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Marziyeh Aliabadi; MohammadHosien Najafimood; Abbas Khashei Siuki; Ali Shahidi
Abstract
Considering the limited water resources and the high rate of evaporation, water crisis is one of the most important issues in the country. Due to the importance of Flixweed as a medicinal plant, its water requirement and its single and dual plant coefficients were investigated in the lysimeter laboratory ...
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Considering the limited water resources and the high rate of evaporation, water crisis is one of the most important issues in the country. Due to the importance of Flixweed as a medicinal plant, its water requirement and its single and dual plant coefficients were investigated in the lysimeter laboratory of University of Birjand. For this purpose, six lysimeters (of the water balance type) with a diameter of 60 cm and a height of 100 cm were used. Inside all six lysimeters, Flixweed plants were planted with a density of 20 plants/m2, then, evaporation and transpiration were calculated using the water balance equation. Evaporation and transpiration of grass reference was measured directly by three lysimeters and its average was 322 mm. Then, plant coefficients were calculated for four stages of growth (initial, development, middle, and end). In this research, the average values of evaporation and transpiration, evaporation from the soil surface, and transpiration from the target plant were obtained as 202, 23, and 179 mm, respectively. Finally, the individual plant coefficients for the four initial, development, middle and final stages were 0.52, 0.68, 0.96 and 0.57, respectively, and the basic plant coefficients were 0.38, 0.59, 0.94 and 0.52 mm. In general, considering the climate of South Khorasan Province, Flixweed plant is recommended for cultivation due to its low water requirement.
7
farzane golestanifar; abbas khashei; sohrab mahmoodi
Abstract
Estimating potential evapotranspiration values is very important for calculating the water requirement in line with agricultural planning for different crops. For this purpose, in the present study, three polyethylene lysimeters with drains and completely sealed, with a diameter of 60 cm and a height ...
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Estimating potential evapotranspiration values is very important for calculating the water requirement in line with agricultural planning for different crops. For this purpose, in the present study, three polyethylene lysimeters with drains and completely sealed, with a diameter of 60 cm and a height of 100 cm were used to determine the crop coefficient and water requirement of quinoa. Titicaca quinoa seeds were planted on May 7, 2019, with 60 plants/m2. The soil moisture level was recorded by TDR and also the drainage output in each lysimeter was measured before irrigation. In order to measure potential evapotranspiration, the equations of Penman-Monteith, Blaney-Criddle (based on temperature) and Priestley-Taylor (based on radiation) were used. The results showed that the total amount of potential evapotranspiration during the growing season according to the FAO Penman-Monteith (ETo) method was 720 mm, according to the Blaney-Criddle method 581 mm, and according to the Priestley-Taylor method, 754 mm, while the total evapotranspiration of quinoa (ETc) in lysimeters was 553 mm. Also, the value of quinoa crop coefficient (Kc) in the first stage (21 days period), second stage (26 days period), third stage (38 days period) and fourth stage of quinoa growth (34 days period) using the Penman-Monteith method was equal to 0.42, 0.66, 1.03 and 0.71, in Blaney-Criddle method, 0.54, 0.88, 1.28 and 0.82, and in Priestley-Taylor method 0.40, 0.62, 0.97 and 0.68, respectively. These results show the Penman-Monteith method, as the best method, can be used as a criterion for determining the potential evapotranspiration, but the Blaney-Criddle method needs to be calibrated in the region.
7
Akbar Mohammadi; Mohammad Hossain NajafiMood; abbas khashei; Ali Shahidi
Abstract
Crop coefficient is one of the most important factors in irrigation planning and optimal allocation of water resources to plants. The crop coefficient is obtained through the ratio of actual evapotranspiration to reference crop evapotranspiration. In this research, in order to determine the crop coefficients ...
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Crop coefficient is one of the most important factors in irrigation planning and optimal allocation of water resources to plants. The crop coefficient is obtained through the ratio of actual evapotranspiration to reference crop evapotranspiration. In this research, in order to determine the crop coefficients of Narcissus flower, which is an important ornamental plant, an experiment was conducted during 2018 growing season using lysimeters, in Birjand. Three lysimeter was used in this project and water requirement of Narcissus flower was calculated by water balance method. Turf grass with a height of 12 cm was used to determine reference crop evapotranspiration. The base crop coefficients were obtained as 0.42, 0.85, 0.86, and 0.74, and the coefficients of the soil surface evaporation were 0.49, 0.28, 0.25 and 0.22 at, respectively, primary, developmental, middle, and end stages. Finally, the values of Narcissus flower’s crop coefficients at different stages of growth including primary, developmental, middle, and end stages were calculated as 0.91, 1.13, 1.11, and 0.96. The estimation of water requirement and irrigation management of Narcissus flower will be possible using the obtained Kc values.