Research Article
Irrigation
M. Goodarzi; F. Abbasi; A. Hedayatipour
Abstract
IntroductionThe lack of water resources and increase in water demand are among the effective factors in the imbalance of the water resources in each region, and it is necessary to manage the proper use of available water resources in all activities. Water in the agricultural sector is one of the main ...
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IntroductionThe lack of water resources and increase in water demand are among the effective factors in the imbalance of the water resources in each region, and it is necessary to manage the proper use of available water resources in all activities. Water in the agricultural sector is one of the main factors of production, which should be conveyed by irrigation systems to the field level and made available for the plant roots. The necessity of macro-planning in water management and consumption imposes a comprehensive study of the amount of water consumed in the agricultural sector. Hence, this study was conducted with the objective of directly measuring and field-assessing the applied water, water productivity, and water footprint associated with the primary crops cultivated in Markazi Province, all managed by local farmers.MethodologyFor this purpose, 141 farms were selected in the major production areas of the main agricultural and horticultural crops of Markazi province with the coordination of the Agricultural Jihad centers. Then, the volume of water applied was measured without interfering in the irrigation scheduling of the users. To do so, first, the flow rate of the water source (canal, well, aqueduct or spring) was measured with a suitable device (flume and meter) in each of the selected farms. Then, by carefully monitoring the irrigation schedule of the farm, including the time of each irrigation, the number of irrigation throughout the year, as well as measuring the area under crop cultivation, the amount of water used by the crop was measured for each of the selected farms during the season. Also, based on the measured data, the amounts of blue, green and gray water footprints were determined for each of the examined crops. For this purpose, the blue, green and gray water footprints of different crops were calculated using the framework provided by Hoekstra and Chapagain (2008), and Hoekstra et al., (2011).Results and DiscussionThe irrigation intervals in the studied fields varied between 3 and 15 days with an average of 8 days and the average irrigation depth varied between 26.2 and 99 mm with an average of 67.8 mm in different crops. The results showed that the average volume of applied water for the studied crops in Markazi province was 10782 cubic meters per hectare. Also, the minimum and maximum amount of applied water for the evaluated crops was as follows: barley 3783 and 7232, alfalfa 10382 and 19797, beans 8280 and 17840, watermelon 5333 and 7174, walnuts 4420 and 29600, almonds 3850 and 13932, peaches 6872 and 17727, cherries 7050 and 14645, pomegranates 7156 and 20790, and grapes 5937 and 18168 cubic meters per hectare. Furthermore, the average value of irrigation water efficiency index and water footprint was as follows: barley 0.46 and 1642, alfalfa 0.92 and 700, bean 2924 and 0.24, watermelon 9.37 and 117, walnut 0.1 and 6706, almonds 0.16 and 6857, peach 2.48 and 242, cherries 0.73 and 875, pomegranates 1.33 and 636, and grapes 11.2 and 322. Based on the obtained results, the average total water footprint index was equal to 2102 cubic meters per ton. On average, the almond with a water footprint of 6857 cubic meters per ton had the highest share in allocating the water footprint in the crop production of the province. Whereas, the lowest water footprint related to the watermelon with a water footprint of 117 cubic meters per ton. he average values of the irrigation application efficiency index, irrigation water productivity, and water footprint for the examined farms were 72.5%, 1.79 kg/m3, and 2,102 m3/ton, respectively. In summary, the results indicate that the combined volume of irrigation water and beneficial rainfall in the irrigated fields within Markazi Province surpasses the actual water demand of the crops. This underscores the substantial impact of irrigation management on water utilization in the region.ConclusionOn average, the total volume of irrigation water and effective rainfall in irrigated fields and gardens in Markazi Province is more than the actual water requirement of the plant. In general, the results showed that irrigation management has a great impact on the amount of water use in the region. Based on the obtained results, considering that most of the farms and gardens receive water in an intermittent manner, in principle, no special attention is paid to the need for water and even effective rainfall, and the amount of water availability has the greatest impact on water consumption. Therefore, in order to reduce water consumption and improve water efficiency, it is suggested to manage the delivery of water to farmers during the season and according to their crop water needs. Also, the results of the water footprint can be used to improve water resource policies at the province level, land use studies, cropping pattern modification, and environmental sector policies.
Research Article
Irrigation
A.H. Jalali; H. Salemi
Abstract
IntroductionCumin (Cuminum cyminum L.) is an annual and herbaceous plant, with a vertical, round, narrow and branched stem, with a height of approximately 30-60 cm. This plant belongs to the Apiaceae family. This family is known for having plants with aromatic taste. Iran and some countries along the ...
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IntroductionCumin (Cuminum cyminum L.) is an annual and herbaceous plant, with a vertical, round, narrow and branched stem, with a height of approximately 30-60 cm. This plant belongs to the Apiaceae family. This family is known for having plants with aromatic taste. Iran and some countries along the Mediterranean Sea are known as the primary origin for the cumin plant. In addition to Iran, cumin is cultivated in many countries such as Uzbekistan, Tajikistan, Turkey, Morocco, India, Syria, Mexico and Chile. About 300,000 tons of cumin seeds are produced in the world annually, of which China and Asian countries produce 70% and consume 90%. Short growing season (100 to 120 days), low water requirement and the possibility of rained cultivation, non-interference between cultivation and harvesting with other crops and no price fluctuation and proper economic justification are among the factors that interest farmers in cultivating this plant. In different regions, yields of 350 to more than 1000 kg of seeds are obtained from this plant, and 3350 cubic meters of pure water are needed for production. Materials and MethodsThis research was conducted in 2015 to 2017. The first year of the study included the collection and analysis of long-term climatic data of the region, and the second year included the implementation phase of the research. Analyzing meteorological data on the scale of decades and the cases of temperature, precipitation, wind speed, sunshine hours, relative humidity and evaporation from the pan were considered as criteria and by preparing the gradient equations, the rate of reference evaporation and transpiration was calculated. The required statistical information was obtained from 28 synoptic meteorological and climatology stations in Isfahan and some neighboring provinces. In the studies related to soil, apparent specific gravity and volumetric moisture content (field capacity and wilting point), soil salinity, soil texture and agricultural ability class of land in cultivation areas were considered. Soil-related information was used to calculate the soil evaporation coefficient (Ke), which describes the evaporation component in the trait (ETc). In fact, Ke is the basis for calculating the coefficient of reduction of evaporation from the surface layer (Kr) and the fraction of soil wet and exposed to air (few), and for its calculation, the presence of information related to soil characteristics is necessary. To calculate the soil characteristics, in addition to sampling from the fields in the research, the database of 1600 soil profiles in the soil and water research department of Isfahan province was also used. Results and DiscussionThe results showed that 18 cities in Isfahan province had cumin cultivation potential, which had a significant difference in terms of pure water requirement per hectare (5% level) and water consumption at different phenological stages (1% statistical level). In terms of water requirement per hectare, the cities of Isfahan province can be divided into three groups. Average water requirement per hectare in the first group (the cities of Golpayegan, Lenjan, Tiran and Karvan, Shahin and Shahr and Mime), the second group (the cities of Isfahan, Khomeini Shahr, Falavarjan, Shahreza, Kashan, Najaf Abad, Natanz), Mobarake, Dehaghan and Borkhar), and the third group (Aran and Bidgol, Ardestan, Khoor and Biabanak and Nain) were equal to 3000, 3240 and 3770 m-3 ha-1, respectively. The water requirement of the growth development stage in the cities of the third group was equal to 2029 m-3 ha-1, which was significantly different from the cities of the first and second groups (p < 1% level). According to the results, cumin might be a suitable plant for crop rotations in Isfahan province due to its low water requirement and tolerance to moisture stress. ConclusionThe water requirement for cultivating cumin in various regions of the province is notably lower compared to many common crops, such as wheat, barley, and safflower. In 10 out of the 18 cities included in the study, significant water savings of up to 3,240 cubic meters per hectare can be achieved by optimizing water transfer efficiency. For cumin cultivation, this water conservation can even reach 3,000 cubic meters in cities with cooler climates. Surprisingly, in the hot areas of Isfahan province, including Ardestan, Nain, Khoor, Biabanak, Aran, and Bidgol, it is feasible to grow cumin with a water consumption of just 3,770 cubic meters per hectare.
Research Article
Irrigation
M. Koohani; J. Behmanesh; V.R. Verdinejad; M. Mohammadpour
Abstract
IntroductionLand-use changes and development of irrigated agricultural lands are very important factors that affect natural resources such as the quantity and quality of water resources and the environment. Land use change is attributed to two major processes. The first process is the change in land ...
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IntroductionLand-use changes and development of irrigated agricultural lands are very important factors that affect natural resources such as the quantity and quality of water resources and the environment. Land use change is attributed to two major processes. The first process is the change in land cover, which is related to the expansion or limitation of the area of land used (such as pasture, agricultural or urban land). The second process is a change in land cover management type (for example, changes in irrigation, fertilizer use, crop type, harvesting methods or surface impermeability). Recently the Urmia lake has been accompanied by a reduction in water resources and the continuation of this process can completely cause to dry Urmia Lake. One of the approvals of the Iranian government after the formation of the National Working Group for the Lake Urmia restoration program was to prevent the development of agricultural lands in this watershed since 2014. Unfortunately, no serious and effective action has been taken in this case yet, and this process has progressed to cause conflicts in this region. Game theory is one of the most important methods used in modeling and analyzing water and environmental resources conflicts.Materials and MethodsIn the present study, using GMCR + software, the water resources conflicts arising from agricultural land development has been analyzed. In this conflict, by accurately identifying the set of decision-makers and their strategies in the conflict process (Regional Water Company, Agriculture Organization, Justice, and Profiteering Farmers), the model was executed with 4 players, 6 options, and 64 states. Players' performance was assessed once as ideal behavior (importance to the environment, sustainable development, and preference of long-term over short-term interests) and then as the use of completing a questionnaire. Then 4 states in the ideal behavior as equilibrium states and 7 states in the condition of using the questionnaire results were extracted as equilibrium states. The conflict was also examined in the coalition state of 3 government organizations (Regional Water Company, Agriculture Organization, and Justice Organization). Finally, the most probable states of equilibrium in the game results were identified.Results and DiscussionIn the discussion concerning equilibrium points, it is crucial to consider that for resolving the dispute and the proposed solution, we need to examine not only the stability of these points but also the state's priority from the perspective of stakeholders. Based on the discussions and the output results of the conflict model using the GMCR+ model, the optimal response and conflict resolution can be found in scenario 12. This scenario holds a high priority for three key players: the Agricultural Organization, the Regional Water Company, and the Justice Department. However, it doesn't share the same level of priority with the Profiteering Farmers. The reason for this divergence lies in the preference for personal gain and profit pursuit over the broader interests of the entire catchment area.ConclusionIn recent years, despite the imposed restrictions, the Urmia Lake Basin has witnessed a notable increase in the cultivation of water-intensive crops. This shift has transformed arid lands into irrigated ones and altered agricultural areas into residential zones. According to the principles of the tax evasion game, when land development carries no moral or financial consequences for profit-driven farmers, and they are aware that regulatory institutions will not commit excessive resources to prevent and effectively combat the expansion of illegal farmlands, Profiteering Farmers will consistently engage in unauthorized development under any conflict scenario. In light of the revenue potential of this situation and the opportunity to enhance one's social standing, Profiteering Farmers will persist in unauthorized development regardless of the prevailing conflict circumstances. The findings underscore the critical role of the Regional Water Company and the Agricultural Organization. These entities must proactively employ their legal capacities to impede and deter the expansion of agricultural lands. Additionally, the Justice Organization assumes primary responsibility as a crime prevention factor, while its secondary role as a judicial enforcer within this conflict situation appears fitting. Therefore, all situations are stable for Profiteering Farmers. It seems that creating a platform and conditions in which Profiteering Farmers do not develop agricultural land themselves or do not develop land due to the protection of government institutions, can be very thoughtful and effective.
Research Article
Soil science
M. Rafati; M. Malekzadeh; M. Firoozi
Abstract
Intruduction
Increasing industrial activities with the production of pollutants, including heavy metals, is one of the serious problems of modern communities, which has led to their accumulation in the environment. Heavy metals are also one of the important pollutants in landfill leachate. Plants and ...
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Intruduction
Increasing industrial activities with the production of pollutants, including heavy metals, is one of the serious problems of modern communities, which has led to their accumulation in the environment. Heavy metals are also one of the important pollutants in landfill leachate. Plants and soil near the landfill may be contaminated by the leachate. Landfilling is the oldest method of solid waste disposal which can be a threat to the environment and health. Due to its easy operation and cost-effective, landfill is the most widely used method of municipal solid waste disposal in the world. Pollution cleaning technologies to reduce the harmful effects in the locations contaminated with heavy metals can be done by physical, chemical and biological methods. Phytoremediation, as a biological method, uses the green plants to extract, sequester, and detoxify pollutants. This method is a low-cost technique, environmentally friendly, and due to the non-production of by-products, is non-destructive for natural ecosystems. Considering the high moisture of wastes in Iran and their potential to produce leachate, as well as the possibility of contamination of water and soil in the landfill, especially with heavy metals, this study was conducted with the aim of evaluating the accumulation of lead (Pb) and cadmium (Cd) heavy metals in the soil, shoots and roots of artiplex (Atriplex sp.) and oleander (Nerium olander) plants in Aradkooh landfill of Tehran.
Materials and Methods
This study was conducted in Aradkooh landfill which is located in the south of Tehran in the Kahrizak region. About 5200 tons of municipal solid waste were sent to this landfill every day. A part of the solid waste in Aradkoh was placed in various processes to energy and compost, and about 2500 tons of the solid waste was landfilled. According to previous reports, it is estimated that 250 cubic meters of leachate are produced daily in the Aradkoh landfill. In the studied landfill, there is an atriplex plant in four areas and a hand-planted oleander in one area. Ten samples of soil, root, and shoot, totaling 120 total were randomly selected from each growing area of the atriplex plant. Oleander shoots and soil were also tested from 10 different plants for a total of 40 samples. Then the levels of Cd and Pb in the soil, roots, and shoots were assessed. In this study, the outcomes were analyzed employing four key indices: the bioconcentration factor (BCF), the translocation factor (TF), the pollution index (PI), and PINemerow. The BCF and TF indices were employed to assess the phytoextraction and phytostabilization capabilities of plants, while the PI and PINemerow methods were used to pinpoint the most environmentally hazardous heavy metal in the soil.Results and Discussion
According to the results, the concentration of Pb and Cd in shoots of atriplex area 2 (with an average of 19.7 and 5.75 mg/kg, respectively) were significantly higher than in other areas, while the concentration of these metals in root of oleander (with an average of 8.17 and 1.06 for Pb and Cd, respectively) were higher than the shoot. The amount of Pb element in soil of the oleander plant (with an average of 35.13 mg/kg) and Cd in soil of the atriplex area 2 (with an average of 3.78 mg/kg) were significantly higher than other areas. Additionally, the levels of heavy metals in the soil of two plants were higher than the Nemerow index, which indicated high levels of pollution in the sampling areas, but still below the safe levels that was set by national standards (3.9 and 300 mg/kg for Cd and Pb respectively) and the World Health Organization (5 and 40 mg/kg for Cd and Pb, respectively). In addition, bioaccumulation factor of shoot in all growth atriplex areas for Pb and Cd (with an average of 1.44 and 1.3, respectively) were higher than 1.0 while, the root bioaccumulation factors of this plant in any of the growth areas, were not higher than 1.0. In the case of oleander, the shoot and root bioconcentration factors for Pb and Cd were not reported more than one.
Conclusion
In general, it appears that atriplex, a native plant in the Aradkooh landfill, exhibits superior capabilities for absorbing heavy elements compared to oleander. Therefore, atriplex seems well-suited for the extraction of Pb and Cd from the soil, as it can accumulate these metals in its shoots. In contrast, oleander is not well-suited for phytostabilization or phytoextraction of these elements, as it exhibits limited ability to accumulate these heavy metals in its roots and shoots. Consequently, atriplex can be a valuable choice as a resilient species for phytoremediation projects in landfills and areas near mines. It is worth noting that the Pb content in the soil is higher than that of Cd. Although both metals fall within the permissible limits of national and WHO standards, the soil in the Aradkooh landfill is considered to be significantly polluted based on the Nemerow index.
Research Article
Soil science
Z. Khanmohammadi; A. Ahmadi
Abstract
Introduction
Iranian shallot, scientifically known as Allium hirtifolium Boiss. is a perennial plant of the Allium genus and native to Iran. The Allium genus has many antioxidant properties due to its being rich in organic compounds of sulfur and phenol. The shallot is used to treat rheumatic ...
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Introduction
Iranian shallot, scientifically known as Allium hirtifolium Boiss. is a perennial plant of the Allium genus and native to Iran. The Allium genus has many antioxidant properties due to its being rich in organic compounds of sulfur and phenol. The shallot is used to treat rheumatic and inflammatory pains, soothe superficial wounds, treat some stomach diseases, be antispasmodic, and also as a spice and flavoring in some foods. Considering the health benefits of shallot and its application in the food industry, shallot corms are harvested from the natural resources in different stages of growth. Therefore, it is necessary to preserve the natural habitats of shallot and also supply the market demand for this plant. It appears that the cultivation of shallots within agricultural systems could serve as a significant strategy for meeting the demands of the expanding global market. Furthermore, shallots are known for their low water requirements, making their cultivation a focal point in Isfahan province in recent years. Additionally, this crop stands out as a high-income generator in the region. Despite its economic potential, there has been limited research into optimizing the growth conditions for this valuable plant. Hence, this study aimed to explore the impact of urea and cow compost on the yield of Iranian shallots in the Fereydun Shahr region, focusing on the uptake of nitrogen, phosphorus, potassium, and nitrates.
Materials and Methods
This research was carried out in the crop year of 1400-1401 in a field with an area of 300 square meters (32° 55' 53" N, 49° 56' 43" E) located in Fereydunshahr city of Isfahan province. The experiment was conducted according to a completely randomized design. Factorial arrangement of experimental treatments including two fertilization factors (urea and cow compost) was used. Plots with dimensions of 2 × 3 meters were created with a distance of 50 cm between the rows. The treatments were considered as urea fertilization at four levels (0, 120, 240 and, 360 kg ha-1) and cow compost treatment at three levels (0, 40 and, 60 tons ha-1). After plotting and applying cow compost treatments, shallot corms were planted at a depth of 10 to 15 cm in November 1400. Urea fertilizer treatment was applied in two stages, the first stage when the plant germinated (mid-April) and the second stage before flowering (second half of May). All treatments were applied in 3 replications. It should be noted that the treatments in this research are shown as 0-0 (control), 0-40, 0-60, 120-0, 120-40, 120-60, 240-0, 240-40, 240-60, 360-0, 360-40 and 360-60. The corms were harvested in June 1401 and the fresh and dry yield of the shallots was determined. The amount of nitrogen, phosphorus and, potassium in shallots was measured. Nitrate concentration was also measured in the harvested corms based on the Iranian national standard No. 4106. The nitrogen, phosphorus and, potassium uptake by shallots was obtained from the product of yield and the concentration of these elements. Results were analyzed using analysis of variance (ANOVA) procedure and the means were compared using the protected least significant difference (LSD) test at р < 0.05 probability level using SAS 9.3 software.
Results and Discussion
The results showed that the combined use of chemical fertilizer (urea) and cow compost has a significant effect on the shallot yield increment, as the highest yield was obtained in the combined treatment of urea fertilizer 240 (kg ha-1) and cow compost 40 (ton ha-1) application. Although the highest nitrogen concentration and uptake were observed in the treatment of 360 (kg ha-1) of urea along with 60 (ton ha-1) of cow compost, it was not significantly different from the treatment of 240-40 (the treatment with the highest yield). In general, the concentration of shallots nitrate was much lower than the permissible limit according to the national standard of Iran No. 16596. The highest nitrate concentration (24.63 mg kg-1 of fresh weight) was observed in the combined treatment of 120 (kg ha-1) of urea and 60 (ton ha-1) of cow compost application (120-60), which was significantly higher than other treatments. On the other hand, the concentration of shallots nitrate in the 240-40 treatment was significantly lower than the treatments of 360 kg of urea per hectare along with 40 or 60 (ton ha-1) of cow compost.
Conclusion
According to the results, to achieve the best yield, the most suitable level of urea application was 240 kg ha-1 and the best level of cow compost was 40 ton ha-1. It seems, utilization more amounts of urea or cow compost will only cause additional costs to the farmer and a waste of capital. Moreover, it can increase environmental pollution and nitrate concentration of product, which cause to quality decrement.
Research Article
Soil science
Z. Sokhanvar Mahani; N. Boroomand; M. Sarcheshmeh Pour
Abstract
IntroductionPhosphorus (P) is one of the most important elements necessary for plant growth and production of agricultural products. In calcareous soils, phosphorus deficiency is a general issue due to high pH, high soil calcium carbonate content, lack of organic matter and moisture. Phosphorus absorption ...
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IntroductionPhosphorus (P) is one of the most important elements necessary for plant growth and production of agricultural products. In calcareous soils, phosphorus deficiency is a general issue due to high pH, high soil calcium carbonate content, lack of organic matter and moisture. Phosphorus absorption capacity depends on different soil reactions such as: adsorption, sedimentation, stabilization and release. The speed and amount of plant available P depends on the soil reactions. Studying the kinetics of P release from soil is a good indicator to check the status of P uptake by plant. The kinetics of P release in soils is a subject of importance in soil and environmental sciences. The aim of this research was to investigate the kinetics of P release and derive the most suitable equation to describe the release of P from a calcareous soil when subjected to the acidification of rock phosphate and the addition of vermicompost. Materials and MethodsIn order to investigate the ability of acidified rock phosphate and vermicompost in P release, an experiment was conducted with 2 replications on a light-textured soil with low OC and Olsen-P (1.2 mg/kg). One hundred grams air dried calcareous soil was transferred into special containers and 5 treatments including: 1- control (soil), 2- rock phosphate, 3- acidified rock phosphate (20 CC nitric acid 0.1 N and 5 g rock phosphate), 4- vermicompost, and 5- acidified vermicompost (20 CC nitric acid 0.1 N and 5 g vermicompost) were applied. The treatments incubated two weeks in 20±2℃ temperature. The Kinetics of P release was studied by adding 20 mL of 0.5N NaHCO3 to, one gram of air dried treatments. Extraction times were considered to be 0.25 h to 256 h (in 11 times) based on the time of adding the NaHCO3 extractant until filtering. After adding the extractant, the samples were shaken and centrifuged. After filtering, the concentration of released P in samples were determined by spectrophotometer (Model: CE 292 Series2, ultraviolet). For higher accuracy in the measurements, acid-washed containers were adjusted based on the amount of soil moisture which was dried in the oven (105℃). Finally, the P release data were fitted to different kinetic equations. The effect of different fertilizer treatments on P release in specified times and then kinetics parameters were investigated and compared with the control. Results and DiscussionAddition of acidified and non acidified rock phosphate and vermicompost increased the amount and speed of P release in the calcareous soil. Six kinetic equations were fitted to describe the release of P in the period of 0.25 h to 256 h from the soil to evaluate the effect of the treatments. The highest release of P was in vermicompost and acidified rock phosphate treatment, which were an organic fertilizer and a source for preparing phosphate fertilizers. To describe the release rate, kinetic equations were used. The best equations were chosen by highest coefficient of determination (R2) and the least of standard error (SE). The zero, first, second order equations could not describe the release of P in the studied calcareous soil. The R2 value decreased from the zero to second order equation. The simplified Elovich equation described well the release of P from the soil with the average R2 of 0.79 and with the average SE of 0.4. Comparison of the average effect of the studied treatments with the control showed that the acidifed vermicompost and rock phosphate treatments increased the capacity and speed of P release compared to the control. On the other hand, acid addition has increased the capacity and speed of P release in the calcareous soil. ConclusionThe findings indicated an initial rapid release of P, which then decreased over time. Notably, the application of vermicompost and the acidification of the soil with rock phosphate resulted in a pronounced and accelerated release of P. Generally, organic fertilizer treatments exhibited a higher release of P compared to chemical fertilizer treatments. This observation is in accordnce with the findings of the data presented by Ghorbanzadeh et al. (2009), who explored the P release potential of bone meal. Their data demonstrated that the acidification of bone meal accelerated and enhanced P release. To further enhance the practical relevance of these results, it is recommended to conduct this research in the presence of plants.
Research Article
Soil science
M. Bazi Abdoli; M. Barani Motlagh; A. Bostani; T. Nazari
Abstract
IntroductionOrganic matter and alkaline pH are the main causes of nutrient deficiencies in calcareous soils of arid and semi-arid regions. The availability of some nutritional elements, including the micronutrients such as iron, zinc, copper, and manganese is very low in calcareous soils, although the ...
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IntroductionOrganic matter and alkaline pH are the main causes of nutrient deficiencies in calcareous soils of arid and semi-arid regions. The availability of some nutritional elements, including the micronutrients such as iron, zinc, copper, and manganese is very low in calcareous soils, although the total concentration of these elements may be relatively high. Burning crop residues results in substantial loss of nutrients, and may lead to air pollution and human health problems. An alternative approach is to apply crop residues to soil in the form of biochar. The biochar modification with acid may increase the solubility of nutrients (P, Fe, Zn, Cu, Mn) present in biochar, thereby significant improvement in mineral nutrition of plants grown in calcareous soils. Therefore, the object of this study is to investigate the effect of acid-modified biochar from rice residues on the amount of chlorophyll and the micronutrient concentration of quinoa plant (Chenopodium quinoa) in a calcareous soil. Methods and MaterialsThe soil was air-dried and ground to pass through a 2-mm sieve then was analyzed to determine various soil physico-chemical properties using standard methods. To achieve the aim of this study the factorial experiment was carried out based on a completely randomized design in 4 replications. Factors include 3 types of biochar (unmodified, modified by pre-acidic method and modified by post-acidic method) and different levels of biochar (0, 2, and 5% by weight). Then 10 quinoa seeds were planted in each pot at 2-cm depth which after emergence, declined to 3 plants in each pot. The pots were randomly moved twice a week during the growth period to eliminate environmental effects. Irrigation and weeding operations were performed by hand. Determination of chlorophyll content (a, b, and ab) and carotenoids were measured precisely before harvesting in fresh plants using Arnon method. Plants were harvested at 187 days after planting, washed with distilled water and dry with tissue paper. The samples were air-dried and then oven dried at 65˚C to a constant weight in a forced air-driven oven. Then the total micronutrient content of the plant was determined after dry ashing. The statistical results of the data were analyzed using SAS software (9.4) and LSD test (at 5% level) was used for comparing the mean values. Results and DiscussionBased on the variance analysis, all attributes responded positively to different types and levels of biochar and modified biochar (p<0.01). The comparison of the average effect of the studied treatments showed that with the increase in the levels of all three types of biochar, the amount of chlorophyll a, b, total, and carotenoid increased so the highest amount of chlorophyll a, b, total, and carotenoid respectively, with an average of 2.58 and 1.54, 4.13 and 1.36 mg g-1 were obtained from the treatment of 5% post-acidic biochar. The results showed that the highest amount of Fe concentration in shoots with an average of 229.48 mg kg-1 was obtained from the treatment of 5% post-acidic biochar, although there was no statistically significant difference with the treatment of 5% pre-acidic biochar with an average of 220.48 mg kg-1 and its lowest value with an average of 95.95 mg kg-1 was related to unmodified biochar. The highest amount of Zn concentration in shoots with an average of 13.42 mg kg-1 was related to the treatment of 5% post-acidic biochar which showed an increase of 13.24 and 33.26% compared to the treatment of 5% pre-acidic and unmodified biochar, respectively. Also, the highest concentrations of Cu and Mn in shoots were obtained with an average of 3.85 and 23.37 mg kg-1 respectively, from the treatment of 5% post-acidic biochar. ConclusionPost-acidic biochar had better results in terms of physiological indices and the concentration of micronutrients (Fe, Zn, Cu, and Mn) than unmodified biochar in quinoa. The increase of nutrients in quinoa can be attributed to the dissolution of biochar nutrients after being modified with acid and the reduction of pH and the availability of these elements in the soil. Therefore, biochar modified with acid or biochar produced from sources that have acidic properties can be recommended as a suitable method for improving fertility and increasing micronutrients in calcareous soils affected by salt.
Research Article
Soil science
H.R. Owliaie
Abstract
Introduction
Soil classification is the systematic categorization of soils based on distinguishing soil characteristics, aiding in the comprehension of soil properties through soil surveys, and establishing suitable strategies for effective soil utilization and management. One of the main reasons ...
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Introduction
Soil classification is the systematic categorization of soils based on distinguishing soil characteristics, aiding in the comprehension of soil properties through soil surveys, and establishing suitable strategies for effective soil utilization and management. One of the main reasons for creating soil classification systems is to identify the differences in important soil characteristics for management purposes. Globally, Soil Taxonomy (ST) and the World Reference Base for soil resources (WRB) are widely used for soil classification. However, these two classification systems have varying criteria which can pose difficulties when exchanging classification results. After years of intensive worldwide testing and data collection, new versions of the ST and WRB systems have been released. In its current state, ST has a strong hierarchy with six categorical levels: order, suborder, great group, subgroup, family, and series (Soil Survey Staff, 2022), while the WRB has a flat hierarchy with only two categorical levels: reference soil groups and soil units (IUSS Working Group WRB, 2022). Several scientists have endeavored to evaluate the merits and demerits of these soil classification systems and offer recommendations for their enhancement. The arid and semi-arid regions located in the western and southwestern parts of Kohgiluyeh and Boyerahmad Province, distinguished by their considerable diversity in parent materials, topography, climate, and land use, present an excellent opportunity for scrutinizing and contrasting the effectiveness of soil classification systems. Remarkably, no prior research has delved into this subject in this specific geographical area. Consequently, this research aims to compare the effectiveness of the ST and WRB systems in characterizing soil attributes. Furthermore, it seeks to analyze the alterations that these two systems have undergone during an eight-year period, spanning from 2014 to 2022.
Materials and Methods
This study was conducted in the western and southwestern regions of Kohgiluyeh and Boyerahmad Province, specifically in the divisions of Gachsaran, Basht, Choram and Kohgiluyeh. A total of 26 soil profiles were excavated, described, and sampled based on aerial photos, satellite images, topographical and geological maps, as well as field observations. These profiles were selected following the soil description guide provided by the Department of Soil Conservation of the US Department of Agriculture. Subsequently, after reviewing the preliminary results and aligning with the research objectives, 12 representative soil profiles were chosen for further analysis. Soil samples were collected from all genetic horizons and transferred to the laboratory. After air-drying, the samples were passed through a two-millimeter sieve and the routine physical and chemical analyses were conducted, including soil texture, pH, electrical conductivity (EC), calcium carbonate equivalent (CCE), organic carbon, cation exchange capacity (CEC), and gypsum analyses. For mineralogical studies, soil clay minerals were separated and identified using standard methods. Additionally, soil thin sections were prepared from intact soil samples of selected soil horizons and examined under a polarizing microscope. Finally, the soil profiles were classified based on the criteria outlined in Soil Taxonomy (2022) and WRB (2022).
Results and Discussion
Soil Taxonomy and WRB, as the two most popular classification systems, aim to encompass as manysoil characteristics as possible. According to the ST classification, the soils were classified into four orders: Entisols, Inceptisols, Alfisols, and Mollisols. In the WRB system, they were grouped into seven reference soil groups: Regosols, Flovisols, Luvisols, Cambisols, Kastanosems, Gypsysols and Glysols. The results revealed that WRB was significantly more effective in describing the characteristics of the studied soils. One of the key advantages of this two-level system is its flexibility, allowing for the inclusion of additional principal and supplementary qualifiers to cover all essential soil characteristics. Moreover, in many cases, WRB exhibits better prioritization compared to ST. For example, the presence of gypsic, combic, calcic horizons, as well as fluvic and gley properties, can allocate the soil to the reference groups of Gypsisols, Cambisols, Calsisols, Fluvisols, and Gleysols, respectively. However, a limitation of the WRB system is the absence of mineralogical information in soil classification. Enhancing this classification system's quality and making it more appealing to planners could be achieved by incorporating suitable mineralogical attributes for the reference groups or criteria that express soil fertility conditions with relatively straightforward measurements. In addition, it is proposed to add three subgroups to ST: Gypsic Haplustalfs, Fluventic Gypsiustepts and Cambic Haplustolls. Similarly, following the WRB model, it is recommended to introduce a qualifier in ST to indicate the presence of lithological discontinuity. Regarding the WRB system, suggestions include adding qualifiers such as "Cutanic" to gypsisols with clay films, "hypercalcic" to reference groups of Kastanozems and Luvisols with a calcic horizon comprising more than 50% of calcium carbonate, and "aridic" for better expression of soil characteristics with Aridic-Ustic moisture regimes.
Conclusion
The results of this research demonstrated that WRB is more effective in describing the conditions and characteristics of the studied soils. The WRB system, through its diverse set of qualifiers, is capable of representing field conditions more efficiently. However, it is suggested that the surveyors have the freedom to select an appropriate qualifier from the list provided by WRB without limitation, which can enhance its success in practical applications. Furthermore, it is recommended that both classification systems be used to categorize soils, not only to evaluate their efficiency for the soils in other regions but also to gain a comprehensive understanding of their suitability for different contexts.
Research Article
Agricultural Meteorology
A. Gholami; H. Mir Mousavi,; M. Jalali; K. Raispour
Abstract
Introduction
Clouds can be considered as one of the most complex and influential variables of the atmosphere system in forming of the climate structure of the earth. When the condensation process takes place at a higher altitude than the earth's surface, it creates clouds. Cloudiness represents ...
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Introduction
Clouds can be considered as one of the most complex and influential variables of the atmosphere system in forming of the climate structure of the earth. When the condensation process takes place at a higher altitude than the earth's surface, it creates clouds. Cloudiness represents the percentage of the atmosphere that is covered by clouds. Clouds, as one of the most complex variables of the climate system, besides changing the energy balance, are also effective in the spatial and temporal distribution of many climate variables. Clouds have a lot of temporal and spatial variability and can affect the climate through many complex relationships and affect the water cycle. The investigation of clouds holds great significance as they serve as the bridge between synoptic systems and the Earth's surface climatic conditions. Any alteration in cloud-related parameters can trigger a domino effect, influencing various other climatic variables. It's worth noting that Iran exhibits a lower average cloud cover of 26%, notably less than the global average of 50%. This places Iran in the category of countries with relatively minimal cloud cover.Hence, possessing insights into the atmospheric cloud cover conditions in Iran becomes imperative for early detection and management of hydroclimatic crises, particularly in the context of water scarcity and drought-related challenges.
Data and Methods
In the current research, the cloud data of 93 synoptic meteorological stations of Iran have been used in the daily time period during the statistical period of 1991-2021. The amount of cloudiness is an estimate of the nearest octa (eighth) and values 0 and 8 are completely clear and completely cloudy, respectively. In the present study, Kolmogorov-Smirnov, Anderson-Darling and Lilliefors test were used to determine the normality of the data at the 95% confidence level for annual, monthly and seasonal scales.
In the subsequent phase, we employed both parametric and nonparametric methods to discern trends within the cloudiness time series. The parametric approach involved a linear regression test based on the least squared error method, while the nonparametric method employed the Mann-Kendall test. These tests allowed us to identify data trends, accounting for both normal and non-normal distributions of cloudiness. Furthermore, we explored the interplay between cloud cover and spatial factors, namely latitude and longitude, employing Pearson's correlation coefficient. This analysis shed light on the relationships between these variables. Conclusively, we created a spatial distribution map depicting the extent of cloudiness across various stations. This mapping allowed us to dissect the temporal-spatial distribution of cloudiness, comprehend alterations in cloud cover, and investigate the contributing factors behind these changes.
Results and Discussion
The results of Normality Tests according to the Kolmogorov-Smirnov test showed that all the stations did not have a normal distribution however, during the other two tests, except Arak, Kashan, Sarakhs, Takab, Kahnuj, Ramhormoz and Ramsar, other stations had normal distribution. The tests to determine the trend based on the parametric linear regression test based on the least squares error method showed a decreasing trend in 44 stations and an increasing trend in 3 stations of Ardabil, Qom and Sarab. According to the non-parametric Mann-Kendall test, among the stations without normal distribution, Kahnuj, Ramhormoz and Sarakhs stations have a decreasing trend, and no special trend was observed in other stations. The relationship between the two factors of latitude and longitude with the cloudiness variable using the Pearson correlation coefficient indicates a negative relationship (-0.42) between the cloudiness variable and the longitude factor as the amount of cloudiness in Iran's atmosphere decreases with the increase of latitude. Hwoever, the relationship between cloudiness variable and latitude, a positive relationship (0.75) was obtained as the amount of cloudiness increases with the increase of latitude. The survey of the annual cloudiness map of the stations shows the highest amount of cloudiness is in the South, Southwest and East of Caspian Sea. The lowest amount of annual rainfall was in South and Southeast of Iran. The statistical analysis of annual cloudiness data in Iran showed that the amount of cloudiness in Iran is 27.5%. Examining the normal distribution of monthly and seasonal values indicates the non-normality of the data with the Kolmogorov-Smirnov test, but based on the Lilliefors and Anderson-Darling tests, the winter and spring seasons and the months of December, January, February, April and May had a normal distribution and the autumn and summer seasons and the months of June, July, August, September and October did not have normal distribution. Seasonal and monthly trend with linear regression method shows a decreasing trend in winter and spring seasons and cold months of the year. According to the Mann-Kendall method, there was a decreasing trend in the fall season and no significant trend was observed in the summer season.
Conclusion
The purpose of this research was to investigate the temporal and spatial changes of cloudiness in Iran. The results showed a decreasing trend in 47 stations and an increasing trend in only 3 stations and no significant trend was observed in other stations. Also, in monthly and seasonal scales results indicated a decreasing trend in all stations in the cold months of the year and winter, spring and autumn seasons. Examining the relationship between the spatial factors of longitude and latitude with the cloudiness variable using Pearson's correlation coefficient also indicates a negative correlation with longitude and a positive correlation with latitude, and this indicates a large spatial difference in the amount of cloudiness in the country. In general, it can be said that spatial factors (longitude and latitude) were internal factors in the spatial changes of clouds and climatic systems such as Siberian high pressure, sub-tropical high pressure, westerlies system and moisture from the seas of Oman, India and the Persian Gulf and sometimes the Red Sea as external factors were in the temporal changes of clouds. So, cloudiness was a variable that was directly related to other climate variables. Thus, cloud cover was a variable that was directly related to other climatic variables, and its decrease or increase causes the values of elements such as temperature, precipitation, and humidity to change. Therefore, studying this important climate variable and investigating its changes is very important and especially in the discussions of droughts and water crises, it has a special place.
Research Article
Agricultural Meteorology
A. Yahyavi Dizaj; T. Akbari Azirani; Sh. Khaledi; Kh. Javan
Abstract
IntroductionEvapotranspiration is the combination of two separate processes, soil moisture evaporation, and plant transpiration, which amount depends on various meteorological elements. Therefore, identifying the effective factors and the amount of their impact on reference evapotranspiration (ET0) is ...
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IntroductionEvapotranspiration is the combination of two separate processes, soil moisture evaporation, and plant transpiration, which amount depends on various meteorological elements. Therefore, identifying the effective factors and the amount of their impact on reference evapotranspiration (ET0) is important. This component plays an important role in various agricultural studies, including the design of irrigation and drainage systems, reservoir design, and irrigation planning (Ahmadyan et al., 2023). Accurate estimates of evaporation and transpiration play an important role in studies such as global climate change, and environmental evolution, and in various scientific fields such as hydrology, agriculture, forest and pasture management, and water resources management (Kazemi, 2020). Materials and MethodsThe research was conducted in Iran, and the data analyzed encompass various meteorological parameters, including maximum, average, and minimum temperatures, average relative humidity, wind speed, and sunshine hours. These data were collected on a daily basis from 40 synoptic stations across the country. The dataset spans from 1976 to 2020 and was sourced from the Meteorological Organization of the country (IMO, 2022).The research employed the FAO Penman-Monteith method, specifically the 56th version, to estimate seasonal ET0 (evapotranspiration) values.In this research, for statistical evaluations of ET0 and revealing the trend of time series on a seasonal scale, the non-parametric Mann-Kendall (M-K) test; (Kendall, 1948; Mann, 1945) was used. To identify the changing trend of the ET0 time series, the ITA method was used on a seasonal scale. Four meteorological stations and the 45-year time scale (1976-2020) used in the current research, it had a better performance than other interpolation methods, which was used as the superior method. To understand the possible changes of one or more meteorological variables in ET0, the sensitivity of Reference Evapotranspiration to six meteorological variables (relative humidity, hours of sunshine, average temperature, maximum temperature, minimum temperature, and wind speed) was estimated. For this purpose, Sobol's method (Sobol, 1993). Sensitivity analysis was used. Results and DiscussionAccording to the ET0 survey results, the highest amount of ET0 was observed in the spring season in the south and south-eastern parts, and the highest average value was 1050 mm/year in Zabul station. The increase of ET0 in these areas can be due to the sun's radiation and more warming of the earth's surface in the southern latitudes of the country. In summer due to the length of the day and higher temperature, we saw an increase in ET0, especially in the southern and southeastern regions of the country. In autumn, due to the decrease in the length of the day and the decrease in temperature, the amount of ET0 has also decreased significantly in the northern parts of the country. In winter, with a decrease in temperature and an increase in relative humidity, which is more noticeable in northern than southern regions.In the summer season, all stations generally showed an increasing trend in ET0. In most of the stations, the significance level was 5% and it did not follow a specific pattern. In the autumn season, an increasing trend of ET0 was observed at a significant level of 5% in Khoy and Saqez stations, and a significant decreasing trend was observed in Qazvin and Shiraz stations. In the winter season, in the western and northwestern regions, all study stations showed an increasing trend of ET0. Finally, the overall results indicate that there is a significant increasing trend of ET0 during the summer in Iran. The graphical results of the ET0 trend by the four seasons on a scale of 44 showed that, in general, there was an increasing trend in ET0 in both high and low areas in all seasons. The values of meteorological variables have been changed by the Sobol method in the range of 40% to investigate the effect of meteorological elements on ET0 in different seasons of the year. The ranking of the sensitivity coefficient of the most effective meteorological parameter on the increase of the seasonal ET0 using Sobol's method showed that, in general, in the spring season, the minimum temperature had the greatest effect on the reference evaporation and transpiration rate. Also, the ratings obtained in the summer season indicate that wind speed has the greatest effect on the ET0 amount. In the autumn season, wind speed is still the first rank in affecting the rate of evaporation and transpiration. Finally, in the winter, the maximum temperature is the most important influencing factor among the other meteorological parameters. ConclusionAccording to the results, the amount of ET0 was increasing and it has been noteworthy in the eastern half of Iran in recent years. The trend of changes in ET0 showed that most stations had a positive value. The ET0 seasonal time series analysis with the ITA method indicated that in Kerman station; ET0 increased in all seasons and these results were at Bandar Anzali station. It was also observed that the seasonal trend of ET0 was increasing. The results of the sensitivity analysis graphs showed that relative humidity generally had a negative effect, and the other parameters indicates a positive effect in increasing the ET0. Also, the results explained that in spring, summer, autumn, and winter, meteorological variables of minimum temperature, wind speed, and maximum temperature played a greater role in increasing ET0. The findings of the present research and the results of the ranking of the sensitivity of factors affecting the ET0 rate showed that in each period, different conditions prevail in terms of the influence of meteorological elements on the ET0 rate.
