Mohammad hadi Rad; Mohammad Khosroshahi
Volume 30, Issue 3 , January 2024, , Pages 395-408
Abstract
Background and Objective The history of using American mesquite (Prosopis juliflora) for desertification control especially sand stabilization in Iran, is long. Considering the non-native nature of this species, attention should be paid to its ecological requirements, especially water needs or evapotranspiration ...
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Background and Objective The history of using American mesquite (Prosopis juliflora) for desertification control especially sand stabilization in Iran, is long. Considering the non-native nature of this species, attention should be paid to its ecological requirements, especially water needs or evapotranspiration (ET). This can contribute to the sustainability of sand stabilization programs and fine dust control and play an influential role in ecosystem development. Determining plants' evapotranspiration rates through lysimetry is one of the most accurate direct measurement methods. Methodology The experiment using weighing and drainage lysimeters began in 2021 by planting seedlings inside lysimeters located at the Yazd Shahid Sadoughi Desert Research Station. It continued for two years. Nine lysimeters with a volume of 1.95 m³ (height: 170 cm, diameter: 121 cm) and a surface area of 1.15 m² were used. The ET rates and the crop coefficient (Kc) of Prosopis juliflora were studied under different soil moisture levels, including field capacity (no stress), 67% of field capacity (mild stress), and 34% of field capacity (severe) for various growth stages. Irrigation was performed by drip irrigation based on a fraction of field capacity with an appropriate number of droppers calculated for each treatment. For field capacity, 67% and 34% of field capacity treatments, 6, 4, and 2 droppers with an 8 liters per hour flow rate were used, respectively. Each treatment was irrigated twice with the appropriate amount of water based on soil moisture levels. Results The results showed that Prosopis juliflora, under lysimeter conditions and the local climate, had an annual ET rate of 496.5 mm and a Kc 0.21. These values for the 67% and 34% field capacity treatments were 445.4 mm with Kc 0.18 and 275.2 mm with Kc 0.11, respectively. The ET rates of Prosopis juliflora at different growth stages revealed that the highest ET occurred during the development period of 124 days. This corresponds to rapid shoot, branch, and leaf growth. The ET rates in different irrigation regimes for field capacity, 67%, and 34% of soil moisture were 322.1 mm, 281.7 mm, and 158.3 mm, respectively. The lowest ET rate was associated with the final growth stage. The Kc for various growth stages in the field capacity treatment were 0.19, 0.24, and 0.14 for the first, second, and third growth periods, respectively. Under these conditions, a sigmoid growth curve (initial growth, development, and end of growth) can be defined for this plant. Conclusion It is recommended for afforestation with this species in Iran's southern regions, considering its optimal planting density to reduce competition. It is also recommended to pay attention to its ET rate, especially during the hot months of the year when it can exceed 2.5 mm per day. By examining and calculating the ET rates of mature trees with appropriate efficiency in sand stabilization and dust control, it was found that to create a canopy cover area, as mentioned, it is necessary to have 4846 m3 of water per hectare (equivalent to 484.6 mm per year) available to the plant. In other words, with this amount of ET, the plant can expand its canopy cover area to 19.5 m2 and, with 155 individuals per hectare (8×8 meters), cover 30% of the area, which is suitable for sand stabilization.
Reza Norouz Valashedi; Jaber Rahimi; Abbas Alipour
Volume 26, Issue 3 , September 2019, , Pages 640-649
Abstract
The main purpose of this study was to analyze the effective factors on farmers' participation in combating desertification plans in Iran. Thus, a number of farmers as a sample population were selected using Cochran’s formula and multi-stages sampling for selecting samples was done. A questionnaire ...
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The main purpose of this study was to analyze the effective factors on farmers' participation in combating desertification plans in Iran. Thus, a number of farmers as a sample population were selected using Cochran’s formula and multi-stages sampling for selecting samples was done. A questionnaire was used to collect data whose validity was confirmed by advisor and supervisor professors and some experts of desert organization. The reliability of the questionnaire was confirmed by computing Cronbach's alpha that was more than 0.75. Data were analyzed using SPSS and Expert choice 11 software and results showed that the population of the study had low literacy and income. They also had participated very few in education courses, whereas it was observed a significant positive relationship between variables such as literacy, income, and participation in education courses with the participation variable. Also, the correlation relationship between independent factors such as psychological, cultural, economic, education/extension and institution factors with the dependent variable of participation variable showed that except psychological factor, all of those factors had a significant relationship (sig level of 0.01) with participation variable. The results of the regression analysis also revealed that social/cultural and economic factors were the most important factors on the participation variable and explained 66% of participation changes. The model output indicated that rural communities showed significant interest in the city.
Fatemeh Bahmani; Hosin Pirisahragard; Jamshid Piri
Volume 26, Issue 1 , June 2019, , Pages 201-213
Abstract
Estimation of the soil temperature in arid regions is one of the most important issues in planning the projects of desertification, water resource management, and establishment of vegetation.The present study aimed to compare the accuracy of artificial intelligence methods in order to estimate soil daily ...
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Estimation of the soil temperature in arid regions is one of the most important issues in planning the projects of desertification, water resource management, and establishment of vegetation.The present study aimed to compare the accuracy of artificial intelligence methods in order to estimate soil daily temperatures using meteorological data (daily minimum and maximum of temperatures, sunshine, and evaporation), as well as, identifying the most important factors on soil temperature in Zabol and Shiraz synoptic stations. For this purpose, soil daily temperature was estimated at 5, 10, 20, 30, 50 and 100 cm depths by using the three-year period data (2011-2014) and artificial neural network, neuro-fuzzy adaptive genetic programming, and combined neural network-genetic algorithm approaches. Thae results were evaluated using the root mean square error (RMSE) and mean absolute error (MAE) and determination coefficient. Based on the results, there was more dependence between the air temperature and soil temperature at the topsoil so that, the highest and the lowest correlation between actual and simulated data were observed at 5 cm (mean R2=0.92) and 100 cm depths (mean R2=0.56), respectively. The accuracy of the methods used was different from each other in estimating the soil daily temperature. Based on results, in Zabol and Shiraz stations, combined neural networks - genetic algorithm approach and artificial neural network methods provided the most accurate estimation of soil daily temperature, respectively (the mean RMSE=3.69, 2.86 and mean MAE=3.23, 2.57 respectively). According to the results of the present study, it is suggested that in order to choose appropriate time and depth of seeding in the vegetation reclamation projects in arid regions, through considering of climatic conditions of each region, precise artificial intelligence techniques could be used to estimate the soil daily temperature.
Zohre Akbari; Seyed Hamid MatinKHah; Mohsen Nael
Volume 23, Issue 1 , June 2016, , Pages 23-28
Abstract
This research was aimed to achieve a method resulting in further establishment and survival of Haloxylon ammodendron seedlings as well as increased water productivity. The study was conducted in the Sejzi plain for nine months. In this experiment, Haloxylon ammodendron was cultivated in the study area ...
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This research was aimed to achieve a method resulting in further establishment and survival of Haloxylon ammodendron seedlings as well as increased water productivity. The study was conducted in the Sejzi plain for nine months. In this experiment, Haloxylon ammodendron was cultivated in the study area under two treatments: plastic film and control. Porous plastic films were applied to avoid water loss. Both treatments were under the same conditions.This project was carried out in a completely randomized design over a period of nine months. During this period, indicators such as seedling height and crown diameter were measured. Data were analyzed by SPSS software. Our results clearly showed that the plastic film was a suitable water-supplying technique for the growth of Haloxylon ammodendron seedlings in such areas with severe evapotranspiration and high-speed winds. The land of Sejzi is porous, leading to the water loss; therefore, the success of this method is related to avoiding the loss of water needed for plant growth.
Abolghasem Dadrasi Sabzevar; Mohammad Khosroshahi
Volume 17, Issue 1 , September 2010, , Pages 127-148
Abstract
Low quality flood irrigation are used on desert area of KaleShoor river of Sabzevar since 1992. The main objective of this research was to asses changes in soil salinity affected by low quality flood irrigation. To meet this, 51 soil samples were taken and tested in the laboratory for salinity and indicators ...
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Low quality flood irrigation are used on desert area of KaleShoor river of Sabzevar since 1992. The main objective of this research was to asses changes in soil salinity affected by low quality flood irrigation. To meet this, 51 soil samples were taken and tested in the laboratory for salinity and indicators require. soil samples taken from depth of 0-30cm, 30-60cm and 60-90cm at the beginning, middle and end of the cultivated rows of the land. Three soil samples were also prepared from the control area. The results showed that EC and PH values reduced in all samples, compared with control points. In addition, organic materials and sand particles which carried by flood water, improved the soil structure and texture of the study area. This study also showed that flood irrigation has been able to reduce gypsum from range of root zone and transported to lower layers.