的稳定,有利于作物增产。

A pot experiment was conducted in order to study the effects of different forms of potassium fertilizer on the biomass of three successive crops （oilseed rape, oilseed rape, and rice）, potassium uptake, potassium balance and potassium content of soil. The results indicated that there were the same results between the treatments of citrate-soluble and water-soluble potassium fertilizer compare with K0 treatment （no potassium fertilizer）. They significantly increased the biomass of three crops. The total potassium accumulation amount of three crops increased by 155% compared with K0 treatment. The ratio of potassium balance was 0.79. They could ease the potassium deficit of soil which will contribute to maintain soil potassium balance. However, the treatment of comminuted potassium ores had not significantly effect on the increment of biomass and potassium accumulation amount compared with K0 treatment. The potassium existed in the comminuted potassium ores was difficult to be absorbed by crops. The treatments of citrate-soluble and water-soluble potassium fertilizer had higher soil available K and slowly available K than the others after the first season harvest. Whereas, the differences among the treatments became smaller with three seasons harvest. Therefore, citrate-soluble potassium fertilizer which had the same effect compared with water-soluble potassium fertilizer, can be supplied into soil, increase crop biomass, ease the consumption of potassium and sustain soil potassium balance.