THE INFLUENCE OF IRRIGATION WATER SALINITY AND FERTILIZER MANAGEMENT ON THE YIELD OF ALFALFA (MEDICAGO-SATIVA L)

A field study was conducted on a loamy sand soil to study the effect o f water quality on growth and yield of Alfalfa (Medicago sativa L.). T reatments were replicated three times in a randomized split-split desi gn, with water quality as the main plots, irrigation frequency as the subplots, and six nitrogen-phosphorus combinations as the sub-sub plot s. Basin and sprinkler irrigation systems were used, Alfalfa produced good growth and dry matter yield under both canal (3.2-3.4 dS m(-1)) a nd mixed canal and drainage (6.4-8.6 dS m(-1)) irrigation waters where as, irrigation with drainage water (10.2-15.6 dS m(-1)) reduced the yi eld significantly especially at biweekly irrigation frequency and at l ow nitrogen and phosphorus application, The high nitrogen level enhanc ed the growth of alfalfa and compensated for the reduction of its yiel d under high saline conditions. Under the experimental conditions the basin irrigation system was more appropriate compared with the sprinkl er system for high alfalfa yield and leaching of salt build up in the soil in most of the cases studied.