Effect of Date Residues and Organic Acids on Some Physical Properties of Gypsiferous Soil

Abstract

A laboratory experiment was carried out at the College of Agriculture, University of Anbar, located at 43°20‘09.7“E longitude, 33°25‘36.7“N latitude for the period from 1/10/2021 to 1/10/2022, to study the effect of date residues, organic acids, and wetting / drying cycles on some physical properties of gypsiferous soil. The soil was selected from the site of the Fallujah palm station that located at longitude 43º51'. 05. 36 E. and latitude 33º17'. 46. 82‘N., date residues were added in three levels, without addition (comparison treatment), 0.1% and 0.2% mixed with soil. Organic acids was added at 0% and 0.1% and packaged in plastic cylinders and the treatments were exposed for two levels of wetting and drying cycles (6 and 8) cycles. The stability of aggregates, dispersion ratio, saturated hydraulic conductivity, and cumulative infiltration were measured. The results showed that the addition of date residues by 0.2% improved all the physical properties. Aggregates stability values increased by 13.41% and saturated hydraulic conductivity values decreased, which reached 4.33 cm.h-1. Accumulator infiltration up to 24.01cm and the capillary height reached to 40.0 cm, while the dispersion rate decreased to 37. 27%. The aggregates stability increased and the dispersion ratio, water conductivity and infiltration decreased by adding organic acids when their averages reached 12.12%, 40.77%, 5.19 cm-1 and 21.41cm, respectively. Increasing the number of wetting / drying cycles negatively affected most of the studied properties, as the dispersion ratio increased to 42.08%, and the cumulative infiltration decreased to 21.73 cm.