ULTRA LOW DRIP IRRIGATION EFFECT ON WATER DISTRIBUTION IN SOILS AND SQUASH PRODUCTION

Abstract

Ultra low drip irrigation ''ULDI'' system is a new aspect of micro irrigation.It is known as ''minute or ultra-low flow- rate'' irrigation. This method involves applying water at a very low rate, even lower than the natural soil water intake capacity. Flow rate from minute or ultra-low irrigation system is usually 10 times less than conventional emitters (0.2 L/h).Also; ''ULDI'' gets a continuous moisture and oxygen (air) supply under Field Capacity conditions. The first aim of this study is determine the wetting pattern on soil (ClayandSandy) at different application rates (0.25, 0.5, 1.2, and 2 L/h) and different application times. The second aim is investigated in ''ULDI'' effect on squash production. The results showed the following relationships to describe wetted front advance (width ''w'', depth ''d'', and diagonal ''z''): where α: is in any direction (w, d, or z),c, c1, c2, and c3: are constants that depend on (α) direction, t: is application time (h), K: is hydraulic conductivity (cm/h), and q: is emitter discharge (L/h) . The results of field experiments indicated that the increasing ratio of squash yield when using 0.25 L/h treatment was 41.17 %.