r. bahramloo

Soil erosion and related problems i.e. sedimentation are associated with significant issues and problems on the environment and agriculture, including economic losses, reduction of water quality, storage capacity of reservoirs and agricultural production, among which watershed activities play a prominent role in reducing the amount of soil erosion and sediment yield. For this purpose, in the present research, the watershed management activities were evaluated on the amount of sediment yield, using the Connectivity Index in the Gonbad paired catchment of Hamadan province. In this regard, firstly, the estimation of the continuity index was conducted in the erosion plots installed in the control and impacted watersheds during the events that led to sediment production. Then, a regression relationship was established between the data of the Connectivity Index and the erosion plots sediment yield using the Connectivity Index in order to estimate the rate of sediment yield of control and impacted watersheds. Finally, the impact of watershed practices on the degree of sediment yield was measured by comparing the estimated sediment in control and impacted areas using the Connectivity Index. The results showed that the average amount of sediment produced in the sample and control sub-basins is 0.003 and 0.005 tons per hectare, respectively, that is, the amount of sediment in the sample sub-basin is 45% less than the control sub-basin, and this difference is due to the effect of watershed management operations in the sample sub-basin.

The use of additives to modify the physical, chemical and mechanical properties of soil and soil stabilization is one of the most common methods that have a history. By adding one or more additives to the soil and carrying out the required measures, the engineering properties of soils could be improved due to chemical reactions. Selecting the type and amount of additive depends on several factors such as: soil type, stabilization purpose, additives inherent characteristics, etc.; these are determined based on the technical and economic aspects of the projects. In this study, the effects of the simultaneous use of three types of additives including lime, stone powder and polypropylene fibers on the unconfined compressive strength of a clayey soil were investigated.  To do this, four different levels of lime (0, 2, 3 and 5 percent by weight of soil) and four different levels of stone powder waste (0, 2, 5 and 10 percent by weight of soil) and Polypropylene fibers with different percentages in five levels of 0, 0.25, 0.5 and 1 percent by weight of soil were added into a high plastic clay soil classified as CH. Then, some physical and mechanical characteristics of different mixtures including plasticity, compaction and unconfined compressive strength were determined. The results showed that the samples were stabilized with lime and stone powder waste and reinforcement them with polypropylene fibers modified Atterberg Limits, optimum moisture and maximum dry density of the mixtures. Also, it was found that a combination of waste stone powder, lime and polypropylene fibers containing 5, 5 and 1 percent by weight of soil increased the unconfined compressive strength 8-fold, as compared to the natural soil. The curing time also had a significant impact on the compressive strength of the treated samples in which the 28-day compressive strength of was found to be about 2 times of the 7-day samples.

Recent droughts and water crisis require the use of modern irrigation systems In order to properly use and increase the productivity of water resources. Therefore, this study was carried out to investigate the effect of two irrigation systems (Tape and Furrow Irrigation system) and different nitrogen levels (0,60,120 kg .ha-1) on yield, water use efficiency of garlic product at Ekbatan station, Hamedan Agricultural and Natural Resources Research Center. Experiment was laid out in a randomized complete block design arranged in a split plot with three replication. Two irrigation systems (Tape and Furrow Irrigation) were as main plot and different amount of N (0, 60, 120 kg.ha-1) were as sub plots. The results of analysis showed that effect of different irrigation system on yield and bulb weight wasn’t significant and the yield was equal in two irrigation systems approximately. The average of water productivity in two irrigation systems was 5.6 and 2.4 Kg. m-3. Water consumption in Tape irrigation relative to Furrow irrigation decreased about 54 %. The amount of water productivity in tape irrigation was increased about 103 percent relative to furrow irrigation. Respectively. The maximum of water productivity (4.27 kg/m3) related to 60 kg.ha-1 of N treatment. Considering that the cost-benefit ratio in two scenarios: increasing the area under cultivation and preservation of water resources was 2.84 and 2.54 respectively, therefore the use of drip irrigation system is economical for the garlic product.