yield

Nutrient limitations often reduce crop yield in farmers' fields. Identifying the status of rice plant nutrients in the soil and plant is necessary for plant nutrition management. In rice plant, it is common to use soil chemical properties test to understand the availability of soil nutrients. Although soil tests based on critical level may indicate the adequacy of nutrients, sometimes the rice plant in the field exhibit signs of its deficiency. Flooding conditions in rice cultivation leads to chemical and electrochemical changes in some nutrients, which result in inadequate nutrient uptake by the plant. Solely relying on soil testing in such conditions increase errors in results interpretation and fertilizer recommendations. Therefore, measuring the nutrients characteristics of both plant and soil can be effective in fertilizer recommendations. One method for interpreting leaf analysis results is the use of compositional nutrient diagnosis (CND) method. The aim of this study was to establish reference norms, the range of optimal concentration and nutrients limitation in rice plant using the CND method during 2018 growing season in 60 paddy fields of Guilan province, Iran.

Soil and leaf composite samples were collected from farmers' fields in a standard manner and analyzed using appropriate laboratory methods. At harvest time, the yield of each field was determined. Nutrient indices were assessed by the compositional nutrient diagnosis (CND) method. By employing the cumulative function model of the variance ratio of nutrients and solving third-degree cumulative function equations related to 10 nutrients along with their residual concentrations, yields corresponding to each of them were calculated in terms of tons per hectare. To categorize the yield community into favorable and unfavorable groups, initially, the yield-nutrient function was plotted and the yield groups were separated by identifying the inflection points of the curve. To validate the compositional nutrient diagnosis method, the relationship between the nutrition balance index (r2) and crop yield was evaluated through a scatter plot. Descriptive statistics were conducted using SPSS version 24 and CND calculations were performed using Excel software.

Based on the average of available phosphorus concentration and its critical level 47% of the fields exhibited phosphorus deficiency. According to the critical level of available potassium, except for one farm, the available potassium content exceeded the critical level in all fields. Due to the fact that the minimum amount of micronutrients (zinc, iron, copper, and manganese) was more than their critical level in paddy fields, indicating no deficiency in the studied soils. Available magnesium concentration ranged from 0.8 to 4.6 with the median of 2.4 cmol+/kg. Nearly 75% of the studied soils were deficient in magnesium, based on the critical level of available magnesium (3 cmol+/kg).The average phosphorus concentration in leaves was 0.23% and based on the critical level, there was phosphorus deficiency in two fields. The average potassium concentration in the sample of leaves collected from the fields was 1.57% and based on the critical level, potassium deficiency was observed in rice plant tissue in 55% of the fields. The average magnesium concentration in rice leaf samples was 0.17% and six farms showed deficiency based on the magnesium critical level. The average zinc concentration was 13.69 in rice leaf samples and based on zinc critical level, 58 farms (96%) showed zinc deficiency. Based on the calculated average yields, the target yield was determined as 4133 kg/hectare, and according to the target yield, 43.3% of selected fields were classified as high-yielding and 56.6% were classified as low-yielding group. The CND method correctly recognized the balance of nutrients in rice plant with 55% accuracy. The relationship between yield and nutrients balance index showed that 31% of fields had nutritional balance, 24% had nutritional unbalanced, 22.4% had yield reduction other than nutritional factors such as climate, root depth limitations, pests, and diseases.

The findings showed that: 1- Using only the critical level of soil and plant nutrients for assessing the nutritional status of soil and plants was not efficient in the studied paddy fields. 2- The CND method, due to its consideration of the interactive effects of nutrients, had greater capability than the critical level method in diagnosing nutritional disorders, nutrient deficiencies, and fertilizer recommendations for the studied paddy fields. However, it was not the most accurate, sensitive and unique because factors other than soil fertility and rice plant nutrition, such as climatic conditions and irrigation, and field management, also influence the growth and development of rice plant and its yield. 3- The most important macronutrients and micronutrients needed in studied paddy soils based on the CND method were magnesium and phosphorus (macronutrients) and copper and zinc (micronutrients). 4- The CND method can be as an effective tool for interpreting soil and plant analysis in plant nutrition management at paddy farming systems.
​

After wheat, rice is the main food of Iranian people and has a special role in nutrition, income and job creation in the agricultural sector. Despite the undeniable importance of this crop, it is considered one of the water-intensive plants in the agricultural sector, and due to the water crisis in the country, the continuation of the cultivation of this crop in many regions of the country is facing many problems. The purpose of this research was to evaluate the potential yield (yield in the absence of water, nutrients, pests and diseases) and to estimate the blue and green water footprint of rice in the agro-ecological zones (AEZ) of the entire country. Water footprint calculations were done with the SSM-iCrop2 model for the time period of 2006-2015. The results show that parts of the northern regions of the country, such as Gilan, Mazandaran and Golestan provinces, which are located in the vicinity of the Caspian Sea, have less blue water footprint and more green water footprint, and are suitable areas for rice cultivation. Other provinces of the country, such as Khuzestan, Bushehr, Fars and South Khorasan, which are mainly located in the warm regions of the country, have more blue water footprints and less green water footprints, therefore, these provinces are not suitable for rice cultivation at all.

Knowing and determining the water productivity is the first step to improve it. The aim of this research is to determine the water productivity of potato plants in hot, moderate and cold climates of Kermanshah province. In the mentioned climates, Qasr-e-Shirin, Kermanshah and Sonqor cities, which had the largest area under potato cultivation, were selected as the areas for conducting this research. For this purpose, 35 farms were selected under the conditions of farmers in 2021-2022. The total volume of irrigation water of each of the selected farms was measured during the growing season. Effective precipitation was determined using the USDA equation. The amount of water consumed by farms was also calculated from the total amount of irrigation water and effective precipitation. After harvesting the crop and determining the yield of potatoes by dividing the amount of yield by the amount of water consumed, the water productivity of the selected farms was determined. SPSS software and ANOVA analysis of variance were used for statistical analysis of the results. The results showed that the average volume of potato irrigation water in the sprinkler method in Qasr-e-Shirin, Kermanshah and Sonqor cities was 7507, 7186, and 6739 m3 ha-1, respectively, and their average water consumption was 8002, 7246, and 6783 m3 ha-1, respectively. The average yield of potatoes in these cities was 24100, 35500 and 36100 kg ha-1, respectively. Therefore, the average water productivity of potatoes in these cities was 3.4, 4.9 and 5.7 kg m-3, respectively. Therefore, the results showed that the water productivity of potatoes in Qasr-e-Shirin city is 30%, and 40% lower than in Kermanshah and Sonqor cities, respectively, and the most important reasons are the lower yield and the larger volume of irrigation water and potato water consumption in this city. Therefore, it is possible to increase yield and reduce water consumption and finally increase the water productivity of potato by managing agronomic and breeding, and training farmers in order to reduce water consumption in this city.

Low-cost and high-precision technology is needed in crop yield forecasting to facilitate agricultural management. In this regard, wheat yields in East and West Azerbaijan provinces were modeled with climate indices (De Martonne index, Koppen 1, Koppen 2, Koppen 3, Angstrom, Selyaninov, Ivanov, Aridity, effective precipitation index and vegetation index). In this type of modeling, the combination of indices was used in the form of two, three and four indices. In order to decide on the appropriate climate index selection in each climate of modeling process, multi-criteria decision making (TOPSIS) was used based on 5 evaluation criteria, and Shannon's entropy was used to determine the weight of the criteria. The average increase in similarity index (SIM) for all indices from East Azerbaijan province to West is equal to 13.2%, which shows the better performance of climate indices in West Azerbaijan compared to East Azerbaijan province. Using a combination of indices is highly accurate under the condition of using an index with a better performance in single-index mode, for example, the rate of SIM increase from single-index to four-index mode in East Azerbaijan province is 20.94. The results of multi-criteria decision-making showed that the indices with Ivanov index in West Azerbaijan province and aridity index in East Azerbaijan province have a high impact on wheat yield. Determining the effective climate index in each region for crop yield forecasting is a powerful tool for decision making in product management and improvement.

Appropriate precipitation can play a crucial role in providing soil water content in rainfed fig orchards. Meanwhile, one of the main problems in most rainfed agriculture areas is the unavailability of rainfall data, which satellite rainfall datasets can help to solve this problem. The area investigated in this research is rainfed fig orchards of Estahban and the rainfall data of the meteorological station located in the area was applied for different periods of time. In this research, first, the relationship between yield and distribution of precipitation values in different time scales (monthly, seasonal and annual) was determined. Then the amount of satellite-derived rainfall was found using the rainfall datasets (i.e. CHIRPS, ERA5, ERA5-Land, GPM, PERSIANN and GSMaP) and based on these values, the amount of effective rainfall was calculated using different methods including USDA, ET-Rainfall, and Dependable Rain for the time period range between 2005 and 2021. Results showed, the rainfall in the months of April and then in May and November has had the greatest effect on improving the yield of the crop. Additionally, it is recommended supplemental irrigation events at the beginning of spring to provide higher soil water content for fig orchards in drought conditions. Based on the analyzed statistical criteria, it can be said that GPM was the most suitable dataset and USDA was the best effective rainfall method among the investigated methods in the area.

This study was conducted with the aim of investigating the yield and yield components of Panicum millet plant under the conditions of combined stresses of salinity and deficit irrigation as a split plot experiment in a randomized complete block design with three replications and 48 treatments at the research farm, Faculty of Agriculture, Ilam University. Treatments included four levels of irrigation water salinity including 0.63, 3, 5 and 8 dS/m (S1, S2, S3 and S4 respectively) and four irrigation levels including 100, 80, 60 and 40 (w1, w2, w3 and w4 respectively) percentage of water requirement was done. The traits studied included leaf-to-stem weight ratio panicle length, plant height, shoot weight, thousand seed weight, seed yield and harvest index. The results showed that the applied salinity stress levels had a significant effect on harvest index traits, seed yield, thousand seed weight, shoot weight, panicle length and plant height at the 5% and there was no significant difference only on the leaf-to-stem weight ratio trait. The combined effect of salinity and deficit irrigation stress on all traits except for panicle length was significant at the 5%. Millet in the conditions of no stress (S1W1) and the highest level of stress (S4W4) applied in this study could yield 3.76 and 1.71 tons per hectare, respectively.

Salinity is one of the most important environmental stresses after water stress in Iran, which has affected about 50% of agricultural lands with different intensities. The growth and development of crop plants in these areas are constantly exposed to salinity and other stresses at the same time, which causes morphological, physiological, and biochemical responses. Alleviating the negative effects of salinity in the crops is mainly done by agronomic and breeding methods. The use of appropriate microorganisms is one of the agronomic methods that can directly and/or indirectly reduce some limitations of salinity stress. In recent years, the necessity of biological study in rhizosphere microorganisms to improve nutrition and plant growth and, to control stress factors has been considered. Some species of Trichoderma fungi are known as plant growth stimulants in normal and stressful conditions. Since the bio-treatment of Trichoderma fungus for alleviation of salt stress in the Pinto bean has not been evaluated, so, the inoculation effects of different species of this fungus were studied on the plant growth and development under salinity conditions.

A field split-plot experiment based on a randomized complete block design with three replications were carried out at the Nuclear Agriculture Research Institute in Karaj on Pinto bean plants of Saleh 2. The main factor (salinity) was in two levels of non-saline (ECe=1.1 dS m-1) soil and saline (ECe=6 dS m-1), soil and the secondary factor with 11 levels, including; T. harzianum (MW718882), T. lixii (MW719563), T. ghanens (MW719590), T. virens (MW719876) and (MW719255) and their mutant isolates, namely NAS108 M1, NAS114-M17, ON545796, NAS115 M17, and NAS112M2, respectively, and the control treatment was without inoculation.

The results showed that the effect of salinity and the biopriming on the characteristics of emergence percentage, plant height, harvest index, number of pods, number of seeds per pod, seed weight, seed yield, biological yield, branching, seed protein and leaf area was significant (p≤0.01). Also, the results showed that the interaction effect of salinity and biopriming on emergence percentage, plant height, seed yield, biological yield, seed protein and leaf area was significant at p≤0.01, however, harvest index, the number of pods per plant, The number of seeds per pod and the seed weight were not influenced by treatment interactions. All studied characteristics were significantly reduced under salt stress compared to the control. The decrease in yield component traits was more than vegetative traits. The biopriming of Trichoderma species except T. lixii improved all traits of growth, development and seed protein of the plant in saline and non-saline conditions. T. harzianum, T. ghanens and T. atroviride along with their mutants produced the highest salinity resistance induction. Among them, the effect of T. atroviride was more obvious on saline condition while its mutant was superior in non-saline condition. The symbiosis efficiency of Trichoderma with this plant shows that under non-saline condition the efficiency varies between 16 to 70%, and the lowest is in T. lixii m and the highest in T. atroviride m. Also, except in T. atroviride treatment, the index was declined by salinity to the range of 3 to 58% for the rest of the fungi .

In general, the results of the experiment showed that the growth and development of pinto beans are affected by salinity, inoculation by the Trichoderma species and their interactions. As a result, the effects of different Trichoderma species are not the same under saline and non-saline conditions. Although under salinity treatment, the potential of the fungi in supporting of the vegetative traits, yield and yield component decreased, however, the values of all the traits in saline conditions were higher than the control without inoculation. This article shows that choosing the right and sustainable fungal treatment can partially alleviate the effects of the moderate salinity in the pinto bean plants. Therefore, it is possible to optimize bean production by inducing salinity resistance by selecting suitable Trichoderma. Overall and according to the results, seed biopriming treatment with Trichoderma species improves the vegetative and reproductive traits of pinto bean in saline and non-saline conditions, and the use of T. harzianum, T. ghanens and T. atroviride along with their mutants is recommended to maximize of the plant yield in the field conditions .

In this research, the effect of biochar on the efficiency of irrigation water consumption and the efficiency of nitrogen consumption at different levels of water and nitrogen fertilizer for karla plant was investigated in Zahedan. The experiment was carried out in the greenhouse conditions in a factorial manner and in the form of a completely random design with three replications (planted in February 2018 and harvested in April 2019). The treatments include three irrigation water treatments (I1) 50, (I2) 75 and 100 (I3) percent of irrigation water, four biochar treatments (zero (B1), 1.25 (B2), 2.5 (B3) and 5 (B4) weight percentage of pot soil) and three nitrogen fertilizer treatments (50 (N1), 75 (N2) and 100 (N3) percent of plant fertilizer requirement). Water stress levels during the growing season were measured by weighing the pots daily. Harvesting was done once a week. A total of five harvests were done. The yield and efficiency of irrigation water consumption and the efficiency of nitrogen consumption and soil salinity were calculated at the end of the growing season in each treatment. Also, soil nitrogen and fruit sugar were measured in each harvest. The results showed that the effects of irrigation water and biochar levels on the measured parameters were significant at the probability level of one and five percent. The highest amount of yield (15.5 tons per hectare) was obtained from the treatment of 100% of the amount of irrigation water, which was not significant with the treatment of 75% of irrigation water. The use of biochar up to 2.5 percent by weight of the soil increased the yield. More use of biochar (5% by weight of soil) decreased plant yield. The highest water consumption efficiency (3.14 kg/m3) and nitrogen consumption efficiency (94.55 kg/kg) were obtained with the use of 75% nitrogen fertilizer (150 kg/ha) and 2.5% by weight of biochar. The use of the appropriate amount of biochar reduced the negative effects of moisture stress in comparison with the control. Therefore, it is recommended to use it for the plant and especially in the conditions where the plant is under drought stress or in greenhouses and storages in order to reduce the amount of water consumed and improve the performance of the plant, although it is suggested to test in The farm should also be completed.

Investigating the effects of climate change on improving agricultural productivity is of great importance. It is predicted that the rising temperature trend will continue in the 21st century, leading to changes in the climatic conditions of  regions. Changes in precipitation distribution ، temperature and water resources are considered as harmful consequences of climate change، which could have detrimental effects on agricultural production. . In this study، the impact of climate change and cultivation on different dates was examined in terms of the yield of the 'Parsi' spring wheat variety in the Qazvin Plain. This study covered the period from 2021to 2100, comparing two information sources, LARS-WG and DKRZ, for producing annual climate change data and using the Aquacrop model to simulate the plant’s response to the mentioned changes. During the periods 2021-2040، 2041-2060، 2061-2080، and 2081-2100، the best planting date (February 4, February 20, March 5, March 20, and April 4) for increasing wheat yield was evaluated.  According to the model results in both scenarios 4.5 and 8.5، in all four periods (2021-2040، 2041-2060، 2061-2080 and 2081-2100), the spring wheat yield will increase compared to the baseline.. The highest yield in all of these periods and models is predicted for the period 2081-2100 under the LARS-WG climate model of in scenario 8.5,  assuming planting on February 4, with an estimated yield of 12.43 tons per hectare and a standard deviation of 0.31 tons per hectare. the lowest yield is expected for the period 2021-2040 under LARS-WG climate conditions in  scenario4.5, with planting on April 4, with an estimated yield of 7.87 tons per hectare and a standard deviation of 0.36 tons per hectare. In all four periods (2021-2040، 2041-2060، 2061-2080 and 2081-2100), February 4 is recommended as the most suitable planting date to increase wheat yield in the Qazvin plain.

water resources limitations in the country and the need for healthy food have led to an increased focus on the multifunctional use of water resources, as well as fish production, to meet human needs and improving the economic capacity of farmers. Additionally, aquaculture wastes are valuable fertilizers to enhance agricultural products . Therefore, the aim of this research is to investigate the effect of irrigating with wastewater from red tilapia fish ponds on yield and yield components of Persian Leek (Allium persicum L.). The current experiment was conducted in the research greenhouse of the water engineering department at the Agricultural Sciences and Natural Resources University of Gorgan. The experiment aimed to examine three water quality levels (city water, a 50:50 mixture of pond wastewater and city water, and fishery wastewater) in a completely randomized design based on pot cultivation and performed in  four replications. Results showed that irrigation  water quality had a significant affect on fresh and dry root weight, plant height, fresh weight of the plant, and leaf count per plant at the 1% probability level. while the dry weight of the plant and root length were significant at the 5% probability level. The results indicated that all the mentioned traits increased with the increase in the amount of fishery wastewater. Based on the results, the highest fresh aerial organ weight (13.97 g), fresh root weight (8.58 g), and aerial organ height (26.55 cm) were observed with irrigation using fish pond wastewater. The 50% mixture treatment of fish pond wastewater and city water led to a 5.72% increase in the aerial organ weight of Persian leek plant compared to the city water treatment. Additionally,  since fish pond wastewater essential  nutrients needed for plant growth, using fish pond wastewater in Persian leek plant cultivation is recommended, while further studies are needed for other vegetables.

Evapotranspiration variations (ET0) were investigated and analyzed using Minitab16 software for the 2010-2019 period using the Nizab system's data in Yazd province, and then ET0 was predicted until 2027. Based on the results, the increase of ET0 in cities of Yazd province was affected by the enhancement in wind speed and weather temperature, and the decrease in relative humidity from 2010 to 2019. To determine the appropriate model, Ardakan, Abarkooh, and Taft cities were selected as a representative in each climatic group, and ET0 data for the years 2010 to 2015 were considered as the input data of the software and ET0 data for the years from 2016 to 2019 were used to validate the determined model. The prediction of the determined models showed an increasing trend of ET0 for cold seasons in Ardakan and Abarkoh by 2027. Also, the model prediction showed a decreasing trend of ET0 for hot seasons in Taft by 2027. Also, the ET0 will not change significantly in cold seasons. In Abarkoh and Ardakan cities, autumn-spring crops such as wheat and in Taft city, spring-summer crops such as sunflower will be more affected by ET0 variations.

In order to investigate the effects of drought stress and different LED lights spectra on yield, water productivity and morphologic characteristics of wheat plant, a factorial experiment was performed in the form of completely randomized design in 2022 in the university of Torbat-e Jam, The effects of drought stress include three levels (100, 75 and 50 percent of water requirements) and the effect of different light spectra including six levels (white, 70% red + 30% blue, 100% red, 70% blue + 30% red, 100% blue and 50% red + 50% blue) on wheat plant was investigated. The results showed that by applying drought stress to the amount of 75 and 50% of the water requirement of the plant, fresh weight of aerial parts, dry weight of aerial parts, root fresh weight, root dry weight, plant length, chlorophyll a, chlorophyll b, total chlorophyll, carotenoids, potassium, phosphorus and magnesium concentration decreased and water productivity increased by 18.52% and 27.94% respectively. Also, the results showed that among the different types of LED light spectra application, the highest amount of fresh and dry weight of aerial parts, fresh and dry weight of roots, plant length and water productivity in 70% red + 30% blue light and the highest amount of photosynthetic pigments parameters were obtained in wheat plant under 50% red + 50% blue light. the results showed that the highest concentration of potassium occurred in 100% red light, phosphorus concentration in white light and magnesium concentration in 50% red + 50% blue light.

Water and fertilizer stress have a negative effect on many physical and chemical processes related to the efficiency of water productivity in soybean, thus leading to a decrease in the yield and quality of the plant. Predicting yield response for evaluating irrigation and fertilizer management strategies is of particular importance for making decisions. One of the decision support models in soybean is the CSM-CROPGRO-Soybean model, which is included in the DSSAT software package. The researches in the farm to determine the optimal solutions are done in agriculture and this item, in addition to the cost, is also time consuming, so the aim of this research is to use the DSSAT simulation model to evaluate the yield and water productivity in soybean plant under the conditions of water stress and nitrogen fertilizer were in Hormozgan province.

The current research was idone in the form of split plots in the form of a randomized complete block design in 3 replications, in Hormozgan province and in Haji Abad city in the years 2021 and 2022. The main factor includes no irrigation and supply of 40, 60, 80, 100 and 120% of water requirement and the sub-factor of nitrogen fertilizer amounts included consumption of zero, 50, 100, 150 and 200 kg/hectare. The data and information needed to implement the model include location, meteorological information, soil information and agricultural operations, and the estimation in the model was done using a combination of graphic and statistical methods. Comparison of values and distribution of simulated and measured data was presented with 1:1 graph and line.

The amounts of water use in the treatments of 40, 60, 80, 100 and 120 percent of water requirement in 1400 were 265, 354, 444, 533 and 623 mm, respectively and in 1401 were 259, 347, 435, 541 and 632 mm, respectively. The root mean square of the relative error (RMSEn) based on the years 1400 and 1401 showed that the yield of seeds, pods and biomass and the water productivity based on the yield of seeds, pods and biomass in the first year were 0.162, 0.161, 0.099, 0.304, 0.454 and 0.223%, and in the second year it was 0.195, 0.172, 0.106, 0.349, 0.485 and 0.247%, respectively. Wilmot agreement index (d) in the year 1400 for seed yield, pod and biomass respectively 0.902, 0.891 and 0.939% and for water productivity based on seed yield, pod and biomass respectively 0.828, 0.810 and 0.970 percent. In 1401 were for seed yield, pod and biomass 0.872, 0.885 and 0.936 percent respectively and for water productivity based on seed yield, pod and biomass respectively 0.889, 0.766 0 and 0.961 percent. The closeness of this index to the number one, it indicates the reliability of the simulated values.

In general, based on the statistical results, the simulation of seed, pod and biomass yields under the effect of different irrigation requirements and different levels of nitrogen fertilizer was acceptable and it seems that the use of the model as a useful tool to support scientific research and improving decisions in water use management in soybeans in the study area are recommended.

In this study, the effect of shallow and saline groundwater on the yield andparameters of quinoa in the greenhouse environment in two crop years 2018 and 2019 was investigated. The experiment was conducted in the form of factorial design of randomized complete blocks with 3 replications. The applied treatments included shallow (with depths of 0.6, 0.8 and 1.1 m) and saline (with salinity levels of 1,2, 6 and 10 decisiemens/meter of NaCl salt). The results showed that with the increase of water salinity from 1 to 10 decisiemens/meter and with the increase of the depth of the groundwater level, the percentage of groundwater contribution and the contribution of groundwater decreased significantly. The percentage of underground water participation for different salinity levels of 1, 2, 6 and 10 decisiemens/m in the depths of the water table 0.6, 0.8 and 1.1 meters respectively (37.43, 55.51, 71.12), (35/84, 51.21, 66.68,), (32.57, 46.92, 60.1397) and (30.15, 43/03, 56.93) were obtained. the increase in salinity caused a decrease in biological yield and an increase in the depth of the ponding surface caused an increase in biological yield and grain yield.The general results of the research showed that in none of the treatments, the water requirement of the plant was never provided by underground water in a hundred percent way, and a part of the water requirement of the plant was always supplied through irrigation during the growth period. It can also be said that the use of shallow and salty underground water resources (salinity less than 2 decisiemens/meter) in order to meet the water needs of the quinoa plant can reduce the amount of irrigation and contribute to the evaporation and transpiration of the plant

The Fe iron significantly affects the quantity and quality of agricultural production. Factors affecting the absorption of this element increase its efficiency. Meanwhile, the pH of the nutrient solution plays an important role in iron absorption. Iron is one of the essential elements for plant growth and plays an essential role in chloroplasts. Due to iron deficiency, the activity of several enzymes such as catalase, cytochrome oxidase, and ferroxin is significantly reduced. The amount of iron in the soil is high, but plants only absorb two-capacity of soluble soil, which is negligible compared to the total iron. Soil environmental conditions affect the amount of iron by the plant, so it is difficult to control the uptake of iron by the plant. It has the highest ability to absorb iron and manganese at a pH less than six. For this reason, acetic acid was used to stabilize the pH of the solution. Acetic acid has all the properties of an acid. Acetic acid is a polar solvent and an organic compound. The use of inexpensive organic acid and citric acid in agriculture, despite its positive effects on calcareous soils and their reasonable price, is still not common in Iran. Acetic acid has a carboxylic group and therefore has all the properties of an acid.

The pH solution plays a role in absorbing iron elements. This experiment was carried out in the form of a split-split plot in a randomized complete block design on a strawberry plant of diamant cultivar in the research station of the University of Mohaghegh Ardabili during the years 2015-2017. Ardabil City in northwest Iran is located between Sablan and Baghrou mountain ranges. Due to its high altitude and mountainous nature, this city is colder than other cities in Iran and is considered one of the semi-arid cold regions. The average rainfall of this city is reported to be 400 mm. Factors included acetic acid (zero, one, two, and three percent), iron in two levels (sequestration 25 gr and nano one gr), and two levels of agricultural soap agents (zero and 7.5 %) as foliar spraying. Foliar application of pH nutrient solution from the three-leaf stage of the plant (mid-April) to the end of May, a total of five times 10 days apart in both years, was done. Two weeks after the last foliar application (June of the second year) plant growth indices included leaf fresh and dry weight, root fresh and dry weight. Root length, flower-to-fruit ratio, chlorophyll greenery a, b, and total, leaf iron content and fruit yield per plant were measured.

The results of the analysis of variance showed that the three-way effect of treatments in all studied traits except root length and yield at one percent probability level on leaf fresh weight, leaf dry weight, and chlorophyll a, b and total at five percent probability level on fresh weight and root dryness, flower to fruit ratio and leaf iron content were statistically significant. The three-way interaction of acetic acid, iron, and agricultural soap data showed that the highest leaf fresh weight, leaf dry weight, root fresh weight, root dry weight, ratio of flowers to fruits, chlorophyll b, total chlorophyll and the amount of leaf iron related to the treatment acetic acid two percent of sequestration iron in combination with agricultural soap (7.5 %) and in chlorophyll a, it was related to the treatment of acetic acid one percent of sequestrin iron in combination with agricultural soap. The lowest amount of fresh and dry weight of leaves, fresh root weight and dry root, flower-to-fruit ratio, and leaf iron content were related to the treatment of acetic acid zero with Nano iron with agricultural soap (control). The lowest Chlorophyll b and total chlorophyll were related to the treatment of acetic Acid three percent with Nano iron with agricultural soap (control). In addition, the interaction between acetic acid and iron at the level of five percent probability on root length and yield was significant.

It can be concluded that acetic acid two percent on the absorption of iron fertilizer, along with agricultural soap (7.5 %) application, has better results than other treatments and qualitative traits of strawberry fruit. In general, it can be concluded that the pH of the nutrient iron solution can improve plant growth and crop yield. The iron level of sequestration iron with two percent acetic acid with agricultural soap 7.5 % due to increasing the bicarbonate of the soil in the Ardabil region has caused the absorption of nutrient elements, especially iron by strawberries. The shelf life of the solution on the leaf surface had a more favorable effect on most growth indices in the strawberry Diamant cultivar in Ardabil soil conditions.

The constraints of water resources and the imperative to enhance water efficiency in the production of vegetables and summer crops, on one hand, along with the economic importance of cucumber production in the country, on the other hand, reveal the necessity of investigating management indicators in cucumber production. The present study was conducted on a national scale with the objective of directly determining the applied water and water productivity indices in cucumber production fields across the country during a single crop year (1399-1400) in more than 180 selected farms, including about 70% of the cultivated area of cucumbers in the country. The results of the study revealed a highly significant disparity in various parameters among the selected provinces, including the volume of irrigation water, applied water (the sum of irrigation and effective precipitation), yield, and water productivity indices. The volume of applied water for cucumber cultivation exhibited notable variation, ranging from 4158 m3/ha in Hormozgan province to 8898 m3/ha in Razavi Khorasan province. The weighted average of applied water volume was calculated to be 7043 m3/ha. Similarly, the average yield of cucumbers displayed considerable diversity, ranging from 12750 Kg/ha in Zanjan province to 32956 Kg/ha in Razavi Khorasan province. The weighted average yield stood at 25219 Kg/ha. The calculated water productivity indices for both irrigation water and applied water were 4.27 Kg/m3 and 4.20 Kg/m3, respectively. Notably, the province with the lowest applied water productivity was Zanjan (2.21 Kg/m3), while the highest was observed in Fars province (6.59 Kg/m3). Based on the results, the total water requirement for cultivating cucumbers across an area of 55000 hectares in the country was estimated to be 330 MCM.

Most of the regions of the globe have faced changes in the precipitation regime and CO2 concentration with the increase in temperature (especially the minimum temperature). Considering that two-thirds of Iran is considered to be arid and semi-arid regions, which will cause climate changes and successive droughts, and this process will affect agricultural ecosystems and their performance. The aim of this research is to simulate the effects of climate change on growth, biomass yield and corn grain under climate change conditions in Shushtar and Safi Abad cities in the northern part of Khuzestan province in 2020-2050. For this purpose, the production data of precipitation, minimum temperature, maximum temperature and sunshine hours of the LARS-WG statistical model using HADCM3 atmospheric general circulation model and under emission scenarios A2 and B1 were used in the periods of 2020-2050. AquaCrop model was used to simulate plant performance and growth. Before use, the AquaCrop model was calibrated and verified by field data collected in the region. Then, the values of seed yield and biomass in future periods were simulated for the treatment of 50% of the water requirement of the plant. According to the results, under A2 emission scenarios, the evaluation results of the LARS-WG model showed that it had a suitable forecast for the climate parameters and the simulation of the future growing season. And the increase in minimum and maximum temperature will be the average increase in precipitation. The length of the growth period for each station will decrease with the increase of GDD according to the climatic parameters of the region under the influence of climate change. Biomass and grain yield will also increase by one to two tons in different horizons and scenarios assuming the current planting date and full irrigation remain constant.

In this research, the physical and economic productivity of water was investigated in cultivation of bread wheat cultivars (in Qazvin, Iran in 2020). The main treatments were included rainfed and irrigated cultivation, and the sub-treatments were included cultivars of Sorkh-tokhm (E1), Backcross Roshan (E2), Bam (E3), Azar2 (E4) and Kavir (E5). The experiment was performed in a randomized complete block design and with three replications. The amount of dry biomass, grain and straw was measured between 3495-4377 and 3501-4363 kg.ha-1 (in rainfed cultivation) and between 5022-9027 and 4525-8440 kg.ha-1 (in full irrigation), respectively. As a result, the Backcross Roshan cultivar (in full irrigation) was introduced as a suitable bread wheat cultivar. The amounts of physical water productivity in production of seeds, straw and biomass of Backcross Roshan cultivar were 1.67, 1.57 and 3.24 kg.m-3, respectively. Also, the economic water productivity for above parameters was estimated as 68,791, 39,896 and 124,842 Iranian rials.m-3, respectively. By changing the seed cultivar, the economic water productivity amount in full irrigation cultivation was increased to 20% (in compared to rainfed cultivation). By using the empirical models, economic water productivity amount was simulated based on the physical water productivity. The polynomial model with the R2 coefficient = 0.996, was recognized as the optimal model. The results showed that the seed cultivars with high water consumption and low economic productivity, should be removed from the region crop cultivation pattern. By the optimal use of fresh water resources in the agricultural sector, are provided the more economic benefits for farmers.

The depth and width of the soil wetting pattern determine the spacing between irrigation laterals and the irrigation drippers that influence their numbers and the overall cost of the irrigation system. Therefore, researchers look for solutions to adapt the soil wetting pattern to the pattern of crop root growth as much as possible such as adjusting the irrigation depth and irrigation intervals, utilizing physical, capillary, and hydraulic barriers, as well as pulsed management. Pulsed drip irrigation can replace the usual method of continuous irrigation due to its ability to improve the distribution of soil moisture and consequently crop yield. It also, prevents the accumulation of water in a specific point of the soil and decrease evaporation by improving moisture distribution in the soils with heavy texture and in the soils with a light texture, can lead to a reduction of deep percolation bellow the crop root zone. The results of studies have shown that pulsed drip irrigation can have a positive effect on reducing the clogging of irrigation drippers by providing the possibility of using a dripper with a high flow rate. Therefore, the general results of the research show that the use of pulsed drip irrigation can improve crop yield and water productivity. The purpose of this study is to review the experiences of using different management methods to improve the soil wetting pattern in drip irrigation systems and also provide experimental equations for simulating the soil wetting pattern under drip irrigation systems with emphasis on pulsed management.