Blogs

This article investigates the effects of petroleum mulch on vegetation and soil in the sandy deserts of Samad Abad, Sarakhs, in Khorasan Razavi province. Petroleum mulch is a common method for stabilizing mobile sands in Iran, but its effects on vegetation and soil have been less studied. In this research, sampling was conducted in both mulched and control areas to assess vegetation cover and soil attributes. The results showed that while there was no significant difference in total vegetation cover and the density of dominant species such as Astragalus squarosus and Convolvolus hamadae between the mulched and control areas, the total volume and green matter of plants were significantly higher in the mulched area. Additionally, the organic matter content in the soil at a depth of 20-80 cm was significantly higher in the mulched area compared to the control. These findings suggest that petroleum mulch can improve plant growth conditions and increase soil organic matter.

This article compares the effects of oil mulch, non-oil mulch (such as Chinese mulch made from recycled plastics), and moisture absorbent materials (from Belgium and France) on the germination of four plant species (Calligonum comosum, Cyperus conglomeratus, Smirnovia iranica, Haloxylon aphyllum) and the stabilization of shifting sands in desert areas. The results show that oil mulch has a significant impact on germination at 1% and 5% levels, outperforming other methods due to its resistance to regional winds, which minimizes seed displacement.

The study used a split-plot statistical design, and data were analyzed using SAS software. The findings indicate that oil mulch is the best option for creating a germination-friendly environment under natural conditions (considering rainfall and wind patterns). Additionally, seeds of Haloxylon and Smirnovia showed the highest germination rates.

Recommendations include further investigation into the use of moisture absorbent materials for stabilizing potted seedlings, increasing the concentration of Chinese mulch to enhance its effectiveness, and documenting the impact of oil mulch during the seed establishment phase.

The November 1979 issue of National Geographic highlights Iran’s use of oil-based mulch to stabilize shifting sand dunes near Ahvaz. This method reduced sandstorms and enabled reforestation in the desert.

This study investigates the long-term effects of oil mulch on biodiversity indices of soil macrofauna and vegetation in the Jask region. Results indicate that oil mulch significantly increases the richness and diversity of soil macrofauna but has no significant impact on plant diversity after 10 to 14 years.

This study evaluates the effects of using petroleum mulch for sand dune stabilization and the potential soil contamination by Polycyclic Aromatic Hydrocarbons (PAHs). Petroleum mulch, produced from heavy petroleum residues, has been widely used in Iran to combat desertification. Soil samples were collected from various regions in three provinces: Khuzestan, Kerman, and Sistan. The PAHs content in soils beneath the mulch layer and in control (non-mulched) sites was measured. The results indicated that the levels of PAHs, particularly Benzo(a)pyrene (BaP), in soils beneath the mulch layer were below the permissible limits set by national standards. Additionally, the penetration of these compounds into the soil depth was minimal, decreasing to 1/40 of the initial amount after several years. Therefore, petroleum mulch and the contaminated soils are considered safe materials.