Document Type : Research Paper
Authors
1
MSc, Department of Water Science and Engineering, Faculty of Agriculture, University of Birjand.
2
Assistant Prof., Department of Water Science and Engineering, Faculty of Agriculture, University of Birjand.
3
Professor, Department of Water Science and Engineering, Faculty of Agriculture, University of Birjand.
4
Associate Prof., Department of Water Science and Engineering, Faculty of Agriculture, University of Birjand.
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 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.
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