Showing 16 results for Water Productivity
A.r. Tavakoli, H. Hokmabadi, A. Naderi Arefi, A. Hajji,
Volume 25, Issue 4 (12-2021)
Abstract
Due to limited access to water, it is necessary to determine the comparative advantage of crops and horticultural products in different parts of the province and identify products that lack the desired productivity. Then, find ways to improve water productivity or replace products with higher comparative advantage with low-yield products. Based on this, the crop and economic productivity index of the province's agricultural and horticultural products under surface irrigation systems was determined. Based on the results of gross economic productivity of horticultural products, pistachio with 48690 Rials per cubic meter had the highest economic productivity, and grapes with 30220 Rials per cubic meter (62% of pistachios) was in second place. In addition, water quality for pistachios can never be generalized for grapes and other crops, and this is a tremendous advantage for pistachios that low-quality water resources can also be used. The lowest gross economic productivity of water for barley, alfalfa, and wheat is equal to 3790, 3990, and 4570 Rials per cubic meter, respectively. The study of fodder corn shows that the net profit from the cultivation of this crop in the surface irrigation system is equal to 51.78 million Rials per hectare and its net profit in the strip drip irrigation system (tape) is equal to 110.87 million Rials, which it has a 2.14-fold increase compared to the conventional irrigation method. The comparative advantage of horticultural products was higher than that of crops, and the replacement and development of orchards instead of some crops is recommended as a solution. In addition, solutions that can be recommended to improve the productivity index include the use of a drip irrigation system (tape) for crops (fodder corn, tomatoes, summer crops, and potatoes) and the use of drip irrigation (normal, subsurface, and subsurface modified drip) for horticultural products. Examination of practical experiences of using tape irrigation system for wheat and barley showed that this method has not improved the agricultural and economic productivity index, which indicates the lack of comparative advantage of wheat and barley cultivation in Semnan Province even with tape irrigation system.
A. Mehrabi, M. Heidar Pour, H. R. Safavi,
Volume 25, Issue 4 (12-2021)
Abstract
Designing an optimal crop pattern and on-time water allocation of water resources along with deficit irrigation are among the optimal solutions to maximize the water economic efficiency index. In this paper, the simultaneous optimization of crop pattern and water allocation are discussed using the deficit irrigation method. The study area is located west of the Qazvin plain irrigation network. The six different levels of percentage reduction of irrigation rate (0, 0 to 10, 0 to 20, 0 to 30, 0 to 40, and 0 to 50%) in three climatic conditions consist of dry, normal, and wet years were compared. The best irrigation scenario was selected for each year, and the results were compared with the existing crop pattern of the same year. The new crop pattern included the main crops of the region and the addition of rapeseed. The objective was to reach the maximum net benefit per unit volume of water by considering the maximum extraction of monthly and annual surface and groundwater. The results showed that the best scenario in the dry year was maximum deficit irrigation up to 20%, in a normal year full irrigation, and a wet year maximum deficit irrigation up to 10%. The improvement of economic water productivity in a dry year was 52.2%, in a normal year 41.5%, and in a wet year is 19.6% compared to the existing crop pattern. The average percentage of annual irrigation supply increases from 64.3 to 91.7% in a dry year, from 70 to 100% in a normal year, and from 77.5 to 97.1% in a wet year. Also, the relative yield of all crops, especially wheat, alfalfa, and sugar beet significantly increases. Therefore, the gravitational search algorithm as an optimization model can be considered in selecting the suitable crop pattern and allocation of surface and groundwater resources concerning economic benefits in irrigation networks management.
M. Safavi, A. Asareh, M. Khorramian, D. Khodadadi Dehkordi, A. Egdernezhad,
Volume 26, Issue 1 (5-2022)
Abstract
The present research was conducted to determine water stress tolerance and water productivity (WP) of 5 alfalfa cultivars as a split-plot design in a randomized complete block with 3 replications in the Safiabad Agriculture and Natural Resources Research Center (SARRC) with Silty clay loam soil texture during 2018-2019. The main plot was 4 levels of water irrigation depth (including 25, 50, 75, and 100% water requirement supply) with a constant irrigation cycle and the sub-plot was the five alfalfa cultivars (Baghdadi, Yazdi, Nikshahree, Omid, and Mesasirsa). Two-year data on forage yield and WP for six harvests (from June to November) were analyzed by SAS software. The results showed that the wet and dry forage yield decreased by applying water stress and the percentage of dry forage increased. The highest yield of dry matter (12.4 tons ha-1) and WP of dry forage (0.94 kg m-3) were obtained from 75% water requirement supply treatment. Baghdadi genotype with wet and dry forage yield 39.1 and 10.7 tons ha-1, respectively, and the WP of dry forage 0.9 kg m-3 was higher than other genotypes. However, the Yazdi genotype had the lowest yield of wet and dry forage (30.3 and 8.5 tons ha-1, respectively) and dry forage WP (0.75 kg m-3). Therefore, the Baghdadi genotype with a 75% water requirement supply is recommended for similar conditions to the climate of Northern Khuzestan to increase water productivity.
S. Jamali, H. Banejad, A. Safarizadehsani, B. Hadi,
Volume 26, Issue 1 (5-2022)
Abstract
This research was conducted to study the effect of deficit irrigation and saline water on yield and yield components of Peppermint in the experimental research greenhouse of Ferdowsi University of Mashhad from 2018 to 2019. This research was performed as a factorial experiment based on the randomized complete design with three replications. In this research, irrigation levels consist of 4 levels (100 (I1), 80 (I2), 70 (I3), and 55 (I4) percent of FC) and saline water factors consist of 4 levels (0.9 (EC1), 1.9 (EC2), 2.5 (EC3), and 3.4 dSm-1 (EC4)). The result showed that a decrease of the water to 15, 30, and 45 percent have resulted in the reduction of shoot fresh weights (to 15.8, 28.4, and 30.1 percent), shoot dry weights (to 7.1, 11.5, and 11.5 percent), and root dry weights (to 4.6, 9.2, and 9.2 percent), respectively. Also, results showed that irrigation with EC2, EC3, and EC4 has resulted in a decrease in shoot fresh weights (to 12.7, 28.5, and 34.0 percent), shoot dry weights (to 3.6, 11.6, and 11.6 percent), and root dry weights (to 6.7, 12.4, and 14.6 percent), respectively. The result indicated that interaction effects of salinity and water stress decreased peppermint water productivity, as the highest and lowest peppermint water productivity with 3.54 and 2.06 Kgm-3 were in the EC1I4 and EC3I1 treatments, respectively. Results revoluted that maximum dry yield and peppermint water productivity were in the EC1I4, so this treatment was recommended for irrigation of peppermint.
N. Salamati, H. Dehghanisanij, L. Behbahani,
Volume 26, Issue 2 (9-2022)
Abstract
Increasing crop production per unit volume of water consumption requires recognizing the most dependent variable in drip irrigation to the volume of water consumption and also identifying the most important variables independent of water productivity in surface and subsurface drip irrigation for optimal use of available water resources. The present research was carried out in Behbahan Agricultural Research Station during four cropping seasons (2013-2017) on a Kabkab date variety. Experimental treatments include the amount of water in the subsurface drip irrigation method based on two levels of 75% and 100% water requirement and in surface drip irrigation based on 100% water demand. Data were analyzed using a randomized complete block design with three replications. The results of the analysis of variance of the mean of different irrigation treatments in quantitative traits showed that the effect of irrigation was significant at the level of 1% in terms of cluster weight index, fruit weight, and fruit flesh to kernel weight ratio. The results of regression analysis of variance showed that in the dependent variable of cluster weight, the consumption water volume explained 19.1% (R2 = 0.191) of the fluctuations of the dependent variable (cluster weight). Among all the studied variables, the volume of water consumption explained the most significant changes in date cluster drying. Fruit moisture with t (2.096) and equivalent beta coefficient (0.046) had a significant positive effect on water productivity at the level of 5%. The results of the Pearson correlation coefficient showed that the effect of yield on changes in water productivity was much greater than the volume of water consumed so the yield caused significant changes in water productivity. While the effect of water consumption on water productivity was not significant.
M.r. Bahadori, F. Razzaghi, A.r. Sepaskhah,
Volume 26, Issue 3 (12-2022)
Abstract
Inefficient use of limited water resources, along with increasing population and increasing water demand for food production has severely threatened agricultural water resources. One way to overcome this problem is to improve water productivity by introducing new crops that tolerate water stresses such as quinoa. In this study, the effect of water stress at different stages of plant growth (vegetative, flowering, and grain filling) was studied on plant parameters, yield, and water productivity of quinoa (cv. Titicaca). This study was conducted under field conditions and the treatments were performed as a block experiment in a completely randomized design with four replications. Experimental factors were: treatment without water stress or full irrigation (F) and water stress treatment (D) at 50% of the need for full irrigation at different stages of quinoa growth. The application of deficit irrigation during different stages of plant growth decreased stomatal conductance, leaf area index, leaf water potential, seed yield, and water productivity, while deficit irrigation increased the green canopy temperature. According to the results of the present study, the flowering stage of quinoa was very sensitive to water stress leading to produce lower yield compared with the amount of yield obtained when vegetative and or grain filling stages are under water stress conditions.
A.r. Tavakoli, M. Basirat,
Volume 27, Issue 2 (9-2023)
Abstract
Shifting of surface irrigation to drip system is key tool to reduce water saving. Due to the soil moisture profile variation of the drip irrigation; water distributed of the root zone is not uniform. Moreover, moisture deficit and inefficient fertilizing in drip system due to unavailability in deeper layers of soils is one of the disadvantages of drip system in pistachio orchards with depth root systems. An experiment was carried out by adjusted subsurface drip irrigation (SSDIadj) system in pistachio of Damghan region (Semnan province) in a randomized complete block design with split plot arrangement in three replications for three years. The potassium fertilizer amounts (Fertigation) at three levels (50, 70, and 100% of requirement) were considered as the main plot and the design of conductor tubes of the SSDIadj system in seven levels as sub plots. The irrigation guide tubes were arranged for sand tube irrigation in (control), 40-40-40-40, 40-40- 50-50, 40-40-60-60, 40-40-50-60, 40-40-50-70, and 40-40-50-80. Meteorological data from the nearest meteorological station was collected and analyzed. Yield, water consumption, irrigation water productivity index and growth conditions of ShahPasand pistachio cultivar were determined in different treatments. Data were analyzed using Genstat-12 software and based on the analysis of surplus costs and aerial data, the best treatment including combination of potassium fertilizer and arranged tubes of SSDIadj system was determined. The recommended treatments are including of full irrigation, full potassium fertilizer and guide tubes 40-40-50-70 and or 40-40-50-80. The treatments with stratified conductive tubes in the optimal distribution of water, improving productivity and reducing inefficient consumption water. In addition, there are no restrictions on subsurface irrigation such as root accumulation, root penetration into pores of drippers and as well as accumulation of salts.
A.r. Jafarnejadi, A. Gilani, F. Meskini-Vishkaee, M. Hoseini Chaleshtori,
Volume 29, Issue 3 (10-2025)
Abstract
Rice, as one of the world's most strategic crops, plays a vital role in global food security. This study investigated the effects of different nutrition management approaches on yield and water productivity in dry direct-seeded rice cultivation (local Anbouri Red Dwarf cultivar) at Shavoor Research Station in Khuzestan Province. The experiment was conducted in a randomized complete block design with four treatments, including 1) Farmer's conventional practice, 2) Soil test-based fertilization, 3) Soil test-based fertilization + supplementary nutrition, and 4) 25% reduced chemical fertilizers + biofertilizers, with three replications. Results demonstrated that the supplementary nutrition (4270 kgha-1) and biofertilizer with 25% chemical fertilizer reduction (4356 kgha-1) treatments increased yield by 17% and 19.3 %, respectively, compared to conventional practice (3651 kgha-1). This improvement was primarily attributed to increased panicles per m² (10-14%) and enhanced nutrient uptake efficiency. The biofertilizer treatment also showed the highest water productivity (0.25 kg m-³) and the best benefit-cost ratio (23.25). Economic analysis confirmed that combining biofertilizers with 25% chemical fertilizer reduction significantly reduced costs while maintaining yield. These findings suggest that integrating soil testing with either biofertilizers or stage-specific nutrition represents an effective strategy for enhancing yield, improving water use efficiency, and reducing dependence on chemical inputs in dry-seeded rice cultivation. These methods can be recommended as sustainable models for farmers in arid regions like Khuzestan, which face salinity challenges and water resource limitations.
E. Ebrahimi, M. Gheysari, A. R. Gohari,
Volume 29, Issue 4 (12-2025)
Abstract
Given the rising need for water consumption and the decrease in available water resources, improving water use efficiency appears essential. Using modern irrigation techniques and applying irrigation management based on current, accurate scientific principles will enhance irrigation efficiency. This study aimed to estimate evaporation and windfall losses using meteorological variables and measure these losses in the cities of Isfahan, Golpayegan, and Fereydounshahr under different weather conditions. Evaporation and windfall losses were examined at 3, 6, 9, 12, and 15 hours using two selected equations across three meteorological stations with seven years of weather data. Then, evaporation and windfall losses were estimated using two experimental methods (abbreviated as WD1 and WD2), a science-based method (named droplet size), and field measurements. Results showed that evaporation and windage losses calculated with the empirical equation WD1 were about 2% higher than the field measurement value, while WD2 was about 1.5% lower. The correction factors for WD1 were 0.54, 0.44, and 0.51 for Isfahan, Fereydounshahr, and Golpayegan, respectively, and for WD2, it was 1.62, 1.17, and 1.56, respectively. The differences in evaporation and windage losses at various times of day and months of the year were statistically significant at the 5% level.
