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This article reviews research findings on the application of petroleum-based mulches as an effective method for stabilizing shifting sands in Iran’s arid regions. These mulches form a surface layer that prevents wind erosion, conserves soil moisture, and promotes vegetation establishment. The paper highlights the benefits, challenges, and lessons learned from past sand dune stabilization projects using this technique.

This report, part of the 1973 FAO/UNDP Seminar, explores the distribution, properties, and stabilization efforts of sandy soils and sand dunes in Iran. It covers soil classifications, protective measures, and R&D projects such as petroleum mulching, mechanical windbreaks, and plantation of resilient species. Since 1959, Iran has made significant efforts to combat desertification and stabilize moving sand dunes in regions like Ahvaz, Sabzevar, and Qazvin.
Furthermore, in an official FAO report to the Government of Iran in 1971, the use of petroleum mulch was recommended, provided that the mulch layer can retain moisture and remain stable until full seed germination and seedling establishment.

This paper provides a comprehensive review of mulches used to control wind erosion. The study indicates that crop residues, chemical soil stabilizers, and livestock manure can effectively prevent wind erosion. To be effective, mulches must withstand wind speeds of 38 m/s. Vegetative mulches like wheat straw and prairie hay, when properly anchored to the soil surface, can significantly reduce erosion. Chemical stabilizers such as asphalt and latex emulsions are also effective when applied at sufficient volumes (minimum 3,785 L/ha). Additionally, feedlot manure proves to be a cost-effective mulch for erosion control. However, the high costs of some materials, particularly petroleum-based products, limit their widespread use.

The vigorous rise in the rate of population growth in the world, mostly in the developing countries, and the limitations on agricultural lands and products call for man to bring about a quest for new resources by the year 2000 in order to meets the various demands. The Khuzestan province is located in the south of Iran, which has an area of sandy plains exceeding 350,000 ha. This is in fact 3.5% of the entire state and 29.5% of the entire agricultural land of Khuzestan. The sand encroachment by wind over the agricultural lands, roads, pipelines and residential areas is a serious economic problem in this area. Sand dunes extend from the northwest to southeast of Ahwaz in the Khuzestan province, in the form of tapes. These include some sporadic expansions consisting of over 68 varieties. The two important sand dunes are those located in Albajy with an extent of about 9,000 ha; and that in the southwest of the Karkheh river of 115,000 ha. Research proves that afforestation offers a permanent solution for the sand dune area problem. Selection of a suitable plant species for this purpose is crucial for successful afforestation. As a result, four eucalyptus species were selected in further investigations. The samples of soil, climate, and ground water were collected and analyzed for several parameters using standard procedures. In this study, petroleum mulch is used for soil conservation, especially preventing wind erosion and also based on reserves of precipitation for plants species such as the eucalyptus. After more than 6 years of cultivating four eucalyptus species, the investigation conclusively demonstrated the Eucalyptus Camaldulensis 9616 as superior (adaptation and growth) to other species in the sand dunes of the Khuzestan province.

This study evaluated the effects of Iranian petroleum mulches (anionic, cationic, and clay emulsions) and the soil conditioner "Krilium Merloam" on evaporation reduction from calcareous soil under greenhouse conditions. Both surface and incorporation applications significantly decreased water evaporation, with the highest reduction (8.8%) observed at 10,000 L/ha (surface) and 0.25% (incorporation). Petroleum mulches formed a semi-impermeable vapor barrier and enhanced soil aggregation, restricting upward water flow. The findings suggest that Iranian petroleum mulches are effective alternatives for soil moisture conservation in arid regions.

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 effects of oil mulch on wind erosion control and soil properties in the Abu-Ghoveir area of Dehloran, Ilam. Following mulch application, soil samples were collected monthly over a year from three treatments (mulched, control, and afforestation) at two depths (0–10 cm and 10–50 cm). Soil parameters, including temperature, moisture, pH, electrical conductivity (EC), organic matter (OM), sodium (Na), and sodium adsorption ratio (SAR), were measured. Wind erosion threshold velocity was also determined using a wind tunnel. The findings revealed that oil mulch significantly influenced certain physical and chemical soil properties and effectively increased the threshold wind velocity. The optimal mulch application rate was estimated at 7 tons per hectare. Oil mulch application reduced evaporation, increased surface soil moisture, and provided a suitable substrate for the recovery of native vegetation in arid regions.

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.

The soil seed bank (SSB) is a valuable reservoir of seeds hidden in the soil, playing a crucial role in vegetation establishment under adverse environmental conditions. However, limited knowledge exists regarding the effects of restoration measures on SSB, particularly in arid ecosystems. This study examines the impacts of oil mulching (1 and 3 years after application) and plantations (15-year-old) on the diversity and composition of SSB and aboveground vegetation (AGV) compared to non-restored areas. The results indicate that species richness was low in the studied area (36 species from 16 families), with SSB contributing less than AGV (11 and 34 species, respectively). The highest number of exclusive species was observed in the plantation treatment, while the lowest was recorded in the 1-year mulching treatment. The diversity indices revealed that the highest values occurred in the plantation and 3-year mulching plots. Seed density was significantly greater in the plantation area compared to the other treatments. The analysis of plant composition demonstrated that the plantation treatment was distinct from other treatments, with the 3-year mulching site being the closest to it. These findings suggest a trade-off between the short-term and long-term effects of oil mulching, where initial negative impacts diminish over time, leading to positive ecological outcomes. Ultimately, oil mulching, in combination with afforestation, fosters a favorable microclimate, improving AGV and SSB diversity and composition.