The Effect of First Years of Drip Irrigation Research. a Closed Circuit from Research to Field Implementation.

The effect of First Years of Drip Irrigation research. A closed Circuit from Research to Field Implementation J. Ben-Asher Agri-Ecology group : Katif research center for coastal deserts development. Israeli Ministry of Science The introduction of drip irrigation (DI) to farming practice and scientific research have changed dramatically, our approach to study the rhizospheric processes and Soil-Plant-Atmosphere-Continuum (SPAC). Until the middle 60ies when DI have started in Israel most irrigation studies were focused on one dimensional (1D) systems. Starting DI a new trend of research have shifted to 2D-3D systems. In arid regions R&D directions shifted from low frequency irrigation interval given every several days or even weeks to high frequency irrigation given several times a day. The 1D water availability criteria ranged between field capacity and wilting point whereas under DI it is ranged approximately between saturation and field capacity. Relative agroproductivity per unit water doubled from 1960 to 1980 . The common practice of fertilizer (and herbicides ) broadcasting has changed to simultaneous fertilization and irrigation (fertigation) according to crop fertilizer and water demand . Several studies indicated that under DI , water can contain approximately 2 g L-1 salt without significant yield loss relative to fresh water irrigation. Comparatively, the use of such water by sprinklers caused a yield decrease of 95%. Root distribution was found to adjust itself to exponential increase in oxygen diffusion rate. In this paper we shall review the early research that affected productivity and water use efficiency under DI. The review is subjectively limited to R&D that ended in early 80ies with a believe that the experimental paper of Goldberg and Shmueli   (1970) "Drip irrigation: a method used under desert conditions of high water and soil salinity." has paved the way to the circuit from research to field implementation.