Former and Current Trend in Subsurface Irrigation Systems

The main purpose of this review is to find the diversity in research studies subsurface irrigation systems past two decades. Two periods five years were selected reflect at beginning and end comparing range. A statistical sorting was used investigate distribution papers according objectives, types systems, methods, limitations studies. Results showed that measurements evaluations most presented objectives for both periods. Furthermore, almost 90 percent recent multiple unlike published former period which only 56 them methods. Also, more than a single system. In conclusion, knowledge had been advanced mostly by analyzing traditional systems. Unlike period, advancement has produced current introducing new concentration order measurements, evaluation, designing, respectively.