چکیده:
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.
خلاصه ماشینی:
Fotovata a Soil Science Department, College of Agriculture, Ferdowsi University of Mashhad, Mashhad, Iran Received: 25 February 2013; Received in revised form: 2 July 2013; Accepted: 16 September 2013 Abstract The application of organic amendments can be an appropriate solution to reclaim and improve physical properties of saline-sodic soils.
ir agricultural soils are relative field capacity, plant available water content (PAWC), aeration porosity, bulk density, organic carbon content, and the structural stability index (SI) (Reynolds and Topp, 2008).
Similarly, the physical properties of the amended soils (saturated and unsaturated hydraulic conductivity, water retention capacity, bulk density, total porosity, pore size distribution, soil resistance to penetration, aggregation and aggregate stability) improved (Aggelides and Londra, 2000).
Increasing the Sgi index, PAWC, MWD of the aggregates, and decreasing bulk density by the application of G and municipal solid waste compost was also reported by Emami and Astaraei (2012).
At the end of experiment, saturated hydraulic conductivity (Ks) was measured using a single ring using the Beerkan method and constant head (Lassabatere et al, 2006), the MWD of the aggregates using the wetting method (Kemper and Rosenau, 1986), bulk density using the clods method (Blake and Hartge, 1986), and water dispersible clay using the method described by Rengasamy (1984).
Effect of soil amendments on PAWC The application of organic matter increased PAWC significantly (p&lt;0.
Effect of organic and inorganic amendments on parameters of water retention curve, bulk density and aggregate diameter of a saline-sodic soil.