水和离子在不同粒径团聚体的土柱中的移动

KINESIS OF WATER AND IQNS IN DIFFERENT SI2ED GRANULES OF SOIL COLUMN OF AGGREGATES

用重水(D_2O)和KC1作示踪剂,在间断灌水条件下,研究了D_2O和阴、阳离子在不同粒径土柱中的移动。结果表明,在同一粒径下,D_2O和C1^-在两种土壤中的分布相似。在<2mm团聚体的土柱中呈凸型分布,在2—5mm团聚体的土柱中呈自上而下逐渐减少的分布状态。团聚体粒径<2mm的草甸土,对C1-移动的影响表现为负吸附作用,火山性土则表现为吸附作用。粒径为2—5mm的火山性土和草甸土,对C1^-移动均表现为吸附作用。土壤大团聚体显著地降低了对K^+的吸附作用,很大程度上支配着土壤阳离子代换量。土壤大团聚体可以抑制施肥盐阴,阳离子的淋溶,有利于提高对肥料的利用。

In conditions of uninterrupted irrigation using D2O and KC1 as tracers, a study of the kinesis of D2O, anion and cation in the soil column was made.The result showed that when the same size granules are used, the distributions of D2O and Cl- in the two kinds of soil are very similar; when the soil aggregates are less than 2mm, the soil column assumes the convex distribution, but when the soil aggregates are 2-5mm,the soil column assumes a distribution of gradual reduction from upper to lower parts.The kinesis of Cl- influenced by meadow soil with granules of the aggregates less than 2mm shows negative adsorption, but that of the volcano ash soil shows positive adsorption The effect of volcano ash soil with granules of 2-5mm on the kinesis of Cl- is identical with that of meadow,Both of them show adsorption.The K+ adsorption power of the soil macro-aggregates was considerably reduced and the substitutional capacity of the negative ion was also governed by the soil macro-aggregates.The soil macro-aggregates can check the leaching of the cations and anions in fertilizer salt and are favourable to use of fertilizer.