water requirement, crop coefficients of peppermint (mentha piperita l.) and realizing of simdualkc model

Peppermint is one of the most important medicinal and industrial crops in the world, which due to the importance of water, it is necessary to determine its water requirements accurately. this study aimed to determine the water requirement, single and dual crop coefficients of peppermint. for this purpose, 12 water balance drainable lysimeters were applied. three lysimeters were used to determine grass and three were applied to estimate the evaporation of bare soil. in addition, in the 6 lysimeters, peppermint was planted in two groups. the plants of group a and group b continued to grow until the end of flowering and appropriate extraction time, and the plants were harvested 3 times after reaching a height of 10-12 cm. the average water requirements of peppermint for two lysimeters groups a and b were determined to be 646 and 532 mm, respectively. the single and base crop coefficients for lysimeters in group a were determined to be as 0.68, 1.07, 1.31 and 0.3, 0.88, 1.18 for the initial, development and middle growing stages. for lysimeters in group b, the average of single crop coefficients was determined to be 0.85, 0.92 and 0.95 respectively. calibration and validation of the simdualkc model showed the model’s capability and accuracy for proper irrigation planning and scheduling.