Khosro Shahbazi; Borzoo Yoosefi
Abstract
Therefore, in order to evaluate the cultivability of forage cactus (Opuntia ficus indica L.) in the Naft shahr of Qesir shirin city, Kermanshah province has been considered. Different treatments without irrigation, 1, 15, 30 days, once irrigation in three repetitions for three years were performed based ...
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Therefore, in order to evaluate the cultivability of forage cactus (Opuntia ficus indica L.) in the Naft shahr of Qesir shirin city, Kermanshah province has been considered. Different treatments without irrigation, 1, 15, 30 days, once irrigation in three repetitions for three years were performed based on a completely randomized block design. Cultivation of cactus plant in the first half of November and irrigation began on the first of June. The means of the results were compared using Duncan's multiple range test in SPSS software.The results of analysis of variance showed that the effect of irrigation cycle and the interaction effect of irrigation cycle at the time of measurement on the number of pads and plant height had a significant effect at the statistical level of 0.01. Survival of 75, 57, 43 and 38% of plants was obtained with 15-day irrigation cycle, 30-day treatment, one-time irrigation and no irrigation treatment, respectively. The results of this study show that planting cactus in areas with arid desert climate such as Qesir shirin and Somar in Kermanshah province is recommended due to its high adaptability. Dry forage production Cactus forage can be effective for livestock development in these and similar areas. Also, due to the role of cactus in soil conservation, it is possible to prevent the occurrence of dust, desertification, pasture destruction and soil erosion in the region by developing crops. Also,
Khosro Shahbazi; Ali Salagegheh; Mohammad Jaafari; Mohammad Khosroshahi
Abstract
Gully erosion affects land degradation, particularly in the semiarid reigns. Topographic thresholds are strongly affected by landuse change and destroy of vegetation. The objective of this study was to evaluate topographic thresholds of gully erosion in different landuse including agriculture (AG), fair ...
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Gully erosion affects land degradation, particularly in the semiarid reigns. Topographic thresholds are strongly affected by landuse change and destroy of vegetation. The objective of this study was to evaluate topographic thresholds of gully erosion in different landuse including agriculture (AG), fair rangeland (FR) and weak rangeland (WR) which carried out in Ghasreshirin, Kermanshah, Iran. The topographical parameters were measured in the field and relationship between gully catchment area and slope was analyzed for each landuse. The results revealed that some main topographic characteristics mainly cross-section, width, depth and gully branches length in the FR was significantly lower than in the AG and WR (p<0.05). Furthermore, analysis of gully threshold based on catchment area-slope showed that the critical area for gully formation in AG, FR and WR was 1300, 1689 and 1233 m2, respectively which was significantly lower in FR reducing by vegetation cover. The respective slope threshed was 1, 3 and 3 percent in AG, FR and WR. However, the affected area by gully erosion in AG, FR and WR was 12.4, 14.1 and 21%, respectively. The gully in the agricultural land was more dipper compared with other land uses. The volume of gully channels in FR was 3.4 and 2.2 times less than AG and WR, respectively. It is concluded that rangeland degradation and thereby removing vegetation attribute to severe gully erosion and consequently environmental problems such as soil carbon dioxide emission.
Khosro Shahbazi; ali salajagheh; mohammad jafari; hassan ahmadi; ali akbar nazari samani; mohammad khosro shahi
Abstract
Negative impacts of gully erosion in marl areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. The objective of this research was to evaluate hydraulic flow thresholds of gully erosion in the agriculture (AG), fair rangeland ...
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Negative impacts of gully erosion in marl areas are severe due to improper landuse practices such as irrigation, tillage, overgrazing and degradation of vegetation cover. The objective of this research was to evaluate hydraulic flow thresholds of gully erosion in the agriculture (AG), fair rangeland (FR) and poor rangeland (PR) areas in the Qasre-shirin, Kermanshah, Iran. Nine flumes were performed in the field to determine the critical values of hydraulic parameters including flow discharge, velocity, Froude and Reynolds numbers, Darsi resistance coefficient, shear tension, head-cut dimensions as well as vegetation cover. Results showed that respective critical value of discharge as the gulling thresholds for AG,FR and PR was 1.53, 12.0 and 4.49 li/s indicating significantly higher (p<0.05%) in the FR due to higher vegetation cover. In addition, there were no significant differences for flow disturbance based on Froude number, while the respective value of Rinuldze number in the AG, FR and WR were obtained 3113, 26092 and 9525 significantly higher in the FR. Furthermore, the critical level of shear tension for gully formation in the AG, FR and WR were found 12.12, 14.01 and 9.28 Nm-2, respectively showing significant differences among them. Finally, it is concluded that hydraulic flow parameters as the gully triggering are strongly affected by vegetation cover through landue practices so that higher plant cover in the FR was the key factor resulting in significant enhancement of gully.
