تعیین نیاز آبی گشنیز (.Coriandrum sativum L) به روش لایسیمتری در منطقه‌ای با اقلیم نیمه خشک

The estimation of crop water requirement is one the most important stages for designing different irrigation systems, programming and corrected management of water resources. Therefore, to determine the water requirement for Coriandrum sativum L. a study was conducted in College of Agriculture Research Farm at Razi University in the city of Kermanshah during two years, 2010 and 2011. For this purpose, three water balance drainable lysimeters with the diameter of 1.20m and height of 1.40 m were used. During the investigation, the irrigation was determined by using data logger equipment of (IDRG). The soil humidity was determined in the field capacity condition. The evapotranspiration was calculated using water balance equation. Finally, the Coriandrum sativum L. water requirement was determined to be 722.95 and 580.64mm for years 1388-1389 and 1389-1390, respectively. Meanwhile, the potential evapotranspiration using the Penman Monteith equation was calculated to be 643.58 and 530.17mm for the first and second year of investigation, respectively.