EVALUATION OVERLAP THE SOIL TILTH AND AGRICULTURAL PRODUCTIVITY WITHIN PHYSIOGRAPHIC UNITS VARIED IN THE EUPHRATES PLAIN

Abstract

Soil tilth is one of the key indicators reflecting soil viability for agricultural use. It results from the interaction of morphological properties such as texture, structure, and consistency, which are influenced by geographic location, climate, and physiographic setting. This study aimed to evaluate the interaction between morphological tilth and agricultural productivity across diverse physiographic environments in the Euphrates Plain within Al-Anbar Governorate. The research focused on analyzing major morphological characteristics (color, structure, consistency, and horizon depth) and linking them with both soil tilth indices under wet and dry conditions and a soil productivity index. Fieldwork was conducted on 32 agricultural sites distributed across five physiographic units: high basins, low basins, river levees, river meanders, and river breaks. The Dickinson method was used to estimate soil tilth, while Ranst’s formula was applied to calculate productivity. Results showed a strong positive correlation between wet-condition tilth and agricultural productivity, especially in river levees and meander zones, which recorded the highest values. In contrast, tilth and productivity values were lower in low basins and poorly drained areas. GIS-based spatial analysis revealed a significant overlap between soil tilth distribution and productivity patterns. The study concluded that positive interaction between morphological traits and tilth enhances soil performance and can be adopted as a preliminary diagnostic tool to determine the suitability of lands for sustainable agriculture across varying physiographic settings.