Document Type : Research Paper

Authors

• Zahra Abbasnasab ¹
• navazollah moradi ²
• Yahya Esmaeilpour ³
• Hamid Gholami ⁴
• Mehdi Biniaz ²

¹ PhD Student of Desert Control Management, Department of Natural Resources Engineering, Faculty of Natural Resources and Agriculture, University of Hormozgan, Bandar Abbas, Iran.

² Assistant Professor, Department of Natural Resources Engineering, Faculty of Natural Resources and Agriculture, University of Hormozgan, Bandar Abbas, Iran.

³ Associate Professor, D6epartment of Natural Resources Engineering, Faculty of Natural Resources and Agriculture, University of Hormozgan, Bandar Abbas, Iran

⁴ Professor, Department of Natural Resources Engineering, Faculty of Natural Resources and Agriculture, University of Hormozgan, Bandar Abbas, Iran

Abstract

Background and Objectives
Applying organic and eco-friendly additives for soil protection and wind erosion control offers an economical and practical solution. Among these, nanoparticles have emerged as an effective soil stabilization method. Chitosan, a natural, non-toxic, and biodegradable polymer, shows promise for mitigating wind erosion, and its composites have attracted considerable research interest. In Iran, large quantities of agricultural waste are generated daily, and their uncontrolled release into the environment not only represents a waste of resources but also contributes to pollution. Converting this waste into biochar presents an optimal strategy for enhancing environmental protection. This study evaluates the efficacy of four bio-amendments: (1) nanobiochar from palm tree stems (NBS), (2) nanobiochar from date palm kernels (NBK), (3) a chitosan-biochar composite from palm stems (ComS), and (4) a chitosan-biochar composite from date kernels (ComK), applied at three levels (0%, 1%, and 2% by weight). Their effects on key soil aggregate stability indicators were assessed.
Materials and Methods
Four amendment materials were produced: nano-biochar from palm stems, nano-biochar from date kernels, chitosan-nano-biochar stem composite (ComS), and chitosan-date kernel composite (ComK). Palm biomass residues (stems and kernels) were collected from Minab villages and ground and pyrolyzed at 300–350°C for 3.5 hours. The resulting biochar was converted into nano-biochar using a planetary ball mill. Chitosan was extracted from shrimp shells obtained from Bandar Tiab’s shrimp farms. The chitosan-nano-biochar composite was synthesized using acetic acid and NaOH solutions in laboratory conditions at Hormozgan University. For the experiment, each amendment was mixed with sandy soil at 0%, 1%, and 2% (w/w) in a completely randomized design with three replicates. The treated soils were maintained in plastic pots under greenhouse conditions (field capacity and 50% moisture) for 90 days. Post-incubation, soil samples were analyzed for physical and chemical properties at Hormozgan University’s Soil and Water Laboratory. Data were analyzed using R software (v3.2.2), with mean comparisons performed via Tukey’s HSD test (p < 0.05), and graphs were plotted in Excel.
Results
The study utilized a sandy-textured soil with near-neutral pH and salinity (15.04 dS/m), where date kernels showed higher carbon and volatile content but lower moisture and ash compared to palm stems. All amendment materials significantly (p < 0.05) improved soil properties, though effects varied by material type and application rate. Specifically, all treatments increased soil pH, aggregate stability, mean weight diameter (MWD) of dry aggregates, and clay-silt dispersion ratio while reducing bulk density and electrical conductivity (EC). Date kernel-derived amendments (NBK, ComK) at higher application rates (2%) were particularly effective, decreasing EC by 18-22% and bulk density by 12-15% while increasing aggregate stability by 30-35% and MWD by 25-28%. In contrast, palm stem-derived amendments (NBS, ComS) showed mixed effects - while increasing MWD by 15-18%, they reduced aggregate stability by 8-10% and increased bulk density by 5-7% at higher application rates. The chitosan-biochar composites demonstrated superior performance compared to nano-biochar alone, with ComK showing the most balanced improvement across all measured parameters. These findings confirm that both nanoscale amendments and organic polymers can effectively modify the physical and chemical properties of erosion-prone soils, with material source and application rate being critical factors determining their efficacy.
Conclusion
All tested amendments enhanced soil quality, underscoring their potential for wind erosion mitigation. Improving soil physicochemical properties is critical for sustainable land management and dust storm control. Implementing technical and management strategies to optimize these amendments could significantly reduce wind erosion, addressing the pressing challenge of dust storms.

Keywords

• Soil amendments
• biochar
• chitosan
• wind erosion
• aggregate stability
• sustainable land management