Irrigation
M. Goodarzi; J. Ghadbeiklou; A. Ghadiry; M.A. Khodshenas
Abstract
Introduction
Water is one of the most important factors of development in human societies, water scarcity, specially fresh water which is one of the main limitation for agricultural, economic and social development in most developing countries. Providing and implementing an optimal cropping pattern, ...
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Introduction
Water is one of the most important factors of development in human societies, water scarcity, specially fresh water which is one of the main limitation for agricultural, economic and social development in most developing countries. Providing and implementing an optimal cropping pattern, in addition to better management of water and soil resources, can lead to reducing production risk, increasing the ability to deal with crises, improving employment, better management of providing services to farmers, and providing the possibility of expanding agro-based industries. In many regions of the world, including in Iran, many studies have been done to improve the cropping pattern in different regions. Despite the existing problems in designing and implementing the appropriate cropping pattern in the plains, modifying the cropping pattern based on scientific principles and emphasizing the reduction of water consumption while reducing water consumption provides the possibility of sustainable agriculture and in terms of economic and social aspects. Implementing an optimized cropping pattern in the Farahan Plain is an undeniable necessity to preserve national resources. This study was conducted with the objective of optimizing the cropping pattern in the area, taking into account multiple criteria.
Methodology
In this research, considering the importance of determining the cropping pattern based on the multiple objectives of the decision makers, it was tried to determine the optimal cropping pattern by using mathematical programming and fuzzy logic by establishing a compromise between the objectives of the cropping pattern. The model considered for this study was in the framework of the goal of the maximum ideal distance (Fuzzy Composite Distance). Also, in order to use water resources sustainably, scenarios of cropping patterns are presented based on different conditions of water resources uses. Based on the basin's water resource stability, an optimal cropping pattern was developed to address the conditions of normal water resource exploitation, as well as sustainable and unsustainable scenarios. Each scenario corresponds to a specific period. To achieve this, a multi-objective planning approach was utilized, integrating water, food, energy, and economic profit indicators. The resulting optimal cropping pattern considers stable water resource utilization during normal, drought, and wet periods, ensuring sustainable conditions.
Results and Discussion
The results showed that the amount of water consumed by the optimal cropping pattern compared to the existing cropping pattern under normal, drought and wet conditions is reduced by 23.2, 29.2 and 18.1%, respectively. On the other hand, compared to the existing cropping pattern, the amount of calories produced by the optimal cropping pattern under normal, drought and wet conditions increases by 51.7, 61.9 and 45.2%, the average energy efficiency increases by 40.9, 42.8 and 35.8% and the net profit productivity increases by 43.3, 30.9 and 44.2 %, respectively. Based on the obtained results, it can be seen that in the optimal cropping pattern in drought conditions, the cultivated area of crops such as potatoes, onions, tomatoes, grain corn, sugar beets, beans, alfalfa and watermelons should reach to the zero or be at the lowest possible level. In normal and drought conditions, the cultivated area of these crops should be minimal. On the other hand, the area under cultivation of crops such as fodder sorghum, fodder corn, saffron, cumin, camellia and medicinal plants should be increased and the cultivation of these crops should be promoted at the region. Also, regarding horticultural products, the cultivated area of walnut, apple, peach, apricot and almond orchards should be minimized and replaced with plants such as grapes, oleaster, jujube, barberry, rose, and figs.
Conclusion
Based on the obtained results, it was found that the use of the optimal cropping pattern derived from the indicators of water, food, energy and economic profit is completely superior and preferred over the existing cropping pattern and single purpose optimal cropping pattern. In order to achieve sustainable water resource management, it is recommended to modify the cropping pattern during drought, normal, and wet periods based on the suggested optimal cropping pattern. The existing cropping pattern currently falls short in terms of achieving the four objectives of water, food, energy, and economic profit. Therefore, it is crucial to develop main plans and strategies in the Farahan Plain that align with the implementation of the proposed optimal cropping pattern. By doing so, it will be possible to optimize the allocation of water resources and achieve improved outcomes in terms of water availability, food production, energy efficiency, and economic profitability.
Soil science
A. Zeinadini; M.N. Navidi; A. Asadi Kangarshahi; M. Eskandari; S.A. Seyed jalali; A. Salmanpour; J. Seyedmohammadi; M. Ghasemi; S.A. Ghaffarinejad; Gh. Zareian
Abstract
Introduction: Iran is one of the most important countries in citrus (oranges) production. Citrus fruits are grown in different soils with a wide range of physical, chemical and fertility properties in the country, although some restrictions in the cultivated lands cause yield loss. In this regard, the ...
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Introduction: Iran is one of the most important countries in citrus (oranges) production. Citrus fruits are grown in different soils with a wide range of physical, chemical and fertility properties in the country, although some restrictions in the cultivated lands cause yield loss. In this regard, the present study was conducted to investigate the effect of physical, chemical and soil fertility characteristics on citrus yield in important areas under cultivation, the regression relationships of characteristics with yield, and the rating of soil and land parameters. Materials and Methods: The 138 oranges orchards (118 orchards for rating and 20 orchards for validation) were selected in Fars, Mazanderan, Kerman and Guilan provinces. In each garden, a questionnaire was completed, a soil pedon was studied and soil samples were taken to carry out the appropriate physicochemical analyses. The selected soil and land characteristics were soil salinity (EC), exchangeable sodium percentage (ESP), pH, gypsum content, soil calcium carbonate (TNV), organic carbon (OC), clay, sand, silt, gravel, and soil available phosphorus and potassium contents. From the whole obtained data, 20 data were considered for validation purpose and the remaining data were used for modeling based on stepwise multivariate and simple regression methods. In these equations, the relationship between yield, as dependent variable, with soil and land characteristics, as independent variables, was investigated. Finally, land characteristics rating was obtained by the FAO method and the proposed crop requirements table was evaluated using the validation dataset. Results and Discussion: The results of descriptive statistics analysis showed that the variance values for available potassium, sand, clay, gravel and TNV were high and for pH and OC and gypsum were negligible. Therefore, most soil properties have a wide range of variation which could be related to the fact that oranges are grown in a wide range of soil types. The value of TNV varied between 10 and 33.3%. The presence of carbonate in soil reduces the availability of macro- and micronutrient elements in direct and indirect manners. The average of EC in the studied orchards was 5.4 dS.m-1. Minimum, maximum and average of ESP were 1.7, 28 and 10.7, respectively. The lowest and highest salinity and sodicity were observed in Mazandaran and Kerman soils, respectively. Maximum, minimum and average percentage of gypsum were 12, 0.36 and 3.54%, respectively. The highest amount of gypsum was observed in Bam and Shahdad regions of Kerman province and the lowest gypsum content was observed in Mazandaran and Guilan provinces. The soil pH varied from 6.63 to 8.8 with the average of 7.8. The soil OC values were between 0.05 and 3.53% and its average was 0.89%, showing the fact that the most studied soils were poor in organic matters. The average of soil available phosphorus and potassium in the studied orchards for citrus was less than the critical level. The average, minimum and maximum of available potassium were 224, 100 and 360 mg.kg-1, respectively. The mean, minimum and maximum amounts of available phosphorus were 21.6, 8 and 45.9 mg.kg-1, respectively. According to the multivariate regression model, among soil properties, EC, ESP, TNV, gypsum, gravel, available phosphorus and potassium were selected by the model. The determination coefficient of the model was 0.95, indicating that these properties have the greatest effect on citrus yield. Simple regression equations demonstrated that TNV, gypsum, EC, ESP, sand, clay, gravel, available potassium and phosphorous had the highest correlation (R2 > 0.6); and soil OC and pH had the lowest correlation (R2<0.2) with yield. The equations also revealed that soil EC, ESP, gypsum, TNV and gravel percentage had the greatest effect in yield loss, and soil organic carbon, absorbed phosphorus and potassium had the greatest effect on increasing citrus yield. As stated in equations, reported permissible and critical thresholds for effective soil properties on citrus yield, were 2.4 dS.m-1 for EC, 5 for ESP, 1.5% for gypsum, 20% for TNV, 22 mg.kg-1 for available phosphorus, 280 mg.kg-1 for available potassium, 110 cm for soil depth, and >2 m for groundwater level. Finally, evaluating the proposed crop requirements table with validation dataset fitted between citrus yield and soil index, resulted in the determination coefficient value of 0.79, denoting the acceptable accuracy of proposed table. Conclusion: Overall results showed that the main land limiting characteristics for orange production were soil salinity and sodicity, high amount of soil calcium carbonate and gypsum. Among unsuitable physical and fertility properties of soil, salinity and sodicity are the most effective factors affecting yield reduction. Consequently, proper management practices such as introducing cultivars compatible with these soil conditions, soil remediation and leaching operations to reduce soil salinity and sodicity are necessary. Furthermore, in most areas under orange cultivation such as Fars and Kerman provinces, the soil calcium carbonate content is more than the critical level for plant growth. In addition, the averages of soil available phosphorus and potassium were less than the critical levels, which should be considered for nutrient management of orchards. The proposed table of crop requirements seems to be accurate enough to conduct land suitability studies for orange varieties, especially cultivars grown in the north and south of the country.
S. Kermanshahi; K. Davari; majid hashemi nia; A. Farid Hosseini; H. Ansari
Abstract
The requiring of reducing agricultural water demand as the world’s largest consumer of water, for having sustainable water resources is not concealed to anyone. With measurements such as increasing irrigation efficiency, changing in cropping pattern, reducing the cultivation area, etc, this goal can ...
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The requiring of reducing agricultural water demand as the world’s largest consumer of water, for having sustainable water resources is not concealed to anyone. With measurements such as increasing irrigation efficiency, changing in cropping pattern, reducing the cultivation area, etc, this goal can be achieved. In this study, the status of water resources and irrigation demands within the Neyshabour Plane was evaluated by using Water Evaluation and Planning model (WEAP). To assess the effect of these strategies in WEAP model, scenarios with different topics for cropping pattern, reducing cultivation area, and combined scenarios were developed and then the simulations were performed for 20 years in future. The results suggested that above measurements reduced the mean annual water demand of agriculture by 9, 10 and 18 percents respectively and subsequently reduced the average of annual groundwater deficit by 13, 8 and 18 percents. On the other hand these measurements had a significant role in reducing the agricultural water demand, and therefore, in reducing the extraction from different water resources.
