不同改良材料对滨海盐碱土盐分淋溶特征的影响

通过室内土柱模拟试验,研究添加木醋液(稀释400倍,用量200 mL)、粉煤灰(10%土壤体积分数)和园林废弃物堆肥(4%土壤质量分数)对盐碱化土壤盐分淋溶的影响,分析土壤淋溶液和淋溶后土壤的电导率(EC)值、pH值,及水溶性离子(K⁺、Na⁺、Ca²⁺、Mg²⁺、Cl^-、SO^2-₄、CO^2-₃、HCO^-₃)的变化特征。结果显示:以淋溶液EC值低于2 mS·cm^-1为标准,相比对照(CK),添加木醋液、粉煤灰、园林废弃物堆肥分别可使淋溶时间缩短6、12、2 d,加速水溶性离子的淋溶。添加粉煤灰淋溶后,土壤pH值、EC值均较CK显著(P<0.05)降低;添加木醋液、园林废弃物堆肥淋溶后,土壤pH值较CK显著(P<0.05)降低,而土壤EC值显著(P<0.05)升高。综合考虑,试验条件下,以添加粉煤灰对促进盐分离子淋溶的效果最好。

Effects of different materials on leaching characteristics of salinity in coastal saline-alkali soil

In the present study, the effect of addition of wood vinegar (diluted 400 time, 200 mL), fly ash (soil volume fraction of 10%) and garden waste compost (soil mass fraction of 4%) on leaching characteristics of salinity in coastal saline-alkali soil were examined via soil column experiment. The changes of electrical conductivity (EC), pH and water-soluble ions (K⁺, Na⁺, Ca²⁺, Mg²⁺, Cl^-, SO^2-₄、CO^2-₃、HCO^-₃) in the leaching solution and soil after leaching were determined. It was shown that, compared with CK, addition of wood vinegar, fly ash and garden waste compost could increase the leaching of water-soluble ions and reduce the time consumption by 6, 12, 2 d, respectively, when the EC of leaching solution was reduced to 2 mS·cm^-1 and below. With addition of fly ash, the soil pH and EC in soil were significantly (P<0.05) decreased after leaching. However, with addition of wood vinegar or garden waste compost, the soil pH was significantly (P<0.05) decreased, yet soil EC was significantly (P<0.05) increased after leaching. Therefore, under the experiment conditions, addition of fly ash showed the best promotion effect on salinity leaching.