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Climate change and its impacts are one of the most important concerns among organizations related to agriculture and the environment issues worldwide. Water scarcity and inadequate soil moisture content are the most challenges of this situation in the arid and semi-arid regions. Thus, maintaining soil moisture content through micro-catchment runoff harvesting system is a crucial solutions in this areas, especially in the forest, range and steep slope rain-feds areas. The objectives of this research were to determine the effects of the crescent-shaped bunds system in harvesting surface runoff to combat drought stress, improving soil quality, and reduce erodibility, which was carried out in three forest sites in the upstream Karkheh river watershed including lam, Lorestan, and Kermanshah provinces, West Iran, during three years (2022-2024). After the construction of the bunds by Natural Resources Office of the mentioned provinces, soil moisture was measured regularly and repeated several times per month at the bund bottom, bund downwards and between the bunds as well as control plot (without bund construction) during three years. Furthermore, soil sampling carried out and subjected to soil analysis. Partial dead trees were counted in certain plots (four 100-150 m2 plot in each site), and aboveground cover was also estimated, using a 1 m2 quadrate plots (10 plot in each treatment). The results of this study explored that among the four soil moisture measurement points, including the bottom of bund, bund downwards, between the bund and the control (without bund), soil moisture storage in sub layer (15 to 30 cm) were about 26, 21, 20 and 16 percent, respectively, which was significantly higher in the bund bottom compeered with control plot. After three years, the ratio of infected-dead trees to healthy trees decreased significantly from about 21% in the first year to about 10% in the third year in bund treatments. The aboveground cover, including bare soil, canopy cover, plant litter, and gravel, changed in bund treatment, such that the canopy cover and litter increased by about 17% and 6%, respectively, while there was no fund significant difference in control plot. Also, bunds were suitable for the germination and growth of oak seeds, medicinal plants, and valuable forage species. The results of this study also showed that due to the effective role of bunds cause the biomass growth and plant litter storage inside the bunds, soil organic matter increased and consequently improved some soil characteristics. Accordingly, the amount of soil organic matter stored in the third year in the bunds and control treatments was 3.7 and 1.8 percent, respectively, which were significantly higher in bunds areas. The average bulk density also decreased in the bunds areas compared to the control treatment, but it was significant in the Lorestan province site. In addition, bunds contributed to significant increase in the increase and very coarse soil aggregates, causing increase in cation exchange capacity, major soil nutrients and some micronutrients. Finally, increasing soil organic matter and runoff accumulation in bunds reduced soil erodibility and adversely soil sustainability, regarding due to redaction soil erodibility index (0.20) compared to control treatments (0.35). According to the results of this research, the proper and precise construction of these bunds whiteout the use of heavy machinery is a simple, cheap, and effective method for harvesting rainwater causing soil moisture storage and subsequently enhancement of plant biological growth as well as improvement the key soil characteristics, including organic matter, increasing the proportion of coarse aggregates, bulk density, and soil nutrients, which ultimately leads to soil sustainable, carbon sequestration, curtailing flooding hazards on the hill-slope, and strengthening subsurface flow.
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