RESPONSE OF WATER USE EFFICIENCY TO SOIL MANAGEMENT PRACTICES AND WATER TABLE LEVELS

Abstract

Two experiments were carried out in eighteen double wall concrete lysimeters of the size 1.25 m × 1.25 m in area and 1.25 m deep using the cultivar Faba bean (Vicia Faba L.) and Corn (Zea mays L.) during, 2010 and 2011 seasons, respectively to estimate the contribution of water table to meet the water requirements, the impact soil management practices including compost; and the interaction effect of both them on either faba bean or corn crop. The lysimeters were connected to a tank with Marriotte siphon and a piezometer to maintain the water table level at the desired depths, which consisted of 50, 70 and 90 cm from the soil surface. There were two compost treatments, which consisted without compost and with compost treatments. The amount of compost was 20 Ton per feddan, which mixed with the 30 cm depth from the soil surface. The obtained results could be summarized as follows:-

Reference evapotranspiration (Eto):- The values of climatic conditions and reference evapotranspiration (Eto) calculated according to the modified penman equation (mm/day) for faba bean and corn crops were follow the changes in the climatologically norms during the growth season.

Water use from water table:- The highest water table contribution for faba bean and corn crops value is obtained under the shallowest water table depth (50 cm) and it reduces with increasing the depth of water table from soil surface in with and without compost treatments. Also, the result show that the considered crops (faba bean and corn crops) has different ability to take up water even with the same water table level. The values of water table contribution are increased as the plant progressed then it decreases a