IMPACT OF A SOIL CONDITIONER ON SOME SELECTED CHEMICAL-PROPERTIES OF A CALCAREOUS SOIL

There is a paucity of information on the effects of gel-forming conditioners on soil chemical properties in arid and semiarid regions such as Saudi Arabia. We conducted a greenhouse pot experiment and examined the status of selected chemical properties of a calcareous sandy loam soil. The objective was to observe the effect of two irrigation intervals and a soil conditioner (Aquasorb) on selected soil chemical properties. Aquasorb at the rates of 0.0%, 0.2%, 0.4%, and 0.6% (by weight) was applied to the top 10 cm of soil in each pot. The treated and untreated soils were irrigated every 5 or 10 days and incubated for 45 days. There was no significant effect of the irrigation intervals on soil chemical properties after 45 days of incubation. Aquasorb application increased soil pH significantly, compared with the control in both soil layers (0-10 and 10-20 cm). Electrical conductivity was significantly higher in the upper soil layer of treated samples than the control and remained unchanged in the lower depth. Aquasorb application caused an increase in AB-DTPA-extractable Zn and a decrease in extractable Fe and Mn only in the upper soil layer. Extractable Cu, K, and P were not affected by Aquasorb application in either soil layer. These results indicate that application of gel-forming conditioner may have deleterious effects on some selected soil chemical properties.