钾镁供应浓度及比例对温室土壤K-Mg吸附特性的影响

Effects of Concentrations and Ratios of K^+ and Mg^(2+) ions on Their Adsorption to Soils Under Sunlight Greenhouse Cultivation

不同钾、镁浓度及摩尔比供应对大田及温室土壤K+,Mg2+离子吸附特性影响的研究结果表明:大田及温室土壤对K+,Mg2+离子的吸附量均随其供应浓度和比例的增加而增加,日光温室栽培下土壤对K+的吸附量显著小于大田土壤;K+/Mg2+为2∶1时不同土壤对Mg2+离子吸附量的差异均较小,K+/Mg2+为1∶1时,温室塿土Mg2+的吸附量低于大田土壤,而潮土温室和相应大田土壤间的差异较小;随供应的K+浓度和比例升高,土壤对Mg2+离子的吸附量显著降低。随K+,Mg2+离子浓度提高,大田土壤K+吸附率均呈对数趋势下降,而温室土壤K+吸附率呈对数趋势增加;不同K+/Mg2+对大田土壤K+吸附率影响较小,而温室土壤在K+/Mg2+大时K+吸附率较大;不同土壤对Mg2+的吸附率随K+,Mg2+离子浓度变化未表现明显的规律性。随着K+,Mg2+离子总浓度的增加,土壤中Ca2+离子的解析量呈直线增加,不同K+/Mg2+对Ca2+离子解析量影响的差异较小,温室土壤Ca2+离子解析量大于大田土壤。

This paper had studied the effects of different concentrations and ratios of K^＋ and Mg^2＋ ions on the adsorptions of K^＋ and Mg^2＋ ions by soils under sunlight greenhouse and field crop cultivation patterns. The amounts of K^＋ and Mg^2＋ ions adsorbed by soils under both sunlight greenhouse and field crop cultivation were increased as the increasing supply of K^＋ and Mg^2＋ ion concentrations. The amounts of K^＋ ions adsorbed by sunlight greenhouse soils was significantly lower than that of field crop soil. When the ratio of K^＋ and Mg^2＋ ions was 2 ： 1, there was no difference between the amounts of Mg^2＋ ions adsorbed by sunlight greenhouse and field crop soil; when the ratio of K^＋ and Mg^2＋ ions was 1 ： 1, Mg^2＋ ions adsorbed by anthrosols under sunlight greenhouse cultivation was lower than that under field crop cultivation; for the fluvoaquic soil, the difference of Mg^2＋ ions adsorbed by soil under sunlight greenhouse cultivation and field crop cultivation was not significant; Mg^2＋ ions adsorbed by soils were significantly decreased as the increases of K^＋ ion concentration and its ratio in solution. As the increasing concentration of K^＋ and Mg^2＋ ions in solution, the rate of K^＋ ion adsorption by field crop soil declined in exponential pattern; on the contrary, the rate of K^＋ ion adsorption by sunlight greenhouse soil increase in exponential pattern. The ratio of K^＋ and Mg^2＋ ions had not significant effects on KZ^＋ ion adsorption rate by field crop soil; when ratio of K^＋ and Mg^2＋ ions was increased, the rate of K^＋ ion adsorption by greenhouse soil was also increased. As the increasing concentration of K^＋ and Mg^2＋ ions in solution, the rate of Mg^2＋ ion adsorption by different soils remained unstable. Increasing the concentration of K^＋ and Mg^2＋ ions in solution significantly increased the desorption of Ca^2＋ ions irom soil into solution; the Ca^2＋ ions desorbed from soils under sunlight greenhouse cultivation were higher than that from soil under field crop cultivation; and the ratio of K^＋ and Mg^2＋ ions had not significant effects on Ca^2＋ ions desorbed from the soil.