Improving Soil Physical Indicators by Soil Amendment to a Saline-Sodic Soil

The application of organic amendments can be an appropriate solution to reclaim and improve physical properties of saline-sodic soils. In this research, an experiment was performed under greenhouse conditions to study the effect of amendments to the physical properties of loamy saline-sodic soil. The five treatments were control (without amendment), municipal solid waste compost (MC), vermicomposting (VC), poultry manure (PM), and gypsum powder (G). They were carried out in a completely randomized design with three replications. Each treatment comprised 10 ton/ha of the specified soil added to the soil. The results showed that soil amendments decreased bulk density (p<0.05) and increased mean weight diameter of aggregates (MWD) (p<0.05) over the control. The saturated hydraulic conductivity (Ks) for the G treatment was significantly higher than other treatments (p<0.05). The addition of amendments significantly increased the Sgi index, which is defined as the slope of the retention curve at its inflection point, but the Sgi index between the G and MC treatments was not significant (p<0.05). In addition, plant available water content (PAWC) increased significantly (p<0.05) for organic amendments over the G and control treatments, and a maximum value was observed for the PM treatment. The positive effects of the amendments showed that the application of organic and/or inorganic amendments can be recommended for saline-sodic soil to improve soil physical quality.