Reuse of Drainage Water of Fish Ponds in Soybean Cultivation under Sprinkler Irrigation System

Nowadays the limited water resources in Egypt lead to use the drainage water effluent in agriculture, particularly in reclaimed desert land which inherently deficient in organic matter, nutrient and trace elements. Therefore the aim of this study is maximizing benefits from drainage water of fish ponds in irrigation of soybean crop and using it as new water recourse. Two field experiments were carried out during growing seasons 2012 and 2013, in research farm of National Research Center (NRC), Nubaryia province, Egypt to study the effect of fertigation rates and using drainage water of fish ponds in irrigation of soybean. Study factors were water quality (traditional irrigation water “TW” and drainage water of fish ponds “DWFP”) and fertigation rate “FR” (25%, 50%, 75% and 100% from recommended dose from NPK).The following parameters were studied to evaluate the effect of study factors :(1) Calculating the lost amount of wastewater of fish ponds per season without any benefit. (2) Growth characters (3) Yield (4) Irrigation water use efficiency of soybean "IWUE soybean” and (5) Oil and protein content. Statistical analysis of the effect of the interaction between study factors on growth, yield, irrigation water use efficiency of soybean and oil and protein content indicated that, maximum values were obtained for yield, IWUE, oil and protein content of soybean under DWFP x FR100% NPK, also indicated that, there were no significant differences under DWFP x FR100% NPK > DWFP x FR75% NPK this means that, using drainage water of fish ponds as a new source for irrigation will save traditional irrigation water and save 25% from minerals fertilizers under sprinkler irrigation system.