حمید زارع ابیانه

Investigating the application of biochar on the physical and hydraulic properties of soil is important due to its effect on water conservation and management. According to our knowledge, no complete studies have been done on the effect of sunflower stem biochar particle size on the physical, hydraulic and soil moisture characteristics of the soil. Therefore, the purpose of this research was to investigate the effect of sunflower stem biochar particle size on some physical and hydraulic properties of sandy loam soil in laboratory conditions.

In order to investigate the physical and hydraulic properties of the soil, a combination of 3% by weight of three sizes of 0.5, 0.5-1 and 1-2 mm sunflower stem biochar particles was used with a sandy loam soil. For this purpose, the parameters of bulk density, porosity, saturated moisture, field capacity moisture, available water, moisture at permanent wilting point, discharge, flow velocity, hydraulic conductivity, pore water velocity and soil water characteristics curves were measured.

The results showed that the size of biochar particles has a significant effect on physical and hydraulic properties at the 1% probability level and also on soil water retention at the 5% probability level. The application of 0.5-1 mm size of biochar had the greatest effect on soil properties, so that it caused a decrease of 14.74% in bulk density, an increase of 21.17, 22.5, 34.78 and 44.44% in porosity, saturated moisture, field capacity and available water compared to control soil. Application of 0-0.5 mm particles of biochar caused a 24.39% increase in permanent wilting moisture and a 92.93% decrease in discharge, flow velocity, hydraulic conductivity, and also a 94.04% decrease in pore water velocity compared to the control soil. Investigating the soil water characteristics curves showed that all three sizes of biochar particles increased water retention in the soil. Biochar caused an increase in volumetric moisture content at all measurement points, especially at suction from 0 to 2000 cm. In this range of suction, biochar increased medium and fine pores and thus increased soil water retention in this suction. The addition of biochar to the soil also increased the field capacity, permanent wilting point and available water.

Arid and semi-arid areas with limited access to sustainable water resources generally have light textured soils with low water holding capacity. Therefore, these soils are the priority for structure improvement and as a result improving physical and hydraulic properties. According to the obtained results, the application of biochar improves the physical and hydraulic characteristics of these soils. Therefore, the findings of this research can be very useful in water management.Key words: Sunflower stem biochar, particle size, bulk density, saturated hydraulic conductivity, available water

Due to several factors, including anthropogenic global warming, drought is increasing in many arable areas which is one of the major threats to global food security. Abiotic stresses such as water deficit severely reduce crop productivity. Using strategies subsurface irrigation with porous clay capsules and natural nanobiochar amendment could be pivotal in reducing water and nitrogen fertilizer inputs as well as the effects of abiotic stresses on plants. Biochar addition to soil may improve soil physical and chemical characteristics. Soil water retention in the root zone enhances under the same irrigation schedule following biochar application. Biochar could improve plant access to soil nutrients and pivotal in reducing fertilizer inputs to agricultural soils.

Greenhouse experiments were conducted in two years (2019 and 2020) on broccoli planted in sieved and non-sieved samples of a loam soil amended with natural nanobiochar (i.e., 0 and 10% by weight) under three irrigation regimes (i.e., 100, 75, and 50% of full irrigation) and two levels of nitrogen fertilizer (i.e., 225 and 300 kgha-1 N). The irrigation system was porous clay pitcher subsurface irrigation. The full irrigation (FI) treatments were watered to refill the pore space in the rooting zone to the field capacity (100% FI), while in deficit irrigation treatments plants received 75% of the full irrigation (75% FI) or 50% of the full irrigation (50% FI). Fertigation treatments included two levels of N fertigation (i.e., 225 kg N ha-1 and 300 kg N ha-1) in the seedling, vegetative growth and green head stages were applied. Physiological and morphological traits of broccoli including secondary head fresh and dry weights, secondary head density, concentration of nutrients, total chlorophyll and leaf proline were investigated.

Plants exposed to deficit irrigation and nitrogen fertigation presented a significant decrease in head fresh and dry weights, head density and also total chlorophyll, while an increase in the leaf proline content was observed. The application of NNB in soil mitigated the drought and nutritional stresses effects on the morphological traits. The results showed significant effects of the natural nanobiochar application in sieved and none-sieved soils on head fresh and dry weight, head density, total chlorophyll and leaf proline for both seasons (2019 and 2020). Natural nanobiochar addition to both sieved and non-sieved soils improved the head fresh and dry weights, head density, and total chlorophyll content. Moreover, it significantly reduced the leaf proline of broccoli plant under deficit irrigation and nitrogen fertigation. The highest values of fresh and dry weight, head density and calcium, magnesium and chlorophyll concentrations were 99.26 g, 39.79 g, 0.92 g cm-3, 5.96 mg g-1, 3.52 mg g-1 and 2.52 mg g-1 in SNAS+NR2+FI, NNAS+NR2+FI, NUS+NR2+FI, SNAS+NR2+FI, SNAS+NR2+FI and NUS+NR2+FI treatments, respectively. As well as, the lowest value of leaf proline was 0.08 µmol g-1 in NNAS+NR2+FI treatment.

Our study demonstrated some of the beneficial effects of natural nanobiochar as an organic amendment for promoting crop productivity. Hence, the integration of natural nanobiochar addition along with deficit irrigation and low N fertigation condition could be considered as a viable and optimum approach in terms of water and fertilizer saving, yield and cost. Thus, the combination of this technique and sub-surface irrigation with the porous clay pitcher system will particularly be useful in arid regions that frequently suffer with water shortages condition.

Irrigation is of major importance in many countries. It is important in terms of agricultural production and food supply, the incomes of rural people, public investment for rural development, and often recurrent public expenditures for the agricultural sector. Yet dissatisfaction with the performance of irrigation projects in developing countries is widespread. Despite their promise as engines of agricultural growth, irrigation projects typically perform far below their potential. A large part of low performance may be due to inadequate water management at system and field level. Performance evaluation is an essential part of irrigation systems. Performance of irrigation systems is evaluated for a variety of management objectives. Several researchers have proposed various indicators to assess the performance of irrigation systems. Most of them focused on internal processes of irrigation schemes that relate performance to management objectives such as the area irrigated, crop patterns and distribution and delivery of water. Most of researchers have conducted studies to assess the performance of irrigation management process using financial and physical indicators. Comparative indicators are more suitable than process indicators due to the real evaluation of network performance. Comparison aims to improve the performance of the schemes by identifying shortcomings and benchmarking best practices. In this research the performance of the Gavoshan Irrigation Network in the Kamyaran region of Kurdistan Province was evaluated using some comparative indicators provided by the International Water Resources Management Institute (IWMI) at three groups of comparative performance indicators: agricultural output, water supply and financial indicators.

In this research, the irrigation and drainage sub-system network of B2 construction area of Kamiyaran Bilehvar plain located in the Gavshan reservoir dam in the south of Kurdistan province with an area of 3500 hectares was evaluated. Comparative performance assessment in irrigation schemes is possible through use of comparative indicators. External indicators are those indicators based on outputs and inputs from and to an irrigated agricultural system. In this research Using the indicators of the International Water Management Institute (IWMI) in three groups, agriculture, water consumption and network performance were evaluated. These indicators need data that is available and easily to analyze. The data required includes the crop yield the irrigated area of the plant in the cropping season the water requirement of the plants the cultivation pattern and the information about the amount of water delivered to the network. The indicators of Output per unit command area, Output per unit cropped area, Output per unit irrigation supply, Output per unit water consumed, Relative water supply, Relative irrigation supply, Irrigation ratio, cropping intensity and Water delivery capacity were investigated. The water supply indicators are based on irrigation and water supply/delivery measurements being related to demands or irrigated area.

Irrigation water management is ultimately meant to enhance agricultural production through sustainable water use. Annual relative water supply and annual relative irrigation supply were evaluated for the agricultural system. Annual values of four water supply/demand values were determined. These indicators provide the basis for comparison of irrigated agriculture performance and they relate output to unit land. The performance results of the studied network in terms of water and land efficiency show that the performance of the current state of the network is generally reasonable. The analysis of water consumption performance showed that the values of relative water supply and relative irrigation supply were calculated as 1.3 and 0.94, respectively which means that the water required by the network is supplied by 0.06 less. And the demand for irrigation is slightly more than its supply, which should be made aware of the dangers of excessive demand by educating users. The difference between the values of RWS and RIS is due to the rainfall in the network area during the cropping season. In this study, in general, RWS and RIS values show that the water requirement of crops in the network are supplied. Physical performance was evaluated well in terms of cultivation intensity and irrigation ratio. The water delivery capacity of the main channel of the Gavoshan network is 0.97, which means that the water needs of crops are approximately met for the current cropping pattern. However, in the event of a change in cropping pattern, to avoid water stress first the capacity of the irrigation channel to supply the water needs of the new crop pattern in the peak month of the plant should be checked.

Tracing the reactive material through soil is crucial for the health of the environment, water resources and agricultural products. One of the widespread elements in agricultural lands is sodium, which affects on soil physical structure and water movement and solute transport in soil. Therefore, it is important to trace and remediate the sodium transport through the soil and know the fate of this element in the root zone. Many factors can affect the transport of an ion through porous media, in which soil moisture condition and application of amendment such as vermicompost are very effective due to altering the hydraulic and physical conditions of the soil. Therefore, the aim of the current study is to model the sodium transport in natural soil and soil amended with vermicompost under saturated and near-saturation conditions with three models of equilibrium, one-site sorption and two-site sorption. Moreover, sensitivity analysis was employed to explore the effective parameters of the breakthrough curve of sodium.

Two media including natural soil with loamy sand texture and soil amended with vermicompost were prepared, in which amended soil was achieved by mixing 1.45 gr vermicompost with 100 gr natural soil. In order to conduct the experiment, 350 gr of each soil sample was placed into the columns with a length and a diameter of 10 and 5.95 cm, and then all soil columns were saturated for 24 hrs and leached with distilled water for another 24hrs. After leaching, a solution containing 1mM KNO3 and 0.435mM NaCl was applied with flow rates of 3.17-4.28 and 2.5 cm3/min for 270 minutes under saturated and near-saturated conditions (water saturation (Sw)=1 and 0.98), and soils were leached with distilled water again under aforementioned conditions during 300 minutes. The effluent solutions were collected and their Na contents were measured using flame photometry. Next, Hydrus-1D program was employed to simulate the experimental breakthrough curves of sodium using Advective-Dispersive equation coupled with equilibrium, one-site sorption and two-site sorption models. The unknown coefficients were KD for equilibrium model, KD and α for one-site sorption model and KD, F and α for two-site sorption model. The sensitivity analysis was performed for all unknown coefficients of the models to clarify the role of each coefficient on the simulated curve.

The values of RMSE for equilibrium, one-site sorption and two-site sorption models were respectively 0.02-0.19, 0.003-0.03 and 0.003-0.03, which indicates equilibrium model has an unacceptable accuracy compared to the one-site and two-site sorption models, and two-site model has the highest accuracy. Equilibrium model had poor performance at all parts of all curves, while the poor performance of the other models occurred at the breakthrough point and slop of some curves. The relatively similar accuracy of one-site model with two-site model and the fraction of sorption sites (F)<0.5 in two-site model indicated that the transport of sodium in the both soils was mainly controlled by the sorption/desorption kinetic process. The application of vermicompost and desaturation from Sw=1 to 0.98 decreased the values of F to 66.5 and 85.5% respectively, indicating that the kinetic process was more predominant in amended soil and unsaturated conditions. The values of distribution coefficient (KD) were altered by changing the conditions in all models. The values of KD increased by the application of vermicompost and soil desaturation to 3.4 and 12.6%, respectively. It shows that the sorption capacity of amended soil is higher than that of un-amended soil, and it is increased under unsaturation conditions compared to saturated conditions due to the presence of air bubbles in soil and a delay in water and solute transport. Employing the fraction of sorption sites in two-site model compared to on-site model changed the values of first-order rate coefficient (α) from 0.01-0.032 to 0.005-0.016 min-1 leading to a reduction by 47%. The values of α were decreased by a reduction in flow rate due to the lower sodium diffusion. The results of sensitivity analysis showed that KD had the most effect among the coefficients on fitting the breakthrough curve, and altered all parts of the curves including the breakthrough and peak points and the slope. The one-site model had low sensitivity to α, which its variation led to a small change around the peak point. The sensitivity of two-site model to the both coefficients of F and α was moderate, by which the curve had a variation on the peak point and slope. Overall, the sensitivity of coefficients of two-site model showed the trend of KD>F>α.

The cucumber is one of the semi-tropic vegetables of economic importance that is widely cultivated worldwide. To optimally grow this plant in the greenhouse environment, the requirements for cucumber moisture should be fulfilled. Due to the high efficiency of the irrigation method, two methods of capillary wick irrigation and drip irrigation, among the different irrigation methods, are of interest for this purpose. Thus, the current research was undertaken to determine the effectiveness of the wick irrigation method compared to the drip irrigation method on the yield and some growth characteristics of greenhouse cucumber plants in three different soil textures under the conditions of pot cultivation in the greenhouse environment.

This study was conducted for two cultivation periods as a factorial, based on a complete randomized design with three replications in different soil textures including clay-loam (CL) marked with (S1), sandy-clay-loam (SCL) marked with (S2), and sandy-loam (SL) marked with (S3) on greenhouse cucumber Nagene cultivar with two methods of capillary wicking and drip irrigation as well as same nutrition program. The greenhouse used in this project was in the form of a tunnel with a plastic coating, with a height of 3 meters, and an opening width of 4.4 meters. The cultivation of the cucumber plant was carried out in the first half of March and the second half of August of the following year using a pot method with a soil culture bed. Several investigated characteristics, including plant height, stem dry weight, number of leaves, fruit weight, fruit number, main root length, number of root branches, root dry weight, and plant fresh weight were subjected to statistical analysis after sampling as well as measuring in SAS and Excel environment.

The results revealed that the effect of irrigation method, soil texture, and their interactions on vegetative traits of cucumber, the effect of irrigation method on vegetative and reproductive traits, and the impact of soil texture on root organs were different at 0.01 level of significance. In the vegetative part, the stem height, stem dry weight, total leaves, total plant weight; and in the reproductive part, the number of fruits and total fruit weight; and in the root section, the root length, number of root branches, and dry root weight in soil texture CL were affected by drip irrigation method. In wick irrigation, the reproductive traits and root organs in SL soil texture outperformed others. The effect of wick irrigation on fruit production and plant biomass was observed to increase in three soil textures of CL, SCL, and SL with values of 760.98, 782.58, and 995.56 grams, respectively; in drip irrigation, it was observed to increase with values of 1315.81, 1131.71, and 736.22 grams respectively. In all three soil textures, the effect of wick irrigation on root organ traits was almost the same, while the influence of drip irrigation on root traits in CL, SCL, and SL textures diminished, respectively.

The results indicated that in the reproductive part and root organ, the wick method was not preferable to the drip method, while the opposite trend was observed in the vegetative part. Although the wick irrigation method was not superior to drip irrigation in the production of cucumber, being successful in its application due to the simple management of the system by eliminating pumping and advanced irrigation equipment, its self-irrigation and its superiority in the production of vegetative traits can be successful in plants with economic value in the vegetative sector.

This study was performed to evaluate the AquaCrop model in the crop yield, biomass, crop, and biomass water use efficiency of greenhouse cucumber with two methods of the capillary wick and drip irrigation and three soil textures including Clay-Loam marked with (S1), Sandy-Clay-Loam (S2) and Sandy-Loam (S3) in three replications and two cultivation periods in spring 2018 period (1) and autumn 2018 period (2). Data analysis was done based on compound analysis of variance and mean comparison was done based on Duncan's multi-range test. The data of the first period was used for calibration and sensitivity analysis, and the data of the second period was used to validate the model. The root-mean-square error (nRMSE) and coefficient of determination (R2) were used to validate the model. Based on results in the drip irrigation system, the maximum yield, and water use productivity were observed with 79.64 ton/ha and 46.54 kg/m3 in T2S1 treatment, and in the capillary wick irrigation system, the highest yield, and water use efficiency were observed with 62.05 ton/ha and 44.76 kg/m3 in W2S3. The model investigation results revealed that the highest simulation accuracy was observed in W2S3 treatment so that the nRMSE index in crop yield, biomass yield, crop water use efficiency and biomass water use efficiency were respectively 2.80, 1.70, 1.10, and 1.70 percent were calculated. Due to the optimality of all conditions in the model, most of the estimated parameters were higher than the observational data, still, the increasing and decreasing trend of model simulation in estimating product performance values was completely consistent with the observed data.

Roughness coefficient is an effective factor on water velocity and discharge in drain pipes. Roughness coefficient in experimental box model with dimensions of 100×41×56cm was evaluated with two pipes of smooth and corrugated in a diameter of 63 and 56mm by three series of independent tests. The first set was done on pipes with mineral envelop, the second set on pipes with synthetic materials and the third one on pipes without envelop. The mean values of "n" Manning’s in the smooth pipe with synthetic and mineral envelope and non-envelop materials were measured 0.0106, 0.0111, 0.011, and for the corrugated pipe 0.0088, 0.009, 0.0091. The mean values of "n" Ganguillete-Kutter’s in the smooth pipe with synthetic and mineral envelop and non-envelop materials were obtained 0.0048, 0.0048, 0.0048, and for the corrugated pipe 0.0041, 0.0042, 0.0042. The "n" values from the Reynolds-Darcy Weissbach combination formula in the smooth pipe with synthetic and mineral envelop and non-envelop materials were calculated to be 0.0050, 0.0050, 0.0049 and for the corrugated pipe 0.0048, 0.0048, 0.0049. Two evaluation indexes (R2 and RMSE Error Value) indicated a better result for n value obtained by Ganguillet-Kutter formula. The flow inside the drainage pipes is a turbulent and spatially variable which is affected by the small flows entering the pipe through holes. This flow pattern, while disrupting the uniform distribution of the transverse velocity of the flow, caused flow inhibition and increased Manning's roughness coefficient in the first 30 cm due to the flow rate and low flow speed compared to the second 30 cm. The negligible difference between "n" Manning’s with "n" Ganguillete-Kutter’s is not important and applying 0.011 for Manning coefficient in smooth pipe and 0.009 for corrugating pipe with envelop is satisfactory. 

One of the major issues in arid and semi-arid areas, namely Iran is water scarcity. Therefore, in the present study, the use of rainbow trout effluent in the sprinkler irrigation system for potato cultivation was investigated for three years (2019-2021). This research was conducted in the form of a factorial experimental format based on a completely randomized design with three replications. The investigated factors include irrigation at two levels, A1 (irrigation with well water) and A2 (irrigation with fish effluent), as well as washing the leaves of the plant in four levels they are Before applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B1), after applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B2), The leaves were washed with fresh water for ten minutes both before and after applying the fish farm effluent to them (B3) and the leaves were not washed at all (B4). The results of this research show that the highest amount of yield, the number of stems per plant, the fresh weight of shoot, the percentage of tubers 80-120 grams, the percentage of tubers 120-150 grams, and the percentage of tubers larger than 150 grams were 565.983 grams per pot, 7.417, 57.608, 32.950, 7.850, 6.039 respectively. These highest amounts were all the results of applying A2 .

A cultivation pattern in accordance with environmental conditions that reduces pollution of water and soil resources is one of the most important management strategies. This study aimed to simultaneously combine information related to soil, climate, crops and determine the potential of vulnerability and contamination of the aquifer, based on which susceptible cultivated areas (main cultivation -wheat and alfalfa) were evaluated. ArcGIS 10.3 software was used to investigate the effect of aquifer quality on cropping patterns. Climatic factors, soil parameters, and topographic characteristics were selected as effective parameters in selecting suitable cultivation sites. Nitrate content was collected in 46 wells in Shahrekord plain and averaged by kriging method, and a nitrate concentration map was obtained and combined with vulnerability map and aquifer quality area was investigated. Analytical Hierarchy Process was used to weight and finally, the layers were combined using the weighted linear combinationmethod. The results showed that areas without risk of contamination and with very low potential for contamination were 11 and 51%. Areas with low and medium to high risk of ontamination were 3 and 4%, respectively. About 25% of the aquifer area is in the high nitrate contamination range and its maximum nitrate concentration is 55 mg/l. Very high pollution (more than 75 mg/l) has not been estimated in Shahrekord plain aquifer. According to the results of this study, in terms of aquifer quality, the main part of the aquifer, about 41%, is in the safe range. 33% were classified in the low-risk group and 25% in the dangerous range. In Shahrekord plain, currently 4989 hectares are the area under irrigated wheat cultivation, which according to the results, can be increased to about 22,600 hectares. The current area under alfalfa is 3806 hectares, which according to the results, has the potential to increase the area under 28198 hectares.

Saturated hydraulic conductivity of soil (Ks) is an important soil property in the management of irrigation and drainage issues, including areas covered with palm trees. This study was conducted to determine the amount of Ks in the palmetum lands of Bavi city of Khuzestan province. The amount of Ks was also evaluated using field, laboratory methods and Pedotransfer functions. The amount of Ks in five distances of 0.5, 1, 2, 3 and 5 meters from palm trees with three replications by double ring methods, Guelph permeameter, falling head, Rosetta model and Pedotransfer functions of Cosby et al., Ferrer-Julia et al., Campbell and Shiozawa, Dane and Puckett and Puckett et al. were obtained. Evaluation of the results showed that the double ring methods, Rosetta model and Pedotransfer function of Cosby et al. with a geometric mean error ratio of about 1 were more accurate than other methods. The deviation time of these methods were 4.75, 5.31 and 26.14, respectively. The geometric standard deviation error ratios of these methods to the falling head method were 1.10, 1.40 and 2.08, respectively.

In recent years, due to lack of water, using wastewater including fish effluents, for agricultural purposes has increased. Depending on water quality, irrigation method and type of crop might change. The elements present in the fish effluent interact with each other and it is possible to increase or decrease the absorption of an element through the leaves to have a negative effect on the yield and growth indicators. Therefore, the aim of this research is to provide solutions for the use of rainbow trout wastewater in the sprinkler irrigation system to provide irrigation water for potato cultivation and the effect of leaf washing with appropriate quality on yield, tuber dry matter percentage, diameter and height of stem, tuber specific weight, chlorophyll, photosynthesis, transpiration and stomatal conductance.This experiment was conducted in research farm No. 2 of Kurdistan University ,Dehgolan plain in Kurdistan province in the form of a factorial experimental format based on a completely randomized design with three replications in the summer of 2019, 2020 and 2021. The investigated factors include irrigation at two levels, A1 (irrigation with well water) and A2 (irrigation with fish farm effluent), as well as washing the leaves of the plant in four levels, B1 (Before applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water), B2 (after applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water), B3 (The leaves were washed with fresh water for ten minutes both before and after applying the fish farm effluent to them) , B4 (the leaves were not washed at all).Sprinkler irrigation system with micro sprinkler was used to irrigate. At the end of the growing season, the tuber yield values of different treatments were measured. Chlorophyll meter (SPAD-502-Minolta-Japan) was used in order to measure chlorophyll of leaf. The indicators related to gas exchange including photosynthesis, stomatal conductance and transpiration were measured by a portable device (ADC BioScientific LCi Analyzer Serial No. 32648). Data were analyzed with Rstudio, and mean values of the treatments were compared by the least significant difference (LSD) test at 5% and 1% significance level.The results showed that washing the leaves with fresh water significantly affected on the yield and other growth indicators. The highest amount of yield, stem diameter, specific gravity of potato, chlorophyll meter reading, photosynthesis, transpiration and stomatal conductance were 550.8 grams per pot, 9.941 mm, 1.113 g cc-1, 53.59, 22.00 (μmol m-2 s-1), 7.028 (mmol m-2 s-1), 0.4439 (mmol m-2 s-1), respectively. These amounts were results of applying B3 treatment. Also, the highest percentage of potato tuber dry matter was 13.3% and the highest figure for stem height was 35.46 cm, which were the result of applying B4 treatment.The results of this research show that compared to well water, fish effluent increased yield of potato by 16.4%, stem diameter by 4.67%, stem height by 3.72%, chlorophyll meter reading by 9.67%, and stomatal conductance by 15.40%. Also, the results showed that treatment B3 compared to B4, increased yield 64.78%, stem diameter 39.55%, tuber specific weight 48.54%, chlorophyll meter reading 41.21%, photosynthesis by 4.40%, transpiration by 25.86% and stomatal conductance by 10.13%. It is suggested to use the strategy of simultaneous use of fish effluent and fresh water in the sprinkler irrigation system to increase yield and growth indicators.

water scarcity is one of the primary problems in arid and semi-arid regions such as Iran. Many previous studies corroborated that using aquaculture wastewater might be a good alternative for supplying irrigation demand in the arid and semi-arid countries such as Iran. In fact, the effluent of the fish farms that contain a notable amount of phosphor and nitrogen are high nutrition for different plants. Depending on water quality, irrigation method and type of crop might change. The elements present in the fish effluent interact with each other and it is possible to increase or decrease the absorption of an element through the leaves to have a negative effect on the chlorophyll fluorescence. In an attempt to reduce foliar absorption, we used post-washing, pre-washing and pre and post washing. Therefore, the investigated factors include irrigation at two levels, A1 (irrigation with fresh water) and A2 (irrigation with fish farm effluent), as well as washing the leaves of the plant in four levels they are Before applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B1), after applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B2), The leaves were washed with fresh water for ten minutes both before and after applying the fish farm effluent to them (B3) and the leaves were not washed at all (B4). The main objective of the present study is to provide a solution to reduce the negative effects of fish effluent in sprinkler irrigation on chlorophyll fluorescence.

The present study was conducted on pots; the pot experiments were carried out at the research site of the University of Kurdistan. This research farm is located at the Dehgolan plain in Kurdistan province. As presented in the previous section we applied two types of water for irrigation in the treatments including fresh water from the available well in the experimental site and the fish farm effluent from the available fish farm as well as washing the leaves of the plant in different situations including Before applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B1), after applying fish farm effluent to the leaves, they were washed for ten minutes with fresh water (B2), The leaves were washed with fresh water for ten minutes both before and after applying the fish farm effluent to them (B3) and the leaves were not washed at all (B4). In the present study soil moisture was measured in the daily scale before the irrigation then irrigation was carried out based on the efficiency of required soil moisture. The PMS-714 moisture meter was applied for measuring the soil moisture in the experimental site. At the end of the cultivation period, the yield of potato in each pot was collected and measured separately. Then the average of all the potato was applied in the further analyses. Data were analyzed with Rstudio, and mean values of the treatments were compared by the LSD test at a 5% and 1% significance level.

The results of this research showed that B3 compared to B4 increased yield by 10.13%, maximum fluorescence by 20.44%, variable fluorescence by 28.67%, maximum photochemical quantum yield of photosystem II by 6.66%, dry weight of stem 37.98%, dry weight of leaf by108.06% and dry weight of root 125%. previous studies corroborated that effect of leaf washing when unconventional water is used has a positive effect on the absorption of elements by the plant and growth indicators. Also, previous studies showed that the simultaneous use of fresh water and water unconventional methods reduce the toxic effects caused by the substances in the wastewater and improve the yield and physiological indicators of the plant. It has been reported that when leaves are washed with fresh water before and after salt water is applied to the leaves, the concentration of chlorine and sodium in the leaves is lower than when leaves are not washed at all. They stated that when the leaves are washed before applying salt water, the leaves are hydrated and the capacity to absorb elements by the leaf is reduced, and also when the leaves are washed after applying salt water, the elements and materials are washed on the leaf. And leaf absorption is reduced. Therefore, it increases yield. It is recommended to use the strategy of simultaneous use of fish waste and fresh water in sprinkler irrigation system to increase chlorophyll fluorescence and other characteristics of potato plant.

In the investigation of the effect of different mulches on the vegetative characteristics of grape seedlings and comparing them in drip and capillary irrigation systems, an experiment was conducted in the form of randomized complete blocks with three replications. In the main plots, drip and capillary irrigation methods were evaluated, and in the subplots, types of mulches including plastic, no mulch, sand-stubble, and stubble mulch were evaluated. Based on the results of the irrigation method, had a significant effect at the level of 1% on the collar diameter, seedling height, branches number, shading area, and leaves a number. The effect of mulch was also significant on the branches number, branches length, shading area and leaves number at the level of 1%. The highest seedling height, branch length, shade area, and leaf number were observed in the drip irrigation with plastic mulch, and the lowest amount of the mentioned traits were observed in the drip irrigation and no mulching. Based on the average comparison, in capillary irrigation, the application of mulch had no significant effects on the performance of vegetative traits, and in drip irrigation, the use of plastic mulch compared to the no mulch method Caused an Increase in the performance of collar diameter, seedling height, branches number, branches length, shading area and leaves number by 32.27, 47.56, 40, 68.61, 62.36 and 61.18%, respectively. Based on the results, there is no need to use mulch in capillary irrigation, and it is recommended to use transparent plastic mulch in drip irrigation.

In recent years, due to limited water resources in Malayer plain, irrigation methods are changing from surface to under pressure. The purpose of this study was to investigate changes in soil quality due to changes in irrigation methods. For this purpose, 14 farms and 2 orchards equipped with sprinkler and drip irrigation system were selected and their soil quality changes compared with the corresponding values before implementation were evaluated by Mann-Whitney statistical test. Soil quality parameters included acidity (pH), nitrogen (N), phosphorus (P), organic matter (C), electrical conductivity of solutes (ECe) and potassium (K). The zoning map of the studied quality parameters was also prepared using ArcGIS software before and after the implementation of pressurized irrigation systems. The results showed that the difference between the values of the studied parameters before and after the implementation of pressurized irrigation systems including ECe, pH and C were non-significant at the level of 5% probability and the changes of P, K and N were significant. The results of measuring the qualitative parameters showed an increase in the mean values of pH, N, P and C from 7.72 to 7.80, 0.067 to 0.121 mg/kg, 11.01 to 17.95 mg/kg and 0.68 to 0.80%, respectively, compared with before the implementation of pressurized irrigation systems. However, ECe and K values of field soils decreased from 1.06 to 0.53 dS/m and 255.1 to 156 mg/kg, respectively. The results showed that changing the irrigation method reduced potassium and increased soil phosphorus and nitrogen.

Drip irrigation management requires proper information on the horizontal and vertical distribution of moisture in the soil of the root zone. In this study, soil moisture distribution was simulated up to 72 hours after drip irrigation by coefficients of soil water characteristic curve with three different methods in the Hydrus-2D model. These methods were included estimating the soil water characteristic curve of inverse solution methods with soil water characteristic curve data (IS1), inverse solution with soil moisture data after irrigation (IS2), and Rosetta. To determine the accuracy of the simulated moisture values with the measured values, RMSE and R2 were used. The results showed that RMSE and R2 for estimating the soil water characteristic curve in IS1, IS2, and Rosetta methods were obtained 0.008 and 0.999, 0.153 and 0.958, 0.125 and 0.977, respectively. The accuracy of IS1 methods depended on the information of the soil water characteristic curve, Rosetta depended on some early soil properties, and IS2 depended on soil moisture after irrigation. Average RMSE and R2 in the simulation of horizontal moisture distribution for IS1, IS2, and Rosetta were obtained 4.6 and 0.9941, 2.8 and 0.9951, 5.5, and 0.9905, respectively. Also, the mean of these statistics in simulating the vertical distribution of moisture for the mentioned methods were 4.6 and 0.9830, 4.4 and 0.9928, 5.4 and 0.9932, respectively. Finally, the use of IS1 method was recommended due to the shorter time and cost of simulations and the possibility of performing it before the design of the drip irrigation system.

In recent years, increasing population and limited water and arable land in Iran have led to significant investment in greenhouse production. Due to the effect of greenhouse microclimate conditions on the quantitative and qualitative yield of the product, the use of mathematical models to study and microclimate simulation of the greenhouse is necessary. The objective of this research is to apply and analyze an energy balance model using meteorological data outside the greenhouse to simulate microclimate conditions and the transpiration in a greenhouse. The study was conducted in a commercial greenhouse with plastic cover and an area of 4333 square meters. Temperature and relative humidity data were collected inside the greenhouse with 21 data loggers. For collected meteorological data outside the greenhouse, the meteorological station installed on the roof of the greenhouse and the data of the Tuyserkan synoptic meteorological station were used. A combination of energy balance and transpiration equation was used to estimate temperature, relative humidity and crop transpiration inside the greenhouse. Estimated transpiration was modified by combining the energy balance model and the Stanghellini transpiration equation. The pattern of temporal variation of the simulated and measured values of temperature and relative humidity inside the greenhouse was similar. The root mean square error of the simulated temperature for mechanical ventilation and natural ventilation was 0.72 and 0.67, 0.83 and 0.77 daily, and 0.49 and 0.49 degrees Celsius, respectively, for the daytime and night time. The root mean square error of relative humidity for mechanical and natural ventilation was 4.4% day and night, 3.0% for daytime, and 6.0% for night time. After modifying the simulation model, four days of microclimate inside the greenhouse showed that the temperature inside the greenhouse reaches 35 °C during the day and less than 16 °C at night, which are not in the optimal temperature range for greenhouse cucumbers. Due to high temperature (35º C) and low humidity (15% to 30%), evaporative cooling will be required at some hours of the day. The total simulated transpiration was 30.2 mm. The estimated temperature was acceptable, but the estimated relative humidity at night differed from the measured values due to thermal inversion. Estimated transpiration was modified by combining the energy balance model and the Stanghellini transpiration equation. After verifying and modifying the model, the microclimate conditions of the greenhouse were simulated and analyzed for four days. The results showed that by using the energy level model before the construction of the greenhouse, it is possible to estimate the microclimate conditions of the greenhouse and the water requirement of the crop.

Optimal and efficient application of water resources due to the recent water crisis and droughts in the country is very necessary. In this regard, the use of modern irrigation methods is one of the solutions that has been developed to increase water productivity in the country. Therefore, this study was conducted to compare the physical and economical efficiency of water in drip and surface irrigation systems and net benefit per cost in vineyards and walnut orchards. In this study, the volume of applied water was calculated by measuring the flow rate of the water source, the number of irrigations and the hours of irrigation in each irrigation. The water requirement was calculated based on the last 10 years of meteorological data and compared with the estimated water requirement in the national water document. Water productivity was estimated based on yield per unit volume of water (CPD), income per unit volume of water (BPD), and net yield per unit volume of water (NBPD). The results showed that drip irrigation method compared to surface irrigation method reduced the applied water of grape and walnut crops by 40 and 54%, respectively. Water productivity in vineyards and walnut orchards in drip irrigation system was calculated as 25.1 and 1.81 and in surface irrigation as 7.8 and 0.88 kg / m3, respectively. Calculated water requirement based on the last ten years of meteorological data in these two products was greater than the value stated in the National Water Document. Comparison of the average amount of applied water with the calculated water requirement indicated a deficit irrigation in most of the studied gardens. Comparison of Economic productivity of water in the two crops showed that this index in drip irrigation method is much higher than surface irrigation method. Net yield index per unit of water used (NBPD) in drip irrigation method in grape and walnut crops are 231 and 117, respectively, and in surface irrigation method 110 and 115 thousand Rials per cubic meter.

This study aims to simulate runoff and runoff quality of Zarrineh river basin by SWAT model. Calibration and verification were done respectively with monthly runoff statistics in SWAT CUP by SUFI2 method for 1992-2013, for 12 sub basin, 226 HRU and monthly nitrate data for 2006-2009. The highest runoff sensitivity and runoff quality with minimum Pvalue and maximum absolute value Ttest belong to soil cure number and nitrogen hydrolysis. The maximum number in calibration and verification belonged to Zarrineh dam station by R2=NS=0.81 and minimum number belonged to Janagha station by R2=NS=0.47. The value of these two coefficients in calibration of nitrate in all basin were 0.58 and 0.44 and their coefficient in verification were 0.51 and 0.42 respectively. Statistical results showed that a good performance in the SWAT model simulation of monthly flow and nitrate in the basin of Zarrineh river. Then the simulation was conducted by best management practices model. In this study protective measures watershed simulated stone lines, contour lines and mulching considered as a management solution. The best solution was contour lines by 17.89% reduced nitrate amount input to Urmia Lake see also 11.17% discharge the ground water.

Plant water requirement or evapotranspiration (ET) is one of the main components of water balance and a key factor in irrigation planning to improve water use efficiency of agricultural lands. Different methods have been proposed to determine evapotranspiration directly using lysimeter and indirectly using computational methods. Evaporation pan is one of the indirect, simple and suitable methods for estimating the evapotranspiration of the reference plant and the main plant, which shows the combined effects of atmospheric parameters such as air temperature, air humidity, radiation and wind. In this study, using 20-year meteorological data (1999-2018) of the all synoptic stations in Kurdistan province, the value of pan coefficient was estimated using the methods Cuenca (1989), Raghuwanshi & wallender (1998), Modified Snyder, Mohamed et al (2008), Allen and Pruitt (1991), Snyder (1992), Orang (1998), Pereira (1995), Christiansen (1990) and FAO-24 (1997). In order to evaluate the accuracy of estimating evapotranspiration obtained from pan evaporation mehod, the FAO Penman-Mantith 56 method was used. To evaluate the accuracy of the models and to select the best one, four indicators; (RMSE), (MAE), (MBE) and t-test were used. The final results showed that on a daily, monthly and seasonal basis, the methods of FAO-24 (1997) and Christiansen (1990) had the best performance and the methods of Raghuwanshi & Wallender (1998) and Allen and Perot (1991) had the worst performance.

Evaluating the performance of pressurized irrigation systems is one of the important strategies for managing farm water consumption. In this study, 5 sprinkler irrigation systems, 5 drip irrigation systems and 2 tape drip irrigation systems were selected for technical and hydraulic evaluation in agricultural lands of Hamedan. Evaluations were based on the Merriam and Keller method. Measured indices for sprinkler irrigation systems included Christiansen uniformity coefficient (CU), distribution uniformity (DU), potential application efficiency of low quarter (PELQ) and application efficiency of low quarter (AELQ). Also, Indicators measured for drip irrigation systems included uniformity factor (EU), efficiency reduction factor (ERF), potential application efficiency of low quarter and application efficiency of low quarter. The values of CU, DU, PELQ and AELQ for sprinkler irrigation systems were 65.6-80.1, 53.1-65.4, 31.1-55.7 and 28.3-52.5 percent, respectively. Also, the values of EU, ERF, PELQ and AELQ for drip irrigation systems were obtained in the range of 43.4 to 65.7, 0.8 to 1.3, 39.1 to 59.1 and 34.0 to 73.0 percent respectively. The results showed that in all systems the efficiencies under study were lower than expected, which can be attributed to improper design, the difference between the implemented system and the designed system, the impact of climatic factors such as high wind speed, operational problems such as the lack of adjust pressure by farmers, the use of inappropriate equipment and the lack of periodic reviews due to low levels of awareness, the lack of education and economic failures.

In order to investigate the effect of cultivation medium on yield, water productivity and some growth characteristics of strawberry plant, an experiment was carried out in the greenhouse as a factorial based on a completely randomized design with two factors of cultivation medium and irrigation levels. Irrigation treatments at three levels included full irrigation (FI), deficit irrigation at 80 (DI80) and 60% of water requirement (DI60) and four cultivation media including soil (Soil), cocopeat : perlite with volume ratios of 30:70 (C30 P70), 40:60 (C40 P60) and 50:50% (C50 P50). The results showed that the highest values of fruit yield and water productivity among cultivation medium treatments were allocated to C50 P50 treatment with 8.99 kg / m2 and 41.53 kg / m3, respectively, and among irrigation treatments were belonged to FI treatment with 9.53 kg / m2 and 35.88 kg / m3 respectively. The highest values of yield and water productivity in the interaction of the studied factors were 11.41 kg / m2 in C50 P50 composition with full irrigation treatments and 44.78 kg / m3 in C50 P50 composition with 80% water requirement treatments. Based on the results of this study, in case of deficit irrigation application, C50 P50 medium with deficit application of 80% water requirement can be suggested.

One of the concerns of the human society is that the changes caused by global warming change the frequency and amount of precipitation and temperature. This study was conducted to investigate the trend of annual, seasons of cultivation, seasonal and monthly temperature and precipitation changes using the Mann-Whitney test at Ahvaz Meteorological Station. The study period consisted of two 31-year periods from 1957 to 2018. The results of this study showed that the minimum temperature had more changes compared to the average and maximum temperatures in the first 31 years (1957-1987) compared to the second 31 years (1988 to 2018). Mean comparison of minimum temperature and average temperature for the two periods showed that there was a significant difference at the 5% of probability level.  The means of the minimum and average temperature increased from 12.1 to 14.9 and 24.9 to 26.9°C, respectively. Mean comparison of the maximum temperature and precipitation for the two periods showed that there was no significant difference at the 5% of probability level. The averages of the maximum temperature and precipitation decreased from 37.5 to 36.8°C and 226.9 to 188.8 mm, respectively. Also, the study of precipitation trend in the two studied periods showed a high distribution of this climate parameter and a small change in the amount of this factor.

 Vermicompost is a type of biological organic fertilizer obtained from earthworm activity. Vermicompost is used in sustainable agriculture due to its beneficial effects on diversity of plant nutrients and physical-hydraulic modification of soil. However, high presence of solutes in the structure of vermicompost causes soil salinity, increases soil sodium content and changes soil pH. Soil flushing is one of the well known strategies to minimize the mentioned disadvantages of vermicomposting. Although flushing can reduce the soil salinity and sodium content, it leads to transportation of some soil substances such as nitrate, dissolved organic carbon and colloids which their tracing is necessary because of soil quality monitoring and possibility of water resources pollution. The objective of the current study was to investigate the effects of vermicomposting on soil chemical, physical and hydraulic properties and its role on the amount of soil total dissolved salts (TDS), sodium, nitrate, dissolved organic carbon and leaching behavior of colloids.

To treat the soil, 1.45 weight percent of vermicompost (17.68 tones/hectare) was mixed with regular soil. Physical, chemical and hydraulic properties of soil were determined. PVC columns with length of 20 cm and internal diameter of  5.95 cm were used and filled with soil to perform leaching during 24 hrs in saturated condition  experiment. The effluent of columns were collected at various interval times, and their sodium, nitrate, dissolved organic carbon, TDS and colloid contents were measured and the cumulative amounts of them were calculated at 6 and 24 hrs. All experiments were carried out in three replications, and the mean comparison of leaching parameters was done according to Duncan's multiple range test at probability level of 5%.

Vermicompost increased the studied soil chemical properties i.e, organic matter, organic carbon, extractable nitrate, soluble sodium, soluble and exchangeable sodium, EC and TDS to 12.42, 12.9, 118.96, 80.43, 44.48, 109.4 and 109.4 %, respectively and decreased soil pH to 2.35 %. Soil bulk density reduction to 3.81 % and enhancement of soil porosity, saturated hydraulic conductivity and the pore water velocity to 1.38, 7.25 and 5.6 %, respectively are the other results of vermicompost application. The used vermicompost fertilizer caused displacement of soil water retention curve to more moisture around of saturated and permanent wilting points and reduction of air entry potential. In this regard, vermicomposting increased all of soil hydraulic coefficients of van Genuchten model including θr, θs, α and n, and its effect was specially more on θr and α. The result of leaching experiments showed that the amounts of leached TDS, sodium, nitrate, dissolved organic carbon and colloid in vermicompost-containing soil during 6 hrs were 491.4, 65.22, 116.71, 47.68 and 24.86, and during 24 hrs were 946.3, 72.16, 146.26, 95.11 and 41.97 mg/Kg, respectively. For the natural soil, these amounts during 6 hrs were 240.9, 11.84, 20.08, 23.2 and 15.11, and during 24 hrs were 665.6, 15.69, 44.48, 58.34 and 29.39 mg/Kg, respectively. Therefore, vermicompost significantly increased the amounts of leached TDS, sodium, nitrate, dissolved organic carbon and colloid, because of containing more contents of solute, sodium, nitrate and organic matter in its structure. It also increased the porosity and hydraulic conductivity of soil, and made changes in soil water retention curve (P<0.05). The presence of more sodium in vermicompost together with its effect on soil porosity enhancement increased the colloid dispersion and consequently its leaching. In addition, the leaching rate of all of parameters at 24 hrs in comparison to 6 hrs decreased significantly due to high amount of solute leaching through mass flow at initial time of leaching experiment and leaching residual solute by time-consuming process of diffusion.

Although vermicompost can enriched the soil due to increasing nitrate and organic matter contents, it leads to soil salinity and increases sodium contents. Flushing the soil treated by vermicompost removed the amounts of TDS, sodium, nitrate to 10.4, 76.2 and 44.6 % during 24 hrs. Therefore, leaching had a considerable effect on soil sodium reduction and a little effect on soil salinity reduction. Moreover, in comparison to chemical fertilizers, the high nitrate fraction of applied vermicompost resulted in sustainability of soil fertility. It is expected soil salinity and nitrate leaching fraction of vermicompost will be reduce by managing leaching methods, treating vermicompost before using and reducing fertilizer application rate. Thus, the results of current study warn the farmers who used vermicompost in soil to control the soil salinity, ground water pollution and vertical colloid migration.

Climate change is a challenging topic for irrigation researchers as it has affected crop water demand. In the present study, the effects of climate change on minimum temperature, maximum temperature, precipitation, and the water demand of 12 crops including wheat, alfalfa, potato, barley, garlic, cucumber, watermelon, pumpkin, sugar beet, rapeseed, grain maize, and bean were investigated and also a trend analysis was carried out up to the year 2050. The impacts of implementing and not implementing the irrigation efficiency enhancement, the cropping pattern changes and the development of the early-maturing cultivars as the adaptation strategies in combination with climate change scenarios were investigated between the water years 1399–1428 (2020–2050). The results showed that without implementing the adaptation strategies, the net irrigation water requirement would increase by 3.98% to 8.38% compared with the recorded data. Growth in the irrigation efficiency up to the potential efficiency would cause a 19.23% reduction in the gross irrigation requirement on the average. By implementing the cropping pattern changes strategy through stopping the cultivation of some water-intensive crops such as alfalfa and developing the cultivation of rapeseed, net irrigation water requirement would decrease by 10.9%. By replacing late-maturing potatoes by the early and medium-maturing cultivars and developing of early-maturing grain maze cultivation, net irrigation requirement decreased by 8.86%. Furthermore, the results revealed that implementing all the above-mentioned adaption strategies would reduce the gross irrigation requirement by 34.0%. Hence, the three above-mentioned strategies can be used as the measures that executive managers and farmers choose to implement in order to adapt to climate change.

In this study, dry matter yield and water productivity of five clones of potato under irrigation conditions at 100, 90, 80, 70, 60 and 50% water requirement levels were evaluated by AquaCrop model. Field experiments were conducted in split plot design based on randomized complete block design with two years at Ekbatan station of Agricultural and Natural Resources Research Center of Hamedan province. After sensitivity analysis, the results of the first year experiments were used for calibration and the results of the second year experiments were used for model validation. The results showed that this model had an average error of 10.95 and 47.34% in simulating yield and water productivity of potato, respectively. Therefore, this model was less accurate in estimating water productivity than the appropriate estimation of potato yield. Under water shortage conditions, Clone 397008-2 had the highest yield and water productivity at 80% of water requirement with 16.39 ton ha-1 and 3.41 kg m-3, respectively. Therefore, it is recommended that this clone and irrigation use 80% of the water requirement by the farmers in the region to achieve 20% water saving and maximize potato yield and water productivity.