نشریه آب و خاک
سال سی و هفتم شماره 2 (پیاپی 88، خرداد و تیر 1402)

Over the last years, long-term average rainfall has experienced a meaningful decrease (from 250 to 206 mm per year) leading to continuous drought in Iran. In addition, population growth and increasing demand for food put more pressure on the limited available water resources. Thus, the quantitative and qualitative improvement of agricultural products become a necessity. There is 640,000 hectares of alfalfa cultivated land, standing for 5.4% of the total cultivated area. One of the most basic obstacles in these farms is the unsuitable model of water consumption management. Previous studies were conducted with the aim of evaluating the mutual effects of different treatments in controlled plots. Nonetheless, there is a need for large-scale investigations to monitor and improve water productivity in agricultural systems. In this research, the focus was on irrigation management and optimizing irrigation timing as a potential solution to enhance water productivity, considering the fixed irrigation cycles and traditional use of available water resources. The study began by assessing the current water productivity in 11 alfalfa farms located across four regions in Zanjan province, ensuring a suitable spatial distribution. Subsequently, the impact of irrigation management, particularly the adjustment of irrigation timing, was evaluated to determine its effectiveness in improving water productivity in these farms.

Eleven alfalfa farms, covering a total area of 28 hectares, were initially selected in the agricultural lands of Zanjan province. The majority of these farms were equipped with sprinkler irrigation systems. From these 11 farms, two specific farms were chosen to implement the proposed methods aimed at improving water productivity. These selected farms served as experimental sites where the irrigation management techniques were applied and evaluated. Improvement solutions were mainly focused on irrigation management. Each farm was divided into two parts; one part with real conditions (farmers' management) and the second one with controlled conditions. In the controlled treatments, irrigation management was implemented through optimization of irrigation time. A nutritional program was also prepared according to the soil quality of the fields and applied in the controlled treatments. In each farm, basic information such as area, physical and chemical properties of soil and water quality were determined. Irrigation information (such as inflow discharge and irrigation schedule) was measured and determined at least three times during the cropping season. Soil moisture were measured before and after irrigation in order to calculate the water application efficiency. The amount of harvested product and production costs were obtained at the end of the cropping season through measurements and interviews with farmers. In this research, the indicators including the volume of irrigation water, the water use efficiency, and the physical and economic efficiency of water have been calculated to analyze the water productivity.

The volume of irrigation water in alfalfa farms was measured as 14250 m3/ha on average (with the lowest and highest consumption values of 9849 and 20576 m3/ha, respectively). The average of irrigation water in farms with surface irrigation systems equals to 17,806 and in farms equipped with sprinkle irrigation systems is about 13,460 m3/ha. While the net water requirement of alfalfa in study area was 7160 to 7290 m3/ha. The minimum and maximum values of water application efficiency were 38.3 and 82%, respectively, with average of 64%. The average of application efficiency in surface and sprinkle irrigation systems were obtained 50 and 67%, respectively. The measured alfalfa yield ranged from a minimum of 6.5 ton/ha to a maximum of 14.1 ton/ha, with an average yield of 10.4 ton/ha. After implementing the revised irrigation program in the controlled plots, the harvested water decreased by an average of 49.5%. It was observed that the irrigation schedule in most farms followed a traditional and estimated pattern, with the depth of irrigation water in the middle of the growing season exceeding the net irrigation requirement. The water use efficiency (WUE) values varied between 0.42 and 1.28 kg/m3, with a minimum value of 0.42 kg/m3 and a maximum value of 1.28 kg/m3. The average WUE was calculated as 0.79 kg/m3. Analyzing the correlation between water consumption and the water use efficiency index revealed a decreasing trend. As the volume of irrigation water increased, the water use efficiency index experienced a decline. Specifically, an increase of 1000 m3 in irrigation water resulted in a decrease of 0.04 kg/m3 in the water use efficiency index. The implementation of the corrected irrigation program and appropriate to the water demand led to an increase of the mentioned index by 72%.

The lack of proper irrigation programs that consider climatic conditions and the actual needs of the alfalfa plant was identified as a key factor contributing to high water consumption in the farms. Additionally, the inefficient selection and design of the irrigation system led to lower irrigation efficiency than expected. Despite the majority of farms being equipped with sprinkle irrigation systems, the harvested water did not decrease significantly due to inadequate water management practices. These factors ultimately resulted in a decline in both physical and economic productivity indicators in the alfalfa farms. However, the results of the study highlighted that implementing corrected irrigation management, particularly through modifications to the irrigation timing, can lead to a significant decrease in volume of irrigation water and an improvement in both physical and economic productivity.

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.

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.
 

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.

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.

Considering the value of water in agriculture and the limitation of this important and vital resource and the existence of intermittent droughts in the country, saving in consumption and optimal use of available water seems necessary. Today, utilizing saltwater is considered one of the practical and effective approaches to minimize water consumption while achieving acceptable economic performance. Given the scarcity of freshwater sources, the utilization of unconventional water for strawberry cultivation holds significant economic importance. Through the application of innovative technologies, such as magnetic technology, the modification of these water sources can lead to increased quantitative and qualitative yields of agricultural products. Salinity stress, which alters the water and nutrient absorption patterns, directly impacts the plant's yield in terms of both quantity and quality. Strawberry is an important commercial product, and the quantitative and qualitative increase of its yield is emphasized from different aspects. The purpose of this research is to the effect of salinity stress under the influence of a magnetic field on the yield and yield components of the strawberry plant.

The purpose of this research was to investigate the effect of salinity stress under the influence of magnetic fields on the yield and yield components of strawberry plants. The factorial experiment was conducted in the form of a randomized complete block design with three replications in 2021 and 2022 in Neka city. The control treatment included full irrigation in all stages of plant growth with normal water (non-magnetic). The treatments include the type of irrigation water at two levels (Non-Magnetic Water (W1) and Magnetic Water (W2)), and water salinity was at three levels (0.86 dS/m (S1), 20 mM sodium chloride (S2), and 40 mM sodium chloride (S3). The strawberry plant of the Silva cultivar was cultivated in 3 x 4-meter plots with a row spacing of 40 cm and a between the spacing of 40 cm. Magnetization of irrigation water was created by passing water through a permanent magnet with a magnetic field intensity of 0.3 Tesla. The salt used for salinity stress was laboratory sodium chloride. The used irrigation method was drip (tape), and the amount of irrigation water and irrigation cycle was done according to the needs of the plant. Soil moisture monitoring was used to calculate the amount of applied water.

The results of analysis of variance showed that the effect of the irrigation water type and different levels of water salinity on the length, diameter, number of fruits per plant, fruit weight, biomass and plant yield was significant at the 1% probability level. The effect of water salinity on the number of fruits per plant was significant at the 1% probability level and on the fruit length and fruit diameter at the 5% probability level. The interaction effect of irrigation water type and water salinity was also significant at the probability level of 1%. On average, during two years of strawberry cultivation with the application of a magnetic field, the length, diameter, number of fruits per plant, fruit weight, biomass, and plant yield were increased by 9.76, 14.14, 23.05, 27.60, 27.08, and 28.36% respectively. The introduction of 20 and 40 mM sodium chloride resulted in a decrease in the physical characteristics of strawberry fruit and overall yield. The most significant reduction was observed in the number of fruits per plant at the salinity level of 40 mM sodium chloride, exhibiting a 56.69% decrease compared to the control treatment.

The growth of population and expansion of agriculture on one hand and the demand for more harvesting from limited water resources on the other hand, make it necessary to increase water productivity. Lack of water and competition for water resources has caused research to be done in order to reduce water consumption and preserve its resources. Therefore, searching for ways to reduce consumption and preserve water resources is of great importance. One of these methods is using magnetic water. The results of the research showed that the use of magnetic water technology caused a significant increase in the yield and yield components of strawberries compared to the control treatment. In addition, the salinity level of irrigation water had a significant impact on the yield and yield components of strawberries, with the highest yield observed in the treatment without salinity stress when using magnetic water technology. The findings of this study indicate that the application of magnetic water technology can enable the use of low salinity levels and lead to improved strawberry yield.

Wind Erosion is the natural process of transportation and deposition of soil by wind. It is a common phenomenon occurred mostly in dry, sandy soils or anywhere the soil is loose, dry, and finely granulated. Heavy metals are found in the environment and soils may become contaminated by accumulation of heavy metals through emissions from the rapidly expanding industrial areas, mine tailings, disposal of high metal wastes, leaded gasoline and paints, land application of fertilizers, animal manures, sewage sludge, pesticides, wastewater irrigation, coal combustion residues, spillage of petrochemicals, and atmospheric deposition. Soils are the major sink for heavy metals released into the environment by the aforementioned anthropogenic activities and their total concentration in soils persists for a long time after their introduction. The heavy metal contamination of soil and its potential risks to humans and the ecosystem is a significant concern. Windy deposition, which is the process of heavy metals being transported by erosive winds and deposited onto soil, is one of the sources of heavy metal contamination. Due to the geographical situation and climatic conditions such as arid soil, erosive winds are blown in periods of year in Tabas. Since wind are erosion is severe in this area, huge amounts of wind deposition accompanied with erosive winds entered into this town. Heavy metals through the windy deposition are suspended, translated and finally deposited in residential regions, which can create some problems for human health. Therefore, the knowledge of wind erosion and the human risk of these deposits is essential. The aim of this research was to determine the rate of wind erosion and the concentration of some heavy metals in these deposits.

 For this purpose, the rate of suspended load was measured monthly from February 2021 to January 2022. Based on previous information from the erosive winds and storms, suspended depositions were gathered in some directions (north, northwest, northeast, west and southwest) of the Tabas entrance. In addition, the suspended load in the city center of Tabas was also measured. The cumulative load of suspended depositions was measured monthly and the concentration of some heavy metals such as manganese (Mn), iron (Fe), cupper (Cu), and zinc (Zn) were measured in these suspended particles.  Soil digestion was made by Aqua regia (nitric acid and chloridric acid; ratio of 3:1), and after then atomic absorption was used to measure the total concentration of above heavy metals.

The results indicate that Tabas experiences significant wind deposition of suspended loads, with the highest rates entering from the northeast direction and the lowest rates from the southwest direction. This pattern aligns with the wind rose of Tabas, which illustrates the prevailing wind directions in the region. Additionally, substantial suspended loads are observed in the northwest and north directions. The variations in suspended load discharge reveal that the maximum discharge occurs in the city center of Tabas during the months of June and July 2021. This corresponds to the arid climate conditions of these months, where plant growth is limited, soil cohesion is low, and loose soil particles on the surface are susceptible to wind forces. As a result, these loose particles are easily detached by the wind, contributing to the high levels of suspended load. Regarding the spatial variation of heavy metals in suspended particles, the cumulative concentrations of Mn, Fe, Cu, and Zn are found to be higher in the west, northwest, north, and west directions, respectively. This suggests that these heavy metals are transported and deposited in specific areas within Tabas due to the prevailing wind patterns. In terms of temporal variation, the highest concentrations of Mn and Fe in suspended particles are observed in April 2021, predominantly in the northeast and west directions, respectively. On the other hand, the highest concentrations of Cu and Zn are found in May 2021, with the southwest and northeast directions being the primary deposition areas for each metal, respectively. These findings highlight the spatial and temporal dynamics of suspended load and heavy metal deposition in Tabas, emphasizing the influence of wind patterns and climatic conditions on these processes. Understanding these variations is crucial for assessing the potential risks associated with heavy metal contamination and implementing appropriate mitigation measures in the region.

The results of this research showed that most contents of the suspended load are entered from the northeast direction into Tabas. In addition, the spatial variation of heavy metals indicated that the concentrations of studied heavy metals (Mn, Fe, Cu, and Zn) in suspended particles, especially in the western, northwestern, and northern in spring, are very high and they can cause carcinogenic effects on human life. Therefore, the management practices should be mostly made in these directions to control or reduce soil erosion and reduce its damage effects.

In sustainable farming systems, the use of organic fertilizers is of particular importance in increasing crop production and maintaining sustainable soil fertility. Nowadays, the consumption of organic foods is introduced to consumers as an alternative. The result of the application of chemical products is the crisis of environmental pollution, soil and water resources, and the health risk to human society. Nowadays, in order to reduce the effects of misuse of chemical inputs, chemical fertilizers can be replaced with organic biological fertilizers, including animal manure, compost, and green manure. In this regard, chicken manure has a positive effect on the physical, chemical, and biological characteristics of the soil, and due to its richness in uric acid, the nitrogen contained in it is used by the plant much faster than the nitrogen of other organic fertilizers. Vermicompost is considered a good source of soil fertility due to its organic materials. Organic matter in the soil improves the permeability and drainage of the soil and also prevents excessive dryness of the soil by maintaining sufficient moisture. Despite the fact that vermicompost can be used as a fertilizer in organic farming, high levels of this fertilizer may cause salinity effects in the plant, which affects the growth and development of the plant and even it can cause the death of cucumber as one of the crops sensitive to soil and water salinity. The cucumber (Cucumis sativus L.) is one of the important vegetables that can be produced in a greenhouse all year round. Fresh consumption of cucumber throughout the year has increased its production. The development of technology and the short growth period of this product has made it possible to grow it in most climate zones. Therefore, in this research, the effects of different levels of water deficit with the simultaneous application of vermicompost and chicken manure on cucumber plants in the Behbahan region have been investigated.

In this study, different levels of irrigation water, vermicompost, and poultry manure on ground cucumber were investigated. The experiment was performed in the form of split plots based on completely randomized design and the form of stacks. Treatments included three levels of poultry manure (2, 4 and 8 ton ha-1), three levels of vermicompost (3, 6 and 9 ton ha-1) and three levels of water stress (100, 75 and 50% of plant water requirement). Both vermicompost and poultry manure were applied to the soil before planting. Harvest was done every three days. Fruit weight, diameter and length, plant length, the protein of the dry matter of the fruit percentage, and leaf chlorophyll in each plot were carefully measured. Also, the yield and water productivity at the end of the season were calculated. Water productivity  Referring to the yield to irrigation water ratio, is obtained by the following relation (Payero et al., 2009):WP=Y/IR (1)In this equation, WP represents water productivity (kg/m3), Y denotes the yield (kg/ha), and IR shows the amount of irrigation water (m3/ha). Statistical analysis The analysis of variance for the results obtained from different treatments was conducted using SAS software (SAS 9.1, SAS Institute, Cary, NC, USA). The mean values of the main factors and interactive effects were compared using the Duncan method at the 1% and 5% levels of significance.

The results showed that irrigation, poultry manure and vermicompost had a significant effect on the measured parameters at the level of one and five percent probability. Reduction of water consumption reduced yield and yield components, but in this regard, no significant difference was observed between 100% and 75% of water requirement. The highest yield was obtained in the treatment of 100% of plant water requirement and consumption of 4 ton ha-1 of poultry manure and 6 ton ha-1 of vermicompost, in this regard, no significant difference was observed with the treatment of 75% of water requirement. According to the results obtained from this study, it can be said that there is no significant difference in terms of yield between treatments of 75 and 100% of plant water requirement. Therefore, the amount of water given to the plant can be reduced to 75% of the plant water requirement, and with proper management, less water can be consumed without a significant reduction in crop yield. Examining the effects of irrigation water on the amount of the protein of the dry matter of the fruit showed that the highest amount of the protein of the dry matter of the fruit (56.31%) was obtained in the treatment of 75% of the water requirement and the protein of the dry matter of the fruit was less in other treatments. The interaction effect of vermicompost and poultry manure resulted in the highest percentage of cucumber protein at a treatment of 4 tons ha-1 of poultry manure and 6 tons ha-1 of vermicompost (58.42%). However, when the simultaneous use of 8 tons ha-1 of poultry manure and different levels of vermicompost was employed, the percentage of protein in the fruit's dry matter decreased. The combination of drought stress, poultry manure, and vermicompost, along with their interaction effects, significantly influenced the chlorophyll a and b values at both the 1% and 5% probability levels. As the depth of irrigation water decreased, the amounts of chlorophyll a and b also decreased. The treatment with 100% water requirement of the plant showed the highest amounts of chlorophyll a (0.63 mg/g fresh weight) and chlorophyll b (0.36 mg/g fresh weight). However, no significant difference was observed compared to the 75% treatment. Regarding the interactions between vermicompost and poultry manure, it was found that when using 6 tons ha-1 of vermicompost to reduce yield and its components, the use of poultry manure should be reduced to 4 tons ha-1. On the other hand, when higher levels of vermicompost (9 tons ha-1) are used, the application of poultry manure should be reduced to 2 tons ha-1.

According to the results obtained from this research, it can be said that there is no significant difference in performance between the treatments of providing 75% and 100% of the water requirement of the plant, therefore, the amount of water given to the plant can be reduced to the amount of 75% of the water requirement of the plant. With proper management, less water can be consumed without significantly reducing the yield of the product.

Recent studies show that most crops and horticultural plants can form symbiosis with the arbuscular mycorrhizal fungi (AMF) and the endophytic Serendepita indica, simultaneously. The endophytic fungus plays an important role in alleviating environmental stresses in plants. It has also been shown that excessive available phosphorus in soil limits the root colonization by arbuscular mycorrhizal fungi. No information is available on how soil phosphorus affects the establishment of endophytic fungus in root. Barley roots can be colonized by both mycorrhizal fungi and the endophytic fungus Serendipita indica. The objective of this study was to evaluate the effects of single or dual inoculation with Rhizophagus irregularis and Serendipita indica on barley roots under different phosphorus (P) levels. The researchers utilized a monoclonal antibody called MAb32B11 to assess the presence of glomalin, a signature molecule of arbuscular mycorrhizal (AM) fungi, in the roots. The glomalin content was quantified using the enzyme-linked immunosorbent assay (ELISA) method with the MAb32B11 antibody.

In this experiment, barley plants were inoculated with Rhizaphagus irregularis (AMF) and Serendepita indica (endophytic fungus) with three levels of phosphorus from triple super phosphate source. At the end of the vegetative growth period (about three months), the plants were harvested and phosphorus concentration in the plant were measured. A subsample from roots was stored in -20 ºC for determination of glomalin content. The glomalin content in the roots was analyzed using the monoclonal antibody MAb32B11. This antibody was employed to differentiate between the two fungi present in the roots and to quantify the abundance of arbuscular mycorrhizal fungi (AMF) specifically in plants treated with Rhizophagus irregularis. Additionally, the content of glomalin in the soil was determined at the end of the experiment using the same method as described above. The experiment was designed as a factorial completely randomized design (CRD) with three replications.

The results showed that the fresh and dry weights of shoot and root increased significantly in dual inoculation. At zero phosphorus level, shoot and root phosphorus concentrations were significantly higher in treatments with R. irregularis than in those without fungus (control). Under individual inoculation with R. irregularis, or S. indica as well as their dual inoculations, increasing level of phosphorus had no significant effect on shoot and root phosphorus concentration. In dual inoculation, the percentage of total colonization (88%) was significantly higher than that of individual inoculation treatment (68%) but the contribution of each fungus in root colonization under dual inoculation was significantly reduced as estimated by glomalin content of root and determination of total colonization. It was found that with increasing phosphorus level, total colonization percentage significantly decreased and the highest percentage of colonization (61%) was observed at zero level of phosphorus. By increasing phosphorus level, the percentage of root colonization was significantly decreased in individual inoculation by R. irregularis, or S. indica as well as dual inoculation. Results of glomalin assay in soil showed that the glomalin content was high in treatments of R. irregularis but control treatments without fungus and individual inoculation with S. indica had low glomalin. Antibody-reactive root glomalin was less in the dual inoculation treatment (1006.9 µg.g-1) than in the R. irregularis treatment alone (1924.5 µg.g-1) indicating that the presence of S. indica, in root inhibits, root colonization by R. irregularis. Moreover, the increasing of phosphorus level, significantly decreased root glomalin.

The increase of available phosphorus concentration in the soil caused to limit the expansion of the symbiosis of R. irregularis and S. indica, and this limitation was more for R. irregularis. In the case of dual inoculation with both Rhizophagus irregularis and Serendipita indica, the negative impact of phosphorus on colonization percentage was observed to be less compared to single inoculation. Although the percentage of colonization by each fungus decreased in the dual inoculation treatment compared to their individual inoculation, the overall colonization percentage increased significantly. It appears that in the dual inoculation scenario, while the total root colonization percentage increases, the presence of S. indica leads to a decrease in the colonization percentage specifically with R. irregularis. But in general, growth and nutrient absorption in the case of dual inoculation was better than the inoculation of each of them individually. It was also found that increasing the concentration of phosphorus in the soil caused a decrease in root colonization for both fungi, although the negative effect of phosphorus on the colonization of R. irregularis was more than that of S. indica. The measurement of glomalin in soil and root showed that the inhibitory effect of S. indica fungus on R. irregularis is less in soil than in root.

Quince with the scientific name "Cydonia oblonga Mill." is one of the most important horticultural products in the word including Iran. According to the average production from 1994 to 2020, Iran was the fourth largest quince producer in the world. Isfahan province is one of the most important centers of high quality quince production with 2432 hectares of cultivated area and annual production of 25986 tons. Most of the quince orchards are located in the cities of Natanz and Isfahan. Plant nutrition as an important factor in growth, is a function of nutrients and environmental conditions interactions. Assessing the nutritional status of plants is based on precise determination of nutrients and appropriate application method to diagnosis and interpret the results. Various methods have been used to evaluate the nutritional status of the plant, such as the Critical Value Approach (CVA), the Deviation from Optimum Percentage (DOP), the Diagnosis and Recommendation Integrated System (DRIS) and the Compositional Nutrient Diagnosis (CND). The CND method expresses interactions by considering the ratio of one element to the geometric mean of all elements. Then high and low functional groups are separated, by using mathematical and statistical methods and application of cumulative function of the variance ratio of nutrients and the chi-square distribution function. Finally, CND nutrients norms and indices such balance index are calculated step by step. Therefore, considering the importance of the quince production in the country and the lack of sufficient knowledge to determine its nutritional status, the present study was conducted with the aim of investigating the nutritional status of quince trees using the CND method and determining the nutrients norms for this product.

 In order to evaluate the nutritional status of quince trees using the CND method, 28 orchards were selected in the cities of Isfahan and Natanz. The orchards were selected such a way that they had different ranges of yield. The geographical location was recorded for each orchard. Then random and composite sampling of leaves was done from branches without fruit in July 2018. Concentration of nitrogen phosphorous, potassium, calcium, magnesium, iron, manganese, zinc, copper and boron was measured in quince leaves. At the end of season, the yield was determined for each orchard. The orchards divided into two groups based on high and low yields. The CND norms, CND nutritional index and nutritional balance index (r2) were computed based on steps of Parent and Dafir. The balance index of nutritional elements (r2) was calculated by Keith-Nilson method based on the Chi-square statistical distribution function (K2) in Excel software.

According to results of cumulative distribution function of nutrient variance and considering the yield of 23 tons per hectare as the intermediate yield, 25% of the studied orchards were in the high yield group and 75% of the orchards were in the low yield group. After solving the third– rank cumulative function equations of the studied nutrients, the highest yield was obtained for potassium Fci (VK) = 21.98 and the lowest value was for nitrogen Fci (VN) = 15.37. CND standard norms of nutrients and residual value were described as: V*N= 2.91, V*P= 1.39, V*K= 2.91, V*Ca= 2.13, V*Mg= 1.35, V*Fe= -2.01, V*Mn= -3.12, V*Zn= -3.97, V*Cu= -4.85, V*B= -3.51 and V*Rd= 6.78. The CND nutrient index revealed that potassium and nitrogen had the most negative index among macronutrients in the low-yield orchard group. The low amount of soil organic matter and the high presence of sand can contribute to the negative nitrogen index. Among the micronutrients, the iron index was negative in 67.7% of the low-yield orchards. Zinc and copper had the next highest nutritional requirements in most orchards. The presence of calcareous conditions in the soil of the studied orchards may be one of the reasons for this observation. The estimation of the nutritional balance index indicated that the r2 value in orchards with low yield was 60.3% higher than that in high-yield orchards.

 CND nutritional balance index (r2), specially in orchards with low yield was more than zero (20.85), indicating nutritional imbalance in these orchards. Proper management and balanced application of chemical fertilizers should be considered. This can increase the yield and quality of quince production.

 Wind erosion is one of the important processes of soil degradation in arid and semi-arid regions. Increased soil surface resistance is a key factor to prevent wind erosion. Mulch can increase the resistance of soil surface against erosive agents by creating a coating on the soil surface. The effectiveness of mulch on wind erosion control is on the quantity, type, and durability of the used in dust sources of Iran for stabilizing soil surface against wind erosion. In recent decades, petroleum mulch has been broadly used for stabilizing soil surface against wind erosion in dust sources of Iran. Bio-polymers (e.g. cellulose hydrogel and biochar) and naturally accessible materials (e.g. nanoclay) as environment-friendly mulches can be an alternative to chemical polymers and petroleum mulches. In arid and semi-arid regions, wetting-drying cycles play a crucial role in soil aggregate formation and strength. However, there have been limited studies assessing the impact of wetting-drying cycles on the durability of applied mulches. The main objective of this study was to assess the effectiveness of different types of mulches, including inorganic montmorillonite nanoclay, chemical polyvinyl acetate polymer, and biological biochar and cellulose hydrogel, at various time intervals. The study aimed to improve the physical and mechanical properties of soil, as well as control wind erosion in a loamy sand soil using a wind tunnel. Additionally, the durability of these mulches was evaluated over time after subjecting them to four wetting-drying cycles.

 A factorial experiment was conducted based on completely randomized design with three replications. The factors including mulch type (four levels: nanoclay montmorillonite, polyvinyl acetate polymer, biochar and cellulose hydrogel), mulch concentration (Nanoclay montmorillonite: 0, 16 and 32, Polyvinyl Acetate polymer: 0, 8, and 16, biochar and cellulose hydrogel: 0, 65 and 200 g/m2) and duration (21, 42, 63 and 126 days). The soil used in the wind tunnel experiments was collected from a dust source in the southeast of Ahvaz (Site Number 4). Trays measuring 50×30×5 cm were filled with this soil. The soil surface was then uniformly sprayed with an emulsion of Nanoclay and Polyvinyl Acetate. Additionally, biochar and cellulose hydrogel were mixed uniformly with the soil. Water was sprayed on the soil surface to maintain a constant moisture content of 75% of field capacity. After a specified period, soil properties such as mean weight diameter of aggregates, fractal dimension, penetration resistance, and shear strength were measured. The trays were then placed in a wind tunnel, and a wind erosion test was conducted at a wind speed of 20 m/s for a duration of 5 minutes. The amount of soil loss was measured using the weight method. Then, at each time, the best treatment from each mulch (in terms of reducing wind erosion) was selected and subjected to wet and dry cycles (four cycles).

 The results showed a significant interaction effects (p<0.01) of mulch type, mulch concentration and time factors on soil aggregate stability and fractal dimension, penetration resistance, shear strength were significant (p<0.01). Soil loss decreased in soils amended with biochar and cellulose hydrogel and increased in the case of montmorillonite and polyvinyl acetate polymer over the time. The amount of soil loss in soil amended with cellulose hydrogel decreased by 99.3%. The highest amount of soil penetration resistance and shear strength was observed in cellulose hydrogel mulch at the fourth time which were equal to 1038 and 123 kPa, respectively. Over time, the mean weight diameter of aggregates increased in the soil treated with cellulose and biochar hydrogels, but decreased in the polyvinyl acetate and montmorillonite nanoclay treatments. There was a negative correlation between aggregate stability and the fractal dimension of aggregates. In terms of soil loss, at the fourth measurement time, soils modified with cellulose hydrogels, biochar, polyvinyl acetate, and montmorillonite nanoclay experienced reductions of 99%, 71%, 84%, and 85% respectively, compared to the control. After four wet and dry cycles, the soil loss further decreased by 98%, 64%, 76%, and 81% in the respective treatments, compared to the control.

 In general, it can be concluded that cellulose hydrogel presented the greatest effect on reducing soil loss and controlling wind erosion. In the soils amended with biochar and cellulose hydrogel, the effect of mulches on reducing soil loss increased over the time. However, the opposite results were found in the case of polyvinyl acetate and montmorillonite nanoclay polymers. Therefore, biochar and cellulose hydrogel in the long term and polyvinyl acetate polymer and montmorillonite nanoclay in the short term can control wind erosion. Wet and dry cycles at all durations increased soil loss. But their effect remained on soil loss reduction until the end of the fourth cycle. The results revealed that environmentally friendly biopolymers synthesized from biomass components can be considered as sustainable sources to reduce wind erosion. Bio-polymers are a new window into the use of sustainable biomaterials instead of synthetics in wind erosion control.

Knowledge of the spatial distribution of soil salinity and soil organic carbon (SOC) leads to obtaining valuable information that is effective in decision-making for agricultural activities. More than a third of the world's land is affected by salt, which threatens the growth and production of crops, and prevents the development of sustainable agriculture. The high electrical conductivity (EC) content in soils poses significant challenges in arid and semi-arid regions, greatly impacting agricultural production. Saline and sodic soils often exhibit high levels of sodium which is a key characteristic. The presence of sodium ions leads to the destabilization of soil aggregates and the dispersion of soil particles resulting in the closure of soil pores. Consequently, unfavorable changes occur in the soil physical, chemical, and biological properties increasing its susceptibility to water and wind erosion. Additionally, high sodium levels can lead to the decomposition of soil organic carbon (SOC). SOC is crucial for water retention, cation exchange, and nutrient availability, making its reduction in agricultural soils a significant threat to sustainable soil management. Therefore, the investigation of soils in terms of EC and SOC contents and their spatial distribution is of great importance to support decision-makers in agricultural development planning to reduce challenges related to food security in arid and semi-arid regions.

This study was conducted with the aim of investigating the EC and SOC in topsoil (0-30 cm) and subsoil (30-60 cm) layers using four machine learning (ML) algorithms namely, random forest (RF), decision tree (DTr), support vector regression (SVR) and artificial neural network (ANN) performed in Qazvin Plain. The study area includes a part of agricultural lands and natural areas of Alborz and Qazvin provinces, between the Nazarabad and Abyek cities in Iran. This region with an area of 60,000 hectares is located at latitude 35° 54´ to 36° 54´ to the north and 50° 15´ to 50° 39´ to the east. This research was carried out in four stages including (i) soil sampling and measuring the physical and chemical properties of the soil and preparation of environmental covariates from a digital elevation model (DEM) with spatial resolution 12.5 m and Landsat 8 satellite imagery with spatial resolution 30 m by SAGA GIS and ENVI software, (ii) spatial modeling of soil EC and SOC in the topsoil and subsoil layers by the RF, SVR, ANN, and DTr ML algorithms, (iii) evaluating the efficiency of the ML algorithms and determining the relative importance of environmental covariates, and (iv) preparation of spatial prediction maps of EC and SOC in the topsoil (0-30 cm) and subsoil (30-60 cm) layers in the study area.

 The result of the spatial prediction maps of EC showed that the studied area has non-saline to very saline soils up to a depth of 60 cm. It is also possible that the EC equivalent shows a decreasing trend in soil salinity with a depth from 6.05 to 5.55 ds/m from the topsoil to the subsoil layer. The highest amount of SOC was observed in the surface layer equal to 3.3%. Globally SOC content decreased from the surface (average of 0.84%) to depth (average of 0.4%). The high spatial variability of SOC showed that the soils of the study area are affected by management activity. Environmental covariates were extracted as a proxy of topography and remote sensing indices including elevation, diffuse Insolation (Diffuse), Multi-Resolution Index of Valley Bottom Flatness (MrVBF), Normalized Differences Vegetation Index (NDVI), SAGA wetness index (SWI) and wind Effect (WE) were used as representatives of soil formation factors. The topography parameters, including the elevation, diffuse insolation, and Multi-Resolution Index of Valley Bottom Flatness, were most closely related to EC and SOC variations in each topsoil and subsoil layer. Elevation can be justified around 50% and 35% of EC and 28.56% and 29.47% of SOC variations in the topsoil and subsoil layers, respectively, followed by the diffuse variable can succeed to justified 19.7% and 25.1% of EC and 27.28% and 27.67% of SOC spatial variations in the topsoil and subsoil layers, respectively.The results confirmed that the RF was recognized as outperforming the ML model for predicting EC in the topsoil (R2 =0.74, RMSE =0.36, and nRMSE= 0.07), as well as predicting SOC in topsoil and subsoil layers (R2= 90 and R2=0.80), followed by the DTr for predicting EC (R2 0.77, RMSE/0.9, and nRMSE 0.17) in the subsoil layer in comparison other models.

The RF (Random Forest) and DTr (Decision Tree) models incorporating topographic parameters demonstrated satisfactory accuracy in predicting the variation of topsoil and subsoil electrical conductivity (EC) and soil organic carbon (SOC) in the study area. Topography plays a crucial role in soil formation, and elevation-based topographic attributes are commonly used as key predictors in digital soil mapping projects. The variability in topography influences water flow and sedimentation processes which, in turn, affects soil development and the spatial distribution of soil properties. The resulting soil maps can be valuable tools for decision-making programs related to soil management in the region.

Savory is considered one of the most important medicinal plants, which is used in various food and medical industries. Nitrogen (N) plays a major role on the growth and yield of medicinal plants. Therefore, an adequate supply of N is required for successful production of savory. However, the application of chemical N fertilizers is associated with many obstacles such as groundwater ‎pollution, N enrichment of surface waters, and drop in the quality of plants. ‎Accordingly, nowadays, great attention has been paid to organic fertilizers. In this regard, humic acid-based fertilizers have shown promising results. Humic acids (HAs) could be converted into nitrohumic acids (NHAs) through the nitration process, in which nitro groups (NO2) are located on the aromatic rings. This process increases the N content of the HA. Thus, ‎‎NHAs can be used as organic N fertilizers in the cultivation of medicinal plants whose organic production is a priority. However, the ‎effects of these types of fertilizers on plant growth and physiological characteristics have not been well ‎understood. Accordingly, the present study for the first time investigates the effectiveness of NHA on the ‎morphological and physiological characteristics of savory, as well as N loss through leaching.‎

In the current study, HA was initially extracted from leonardite (purchased from Yazd Golsang Kavir Company) as a rich source of HA. Then, NHA was prepared through the nitration process using nitric acid (50% by volume). After that, using FT-IR (Fourier transform infrared spectroscopy) and CHNS analysis the extracted HA and NHA were characterized, and their N content was determined. Afterward a ‎greenhouse experiment in a completely randomized design (CRD) with three replications was conducted ‎to determine the effects of 16 treatments, including control (without urea, HA and NHA), urea (U1, U2 and U3), humic acid ‎‎(HA1, HA2 and HA3), nitrohumic acid (NHA1, NHA2 and NHA3), urea-humic acid (U1HA1, U2HA2‎ and U3HA3), and urea-nitrohumic acid (U1NHA1, U2NHA2 and U3NHA3) on the morphological ‎and physiological characteristics of savory plant. The treatment levels were ‎determined as 40, 80, and 120 mg N kg-1 for the first, second and third level of the treatments, respectively. In the combined treatments of urea and HA or NHA, an equal fraction of the total nitrogen (N) was applied. At the end of the experiment, standard methods were used to assess various characteristics, including root length, leaf area, plant height, root volume, wet and dry weights of shoot and root, leaf chlorophyll index, concentrations of phosphorus, potassium, nitrogen, nitrate, and nitrate reductase in both the shoot and root. Additionally, leaching was conducted on specific days during the experiment, and the leachate was collected for nitrate measurement.

The results showed that using the nitration process, some characteristics of the NHA such as total acidity, the content of carboxylic and phenolic groups as well as N content improved as compared to the initial HA. Moreover, the results indicated that most of the morphological and physiological ‎traits of savory plants, including leaf area, plant height, root length, fresh and dry weights of root and shoot as well as chlorophyll index, and the concentration of nitrogen, phosphorous, potassium, nitrate and nitrate reductase enzyme were significantly higher in the NHA treatments than those of HA. In addition, the highest shoot dry weight was obtained in the combined treatments of U3NHA3 and U3HA3 as well as in the U3 treatment alone. The average rate of nitrate concentration increase in the U treatments was 1.77 times higher than the UNHA treatments. According to the results, U3 treatment indicated the highest nitrate loss which by using the U3NHA3 treatment, the mean concentration of nitrate ‎in the leachate decreased by about 40.5% as compared to the U3 treatment.‎

The findings of this research revealed that most of the morphological and physiological ‎traits of savory plant showed better responses to the combined treatments of U3NHA3 and U3HA3 as well as to the U3 treatment alone. However, with regard to the lower accumulation of nitrate in the shoot of savory as well as to the lower nitrate leaching, the combined treatments were preferred. Accordingly, NHA can be ‎a alternative nitrogen source in increasing the yield and growth indicators of savory. However, the reasons behind the fact of the better performance of combined nitrogen treatments than the individual ones require more research in the future.