Investing the impact of environmental indicators on the yield and quality of vetiver plant in soil and pasture protection (case study: side range of barman dam reservoir, gorgan province)

Soil is one of the most important resources in nature. Protecting the soil and reducing erosion in different areas is at the top of empowering the economy. Therefore, in many countries of the world, to protect the environment and natural resources, planting a large area of Vetiver plant under the title (soil bioengineering) has been considered. This study was conducted in the side slopes of Narmab dam reservoir located in Minodasht city, Golestan province. In this research, the soil and roots of Vetiver plant were sampled from the depth of 0-50 cm on the side of the reservoir wall of the dam with different degrees of slope: the first level (60-70 degrees), the second level (70-80 degrees), The third (80-90 degrees) was done with four repetitions. A total of 12 soil samples (untouched) and 12 soil samples along with Vetiver plant roots were sampled using a steel ring and 12 Vetiver plant samples. Soil characteristics include soil texture by hydrometric method, soil moisture by weight method, acidity determination by saturated mud method, electrical conductivity by extraction method and soil salinity with EC meter, percentage of soil organic matter, lime and potassium using Flame photometery device. was taken In the laboratory, in order to investigate the effect of humidity and Vetiver root on the shear strength of the soil, the laboratory direct shear measurement method was used. Vetiver root extract was extracted by soaking method separately using methanol/water (80/20) solvents and the extracts were concentrated using a rotary machine. Finally, the measurement results of soil properties, Vetiver root weight and plant root extract were analyzed using variance analysis and mean comparison and SPSS software. The results obtained from the planting of Vetiver plants on the side slopes of Narmab Dam - Golestan in order to prevent soil erosion and reduce sediments, showed that with the increase in soil slope, the amount of chemical compounds resulting from biological activities increases. In fact, there is a significant relationship between the soil properties and the weight of Vetiver plant roots with the degree of soil slope. On the side slope of Narmab Dam reservoir in Minodasht city, from the first level with a slope (60-70 degrees), the second level with a slope (70-80 degrees) and the third level with a slope (80-90 degrees), respectively, the diameter and weight of the roots from the soil surface It has increased to a depth of 20 cm. The diameter of Vetiver plant roots increased in the first level (2.7 mm), second level (2.9 mm) and third level (3.1 mm). The development of these roots and its deadly threads has increased the shear resistance of the soil in the first level by 25.99%, in the second level by 26.24% and in the third level by 26.67%. Considering the development of Vetiver root system up to several meters on steep slopes, it is a suitable choice for increasing soil adhesion, increasing shear resistance and preventing soil erosion and sliding by rooting deep in the soil. To stabilize the soil and prevent sliding and erosion on steep slopes, Vetiver plant is recommended on steep slopes due to its high adaptability in different climates and conditions, with such intelligent performance and the possibility of growing several meters of roots.