جستجوی مقالات مرتبط با کلیدواژه « wheat » در نشریات گروه « آب و خاک »

Wheat is considered the most important grain and one of the vital food products in Iran. After nitrogen, phosphorus is the most important nutrient required by plants and holds a high priority for the growth, yield and quality of plants. However, due to the introduction of phosphorus in various reactions in the soil, a small amount of consumed phosphorus fertilizer is removed by the plant and the rest of it is left in a non-absorbable form in the soil. The efficiency of using phosphorus fertilizers and the availability of this nutrient is considered as a limiting factor for the production of agricultural products in calcareous soils with alkaline reaction of Iran. Since graphene and its oxidized form, with large amounts of active oxygen groups and high specific surface area, have been proposed by many studies as non-toxic and biocompatible materials in the production of compounds with improved efficiency of using nutrient, therefore to increase the efficiency of phosphorus consumption in soil, in this study, phosphorus was loaded on graphene oxide (GO-P). The present study aims to assess the influence of this compound as a source of phosphorus and its mixing with triple superphosphate fertilizer (GO-P-TSP) compared to triple superphosphate soluble fertilizer (TSP) on the amount of water retention of fertilizers in soil and phosphorus concentration in aerial parts of wheat plant.

Methods and Materials:

Graphene oxide was prepared based on the modified Hamers method. Then graphene oxide was adjusted to certain pH and iron sulfate as a source of iron ions was added to the graphene oxide suspension with vigorous stirring. The mixture was stirred for one hour and then centrifuged for 30 minutes. Then the supernatant was removed and the residue of the compound was dry frozen. In the next step, pH was adjusted with sodium hydroxide (NaOH) solution. Then a certain weight of potassium dihydrogen phosphate salt (KH2PO4) was added to the above suspension. The mixture was stirred for one hour and centrifuged for 30 minutes. After centrifugation, the supernatant was removed and the remains of the phosphorus composition based on graphene oxide were dry frozen. Loading tests were performed in three replicates. pH, EC, bulk density, total concentration of phosphorus and iron and X-ray diffraction spectroscopy (EDS) analysis were measured in the sample of phosphorus composition based on graphene oxide. Then three fertilizer formulations were selected, which included (1) triple superphosphate fertilizer, (2) synthesized phosphorus fertilizer based on graphene oxide, and (3) mixing graphene oxide-phosphorus compound with triple superphosphate fertilizer in a ratio of 50:50% phosphorus.To investigate the water retention behavior of fertilizers in the soil, dried samples of the three studied fertilizer formulations was added into a sandy soil completely and weighed. At the same time, dried sandy soil without fertilizer was placed in another beaker as a control.Then each beaker was added distilled water and weighed. The beakers were weighed once every three days at room temperature until they reached constant mass. The water-retention behavior of the soil was calculated.In order to investigate the effect of three fertilizer formulations on phosphorus availability, soil with low amount of phosphorus was selected and physical and chemical properties of the soil sample were measured at a depth of 0-30 cm. A greenhouse experiment on wheat planting was conducted using a randomized complete design with 3 replications. The treatments included three fertilizer formulations at three fertilization levels (10, 15, and 20 mg kg-1) with 3 replications. The control treatment was performed without phosphorus fertilizer. Plants were harvested 72 days after planting, washed with distilled water and dry with tissue paper. The samples were air-dried and then oven dried at 70˚C to a constant weight in a forced air-driven oven. After harvesting, the weight of fresh and dry matter and phosphorus concentration in the soil and aerial parts of the plant were measured. Statistical data were analysed using SAS software (9.4) and the mean values were compared using LSD tests (at 1 and 5% level).

The composition of phosphorus based on graphene oxide (GO-P) in powder form had 35.5% of total P2O5, 31.1% of soluble in water P2O5, 19.6 of total iron and 15.28% of total potassium. The result of EDS analysis confirmed the loading of phosphorus on graphene oxide. The pH of the phosphorus composition based on graphene oxide was 5.8, approximately 2.5 units higher than triple superphosphate fertilizer. The bulk density of the compound (GO-P) was significantly lower than triple superphosphate fertilizer. The EC of the compound (GO-P) was similar to the EC of the triple superphosphate fertilizer. Soil water retention with synthesized phosphorus fertilizer based on graphene oxide (GO-P) was higher than soil (control) and other compounds added to soil. Experimental results showed that the addition of prepared fertilizer formulas (GO-P and GO-P-TSP) increased water retention in the soil for a longer period of time, while in the soil without adding fertilizer and triple superphosphate treatment, respectively, from 10 and 11 days, the absorbed water completely evaporated. Therefore, the combination of soil with GO-P and GO-P-TSP compared to the soil without fertilizer and the combination of soil with triple super phosphate (TSP) fertilizer had better water retention behavior. The greenhouse experiment results of wheat planting showed that all treatments were significant (P<0.01). Among all the treatments and measured levels, the control treatment showed the lowest value. The highest concentration of phosphorus in aerial parts of wheat (0.31%) and in soil after harvesting (9.5 mg kg-1), fresh (10.6 g per pot) and dry weight (2.03 g per pot) of aerial wheat plants were related to the treatment of phosphorus compounds based on graphene oxide at the level of 20 mg kg-1.

The highest concentration of phosphorus in aerial parts of wheat was related to the treatment of phosphorus compound based on graphene oxide at the level of 20 mg kg-1. Therefore, with more research in the future to produce "nutritious plants" in sustainable, efficient and flexible agricultural systems, we can benefit from technologies based on carbon materials.

Determining and analyzing the indicators of water management for the crops of the country plays an important role in the planning of the agricultural sector.This study was accomplished to investigate water management indicators of irrigation systems in Wheat production in the upstream region of Karkheh basin and specifically Honam plain in Lorestan province. 14 wheat farms were selected in the mentioned area and were subjected to agronomic and water monitoring during the cropping season. Wheat applied irrigation water was determined by recording the irrigation schedule and measuring the flow rates. The water requirement of wheat was estimated by Penman-Monteith method and by applying plant coefficients. The yield and water productivity for wheat farms were obtained at the maturity stage. The results of agronomic and water monitoring of selected wheat fields showed that the type of agricultural, irrigation and fertilizer management of farmers played an important role in the amount of grain produced. Irrigation applied water, yield and WP was statistically different during the growth season for the farms. The average yield, the volume of irrigation water, the productivity of the irrigation water and the productivity of the applied water of wheat in the sprinkler irrigation system were equal to 6845 kg/ ha, 2325 m3/ha, 3 and 1.52 kg/ m3, respectively, and in the surface system equal to 5000 kg/ ha, 3237 m3/ha, 1.3 and 0.94 kg/ m3, respectively. The monitoring of the irrigation program in the selected fields showed that the farmers irrigated the mentioned fields on average 41% less than the full irrigation requirement of the plant. One of the important reasons for this is the special attention of farmers in the region to plant crops with high profitability, such as alfalfa and clover, despite the need for more water than wheat.

Water, food, and energy are three essential sources for maintaining life and fostering socio-economic development, and they are inseparably interconnected. The aim of the present study was to examine the indicators of water and energy efficiency of major agricultural products, namely, wheat and rapeseed, in two different climates in Sari (temperate and humid) and Sharifabad (hot and semi-arid) plains in Iran. To investigate these indicators in wheat and rapeseed crops, data from the agricultural year 2021-22 were utilized. Initially, the number of samples was determined based on the Cochran formula. Then, sampling was done using a questionnaire designed by the authors. The questionnaires numbered 300, and the collected information included inputs and production quantities. The results showed that the average water physical efficiencies in Sari Plain for wheat and rapeseed crops were 1.13 and 0.67 kg/m3, while in Sharifabad Plain, it was 0.83 and 0.35 kg/m3, respectively. Furthermore, the results indicated that the highest level of input energy in Sari and Sharifabad plains for wheat was 80618 and 71072 MJ/ha, respectively. The results also showed that greenhouse gas emissions were higher in Sari than in Sharifabad, probably because of excessive use of fertilizer and pesticide in Sari. The highest greenhouse gas emissions in Sari for wheat were 2495 kg CO2/ha, and in Sharifabad, it was 2299 kg CO2/ha. Overall, the results indicated that crop performance in humid regions was higher than in dry and semi-dry regions, and this indicator depends on various parameters, including water consumption and agronomic management.

Phosphorus is an essential element for all living organisms, and it cannot be replaced by any other element. Phosphorus has however a limited resource, and it is estimated that the extracted phosphorus resources (Apatite) will last for another 50 to 100 years. One of the most widely used technologies for recycling phosphorus is the precipitation of phosphorus from sewage sludge and leachate. Phosphorus Recovery as struvite (NH4MgPO4.6H2O) from sewage sludge has attracted special attention due to its potential for use as an ecological and slow release fertilizer. Struvite is a white, grain-like solid, odor-free and sludge–free ingredient, composed of magnesium, ammonium and phosphate at equal molar concentrations. Therefore, this study is designed to examine the effect of struvite replacement with triple superphosphate fertilizer on some physiological parameters and phosphorus availability in wheat plants in calcareous soils deficient in phosphorus.

Methods and Materials:

Soil with phosphorus deficiency was collected from 0-30 cm depth under arable lands of Hajjiabad-e Seyyedeh located in Ghorveh township, Kurdistan Province, Iran. The soil was air-dried and ground to pass through a 2-mm sieve, followed by laboratory analysis to determine its physico-chemical properties. The struvite used in the research was obtained by optimizing the three main factors of sulfuric acid concentration, solid-to-liquid ratio, and time for the leaching process, and the three key factors of Mg:P ratio, N:P ratio and pH for the precipitation process by Response Surface Methodology. To achieve the aim of this study a factorial experiment was carried based on completely randomized design with 4 replications. The factors included the application of different proportions of struvite replaced with triple superphosphate (S0:P100, S25:P75, S50:P50, S75:P25 and S100:P0) and 4 levels of phosphorus (0, 50, 100 and 150 kg TSP ha-1) and a total of 54 pots. The application rate for struvite was calculated based on total phosphorus (P2O5). Then 10 wheat seeds were planted in each pot at 2-cm depth which after plant emerging and greening, declined to 4 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 applied by hand. Plants were harvested 60 days after planting (beginning of flowering), washed with distilled water and dried with tissue paper. The samples were air-dried and then oven dried at 70˚C to a constant weight in a forced air-driven oven. Phosphorus concentrations in plant extracts were measured by the molybdenum vanadate or yellow method and chlorophyll content (a, b and ab) and carotenoids using the Arnon method. The statistical results of the data were analyzed using SAS software and LSD test (at 5% level) was used for comparing the mean values.

Based on the obtained results, all the investigated treatments and their interactions were significant at p<0.01. However, the interaction effect of fresh weight shoots and height was significant at p<0.05. The comparison of the average data showed that the highest amount of fresh weight shoots (7.79 g pot-1), dry weight shoots (1.130 g pot-1) and height (29.66 cm) was obtained from the application of S75:P25 150 kgTSP ha-1. By use of struvite instead of triple superphosphate fertilizer, the phosphorus concentration and uptake of wheat increased at all three fertilizer levels, so that the highest phosphorus concentration (0.174%) was obtained from S75:P25 150 kg TSP ha-1. However, there was no statistically significant difference for S100:P0 (0.169%) treatment. The highest amount of phosphorus uptake in wheat with an average of 0.197 g pot-1 was obtained from the S75:P25 treatment (150 kg TSP ha-1), compared to the treatment of 100% struvite (S100:P0) and 100% triple superphosphate fertilizer (S0:P100) with the averages of 0.158 and 0.109 g pot-1, respectively, showing 19.79 and 44.67 percent increase. Also, the results showed that the treatment of 150 kg TSP ha-1 100% struvite (S100:P0) compared to 100% triple superphosphate fertilizer (S0:P100) increased the amounts of chlorophyll a, b, ab and carotenoids by 7.78, 3.82, 6.44 and 6.84 percent, respectively.

Despite struvite's low solubility, it is a highly soluble phosphorus fertilizer for plants . However, the reasons for this apparent contradiction and also the specific mechanisms of struvite dissolution are still unclear. Hence, further accurate measurements at different pH and EC conditions with different physical and chemical properties of soil studying phosphorus fractionation in soil will help to better understand the use of struvite. Therefore, it is recommended to optimize the timing and application rate of struvite in relation to the demand for different agricultural and garden crops.

Land suitability is a crucial factor in land use planning and sustainable agricultural production. Evaluating land suitability helps optimize land use, promote sustainable land use, protect the environment, and ensure optimal use of natural resources. This study was conducted in the Abiek region of Qazvin province in northwest Iran, covering an area of 60,000 hectares. After collecting data from 300 soil profiles and determining land suitability classes for wheat cultivation with surface irrigation using the FAO classification system, digital elevation models, Landsat-8 and Sentinel-2 satellite images, and environmental variables extracted from the digital elevation model were used to create digital maps using both traditional and machine learning methods. The results showed that the machine learning method had a higher accuracy rate of 74% and a Kappa index of 68 compared to the traditional method with an accuracy rate of 62% and a Kappa index of 53. The most important environmental variables used in the machine learning model were those extracted from the digital elevation model and Landsat-8 satellite images. The largest area for wheat cultivation with surface irrigation was found in the relatively suitable class (S2), with 30,753 hectares in the random forest method and 21,028 hectares in the traditional method. In contrast, the smallest area belongs to the unsuitable class (N), with 3,052 hectares in the forest method. Additionally, random fields and 7185 hectares were identified in the traditional method. Also, 15,000 hectares of the study area are suitable for wheat cultivation without restrictions.

Due to population growth and Iran's location in arid and semi-arid regions of the world, the need for water and food has increased and as a result, the pressure on water and soil resources will be more than before. On the other hand, the risk of drying up Lake Urmia, which causes environmental problems in the region, requires macro-water planning for the region and the use of optimal cultivation pattern to deal with water scarcity. Therefore, optimal use of water preserves water resources and increases the quality of products. Today more than ever, increasing the production of strategic crops such as wheat requires the proper use of water resources. The main source of food for the Iranian people is wheat and related products, and any action that increases the yield of wheat due to limited soil resources, especially water resources, is important and necessary at the same time. In recent years, significant advances have been made in modeling product growth and development using mechanical models. Plant growth models are increasingly used in the analysis of agricultural systems and simulate the plant's response to growth factors using mathematical equations. The AquaCrop model is one of the dynamic and user-friendly models developed by the FAO. The AquaCrop model receives information about farm, plant, soil, irrigation and climate, and ultimately predicts important parameters such as crop. Wheat yield simulation allows efficient management and better planning under various environmental inputs such as soil and water. To achieve higher accuracy and less model error, field parameters must be properly calibrated by the model to achieve proper performance. Also, calibration of the model, if not done correctly, causes a high error prediction by the model, which leads to incorrect management, water loss, plant drought and other cases. Therefore, using a model that has accurate and close prediction to the AquaCrop model and requires fewer input parameters is essential, which saves time, reduces costs and eliminates calibration errors. However, this model requires relatively large input parameters and is a time-consuming model in the presence of multiple scenarios.3

In recent years, smart models have been able to show high accuracy and become reliable models. Therefore, in the present study, to solve this problem and develop a model with less input data, using the ANN, SVR and SVR-FFA intelligent models and creating 440 scenarios in 2 farms, the performance of the AquaCrop model was compared.99WestW2 farm is located in Miandoab city and has a yield of 6.588 (ton ha-1) and WestW10 farm is located in Mahabad city and has a yield of 5.05 (ton ha-1).

The results of the model are performed using 5 evaluation criteria of Correlation coefficient, Root mean square error, Nash-Sutcliffe coefficient, Wilmot’s index of agreement and, Mean absolute percentage error. The results of this study showed that for both 99WestW2 and WestW10 farms, the SVR-FFA3 model could have the lowest error rate, so that for the yield index, the RMSE value for the mentioned farms was 0.033 and 0.069 (ton ha-1), respectively. The use of three models SVR, SVR-FFA, and ANN and their comparison with the AquaCrop model to predict wheat yield has been done for the first time in this study. The SVR model was able to show the highest accuracy after the SVR-FFA model. For 99WestW2 farm, it can reduce the error rate to 0.043 (ton ha-1) and for WestW10 farm to 0.077 (ton ha-1) and show good performance. The ANN model, after the SVR model, was able to show acceptable accuracy. The ANN model for 99WestW2 farm was able to reduce the error rate to 0.123 (ton ha-1) and for WestW10 farm to 0.094 (ton ha-1). Finally, the ANN model had a relatively higher error than the SVR-FFA and SVR models, respectively, and showed a relatively lower performance than the two models.

Finally, the intelligent SVR-FFA, SVR and ANN models, despite having the least number of inputs, were able to predict yield values in the shortest time and with the highest accuracy. However, the results showed that the lower the model inputs, the weaker the model prediction. For further studies, it is suggested that the ANN model be combined using the firefly algorithm (MLP-FFA) to increase the accuracy of the ANN model and make more accurate predictions of wheat yield.

Iron is one of the essential nutrients for plant growth that its deficiency is considered as an important problem in calcareous soils. Therefore, this experiment was conducted to investigate the effect of different organic matters and their interactions with iron oxide powder on nutrient uptake and yield of wheat in a completely randomized design with factorial arrangement. The experimental factors were organic matter type including lemon pomace, sour grape pomace, tomato pomace, black tea pomace, spent coffee grounds, and their composts (1% by weight), and iron oxide powder on two levels (zero, and 50 mg of iron per kg of soil) as potted culture with three replications. The results showed that shoot dry weight increased significantly in all treatments except (lemon pomace and spent coffee grounds and tea pomace compost and spent coffee grounds compost) compared to the control. Also, most of the treatments caused a significant increase in the uptake of nitrogen, potassium and iron compared to the control. Tomato pomace compost, in comparison to other treatments had the greatest impact on all parameters. The uptake of nitrogen, potassium and iron, were significantly increased by adding tomato pomace compost, which the amount of these increases compared to the use of iron oxide powder alone, were 36.1, 39.7, 148.9 percent, respectively. Also, the comparison between the different pomaces and their compost, showed that the pomaces were more effective than their compost in all parameters except the dry weight of the shoot. Finally, it was found that among all of the treatments, respectively, tomato pomace compost and sour grape pomace, and for the interaction effects of organic matter with iron oxide powder, respectively, tomato and lemon pomace compost, effectively, improved different soil and plant properties, compared to the other treatments.

Soil salinity and sodicity disrupt the balance of nutrients in the soil and create restrictions on plant growth. An experiment was conducted to evaluate the application of sulfur along with Thiobacillus bacteria and plant growth-promoting bacteria isolated from saline-sodic soils on the performance and concentration of micronutrients in wheat (Chamran cultivar) in saline-sodic soils in a factorial design within a completely randomized design, in three replications in greenhouse condition. The experimental factors included three types of saline-sodic soil (S1: SAR=13 and EC=8 dS m^-1), (S2: SAR=15 and EC=10 dS m^-1), and (S3: SAR=17 and EC=14 dS m^-1), four levels of plant growth-promoting bacteria (B0: control, Pseudomonas alcaliphila, Rhizobium pusense, and Bacillus subtilis) and two levels of sulfur along with Thiobacillus thiooxidans bacteria (T0: no application and T1: application of 31.4 grams per pot (10 tons per hectare) of powdered sulfur along with T. thiooxidans bacteria). Based on the sequencing of the 16S rRNA gene, the superior plant growth-promoting bacteria were identified as Pseudomonas alcaliphila, Bacillus subtilis, and Rhizobium pusense. The results showed that adding sulfur along with T. thiooxidans bacteria and other plant growth-promoting bacteria at different levels of salinity and sodicity led to an increase in grain yield and concentration of micronutrients compared to the control. At the salinity and sodicity levels of S1 and S3, the highest grain yield was observed in plants inoculated with R. pusense bacteria (13.1% and 88.8%, respectively). The combination of plant growth-promoting bacteria and sulfur along with T. thiooxidans bacteria did not have a significant effect on grain yield and concentration of micronutrients in saline-sodic soils. Overall, the individual application of R. pusense bacteria isolated from saline-sodic soils and sulfur along with T. thiooxidans bacteria plays a significant role in improving the performance and concentration of micronutrients in wheat in saline-sodic soils.

Soil macro- and micro-nutrients can importantly affect wheat and rice tolerance in salt stressed conditions. The objective was to investigate salt distribution and pollution of nitrate and boron, resulted by chemical fertilization, in the non-alkaline and arid area of Khuzestan province, affecting wheat (Chamran genotype) and rice (Anbarbou genotype) yield. The research was conducted in the regions of Arab Asad (region 1) and Veis (region 2) and soil samples were collected from five different stations, in four different seasons and from the depths of 0-30, 30-60, 60-9-, and 90-120, and their salinity, and concentrations of nitrate and boron were determined. According to the results, for region 1, soil salinity at different depths was in the range of 1.96-5.16 dS/m, and for region 2 it was in the range of 1.90-4.92 dS/m. The highest nitrate concentrations for different depths were equal to 13.5, 18, 8.5, and 9 ppm (region 1) and 12.5, 16, 10, and 7 ppm (region 2). The corresponding values for boron were equal to 37, 49, 27 and 23.5 (region 1), and 37.5, 48, 28, and 24 (region 2). Increased levels of salinity decreased the yield of the two crops as wheat yield decreased by 17.8% (region 1) and 15.9% (region 2), and rice yield by 12.9% (region 1), and 14.4% (region 2). Investigating the distribution of salt, nitrate and boron in wheat and rice fields can be beneficial for the farmers to favorably use the present resources for optimum yield production.

IntroductionWheat (Triticum aestivum L.) has become very important as a valuable strategic product with high energy level. The importance of investigating environmental stresses and their role in predicting and evaluating the growth and crops yield is essential. A wide range of plant response to stress is extended to morphological, physiological and biochemical responses. Considering the rapid advancement in computer model development, plant growth models have emerged as a valuable tool to predict changes in production yield. These growth simulation models effectively incorporate the intricate influences of various factors, such as climate, soil characteristics, and management practices on crop yield. By doing so, they offer a cost-effective and time-efficient alternative to traditional field research methods. Material and MethodsThis research was conducted in the research farm of Varamin province, which has a silty loam soil texture. The latitude and longitude of the region are 35º 32ʹ N and 51º 64ʹ E, respectively. Its height above sea level is 21 meters. According to Demarten classification, Varamin has a temperate humid climate. The long-term mean temperature of Varamin is 11.18 ° C and the total long-term rainfall is 780 mm. In this study, in order to simulate irrigated wheat cv. Mehregan growth under drought stress, an experimental based on completely randomized blocks (CRBD) including: non-stress as control (NS), water stress at booting stage (WSB), water stress at flowering stage (WSF), water stress at milking stage (WSM) and water stress at doughing stage (WSD) with three replications during growth season 2019-2020 was carried out in Varamin, Iran. Crop growth simulation was done using SSM-wheat model. This model simulates growth and yield on a daily basis as a function of weather conditions, soil characteristics and crop management (cultivar, planting date, plant density, irrigation regime). Results and DiscussionBased on the results, the simulation of the phenological stages of irrigated wheat cv. Mehregan under water stress condition using SSM-wheat model showed that there was no difference between observed and simulated values. Summary, the values of day to termination of seed growth (TSG) were observed under non- stress, stress in the booting stage, flowering, milking and doughing of the grains, 222, 219, 219, 221, 221 days, respectively andsimulation values with 224, 221, 220, 221, respectively. However, with their simulation values, there were slight differences with 224, 221, 220, 221, respectively. Acceptable values of RMSE (11.7 g.m-2) and CV (3.5) indexes showed the high ability of the SSM model in simulating the grain yield of irrigated wheat cv. Mehregan under water stress conditions. Grain yield values were observed in non-stress conditions of 5783, water stress in booting, flowering, milking and doughing of the grain stages in 5423, 5160, 5006 and 5100 kg. h-1, respectively. While the simulated values were 5630, 5220, 4920, 4680 and 4880 kg. h-1, respectively. Based on the findings, observed and simulated values of leaf area index (LAI) were observed under water stress condition in the booting, flowering, milking and doughing of the grain stages (4.3 and 4.47), (4.33) and 4.46), (4.4 and 4.57) and (4.4 and 4.58) cm-2, respectively. Evaluation of the 1000-grain weight of irrigated wheat cv. Mehregan under the water stress showed that the SSM model was highly accurate. RMSE (4.6 g.m-2) and CV (1.8) values indicate the ability of the SSM model to simulate the 1000-grain weight of irrigated wheat cv. Mehregan. Also, the simulated values of the harvest index were 34.7 % in non-stress conditions, which decreased by 6 % compared to the observed value. Harvest index values were observed under water stress conditions in the in the booting, flowering, milking and doughing of the grain stages in 30.2, 29.3, 29.9 and 29.5 %, respectively. Compared to its observed values, it was reduced by 3, 3.5, 5, and 5.5 %, respectively. ConclusionBased on the findings, the slight difference between the observed and simulated values demonstrates the SSM model's capability to accurately capture water stress impacts on the phenological stages, grain yield, and yield components of irrigated wheat cv. Mehregan during critical growth stages, including booting, flowering, milking, and doughing. The results indicate that the SSM model is effective in simulating wheat growth under water stress conditions, showcasing its potential as a valuable tool for modeling irrigated wheat growth. The model's ability to account for water stress and its effects on various growth parameters makes it a reliable and efficient tool for predicting crop performance in water-limited environments.

The most soils of Khuzestan province are calcareous with different degrees of salinity, however, they play a significant role in the country agricultural production. One of the new methods to deal with environmental stresses is the use of plant growth stimulants. The aim of this study was to investigate the effect of application of growth stimulants on wheat yield components in saline soil, environmental and climatic conditions of Khuzestan province. Experiment was performed in three replications as randomized complete block design with soil salinity of 8 dS m-1 and water salinity of 3-4 dS m-1 under seven different treatments consisting of control, free amino acid, seaweed, seed treatment, humic acid, fulvic acid and combination in 2018 for two years. The use of seaweed, humic acid and amino acid caused a significant increase 30, 25 and 24 % of grain yield as compared to control treatment (p ≤0.05). The results of economic analysis showed a significant advantage of the humic acid application in increasing wheat yield (profit to cost ratio = 13.38). Application of plant growth stimulants on the macro and micro nutrients concentration in wheat leaves was not significant in almost all stages of plant growth compared to the control (p ≤0.05). In addition, the application of growth stimulants in calcareous soils of Khuzestan due to high soil buffering capacity did not have a significant effect on soil salinity, pH and sodium uptake ratio. Therefore, it is recommended that in wheat fields of Khuzestan province with saline and calcareous soils, in addition to basic fertilizers, humic acid be used as foliar application in two growth stages of tillering and booting to increase stress plant resistance and improve crop yield.

Wheat, as one of the most important crops in Iran and all around the world, has taken a significant share of the area under cultivation and production. The lack of water resources in the dry climate of Iran makes it necessary to use the available water resources to the optimal level. The analysis of optimal water consumption in agricultural production is done by using the water efficiency index. In this study, rainwater productivity in rainfed wheat cultivation in Kurdistan province was estimated using the AquaCrop-GIS model. Performance information was collected from the Agricultural Products Insurance Fund in the six-year period from 2014-2015 to 2019-2020. Also, information from synoptic meteorological stations and the global soil data bank were used for the required basic information. The model results show a 90% agreement index in the simulation process. Also, according to the average water productivity index calculated by the model, a zoning map of the areas prone to rainfed wheat cultivation was presented. Kamyaran district, having an average water productivity index of 0.68 kg/m3, was identified as the most suitable part of the province for dry wheat cultivation. According to the special conditions of Kurdistan province, it is suggested that the development of the cultivated area should be done according to the priority of more susceptible areas and based on the rainwater productivity index in the province.

By evaluating irrigation systems, their performance can be improved. The purpose of this study was to evaluate the center pivot irrigation system in some fields of Semnan province. Also, the amount of water consumption in the field was compared with the water requirement and the national water document. For this purpose, center pivot irrigation systems were studied in three fields. Average potential and actual application efficiency (PELQ and AELQ), distribution uniformity (DU), uniformity coefficient (CU) and evaporation and wind losses were 69.1, 67.2, 76.7, 82.1 and 7.6% respectively. The average of the above parameters was good. The operation of center pivot systems was easier than other sprinkler systems due to the mechanization of center pivot systems. Technical problems in one system reduced uniformity and efficiency. The volume of water consumption in field 3 was less than the irrigation requirement thus deficit irrigation was done. Irrigation water productivity in alfalfa and wheat fields was 0.92 and 0.79 kg/m3, respectively. Considering appropriate irrigation frequency and time, night irrigation to reduce evaporation and wind losses and paying more attention to educating farmers on proper operation of system were the important factors in increasing irrigation efficiency and water productivity.

Biofertilizers play major role in sustainable agriculture. For provide them, different carriers are used to increase the longevity and survival of the bacteria. Biofertilizers are being used in two general forms; solid or liquid. For making biofertilizers, various types of material are used to inoculate seed or soil. A suitable material for carrying microorganisms should have certain characteristics such as high water holding capacity, chemical and physical uniformity, easy to sterilize by autoclaving or gamma-irradiation, absence of toxic compounds for microbial strains, and environmental safety. At the same time, these materials should have a near-neutral or easily adjustable pH and be locally abundant at reasonable cost. Liquid or solid biofertilizers have their own advantages or disadvantages. The aim of this study was to investigate the survival of Enterobacter cloacae S16-3 bacterium on different liquid carriers during one year.

The liquid carrier consisted of 9 treatments containing glycerol, polyethylene glycol (PEG), trehalose, carboxymethyl cellulose (CMC), arabic gum, polyvinyl pyrrolidone (PVP), glucose and starch with different amounts and in different combinations. In this study, bacterial inoculants prepared with the same initial population (109 CFU mL-1) after storage at room temperature were compared for the survival of the bacterium. The bacterial population was counted at 0, 15, 30, 60, 90, 120, 180, 270 and 365 days. For counting the bacteria in microbial carriers, after dilution series preparation, bacterial suspension was used in strip culture in a plate. In this research, the effects of prepared inoculants on germination and growth of wheat seedlings in sterile conditions in a plate and pot culture at the end of the fourth month were investigated. In pot culture, characteristics such as shoot and root length, the wet and dry weight of shoot and root, total wet and dry weight of shoot and root were measured.

The bacterial counting results showed that among the tested carriers, the most population was counted after one year in formulation F5 (arabic gum, starch and PEG) (107 CFU mL-1) and the lowest population was counted in formulation F7 (glycerol, trehalose, glucose, arabic gum, and PEG), so that after 6 months no alive cells of bacteria were counted. Also, the results of germination test and growth of wheat seedlings cultivating in a plate showed that the materials used in microbial carriers did not have any inhibitory effect on germination of the seeds, and even, in some cases, they could encourage their germination and growth. So that ten seeds in each inoculum started to germination simultaneously. In pot culture, F9 formulations (glycerol, glucose, arabic gum and PEG), and F4 (trehalose, arabic gum, and PEG) in terms of root fresh weight and total fresh weight had better means. The root fresh weight of the formulations were 1020 and 740 mg and the total fresh weight of 1800 and 1390 mg, respectively. The comparison of these carriers with control (without bacteria and carrier) and suspension of bacteria (non-carrier inoculation) showed that these carriers could be more effective in all measured characteristics.

Currently, the application of different materials in bacterial liquid formulation is considered to be of high importance as an innovative technological strategy to maintain the metabolic stability of microorganisms. Finally, according to the results of this experiment and the convenience and availability of the carriers, the F5 and F9 formulations can be suggested for further studies.

In order to evaluate the efficiency of six different macroscopic water uptake functions, consisted of additive (M1), multiplicative (M2, M3 and M4) and conceptual (M5 and M6) models using field data of Ghods cultivar of wheat under salinity and drought stress, a study was conducted in the research field of university of Birjand during 2005-06 in split plots design based on randomized complete blocks (RCBD) with three replications. In this study, the main plots consisted of different levels of salinity (1.4, 4.5 and 9.6 ds m-1) and sub plots consisted of four levels of irrigation (50, 75, 100 and 120 percent of crop water requirement). The results showed that the additive model (M1) estimated yield less than actual amount. In other word, the effect of combined stresses on wheat yield was less than the one as compared to summation effects of salinity and water stress. The effect of drought stress on reduction of yield was more than salinity stress. The results also revealed that reduction functions of M6 and M5 models were better fitness to measured data than the other functions. The results revealed that M6 model estimated the reduction of relative yield of wheat under simultaneous stresses conditions of salinity and drought better than other models ( RMSD=0.17), although the M5 model also had acceptable accuracy (RMSD = 0.22).

The use of potassium solublizing bacteria (KSB) in soils containing an accumulation of insoluble and non-absorbable potassium by plants can help further solubility of these potassium mineral sources in the soil and thus the uptake of this element by the plant. Also, the application of KSB on the yield and yield components of wheat can prevent the overuse of potassium chemical fertilizers and instead predispose soil conditions for the development of plant nutrition. Therefore, the aim of this study was to determine the effect of application of KSB in comparison with the application of common potassium chemical fertilizers in the country's farms on quantitative and qualitative traits of wheat grain. To study the effect of application of KSB on the yield of wheat cultivars in southern Kerman, Iran, this experiments were performed over two years in the form of split plots in a randomized complete block with three replications in the research farm of Islamic Azad University of Jiroft in loamy sand soil. Various wheat cultivars including Chamran 2, Barat and Khalil were located in the main plot and sources and amounts of calcium were at four levels: 1. Control (without fertilizers) 2. Application of chemical sulfate potassium (at the rate of 200 kg / ha based on soil test results 3. Half of the recommended chemical fertilizer at the rate of 100 kg/ha + consumption of KSB from the source of Potabarvar biofertilizer at the rate of 100 g/ha 4. KSB (at the rate of 100 g/ha as the seed treatment), were placed in sub-plots. The results showed that wheat cultivars showed different reactions to different levels and sources of fertilizer during the two years of the study. The highest grain yield in Chamran 2 cultivar was obtained by applying KSB at the rate of 8 t/ha. Application of KSB alone in Khalil cultivar and application of potassium solfate along with KSB in Barat cultivar produced 7.49 and 7.6 tons of grain per hectare, respectively, Whithout significant different by 8 tons per hectare. Application of KSB could significantly improve grain yield, spike length, number of grains per spike, grain nitrogen percentage and grain protein percentage. The results showed that the applied KSB improved the quantitative and qualitative traits in wheat grain. Although the application of potassium sulfate based on soil test results also had an effective role to increase wheat traits, but it is suggested that in agriculture based on sustainability in agriculture, potassium biofertilizer should be used with half of the recommanded potassium sulfate fertilizer. In addition to reducing the consumption of chemical fertilizers, this can be effective in reducing wheat production costs and farm health.

In this study, a modified version of standard precipitatıon index (SPI), namely Agriculture-SPI,or aSPI was used to assese the impacts of drought on rainifed wheat yield in North Khorasan province,northeast of Iran. In the aSPI index, the effective rainfall is used instead of precipitation. The USDA-SCS, method was used for effective rainfall calculation. Both indices were worked out , using 30-years (1989-2018) monthly rainfall and temperature data. Rainfed wheat yield data for the period of 2004 to 2018 were also retrived from local oranizations and standardized for comparisons in different SPI time windows of 1, 3, 4, 5, 6, 7, 8, 9 and 12 months .The obtained annual yields were correlated with SPI and aSPI values in selected timescales. The results showed that in Bojnord station, the rainfall druring November-May period, in Shirvan, Faruj and Esfarayen stations April-June, in Maneh-Semelgan station, November-December period and in Jajarm station, October-June period rainfall, are the most signifcant variables affteting the rainfed wheat according to drought indices used in study region.

The aim of this study was to investigate the effect of crop type on soil carbon accumulation in soybean (Glycin max L.) and wheat (Triticum aestivum L.) rotation, in 150 fields of soybean and 89 wheat fields in Gorgan county, in the cropping years of 2016-2017 and 2017-2018, respectively. In order to determine the amount of organic carbon and its changes, soil samples from two depths of 0-15 cm (first depth) and 15-30 cm (second depth) were prepared and then soil carbon was measured by Walkley-Black method. Spatial distributions of soil organic carbon and carbon accumulation potential at different depths and also, in the pre-sowing and post-harvest stages were performance using different types of interpolation methods in ArcGIS enviroment. The results of interpolation methods showed that Kriging was the best model for interpolation of organic carbon distribution and carbon accumulation in agricultural fields of Gorgan. Average amounts of soil organic carbon in the first depth of soybean fields were as 14.84 mg ha-1and 13.41 mg ha-1for the second depth in the pre-sowing stage. Also, it was estimated as 16.85 mg ha-1 in the first depth and 15.52 mg ha-1 for second depth, in the post-harvest stage. The amounts of soil organic carbon in the wheat fields were determined about 16.78 and 15.25 mg ha-1for first and second depths in the pre-sowing stage, respectively. Those were 13.68 and 12.30 mg ha-1for of first and second depths in the post-harvest stage sampling, respectively. The results showed that the eastern, northern, northeastern, southern, southeastern and central parts of the county had the highest carbon accumulation due to access to modern irrigation systems, more water resources, better crop management, suitable return of crop residue to the soil, develop of minimum tillage, minimizing the burning of residue and using manure. Results showed that the western and southwestern parts of the county had the lowest carbon accumulation.

Irrigation plays an important role in increasing crop yield especially in arid and semi-arid regions, where optimizing irrigation depth and leaching is crucial. Using simulation models such as AquaCrop help to analyze different irrigation scenarios and also help farmers to optimize water resources management in such conditions. In this study, calibrated and validated AquaCrop model was used for two wheat varieties in Birjand region and one wheat variety in Mashhad region. A Matlab program has been developed to link to the AquaCrop in order to achieve the optimized values of irrigation and leaching in the water constraint conditions. The optimization results showed that net profit for the best irrigation and leaching management at all salinity levels and different wheat varieties, except for salinity levels of 8.6 and 10 dS m-1 in the Mashhad variety and level of 9.6 dS m-1 in the Roshan variety, was more than the current management researches of Shahidi and Haghverdi. While the aim is to achieve maximum profit and minimal drainage water, the model by changing the type of irrigation management and reduce leaching, especially in the last two irrigations only, reduced the amount of water consumed and the amount of drainage water to zero. The results also showed the reduction of gross irrigation water in the salinity levels more than tolerance threshold of wheat was less than the other salinity levels and the difference was completely negligible. Because in high salinity levels, yield reduction in deficit irrigation was more in comparison with low salinity levels, therefore deficit irrigation in salinity levels of more than the wheat tolerance threshold is not economic. Generally, the optimization results showed that in the area of Birjand and Mashhad, using the best irrigation and leaching management at different salinity levels can increase the benefit of wheat cultivation.

Saving, optimizing water consumption, and improving productivity and efficiency indicators in agricultural sector are important and necessary. Miandoab region is of particular importance as a model of reducing consumption in order to conserve real water for the restoration of Lake Urmia. This research was conducted to evaluate water consumption reduction scenarios at the farm level using AquaCrop plant model in Miandoab region. For this purpose, the information on farms related to the sustainable agriculture project of Iran's Wetlands Protection Plan in Miandoab region was used. The data from the first year (the crop year 2016-2017) and the second year (the crop year 2017-2018) were used for model calibration and validation, respectively. The evaluation of statistical indicators shows the accuracy and high ability of the model in simulating grain yield. After the calibration and validation of the model, the irrigation planning scenarios were analyzed and evaluated in the form of reducing irrigation depth by 10, 20, and 30% for the conditions of the second year. The results of field measurements in 2017-2018 showed that the average irrigation depth and the applied irrigation (Irrigation + effective precipitation) for wheat were 405.44 and 580.44 mm respectively and mean grain yield was 8340 kg/ha, then irrigation water productivity and applied irrigation productivity were 2.27 and 1.52 kg/ , respectively. Also, the results of the study of deficit irrigation scenarios showed that the S3 scenario (30% irrigation water reduction) will reduce only 10% crop yield and water productivity will increase from 1.53 to 1.72 kg/ . The values of water productivity indices were calculated using balance components and performance simulated by the model for each farm. In general, the results showed that it is possible to increase the grain yield of wheat and water productivity using AquaCrop model for proper and accurate irrigation planning and crop management improvement, in order to save and conserve water on a farm scale.