Biochar and Gypsum Synergy for Restoring Degraded Desert Soils and Enhancing Lettuce Productivity in Western Iraq

Abstract

In a field study carried out on desert soil in the Tash area of Anbar Governorate during the cultivation of the lettuce crop in the autumn season of 2025, the effect of adding different levels of biochar (0, 5, 10 tons/hectare) and agricultural gypsum (0, 2, 4 tons/hectare) was tested according to the design of the complete random sectors with three repeaters, to enhance soil properties The results showed moral differences between the parameters at the level of 0.05, as the additions led to a decrease in the apparent density, salinity and the ratio of mutual sodium, and a high porosity, cohesion, organic matter, cation exchange capacity and concentration of nutrients (nitrogen, phosphorus and potassium), due to the carbon-rich porous structure in biochar and its role in nutrient reservation and preventing them, in addition to the role of calcium in agricultural plaster in the cohesion of molecules, reducing their separation and improving ionic balance. The combined treatment (10 tons of bio-coal + 4 tons of gypsum) recorded the best values in most qualities and the highest productivity of lettuce, confirming that the integrated use of these improvers is an effective means of reclaiming dry and semi-arid desert lands and achieving agricultural sustainability.