Investigating the Effect of Bentonite Clay Mulch Combined with the Cultivation of Nitraria Schoberi in Controlling Wind Erosion (Case Study: Sejzi Region of Isfahan)

   The increasing trend of land destruction in many parts of the world is a serious threat to humanity. Desertification, which is one of the manifestations of this destruction, has affected most of the countries. What is certain is that today the phenomenon of land degradation and desertification in the world and especially in Iran is progressing rapidly and every day it is taking over more areas. The intended method in this research includes the laboratory use of 10 micron bentonite clay through a wind tunnel and determining its hardness by preparing a suspension on the surface of the windy sand; also using different percentages of this clay along with the cultivation of seedlings of Nitraria schoberi, which is resistant to salinity and dehydration. This method is of interest and can be a suitable moisture absorber for storing soil moisture and plant establishment, and also a good alternative to oil mulches that are harmful to the environment. Considering the importance of the problem of dust phenomenon as well as the crisis of drought and lack of water in Sajzi region of Isfahan city, the aim of this research is to establish vegetation cover in critical areas where there is no possibility of fighting except oil mulch or it is difficult to do so. More specifically, the experiment is done by using 10-micron bentonite clay in the pit of Nitraria schoberi seedling cultivation and sprinkling it on the surfaces of the harvesting and transportation area, while reducing the frequency of irrigation and reducing the amount of wind erosion.

In this research, which investigates the use of processed bentonite clay in moisture storage to control soil erosion, by adding this material to the soil, its ability to control wind erosion was investigated in the form of statistical analysis. Bentonite clay can be used with less volume and longer shelf life to control desertification. The 10-micron bentonite clay used in this research is homogeneous in water and can be used to control wind erosion on the soil surface; it reduces water consumption, increases seed germination and increases crop yield. Vegetation can be an effective factor in increasing the roughness of the soil surface and reducing the wind speed. The higher the density of vegetation and the longer its duration on the soil surface, the greater its role in preserving and maintaining the soil.

Effect of bentonite treatments on moisture content In the field experiments, a randomized complete block design was implemented, in which 10-micron bentonite with percentages of 2, 4, 6, 8 and control were used in the cultivation pits with the symbol of Nitraria schoberi seedling cultivation. Also, in 7 time stages of irrigation stress after cultivation (6 periods of alternating irrigation with intervals of 18 and 32 days) and the last irrigation period with an interval of 54 days, the soil sampling of the cultivation pits was done with an auger, and after being transferred to the laboratory, the percentage of moisture was determined. In this experiment, the effect of bentonite on the moisture level at the depths of 0-10 and 10-20 was statistically significant at the level of 1%. The results of comparing the averages showed that in the first stage of sampling to determine the percentage of moisture in the depths of 0-10 and 10-20 cm, with the increase of bentonite, the amount of soil moisture increased significantly. The highest percentage of soil moisture was observed in treatment 8 and the lowest in the control treatment. The amount of soil cell resistance According to the results of variance analysis of the data, the effect of bentonite treatments on soil hardness and erosion was significant at the level of 1 and 5%. Speed 5.7 was obtained in the bentonite treatment of 4 grams per liter and the lowest amount was obtained in the control treatment. In speeds 11 and 28, the highest soil cell resistance was observed in the treatment of 4 grams of bentonite and the lowest amount was observed in the control treatment.

Today, the phenomenon of wind erosion and its consequences is considered as one of the processes of land degradation in arid and semi-arid regions. The preliminary economic assessment of the use of 10-micron bentonite clay instead of other moisture absorbents in maintaining moisture and reducing irrigation frequency shows that this material is easier to access and the cost of its preparation is much lower. The positive effect of bentonite in reducing soil erosion can be due to the fact that bentonite is a clay mineral from the montmorionite family with expansion properties that is created by the weathering of volcanic ash. Also, due to its unique properties, it can be used in increasing the pulp index of the source soils. According to the results of this research, bentonite mineral can be effective in controlling the internal erosion of materials, so that the amount of erosion decreases with the increase of bentonite percentage. The results of this research on the reduction of erosion rate by increasing the bentonite percentage of the soil are consistent with the results of the research of Zumardian and Khushkho (2013). The results of this research showed that according to the method applied in random complete blocks, different treatments of bentonite had an effect on the moisture level and also on the hardness and erosion of the soil in the wind tunnel and shear vane stage. The effectiveness of the soil depends on the amount of bentonite used, the amount of moisture and wind speed, so with the increase in the amount of bentonite in the soil, the hardness and moisture of the soil increased as well.