盐性大白土淋溶洗盐技术研究

Studies on the Sprinkling and Washing Techniques of Salty Soil

对兰州市东郊大沙沟13km处的氯化物盐性大白土,采用微区试验和土柱模拟的方法进行淋溶洗盐试验研究,结果表明:兰州地区用黄河水对土壤容重为950kg/m3、全盐含量为0.497%的氯化物盐性大白土淋溶冲洗,在不计蒸发量和降水量的情况下,达标土层厚度60cm,每m3的冲洗灌水定额为0.414m3,达标土层厚度100cm,每m3的冲洗灌水定额为0.517m3;添加不同土壤改良剂可有效提高洗盐效率,缩短洗盐周期;盐性大白土经黄河水淋溶洗盐后,pH略有下降,脱去盐离子以Cl-、SO2-4、Na+、K+等可溶性强的离子为主。

The salt leaching experiment was carried out on the improvement of chloide solonchak occurring in the eastern suburb of Lanzhou City by small area test and earth column imitation test. The results showed that the salty soil with a density of 950 kg/m^2 and salt content of 0.497% could be improved by bleaching with the water from Yellow River. Water requirement for the 60 cm deep salt layer up the standard was 0.414 m^3,and 0.517 m^3 for the 100 cm deep soil layer ignoring natural evaporation and rainfall. The effectiency of salt bteaching could be improved by adding different salt modifers to shorten bleaching. Soil pH decreased slightly, after bleaching and the removed ions were mainly Cl^- 、SO^(2-)_4 、Na^+ 、K^+ etc with high salability.