نشریه مدیریت آب در کشاورزی
سال هشتم شماره 2 (پیاپی 16، پاییز و زمستان 1400)

The water crisis is one of the most important factors that limit the production of agricultural products in arid and semi-arid regions, which requires the optimal consumption of water in agriculture to achieve food security in these regions. To investigate the economic efficiency of water and nitrogen fertilizer on Quinoa, an experiment was conducted as a split-plot based on a randomized complete block design with three replications in 2018 at Ferdowsi University of Mashhad. Treatments included three irrigation methods (furrow irrigation (FI), fixed alternate furrow irrigation (FAFI), and variable alternate furrow irrigation (VAFI)) and three-level of nitrogen fertilizing (50, 100, and 200 Kg/ha). The different furrow irrigation methods on the economic productivity of fertilizer, CPD, BPD, NBPD, and PFP were highly significant (p < 0.01). The different levels of nitrogen fertilizer on the economic productivity of fertilizer, BPD, NBPD, and PFP were significant at 1 percent levels (p < 0.01), and on CPD was significant at 5 percent levels (p < 0.05). The interaction effects on the economic productivity of fertilizer and PFP were highly significant (p < 0.01) and on NBPD and BPD were significant at 5 percent levels (p < 0.05). The results showed that under traditional furrow irrigation conditions, increasing the nitrogen fertilizer reduces the economic efficiency of water and fertilizer (compared to using 50 kg/ha N). The results showed that the highest economic and physical water productivity and BPD were obtained in the treatment of variable alternate furrow irrigation + 200 kg/ha of nitrogen.

Water is one of the most important factors limiting agricultural development. The proper water management on the farm is also significant. To improve the existing conditions, a study aimed at investigating the growth characteristics of replacement corms and photosynthetic levels of saffron plants in response to different irrigation methods under water stress. An experiment was conducted on a farm in Ahmadabad Sheikh village, Torbat - Heydariyeh, from September 2020 to June 2021. In this experiment, the main treatment included three irrigation methods (basin irrigation, drip irrigation, and subsurface irrigation) and the sub-treatment of three irrigation levels (100%, 70%, and 40% of saffron water requirement). On May 1, 2021, to determine the traits related to photosynthetic level (number of leaves, leaf length, leaf width, fresh and dry weight of leaves) were sampled. On June 10, 2021, to study the growth characteristics of replacement corms (number of replacement corms, replacement corm diameter, weight wet and dry replacement corm) sampling was done. The results showed that the effect of method and amount of irrigation on the characteristics of replacement corms and photosynthetic level of the saffron plant was significant. The drip irrigation method significantly increased leaf number, leaf length, fresh leaf weight, leaf dry weight compared to basin irrigation and subsurface irrigation methods. The diameter of the replacement corm, the number of replacement corms, wet weight of replacement corm, and dry weight of replacement corm was reducing the amount of irrigation water from 100% of the water required to 70% and 40% due to drought stress caused a significant reduction in leaf number, leaf length fresh weight, dry leaf weight, replacement corm diameter, number of replacement corms, fresh weight of replacement corms and weight dried replacement. Based on these interpretations, choosing a suitable irrigation method along with a sufficient amount of water is significant.

The agricultural sector as the main infrastructure for food security is one of the most important economic sectors of societies and its average share in the GDP of 161 countries studied in 2019 is about 11 percent. In parallel with the role of this sector in the provision of food security and employment of countries with negative side effects on basic resources and the environment, which led governments to reconsider their policies related to the agricultural sector. Governments can, willingly or unwillingly, affect the environmental sustainability of the agricultural sector in a variety of ways. This article focusing on non-systematic review approach and using the reports of authentic international institution (including FAO, OECD, WTO, etc.), deals with the implications of the agricultural sector and policy developments of the recent decade in the OECD member countries. The findings show that agricultural support policies tend to have a negative impact on the environment. Market price supports policies and payments based on output, and payments based on unconstrained variable input use found to be the most environmentally harmful. In contrast, fully decoupled support payments based on non-current crop area are the least harmful. Soil nutrient balance; Greenhouse gas emissions; Water abstraction for agricultural activities; and biodiversity of agricultural lands (crop diversity and homogeneity of landscapes) are among the key indicators that its improvement and deterioration helps to explain the relationship between agriculture and the environment and recent studies by OECD countries show significant gains in some of these indicators.

In recent years, the development of greenhouse cultivation has been recommended to use water resources optimally. Due to the significant differences in the microclimate of the greenhouse with the open air and its effect on the parameters affecting the reference evapotranspiration, special study is needed to use the reference evapotranspiration estimation relationships. The aim of this study was to investigate the reference evapotranspiration difference calculated using timely meteorological data inside the greenhouse and outdoors and long-term outdoor meteorological data for 6 months in Aliabad area of Jiroft city in a greenhouse with tomato cultivation. Reference evapotranspiration inside the greenhouse and outdoors for timely and long-term data in the study period were 342.7, 508.6 and 636.4 mm, respectively. The net solar radiation was 58% lower inside as compared to outside of greenhouse. The percentage difference of reference evapotranspiration inside the greenhouse and outdoors based on timely data was vary for different month of year, as average this difference was 39% during the study. Therefore, notice to actual evapotranspiration in greenhouse is very important for accurate irrigation management.

In the past, human communities have always had plans for the water resources utilization and management. In the communities with water resources constraints, this type of management is more obvious. The present study is an analysis of the status of scientific products indexed in Web of Science databases in the field of sustainable water resources management. To attain this, the relationship between existing studies with effective indicators in the scientific production of this field, such as rainfall, water footprint per capita, blue water consumption per capita, green water consumption per capita and grey water consumption per capita was investigated. Information about these indices was extracted from maps drawn in ArcGIS 10.6.1. Then, the relationship between these indicators and the scientific outputs of different countries in the field of sustainable water resources management was investigated using multiple linear regression in SPSS 21 software. The results of the study showed that, the number of scientific records had a growth rate of 55% from 1800 to 2020, meaning that with the rise of the water crisis, more scientific studies have been conducted on sustainable water resources management. Secondly, the US, China and India have most scientific papers in this field. The results of regression analysis of the effective indicators showed that an increasing in annual rainfall also blue water and grey water consumption per capita has an important role in increasing scientific production in the field of sustainable water resources management.

Safflower is one of the most important oil crops whose yield decreases under water stress. Therefore, determining its response to different irrigation water managements is very important. To do that, in this study, AquaCrop model was used to simulate three irrigation scheduling strategies of safflower for drip, subsurface drip and furrow irrigation methods. At first, AquaCrop was calibrated using data collected from a research farm located at 34˚ 21’ N and 47˚ 9’ E, in Kermanshah, Iran. In the first strategy, apply irrigation up to field capacity at a constant rate (1, 5, 10 and 20 days), in the second strategy, apply a constant amount of irrigation water (values of 10 to 50 mm for drip and subsurface drip irrigation methods and values up to 10 90 mm for furrow method at constant duration 2 and 4 days for drip and subsurface drip irrigation and 10 and 20 days for furrow) and in the third strategy apply water stress levels of 100, 66 and 33% during the growing season for all three Irrigation method was considered. The results showed that the highest yield, biomass and water productivity were obtained in the first and second strategies. Maximum values for yield and biomass were 3.7 and 12.2 fon.ha-1, respectively, and maximum water productivity was 0.54 kg.m-3 in both drip and subsurface drip irrigation and 0.69 kg.m-3 in furrow irrigation. As the second strategy is easier for farmers to implement, it is suggested that this method be used. Therefore, for drip irrigation and subsurface drip scenario, it is recommended to apply 10 mm of irrigation water with a period of two days, and apply 30 mm water irrigation with a period of 10 days.

Corn is one of the most important agricultural products that has a major contribution in supply of country's food needs. Corn is sensitive to water stress and under these conditions, its yield is reduced. Limited water resources in most parts of the country have caused farmers to not have enough water to meet the water needs of corn.Therefore, if a suitable tool is available to accurately determine the time and amount of irrigation, a suitable crop can be harvested with less water. Adequate knowledge of growth stages and water requirement of corn during the growing period can play an important role in preventing the loss of water resources and reduce stress and increase yield per unit area. According to research, the net irrigation water requirement of corn in the country is about 6852 m3/ha on average. The most sensitive stages of corn growth to water stress are flowering and grain formation. Implementing optimal management of water consumption in this product by using the method of constant or intermittent furrow irrigation method instead of the usual irrigation method, using drip irrigation tapes instead of traditional irrigation of stacked atmosphere. The use of seedling cultivation, selection of early cultivars and cultivars that are in maximum compliance with the climatic conditions, quality and quantity of available water, the use of drought tolerant cultivars and change of planting arrangement is possible.

In order to investigate the effect of single irrigation water quality on rainfed wheat yield, a study was conducted in Qazvin region. Treatments included four levels of water salinity with electrically conductive equal to 0.5 (S0), 4.9 (S1), 6.4 (S2) and 8.7 (S3) dS. m-1 and a rainfed treatment (D). The field experiment was conducted in plots with dimensions of 3 × 3 m. Statistical analysis was performed in the randomized complete block design. Irrigation was done as a single spring irrigation in stage of wheat clustering. The results showed that the effect of irrigation water quality on the total biomass, straw and grain yield of wheat was caused an increase of 18%, 12% and 26%, (in S0 treatment) an increase of 10%, 7% and 15%, (in S1 treatment) a decrease of 8%, 4% and 13%, (in S2 treatment) and a decrease of 21%, 13% and 34%, (in S3 treatment) respectively, in relative to rainfed conditions. Therefore, single irrigation up to salinity level of S1 was acceptable and more than, that was not recommended. Grain yield compared to straw yield increased in S0 treatment and decreased in S3 treatment, by a more intensity. So that salinity stress intensified the decrease in wheat grain production. On the other hand, the amount of water productivity in D, S0, S1, S2 and S3 treatments was calculated equal to 2.26, 2.462, 2.3, 1.93 and 1.644 kg. m-3, respectively. Also, a linear equation was presented for estimate the amount of water productivity, based on the water salinity amount. The general result is that the using of water resources with salinity up to S1 level in single irrigation of rainfed wheat, will increase the production and economic efficiency in Qazvin agricultural sector.

Deficit Irrigarion in water scarcity is the most important strategy to maintain crop water productivity.Therefore, cultivating drought-resistant crops such as quinoa can increase physical productivity on farm. To evaluate the yield and growth of quinoa plant in deficit irrigarion, data is needed on the yield response factor to water stress. In this study, Quinoa cultivar Titicaca was cultivated in two cropping years of 1398 and 1399. To evaluate different irrigation, 4 treatments: full irrigation, 30% allowable moisture drainage, 50% allowable moisture drainage and 70% allowable moisture drainage based on Soil moisture determinayion was applied at different periods of plant growth. Based on the results obtained, in the two crop years, the initial growth period was 20 days, the development period was 30 days, the middle period was 28 days and the final period was 12 days. The most sensitive growth period in quinoa plant was determined as the middle period with a yield response factor of 0.88. On average, with a consumption of 2563 cubic meters of water, the maximum productivity will be about 1.85 kg per cubic meter. In general, the results show that this plant has a high resistance to deficit irrigation and therefore this plant can be grown in areas with water shortage and good performance can be expected in water stress conditions.

In this study, the ability of water cycle algorithm in combination with ANN to model the volume of water delivered to the Irrigation and drainage network and determine the effective characteristics, was investigated. For the input of artificial intelligence models, five Features include the volume of water delivered to Sefidrood Irrigation and drainage network for one lags, flow and inlet volume for seven lags, level and reservoir volume for ten lags, were chosen. Using a hybrid algorithm, feature selection method and sensitivity analysis, a triple combination of features (with MSE of 0.00045) is the best input combination. The volume of water delivered to Sefidrood Irrigation and drainage network for one lags according to sensitivity analysis has been the most effective feature in its modeling. Then the artificial neural network weights were optimized to increase efficiency and with the help of two meta-innovative algorithms: water cycle without evaporation (WCA) and water cycle with evaporation (ER.WCA). The ANN-ER.WCA hybrid model with the highest accuracy (with values of R, NRMSE, MAE and NS equal to 0.9915, 0.0975, 0.0090 and 0.9829 in the test period, respectively) is in the first priority and the ANN-WCA and ANN models are next in line, respectively.

This research was conducted at the research field of West-Azerbaijan (Saatloo station, 45° 10′ 53˝ E/ 37° 44′ 18˝ N and 1338 m above sea level), located 25 km from Urmia city (Iran) during 2019-2020 cropping seasons, as a factorial layout based on randomized complete block design with three replications. The first factor includes different amounts of irrigation at three levels (supply 100, 75 and 50% net irrigation requirement) and the second factor was planting at four levels (plot planting, planting three lines on the ridges (ridges width=30 cm), planting four lines on the ridges (ridges width=45 cm) and planting five lines on the ridges (ridges width=60 cm)). The results showed that there was no significant difference between different levels of irrigation for yield traits and grain yield components (except 1000 grain weight). Traits such as number of spikes per unit area, grain yield, biological yield and spike yield were significant differences for planting methods. Mean comparison showed the highest number of spikes per unit area (676 spikes), grain yield (7773.3 kg ha-1), biological yield (17696 kg ha-1) and spike yield (0.91 kg m-2) was obtained from three planting methods. The highest chlorophyll index and relative leaf water content were obtained from supplying 100% of the net irrigation requirement and the highest internal temperature of leaf, proline and ion leakage percentage were obtained from supplying 50% of the net irrigation requirement. Also, the highest amount of chlorophyll index was observed in the three-line planting method on the ridge and the relative leaf water content was observed in the five-line planting method on the ridge. Due to water shortage and drought, irrigation of 50% of the net irrigation requirement (reduction of 50% of water volume) and planting of three lines on the ridge is recommended.

This research was conducted to investigate the effect of using transparent plastic mulch on yield and water use efficiency in green beans cv. Alamout in deficit irrigation conditions. Research was performed as split plots experiment based on completely randomized blocks design with three replications in 2018 at the Research Farm of Agricultural Faculty, University of Zanjan, Iran. The experiment treatments were deficit irrigation in three levels (100%, 80% and 60% of crop water requirements) as the main plot and transparent plastic mulch in two levels (use and non-use of mulch) as the subplot. Results showed, application of mulch increased significantly mean leaf chlorophyll content, mean relative leaf water content, mean leaf area, mean number of pods per plant, mean yield and mean water use efficiency compared to control treatment (16.8%, 5.2%, 11.2%, 34%, 38% and 39% respectively). Applying of deficit irrigation at 20 and 40% decreased significantly mean leaf chlorophyll content (20.6% and 30.3%), mean relative leaf water content (11.1% and 21.0%), mean leaf area (17.8% and 59.9%), mean number of pods per plant (10% and 43%), mean yield (24% and 53%) and mean water use efficiency (12% and 34%) compared to treatment of 100% crop water requirements. Interact effects of deficit irrigation and mulch increased significantly leaf chlorophyll content, leaf area and number of pods per plant such that at each irrigation level use of transparent plastic mulch increased mean values of these traits.

In recent years, some experts stated that the development of new irrigation systems has led to an increase in irrigated area resulting increase water consumption from reservoirs and reducing aquifer charging. Because they do not have a positive effect on the water balance of the basin, they are considered as inefficient activities. Critics states irrigation methods do not really save water. They believe that in estimating the efficiency of irrigation, runoff and deep percolation are not part of the losses and can be used in some way. The key point in evaluating the effectiveness of modern irrigation systems should be based on the expected capabilities. In other words, the scale of the systems must be specified. Naturally, the performance of the irrigation systems in the agricultural sector with the aim of preventing water losses (increasing irrigation efficiency and water productivity) on a farm scale. Studies show that with the implementation of modern irrigation systems during the last three decades, the irrigation efficiency in the country has increased from 29.7 in the 1990 decade to 43.8% in the 2010 decade. Its main message is to reduce water losses inside the farm and the effectiveness of these systems. Therefore, as expected from modern irrigation systems, reduction of runoff losses and deep percolation and water supply in the root zone of the plant has been successful. Due to the lack of control over water abstraction from reservoirs, its effects on the basin scale and groundwater aquifers may not be tangible. The solution to these cases is related to other responsible organizations.

Water is the main factor in forest production and rain and snow are the most important sources of forest water supply. But always a percentage of rainfall is lost and comes out of the forest surface water cycle. That part of the rain that does not reach the soil of forest ecosystems is divided into two parts. This article reviews the concept of rainfall in the forest and the impact of its components on the water balance of watersheds. Rainfall of trees plays an effective role in determining the amount of rainfall reaching the forest floor and therefore is an important part of the water level in the ecosystem of forest structures. Loss from the canopy surface and evaporation from the forest floor debris. It also focuses on the hydrological cycle and the food cycle in terrestrial ecosystems. If you know the amount of rainfall in areas with dry season during the growing season, if the amount of rainfall is high, according to the water needs of the mass, by performing thinning operations, to establish regeneration and also to meet the water needs of species The plant helped effectively. A large share of summer rainfall in the forest in the form of rainfall is out of reach of the forest massif; Therefore, it is necessary to know the amount of rainfall, especially to evaluate and measure evapotranspiration in forest ecosystems and therefore for the proper management of forest watersheds.

Development Research Institute during the last three decades has produced clay emitters and has implemented the system on a small scale in several areas of Kerman province in pistachio orchards. Because the hydraulic characteristics of the emitters used in the gardens are unknown and their operating time is also unknown, therefore, it is impossible to evaluate the performance of emitters used in these gardens. In order to evaluate the hydraulic performance of the emitters in terms of the coefficient of construction variation and also changes in the seepage behavior in laboratory conditions. 400 clay emitters were studied at Agricultural Engineering Research Institute of Karaj. To investigate the coefficient of construction variation, the emitters were grouped into groups of 20, and each group was tested at a constant hydrostatic pressure of 1.75 m using water with a quality of 0.83 dS/m. The results showed that the values of the coefficient of variation of the 20 packages under test were in the range of 23 to 73%, which was higher than the declared 20% of the ASAE standard and was found to be unacceptable, and if these emitters are used, the plants in different parts of the farm/garden will not receive equal water. Therefore, in these conditions, the use of these emitters in the subsurface irrigation of plants is not recommended. To investigate the seepage behavior of clay emitters over time, the discharge changes of 7 emitter groups at three hydrostatic pressures of 0.5, 1, and 2 m were tested. Seepage measurements from clay emitters for 1000 hours showed that as water passes through the pores of the emitter’s body, the water-soluble salts precipitate over time in the porous environment of the clay emitters and cause clogging. The average maximum initial seepage of clay emitters in groups of 7 at hydrostatic pressures of 0.5, 1, and 2 meters was 1.537, 2.578, and 4.783 L/hr.m, respectively. After 1000 hours of continuous testing, the values of final seepage reached 0.939, 1.483, and 1.296 L/hr.m, respectively. Descending values of seepage showed that water-soluble salts precipitate over time in the pores of the emitter body and reduce the emitter permeability. Due to the reduction of emission permeability, it is not possible to sustainable use of them to supply the water needed by crops/gardens in the long term.