Impact of Cultivating Some Legumes Compatible with Rainfed Conditions on Runoff and Sediment Reduction, and Soil Aggregate Stability

Nowadays, it is necessary to use new methods to resolve the issue of soil erosion instead of traditional methods in order to achieve more accurate knowledge and appropriate planning. The cheapest and most appropriate way to conserve the soil is to use vegetation. Therefore, considering the high costs and adverse environmental effects of mechanical methods compared to biological methods of soil conservation, the present study aims to investigate the effect of planting two varieties of fodder vetch as a biological, economic and environmentally friendly solution to reduce runoff, sediment and improve soil properties.

This research was carried out using standard experimental plots with dimensions of 22 × 1.8 meters and a slope of 9%, so that totally nine experimental plots including three treatments and three replications were applied and executed in the form of a randomized complete block design. The three treatments studied in this experiment included Maragheh vetch, Golshan vetch and native wheat of the study region (control treatment), and the studied vetch varieties were planted simultaneously with wheat cultivation in the fall in two consecutive years, 2020 and 2021. Finally, the mean data of runoff, sedimentation and stability of soil aggregates were compared and statistically analyzed.

In general, the studied fodder plants had a significant effect on reducing the runoff and sediment generated from the experimental plots, which shows the importance and role of these plants for the purposes of soil and water conservation. In particular, Maragheh fodder vetch showed excellent performance in reducing runoff and sediment in the study area, therefore planting the mentioned varieties in order to conserve soil and water is prioritized in the study area. The stability of soil aggregates also did not show any significant difference in the studied treatments during the experimental period. Therefore, it can be concluded that the stability of soil aggregates will not change within two years, and more time is needed to observe the change in this soil characteristic.

Conclusion and Suggestions :

The results of this research revealed the significant effect of using forage plants, especially Maragheh and Golshan forage plants, on reducing runoff and sediment in line with the goals of soil and water protection. The use of fodder legumes compatible with the climatic conditions of each region that have suitable plant characteristics such as a strong and dense root and stem system as well as a suitable canopy in order to conserve soil and water and improving the livelihood of the residents of the region and also carrying out early irrigation and supplementary irrigation is recommended in the important stages of the plant growth under drought and low rainfall conditions. Also, conducting researches that investigate the effect of rainfall intensity, amount of rainfall, soil moisture, soil texture and chemical properties of soil on the effectiveness of dry fodder plants in water and soil conservation, as well as the relationship between different climatic, morphological and hydrological conditions of upstream and the effectiveness of dry land fodder plants in the qualitative and quantitative control of runoff, is suggested.