Effects of zeolite on soil aggregation and certain physical properties

The development of the physical and chemical properties of the soil is not only essential for the sustainable agriculture but also for increasing the fertility and productivity of the soil. Despite the use of several organic and inorganic soil conditioners for this purpose, the investigations on the effects of zeolite on soil physical properties are very scarce. This laboratory study was carried out to determine the effects of zeolite (clinoptilolite) with different rates of 0%, 1%, 3% and 5% on soil aggregation and certain physical properties in soils with different textures (clay, loam and sandy loam). While zeolite application increased the rate of soil aggregates smaller than 6,4 mm, it decreased the rate of soil aggregates greater than 6,4 mm in Soils I and II. However, the effect of zeolite application on soil III, that had the highest sand content, showed different effects. While the rate of soil aggregates smaller than 12,7 mm showed decrease, aggregates greater than this fraction increased. Mean weight diameter of Soil I decreased from 9,24 mm to 5,06 mm with zeolite application. These values were obtained as 5,16 mm to 4,14 mm and 2,61 mm to 2,77 mm for Soils II and III, respectively. Zeolite applications significantly (p<0.05) increased aggregate stability of all the soils in all aggregate size fractions as compared to the controls. Dispersion ratio of soils amended with zeolite showed significant decreases. Whereas the aggregate stability of control was 26,64%, it increased to 43,51% with 5% zeolite application, which is almost 63% greater than that of control. While the dispersion ratio of control was 38,46%, it decreased to 30,20% with 5% zeolite application. Zeolite applications on all three soils significantly decreased bulk density and increased porosity and hydraulic conductivity. When means were compared it is seen that the control bulk density value (1,16 g/cm-3) decreased to 1,10, 1,08 and 1,06 g/cm-3 with 1%, 3% and 5% zeolite application, respectively. While the hydraulic conductivity was determined as 21.45 cm/h-1 in control, it was determined as 27,4, 30,51 and 38,37 cm/h-1 for 1%, 3% and 5% zeolite application rates, respectively. Results obtained in this study have shown that zeolite can be used as an amelioration material to improve soil physical properties.