EFFECT OF AMENDMENTS ON SOIL MOISTURE, SALINITY, Cl- CONTENT, SAR, AND K+/Na+ RATIO

Application amendments to saline-alkaline soils is considered to be a good practice for soil remediation. The effects of different amendments (e.g., biochar soil amendment, microorganism agents, polyacrylamide) on saline soils were investigated under a wheat-maize rotation system from 2017 to 2018 in Binzhou, Shandong Province, China. The field experiment was conducted with four soil treatments: control (CK), biochar soil amendment (BSA), polyacrylamide (PAM) and microorganism agents (MA). Surface soil (0-20 cm) moisture increased consistently under various amendment treatments compared with CK during crops growing season, especially under BSA treatment. The effect of amendments on subsoil (20-60 cm) moisture was not significant. Simultaneously, soil amendment remarkably reduced soil salinity at the 0-60 cm depth during wheat growing season especially under BSA treatment. During maize growing season, surface soil (0-20 cm) salinity decreased. Surface soil (0-20 cm) salt content was the lowest under PAM treatment, but the salt content in deeper soil (20-60 cm) changed little. Furthermore, amendments significantly reduced Cl- content and sodium adsorption ratio (SAR), and increased K+/Na+ ratio. Soil moisture content was higher and salinity content was lower during maize growth season compared with those during wheat growth season. As a result, application of BSA, among the three amendments, produced the best effects. Therefore, it can be recommended for wide application in similar saline-alkali soil conditions.