F. Maghami Moghim, A. Karimi, Gh. Haghnia, A. Dourandish,
Volume 17, Issue 65 (fall 2013)
Abstract
The quantity and variability of soil organic carbon (SOC) is one of the most important indices to determine the effect of land use changes on the soil quality. Regarding long-term changes from rangeland to dry farming in the Roin area of North Khorasan, the objectives of this study were to investigate the effect of long-term land use changes on the SOC in different slope faces and use SOC as an index to make a proper decision about the future of land use in this area. 140 soil samples were taken from 0-15 cm soil depth of back slope position of north-, south-, west- and east-facing slopes of rangeland, dry farming, alfalfa dry farming and garden in 7 points. 14 soil samples were taken from irrigated farming, too. The results showed that garden and irrigation farming with averages of 2.03 and 0.78% have the maximum and minimum SOC content. The average of SOC content in rangeland was 1.40% that decreased by land use change to 1.04 and 1.27% in dry farming and alfalfa dry farming, respectively. SOC content in southern slope aspects showed a significant difference compared to other slope aspects. The most SOC content occurred in east aspects. It seems that after long-term land use changes, the SOC content have equilibrated to environmental and land use conditions. The average SOC content in different slope aspects except south one changed from 1.4% in rangeland to 1.11% in dry farming and 1.32% in alfalfa dry farming, which are a suitable value for semiarid regions. In conclusion, to protect land from degradation and considering this fact that dry farming is the main income of the people in the study area, it is recommended to stop dry farming on south aspects and continue on east, north and west aspects with conservation practices.
A. Shabani, A. Jahanbazi, S. H. Ahmadi, M. M. Moghimi, M. Bahrami,
Volume 22, Issue 1 (Spring 2018)
Abstract
In this study, five infiltration models including Kostiakov, Kostiakov-Lewis, Philip, Soil Conservation Service (SCS) and Horton were fitted to the experimental data using the double rings, and the empirical coefficients of these models were determined. Infiltration experiments were conducted in the gravelly sandy loam soil under and between the olive and orange trees in Fasa city, Fars Province, Iran. The results showed that all five models were fitted accurately to the measured data. The accumulated infiltration under the trees was higher than those measured between two trees. Higher infiltration under the tree canopies was probably due to the higher soil organic matter, the lower soil bulk density, and the tree root channeling, which were more pronounced when compared to the small pores in these soils. Despite the positive effect of sand particles on soil infiltration, the big gravel occurrence in soil would decrease the cross section area of water flow path, thereby reducing the infiltration. Therefore, changing the land use and planting olive and orange trees in the gravel soils would increase the infiltration rate and consequently, decrease runoff and erosion rates in such soils.
S. Moghim, J. Rahmani,
Volume 25, Issue 1 (Spring 2021)
Abstract
Improper water managements and overuse of surface water and groundwater mainly for agricultural purposes in Iran have led to the drying of many rivers and groundwater. Climate change adds an extra pressure on the water resources. These changes indicate the necessity of adjustment in water management plans. This study used hydroclimatic variables including precipitation and temperature in Urmia Plain to find appropriate crops that needed the minimum irrigation water. In addition, the best time for planting each crop is determined. To find the proper crops for the region, the daily water, as required for each crop, was calculated based on climate condition, crop type, and crop growth stage. The results indicates that grape could be the best crop for the region. In addition, early planting (e.g. in spring) reduced the irrigation water needed due to more rain and soil moisture in spring than summer, which could provide crop water requirement. On the other hand, the increased temperature in spring could satisfy heat units required for the fully grown plants like barley.
S. Moghim, A. A. Samavaki,
Volume 29, Issue 4 (Winter 2025)
Abstract
The effect of climate change on agricultural productivity and efficiency is a major concern and challenge for the agricultural industry. Different hydrometeorological variables, such as extreme temperature, precipitation, and their variations, affect the growth and yield of agricultural products. Saffron is one of the most important agricultural products in Iran. Iran produces the largest amount of Saffron globally, and Hamadan Province is one of the major saffron-producing regions in Iran. This study uses different Artificial Intelligence methods not only for clustering and sensitivity analysis of the hydroclimatological variables but also for evaluating the impacts of climate change on Saffron yield in Hamadan Province. Results indicated that the Random Forest algorithm performs the best for sensitivity analysis among all algorithms. Extreme climate change indices, particularly those related to the monthly maximum and minimum temperatures, have the highest negative impact on saffron yield compared to other hydroclimatological indices. Furthermore, the minimum temperature has a more significant negative impact on saffron yield compared to the maximum temperature. Additionally, the counties of Malayer, Nahavand, and Asadabad, located in the south and west of Hamadan Province, exhibited the highest accuracy in sensitivity analysis. The findings suggest that monthly extreme temperatures can be used to assess the risk of saffron production, increase agricultural productivity, and improve decision-making for the cultivation of this product.
