The effect of plants on runoff, sediment yield and soil fertility on sloppy lands of Maraveh-Tapeh

Soil erosion is one of the most obvious factors of soil degradation. Vegetation can affect on maintaining soil fertility and the amount of soil loss by reducing runoff and sediment. This study was conducted in Maraveh-Tapeh in the north-eastern part of Kalaleh watershed, located in 55◦ 56' 35" and 37◦ 49' 01" to investigate the role of plant species on soil stability with in a randomized complete block design with five treatments and three replications. Crop and pasture plants as herbal treatments were included Medicago sativa, Agropyron elongatum, Cyminum cuminum, Hordeum vulgare and a mixture of alfalfa and Agropyron. Plots were considered to have a 22 m long on slope direction (10%) by a wide of 5 meters. Runoff and sediment collecting tanks were installed at the bottom end of each plot to measure runoff and sediment. In this study the effect of cultivated plant species on the amount of soil erosion and fertility was investigated. The average volume of runoff during four years of executing the project was 6.93 and 22.9 m³ha-1in treatments of Hordeum vulgare and Cuminum cyminum, respectively. The average amount of sediment yield was 48.42 and 124.72 kgha-1 in treatments of mixed Medicago sativa and Agropyron elongatum and Cyminum cuminum, respectively. Results also demonstrated that Cyminum cuminum is not an appropriate species for cultivation on steep terrains with the aim of soil conservation due to its reverse effects on increasing runoff and reducing soil fertility in Maraveh-Tapeh.