Showing 14 results for Water Productivity
M. H.nazarifar, R. Momeni,
Volume 15, Issue 56 (7-2011)
Abstract
Deficit irrigation is one of the strategies used to obtain products with maximum profits in recent years. In this context, research on determining appropriate levels of deficit irrigation is essential. Since determining the different levels of performance through field experiments is difficult, the use of simulation models is a strategy through which we can examine the water balance data, simulate the growth process, and to study different managerial scenarios. The purpose of this study was validation and evaluation of CropSyst, a plant growth model, to determine suitable cropping patterns in deficit irrigation conditions. Applying three deficit irrigation scenarios in model, with values of 10%, 20% and 30% on six crops, fava bean, bean, wheat, potato, sunflower and rice, we concluded that the applied deficit irrigation of 10% to bean, potato and beans, 20% to sunflower and 30% to wheat had been suitable, and it is better not to apply deficit irrigation in rice. Also, since in final selection, the rate of water productivity is one of the basic criteria in each crop mentioned above, determining net benefit based on drop index (NBPD) per cubic meter showed that the most NBPD is related to bean with 6853 Rials per cubic meters and the lowest amount is related to sunflower with a value equal to 2809 Rials per cubic meters.
Zahra Saadati, Nader Pirmoradian, Mojtaba Rezaei,
Volume 17, Issue 64 (9-2013)
Abstract
The modeling of yield response to water is expected to play an increasingly important role in the optimization of crop water productivity (WP) in agriculture. In this study, the CropSyst model was used to simulate two local rice varieties yield response under five irrigation treatments consisting of continuous flooding irrigation and irrigation at 0, 3, 6 and 9 days after the disappearance of water from the soil surface. The experiment was conducted at Rasht region during two growing seasons of 2003 and 2004. The model was calibrated using the first year data and validation of that was done using the second year data set. The result of F test shows that there was not a significant difference between the measured and simulated yield at confidence level of 99%. The relative errors of yield estimation were obtained between -0.81 to 12.58% and -2.4 to 19.42% for Binam and Hasani cultivars in 2003, respectively. These values were 0.83 to 16.4% and -2.82 to 21.27% in 2004, respectively. The results showed that due to the CropSyst model ability in simulating yield of rice under different irrigation regimes, this model can be used to explore management optimum options to improve rice water productivity
B. Molaei, M. Gheysari, B. Mostafazadeh-Fard, E. Landi, M. M. Majidi,
Volume 19, Issue 71 (6-2015)
Abstract
Because of limiting water resources and increasing demand for food, it is necessary to investigate the effect of irrigation systems on water productivity. This research was conducted to evaluate yield and yield characteristics of two potato varieties under sprinkler and trickle irrigation systems. The treatments were two irrigation systems (sprinkler and trickle irrigation) and two potato varieties (Burren and Satina) in a randomized complete block design with three replications. Full irrigation was done based on moisture depletion from depth of root development in both irrigation methods.. Potato yield and water productivity (WP) in drip and sprinkler irrigation systems showed significant differences (P<0.01). The highest potato yield (24.08 ton ha-1) and water productivity (3.83 kg m-3) were obtained in drip-tape irrigation and Satina potato variety treatment. Also, the lowest potato yield (12.97 ton ha-1) and water productivity (1.73 kg m-3) were obtained in sprinkler irrigation systems and Burren potato variety. The potato yield in sprinkler irrigation system was obtained 42 percent lower than trickle irrigation system. In sprinkle system, dried top weight and height of stem were respectively higher and lower than those in trickle (Tape) irrigation system for both potato varieties. Overall, trickle irrigation is suggested for cool and dry climate to increase potato yield and water productivity.
F. Oveisi, A. Fattahi Ardakani, M. Fehresti Sani,
Volume 23, Issue 1 (6-2019)
Abstract
Despite the recent droughts in Isfahan province, climatic changes and the rising trend of population growth, as well as development of industrial and agricultural activities, are exposed to the water crisis. Thus, in order to tackle this problem, the essential strategies should including exploring virtual water and water foot print for strategic crops in agricultural sector should be taken into consideration for the management of water supplies at risk. This study was aimed to examine virtual water and ecologic fingerprint of water for the wheat crop in Isfahan Province from the farming year 2006-7 through 2014-15. For this purpose, the quantity of virtual water was extracted using net irrigation demand by NETWAT software and the rate of irrigation efficiency was computed to be 48%. The results indicated that only in 2007, Isfahan province was an exporter of virtual water for the wheat crop, so this province exported about 0.15 billion cubic meters of virtual water to other provinces by wheat exportation, but Isfahan province was the only virtual water in the years (2008-15) and this was due to the annual population rise and the existing drought in this zone. During this period, the rate of the mean annual rate of ecological footprint of water was 5.87 billion cubic meters and Isfahan Province stored this volume of water from the given internal supplies annually, with the mean rate of 0.65 billion cubic meters of virtual water importation at that year.
H. Karimi Avargani, A. Rahimikhoob, M. H. Nazarifar,
Volume 23, Issue 3 (12-2019)
Abstract
In recent years, a lot of research has been done on the Aquacrop model, the results show that this model simulates the product performance for deficit irrigation conditions. But this model, like other models, is sensitive to values of independent variables (model inputs). In this research, the sensitivity of the Aquacrop model was analyzed for 4 input parameters of reference evapotranspiration, normalized water productivity, initial canopy cover percentage and maximum canopy cover for barley. Irrigation treatments included full irrigation and two deficit irrigation treatments of 80% and 60%, the experiment was done in 2014-15 growing season in the field of Abourihan College. The values of measured biomass were used as the base values for treatments. The Beven’s method (Beven et al., 1979) was used for sensitivity analysis of Aquacrop model. The results showed that the model is most sensitive to the reference crop evapotranspiration, So the sensitivity coefficient for this parameter for full irrigation treatments, 80% full irrigation and 60% full irrigation were -1.1, -1.2 and -2.3 respectively. The negative sign indicates that if the value of reference evapotranspiration input is exceeded the actual value into the model, Yield performance is simulated less than actual value. In the meantime, the higher the degree of deficit irrigation, the greater the sensitivity of the model.
A. Rigi Karvandri, A. Mehraban, H. R. Ganjali, Kh. Miri, H. R Mobser,
Volume 23, Issue 4 (2-2020)
Abstract
Water scarcity is the most important factor constraining agricultural production all over the world and water shortage in agriculture must be established to use the deficit irrigation. In order to study the effects of the regulated deficit irrigation and partial root zone drying on the growth traits of Rosmarinus Officinalis L., an experiment was conducted in the center of seed and plant production of IranShahr municipality in 2017. The experiment treatments were arranged as a randomized complete block design with three replications. The irrigation regimes consisted of full irrigation, regulated deficit (RDI75 and RDI55) and partial root zone drying irrigation (PRD75 and PRD55). The results showed that deficit irrigation at 75 and 55 percent of full irrigation resulted in saving 18.6 and 34.3 percent of water consumption, respectively. Comparison of full irrigation and PRD75 showed that dry weight, height of plants and number of shoots per plant were decreased by 6.7, 14.3 and 12.1 percent, respectively. However, proper development of root in PRD75 increased 12.9 percent of water productivity. Therefore, by considering the problems of water scarcity, it is possible to provide PRD75 as a superior treatment and a suitable strategy to cope with the water crisis in order to move towards a sustainable agricultural system.
M. Mokari,
Volume 24, Issue 4 (2-2021)
Abstract
Optimal use of water resources seem to be necessary due to climate change and the recent drought conditions. One of the most important and effective management strategies is increasing water productivity in agriculture. Irrigation method and the use of different levels of nitrogen fertilizer are the effective factors in increasing the water productivity. Therefore, this study was conducted to investigate the effect of the irrigation method and nitrogen fertilizer on the harvest index and water productivity of two wheat cultivars with 36 treatments as a split-split plot based on a completely randomized design with three replications in the research farm of Natural Resources and Agricultural Research Center of Kashmar, during the 2018-2019 time period. The treatments were two irrigation methods including end blocked border and drip irrigation (tape) as the main plots, three levels of the nitrogen fertilizer from urea source including 0, 50 and 100 kg/ha as the sub plots and two cultivars of wheat including Pishgam and Sirvan as the sub-sub plots. The results showed that by changing the border irrigation method to the drip irrigation (tape) method, the harvest index and water productivity were increasesignificantly. The results also showed that grain yield and its components, including harvest index and water productivity, had no significant difference in 50 and 100 kg/ha nitrogen levels. On the other hand, grain yield and its components, harvest index and water productivity, were significantly higher in the Sirvan cultivar rather than the Pishgam one (P<0.01). According to the results obtained from this study, the drip irrigation method, 50 kg/ha nitrogen level and Sirvan cultivar could be recommended for the study region.
A.r. Tavakoli, H. Hokmabadi, A. Naderi Arefi, A. Hajji,
Volume 25, Issue 4 (3-2022)
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 (3-2022)
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.
