The use of pore volume characteristics and soil moisture release curve to determine physical quality of soils with different gypsum contents

Abstract

A newly proposed concept of soil physical quality and its development as a guide to assess the extent of soil degradation or improvement and to determine appropriate soil management. The study aimed to: evaluate the soil physical quality index of gypsiferous soils under different management systems as well as determine the optimal pore size distribution and the optimum moisture-tension curve based on the quality of the physical soil properties under different management systems and diagnose the distribution of pore sizes and moisture-tension curves that could be used to predict the changes in the physical quality of gypsiferous soils because of the applied agricultural management pattern. Physical indicators measured on undisturbed soil samples collected from 15 selected sites in Salah Aldeen Governorate, with different gypsum content (30 to 301 g kg-1 soil). The results showed that the best distribution of measured pore size (h) S *, (Normalized pore volume) was for a group of soils that were largely similar in terms of shape and location parameters. Accordingly, the optimal pore distribution considered representative of these soils. The results showed the possibility of using the (Dexter-S) indicator correctly and in coordination with the distribution of pore size and the soil moisture characteristic curve to calculate the physical soil quality in soils of different gypsum content. Corresponding author: E-mail(wa.alkayssi@tu.edu.iq) Al- Muthanna University All rights reserved