几种常用绿地改良材料对土壤水分特征的影响

Effects of Modified Materials Commonly Used on Green Belt on Soil Water Characteristic

分析了几种常用绿地土壤改良材料及其不同配比对土壤水分特征曲线和水分常数的影响,结果表明:利用RETC软件对各配比土壤水分特征曲线van Genuchten方程的参数拟合效果较好,R2均大于0.99;随着砂粒含量的增加,土壤田间持水量降低,土壤中水分有效性比例增加,但砂粒粒径对土壤水分常数影响不显著;绿化植物废弃物能提高土壤田间持水量和有效水含量,降低土壤凋萎含水量;绿化植物废弃物还能提高有效水占田间持水量的比例,以20%绿化植物废弃物的用量为最大,为49.59%;聚丙烯酰胺(PAM)虽然能提高土壤田间持水量,但阻碍土壤水分的释放,降低土壤水分的有效性;脱硫石膏可以增加土壤田间持水量和水分的有效性。综合而言,以70%土、10%砂、20%绿化植物废弃物和0.5 kg/m^3脱硫石膏的配比相对最佳。

The analyses on water characteristic curves and water constants of soils made from several common modified materials with different ratios showed that RETC software well simulated the parameters of van Genuchten equation for water characteristic curves （all R2〉0.99）. Soil field water capacity reduced but soil water availability increased with the increase of sand content. Sand grain size influenced soil moisture constant insignificantly. The greenery waste increased soil field water capacity and available water content, but decreased wilting water content. The greenery waste increased the proportion of available water in field water capacity, which reached to highest （49.59%） in soils with 20% proportion of greenery waste. Although PAM increased soil field water capacity, it inhibited the release of soil water, thus reduced the effectiveness of soil water. In addition, desulfurization gypsum increased soil field water capacity and soil water effectiveness. In general, the best soil was composed with 70% soil, 10% sand, 20% greenery waste and 0.5 kg/m3 desulfurization gypsum in volume.