عنوان مقاله [English]
The use of shallow groundwater as a source of irrigation water can be used in different plains located in southern, northern, western and north western parts of country during most crops planting period. In this investigation Lysimetric experiments were conducted to determine the contribution made by groundwater to the overall water requirements of (Stevia Rebaudiana B.). The plants were grown in 36 columns, each having a diameter of 0.40 m and packed with silty clay soil. The three replicate randomized complete block factorial experiments were carried out using different treatment combinations. Nine treatments were applied by maintaining groundwater, with an EC of 1, 2, 6 and 10 dS/m, at three different water table levels (0.7, 0.9 and 1.20 m) with supplementary surface irrigation. The supplementary irrigation requirement for each treatment was applied by adding water (EC of 1 dS/m). The average percentage contribution from groundwater for the different treatments (1, 2, 6 and 10 dS/m) and water table depths (0.7, 0.9 and 1.2 meter) as (66.5, 57.7, 45.3) and (61.5, 52.7, 42.1) and (59.9, 49.4, 41.0) and (59.0, 46.6, 40.1) percent of the average annual (Stevia Rebaudiana B.) water requirement respectively. The overall results showed that the shallow ground water with quality less than 2 dS/m can be used to compensate a most part of the annual plant water requirement.