Mehdi Zangiabadi
Abstract
Measuring the actual evapotranspiration of rice is very important for appropriate and optimal water management in the Northern provinces of Iran. The present study aimed to measure the actual evapotranspiration for two Shiroudi and Hashemi cultivars of rice, in paddy fields of Sari Agricultural and Natural ...
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Measuring the actual evapotranspiration of rice is very important for appropriate and optimal water management in the Northern provinces of Iran. The present study aimed to measure the actual evapotranspiration for two Shiroudi and Hashemi cultivars of rice, in paddy fields of Sari Agricultural and Natural Resources University (SANRU). For this propose, six drainage lysimeters were designed and constructed. After cultivating rice inside the lysimeters, the amount of precipitation, irrigation water, and deep percolation were measured in 5-days intervals. Investigation of the lysimeter results showed differences between water requirement and also deep percolation of the two studied cultivars in growth period (seeding to harvest): water requirement was 351 and 397 mm and the deep percolation was 48 and 97 mm, for cultivars Shiroudi and Hashemi, respectively. Also, the crop coefficients were obtained by comparison of the lysimeter’s actual evapotranspiration and 14 indirect methods of reference evapotranspiration estimation. Considering the cultivars and the estimating method, the crop coefficients were in the following ranges: 0.73-1.12 for the initial stage, 0.83-1.41 for the middle stage, and 0.64-1.15 for the final stage. Also, the average estimation Error Percentage (PE) of the resulting crop coefficients compared to the recommended coefficients of FAO-Penman-Monteith method, is 11%, 11% and 8% for Hashemi cultivar and 15%, 23%, and 16% for Shiroudi cultivar, in initial, middle and final stages, respectively; which shows the necessity of determining crop coefficients for each cultivar under local conditions. The coefficients obtained in the current study can be useful to calculate the water requirements of Hashemi and Shiroudi cultivars based on indirect estimation methods for designing water projects and water delivery in the irrigation and drainage networks in the research area.
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Hossein Beyrami; Mohammad Hassan Rahimian; Farhad Dehghany
Abstract
Water and soil resources of the country are limited, and the optimal use of water resources in agriculture requires estimation of the exact amount of water consumption by different plants in different conditions. This study was conducted to investigate evapotranspiration, crop coefficient, and water ...
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Water and soil resources of the country are limited, and the optimal use of water resources in agriculture requires estimation of the exact amount of water consumption by different plants in different conditions. This study was conducted to investigate evapotranspiration, crop coefficient, and water requirements of salicornia under lysimetric conditions in a factorial experiment with completely randomized design. The experimental treatments were two species of salicornia (Salicornia bigelovii and Salicornia persica) and two levels of irrigation water salinities (8 and 25 dS.m-1) in three replications. The actual evapotranspiration (ETa), reference evapotranspiration (ET0), and crop coefficients (Kc) of salicornia species were determined at three main salicornia growth stages. The results showed that increase in irrigation water salinity from 8 to 25 dS.m-1caused significant changes in yield (biomass and seed yield) of the two salicornia species at the 1-percent probability level. Moreover, the amount of irrigation water consumption in different treatments and replications varied from 28 to 33 thousand cubic meters per hectare. For the salinity level of 8 dS.m-1, the Kc values at the beginning, middle, and end of growing season of bigelovii specie were obtained as 1.18, 1.55, and 1.42, respectively, while for the salinity level of 25 dS.m-1, these values were 1.06, 1.37, and 1.26, respectively. For persica specie, the Kc values of the beginning, middle, and end of the growing season were 1.37, 1.58, and 1.10 (for salinity level of 8 dS.m-1) and 1.15, 1.38 and 1.27 (for salinity level of 25 dS.m-1), respectively. In addition, water use efficiencies of salicornia varied from 0.21 to 0.38 kg.m-3 at different treatments and species.
Zynab sojoodi; Farhad Mirzaei
Abstract
Landscape is of great importance due to environmental values such as oxygen production, freshening air, carbon sequestration, protecting soil against erosion, and biodiversity conservation. Large volumes of urban water resources are used to irrigate water for landscape plant species, but due to lack ...
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Landscape is of great importance due to environmental values such as oxygen production, freshening air, carbon sequestration, protecting soil against erosion, and biodiversity conservation. Large volumes of urban water resources are used to irrigate water for landscape plant species, but due to lack of information about water needs of these plants, water is wasted. In this research, crop coefficient and water requirement of a shrub (Barberry), tree (Cypress), and a herbaceous species (Common couch) was estimated using water balance method and WUCOLS information. The research lasted for six months from 21 March 2018 to 22 September, 2018. To calculate evapotranspiration of landscape, six drainage type “micro-Lysimeters” were used in two different micro-climates and the calculations were done for ten-day intervals. Evapotranspiration was estimated for the whole period of the experiment as 682 mm for water balance method and 626 mm by WUCOLS method. Different evapo-transpiration values were found for both water balance method and the WUCOLS method in different micro-climates. Thus, WUCOLS method could be recommended as a precise, complete and yet practical method in order to estimate the water requirement of landscape plants and, for modeling of water requirement and crop coefficients to reduce water consumption efficiently.
Masoud Pourgholam Amiji; Addolmajid Liaghat; Arezoo Nazi Ghameshlou; Mojtaba Khoshravesh
Abstract
The problem of soil salinity exists in the paddy field areas in Iran, especially in the Caspian Sea coastal areas, due to its proximity to the sea and low altitude with saline and shallow water table. Besides, considering that rice is one of the most important strategic crops for economy of Iran ...
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The problem of soil salinity exists in the paddy field areas in Iran, especially in the Caspian Sea coastal areas, due to its proximity to the sea and low altitude with saline and shallow water table. Besides, considering that rice is one of the most important strategic crops for economy of Iran and the people in this area, this research was necessary in order to investigate the possibility of production of rice in the presence of shallow and saline groundwater table. This research was performed as a physical model (insulated metallic lysimeter) in the Meteorological Research Center of College of Agriculture and Natural Resources, University of Tehran, in 2017. The complete randomized design included two treatments with shallow water table: FSG and SSG, with fresh (control) and saline water, respectively. The salinity of irrigation water was 0.94 dS/m for both treatments. Moreover, for SSG treatment, the EC of shallow groundwater was 20 dS/m at 40 cm soil depth and was regulated as an artificial recharge. The results of salinity profile in SSG treatment showed that there was almost no mixing of fresh and saline water in interstitial zone (under the hard pan from 30 cm to 40 cm of soil surface). In this manner, there was insignificant effect of salinity in the root zone, because of existing of permanent water layer in rice field and downward water flow, which makes an obstacle for upward flow for saline water. This problem did not affect the rice yield, which didn’t decrease. The results of data analysis confirm this and show that shallow groundwater salinity has no significant effect on the parameters like leaf area index (LAI), root length (RL), plant length (PL), membrane stability index (MSI), chlorophyll (SPAD), relative water content (RWC) and the biomass (BIO). The difference between the performance of the control and the salinity treatments was about 1 to 12 percent, while the grain and biological yield in SSG treatment compared with FSG treatment decreased 3.2% and 4.5 percent, respectively. Therefore, considering the significant leaching of soil after cultivation, the negligible loss of yield and upward movement of saline water in the soil, production of rice and other plants in such areas seems possible. Also, with the help of efficient and effective use of lands with shallow saline groundwater, we can decrease the pressure on conventional soil and water resources.
m m; h b; f k; n e
Abstract
The agricultural sector is known as the largest consumer of water. Due to limited water resources, water productivity needs to be enhanced in this sector. The concept of water productivity has attracted the attention of policy makers in food and water sector at large scale. Remote sensing is used in ...
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The agricultural sector is known as the largest consumer of water. Due to limited water resources, water productivity needs to be enhanced in this sector. The concept of water productivity has attracted the attention of policy makers in food and water sector at large scale. Remote sensing is used in the assessment and management of soil and water resources in recent decades. In the present research, this method was used to estimate water productivity. Evapotranspiration and actual production levels of dry matter were calculated using SEBAL algorithms and five images from the Landsat 5TM satellite in Qazvin Plain. The results of SEBAL algorithm in five images and lysimeter data were compared and evaluated in the region. The coefficient of determination ( 15R2"> ) and their mean absolute difference were 0.9948 and 0.446 mm/day, respectively, which demonstrated the accuracy of remote sensing methods in estimating agricultural water productivity at the basin level. The results showed that water productivity varied from 0.18 to 1.35 in the field. The wheat water productivity values from Landsat 5TM images and lysimeter data were 0.73 and 0.85 kg/m3, respectively, which are relatively close to each other.
r n; a k
Abstract
Increasing crop production depends on supplying crop water demands, thus, accurate estimation of crop water requirement helps not only to crop production, but also is effective in the management of water resources. Based on this, the purpose of the present research was to investigate the estimates of ...
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Increasing crop production depends on supplying crop water demands, thus, accurate estimation of crop water requirement helps not only to crop production, but also is effective in the management of water resources. Based on this, the purpose of the present research was to investigate the estimates of reference evapotranspiration from SEBAL and METRIC models using satellite imageries of Landsat 7 and 8 and Terra in the Qazvin plain. In the first step, the estimates of METRIC and SEBAL models with a total of 10 images obtained from MODIS sensor, Terra satellite, and ETM+ sensor, Landsat 7 satellite, were evaluated using lysimeter data for grass reference crop in 2001. Estimates of MODIS sensor with r =0.88, RMSE =1.91, and SE =0.85 mm/day and Landsat ETM + with r =1.00, RMSE =0.91, and SE=0.09 in METRIC model were closer to the lysimeter data compared with the SEBAL model. In the next step, the results of the METRIC and SEBAL models obtained from OLI & TIRS sensor images of Landsat 8 satellite were evaluated with the results of METRIC model on ETM+ due to lack of lysimeter data at the time of checking. Evaluation of the results indicate that the METRIC model with r=0.96, RMSE=0.28 and SE=0.29 mm/day may be recommended as a superior model compared with SEBAL model, for estimating reference crop evapotranspiration in the Qazvin plain.
y h; m gholami; v soltani
Abstract
When irrigating with saline water, salt distribution pattern within the root zone is affected by leaching fraction and crop water uptake pattern, in addition to the chemical interactions of soil solution. In order to evaluate leaching requirement and sensitivity of alfalfa to salinity, a lysimetric study ...
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When irrigating with saline water, salt distribution pattern within the root zone is affected by leaching fraction and crop water uptake pattern, in addition to the chemical interactions of soil solution. In order to evaluate leaching requirement and sensitivity of alfalfa to salinity, a lysimetric study (cylindrical lysimeters with internal diameters of 40cm and height of 180 cm) was conducted in completely randomized design with 3 levels of irrigation water salinity (3, 7 and 13 dS/m) and 3 levels of leaching fractions (12%, 25%, and 50 %) as a factorial experiment with 4 replications. After packing, soil columns were leached until drainage water salinity reached 3 dS/m and, then, were sown with alfalfa (Yazdi cultivar). To prepare different irrigation water salinity, natural saline water from Sadouq Salinity Research Field with salinity level of 14 dS/m was blended with tap water in different ratios. The amount of applied water was based on crop water consumption in addition to leaching fraction which was carefully weighed. The collected drain water was weighed again after 48 hr in which drain water quality was measured too. The least required irrigation cycles to reach steady state conditions was 12 cycles which increased with increasing salinity level and decreasing leaching fraction. Generally, results showed that implementation of a defined leaching fraction can reduce soil salinity more than WatSuit predictions. Therefore, soil salinity control at a desired level can be obtained with less leaching fraction level. This is especially important for optimum water utilization under saline conditions when irrigation is linked to application of more salts.
H GHAMARNIA; Milad farmanifard; SH SASANI
Abstract
Scarcity of water resources in spite of burgeoning population makes them important and necessitates optimum use of these resources. Shallow groundwater is a resource that has been ignored in irrigation management, while it is an available free source of water which can provide at least part of plants ...
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Scarcity of water resources in spite of burgeoning population makes them important and necessitates optimum use of these resources. Shallow groundwater is a resource that has been ignored in irrigation management, while it is an available free source of water which can provide at least part of plants water requirement. Therefore, a two-year experiment was conducted in 2009-2011 to find the effect of shallow groundwater tables, at 60, 80, and 110 cm depth, on water requirement, water use efficiency (WUE) and yield of three wheat cultivars, namely, W33g, Cross Alborz, and Bahar. Experiments were performed at RaziUniversity lysimeter research station No1 as a randomized complete block factorial experiment with three replications. In these experiments, 45 tubular poly ethylene lysimeters with 1.20m height and 0.30m diameter were fixed in the ground with 1m distance from each other. The highest utilization of groundwater was found for the water table depth of 60 cm and the lowest was found for the 110 cm depth. The 2-year average contribution to different cultivars by groundwater in depths of 60, 80, and 110 cm was 63%, 55% and 45%, respectively. The results for Cross Alborz cultivar showed no significant difference (P<0.01) in WUE between the three water table depth treatments. Overall, the optimum WUE and yield was found at water table depth of 80 cm.
V GHOLAMI; SH DERAKHSHAN; Z DARVARI
Abstract
Scarcity of water resources in spite of burgeoning population makes them important and necessitates optimum use of these resources. Shallow groundwater is a resource that has been ignored in irrigation management, while it is an available free source of water which can provide at least part of plants ...
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Scarcity of water resources in spite of burgeoning population makes them important and necessitates optimum use of these resources. Shallow groundwater is a resource that has been ignored in irrigation management, while it is an available free source of water which can provide at least part of plants water requirement. Therefore, a two-year experiment was conducted in 2009-2011 to find the effect of shallow groundwater tables, at 60, 80, and 110 cm depth, on water requirement, water use efficiency (WUE) and yield of three wheat cultivars, namely, W33g, Cross Alborz, and Bahar. Experiments were performed at RaziUniversity lysimeter research station No1 as a randomized complete block factorial experiment with three replications. In these experiments, 45 tubular poly ethylene lysimeters with 1.20m height and 0.30m diameter were fixed in the ground with 1m distance from each other. The highest utilization of groundwater was found for the water table depth of 60 cm and the lowest was found for the 110 cm depth. The 2-year average contribution to different cultivars by groundwater in depths of 60, 80, and 110 cm was 63%, 55% and 45%, respectively. The results for Cross Alborz cultivar showed no significant difference (P<0.01) in WUE between the three water table depth treatments. Overall, the optimum WUE and yield was found at water table depth of 80 cm.