The Effect of Rainfall Storage Methods on Soil Properties of Arid Rangelands (Case Study: Bastak, Hormozgan Province)

Lack of rainfall and its high temporal and spatial variation are the main problems of vegetation restoration in Iran.  Rainfall harvesting methods can play an effective role in improving soil moisture. Rainfall harvesting operations have a great impact on the structure and function of ecosystems. Therefore, the present study investigates the changes of soil properties as a result of implementing two rainfall harvesting methods (water spreading system and micro-catchment) in arid rangelands of Hormozgan province. First, 45 soil samples were taken from control, micro-catchment and water spreading system sites and their physical and chemical properties were measured in the soil laboratory. One-way analysis of variance was used to compare the different sites in terms of soil properties. The rate of change index was used in order to assess the performance of soil properties and the overall performance of each of the rainfall harvesting methods compared to the control. Synergy and trade-off relations between soil properties were investigated using Pearson correlation coefficient. The results showed that except EC, pH, TNV, water spreading system had a significant effect on soil properties. EC, pH, TNV, calcium, magnesium, nitrogen and sand had negative performance in the water spreading system, and the rest of the soil properties had positive performance. The overall performance of soil properties was 31 and 11% in the micro-catchment, and 52 and 25% in the water spreading system. Sand had a significant trade-off relationship with most soil chemical properties. The highest trade-off was observed between sand and silt (p <0.01, R2 = -0.99). The highest synergy was observed between silt and phosphorus (p <0.01, R2 =+0.87), and next phosphorus and OC (p <0.01, R2= +0.72). In general, the positive impact of water spreading system on the soil properties of arid rangelands was greater than the micro-catchment in this region.