ABSTRACT

Electrolytes have been verified as a vital internal factor controlling soil aggregate stability (SAS). Several reports have focused on whether potassium promotes or demotes SAS and have shown contradictory results in different soils and clay mineralogy. Only a few studies have investigated such an effect on a soil-plant system, even though this information is critical for soil management practices to maintain soil structural stability. This research studied the dynamics of SAS as influenced by potassium in a soil-plant system. Corn as a test plant was grown on Haplic Acrisols (Typic Paleustults) in a greenhouse. The potassium adsorption ratio (PAR), cation ratio of structural stability (CROSS), and SAS were recorded on the day before planting (day 0), the day of planting (day 1), days 10, 20, 30, and the day of harvesting (day 55) at the tasseling stage. The corn growth, biomass, and potassium uptake were also examined. The relationship between soil and plant parameters was statistically tested. The results showed the existence of SAS dynamics caused by soil potassium change, with agreement among the responses for PAR, CROSS, and plant uptake. Within 24 h of soil treatment with potassium, the SAS move rapidly from 74% to 96%. It remained steady at 96–97% when the corn was in the vegetative stage and then fell significantly (α = 0.05) to 88% when the corn was in the tasseling stage, where the potassium uptake was maximized. The results implied that SAS is a sensitive index of soil physical quality associated with potassium, especially for tropical kaolinitic soils.

摘要

电解质已被证实是控制土壤团聚体稳定性 (SAS) 的重要内部因素。一些报告集中在钾是促进还是降低 SAS 上，并在不同的土壤和粘土矿物学中显示出相互矛盾的结果。尽管这些信息对于保持土壤结构稳定性的土壤管理实践至关重要，但只有少数研究调查了这种对土壤-植物系统的影响。本研究研究了土壤-植物系统中钾对 SAS 的影响。在温室中的 Haplic Acrisols (Typic Paleustults) 上生长作为试验植物的玉米。在种植前一天（第 0 天）、种植当天（第 1 天）、第 10、20、30、以及在雄雄阶段的收获日（第 55 天）。还检查了玉米生长、生物量和钾吸收。对土壤和植物参数之间的关系进行了统计检验。结果表明存在由土壤钾变化引起的 SAS 动态，与 PAR、CROSS 和植物吸收的响应一致。在用钾处理土壤的 24 小时内，SAS 迅速从 74% 上升到 96%。玉米处于营养期时稳定在96-97%，然后显着下降（在用钾处理土壤的 24 小时内，SAS 迅速从 74% 上升到 96%。玉米处于营养期时稳定在96-97%，然后显着下降（在用钾处理土壤的 24 小时内，SAS 迅速从 74% 上升到 96%。玉米处于营养期时稳定在96-97%，然后显着下降（α  = 0.05) 到 88%，当玉米处于抽雄阶段时，钾的吸收量最大。结果表明，SAS 是与钾相关的土壤物理质量的敏感指标，尤其是对于热带高岭土。