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

Document Type : Research Paper


Soil Science Department, College of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran


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.