This study compared the effects of three mulches (petroleum, sand, and pine straw) on eucalyptus seedbeds. The petroleum mulch, a water-based petroleum emulsion, outperformed pine straw and native sand in warming the soil and preventing erosion but showed no significant difference in reducing evaporation or nutrient leaching. Applying white sand over the petroleum mulch lowered soil temperatures but proved unstable under rain and irrigation. The findings suggest that petroleum mulch can effectively replace pine straw, while native sand mulch performed poorly.

This study investigates the long-term effects (5, 20, and 40 years) of petroleum mulching and biological fixation (PM-BF) on the chemical, physical, and mineralogical characteristics of stabilized sand dunes in Khuzestan Province, Iran. The results revealed that PM-BF significantly improved vegetation cover and enhanced soil properties such as organic matter, cation exchange capacity, clay content, and electrical conductivity. However, petroleum mulch introduced heavy metals (Ni, Cd, Pb), which peaked in younger PM-BF regions but gradually decreased over time due to leaching. Dust fallout also contributed to the formation of specific clay minerals such as palygorskite and smectite. Although PM-BF supports ecosystem recovery and reduces dust-related impacts, the potential accumulation of toxic metals raises concerns for agricultural and environmental uses.