The effect of three organic fertilizers; viz, chicken manure (ChM, 20 and 40 m3 fed.-1), pressed olive cake(POC, 20 and 40 m3 fed.-1) and cow manure (CwM, 30 and 60 m3 fed.-1) on growth and productivity of cowpea underwater stress condition was investigated. A field experiment was carried out at The Experimental Farm, Fac. Environ.Agric. Sci., Arish Univ., El-Arish, Egypt in summer seasons of 2013 and 2014 in a sandy soil. Irrigation waterrequirements (IWR) were 50% (1050 m3 fed.-1) and 100% (2100 m3 fed.-1) of the estimated crop evapotranspiration.Results showed that20 m3 fed.-1of both ChM and POC were more effective for most vegetative growth parameters andyield components in well irrigated-cowpea in both seasons. Water stressed-cowpeas fertilized by 60 m3 fed.-1 of CwMshowed the lowest reduction in yield (34.07 and 29.86%) in both seasons, respectively, followed by POC fertilizer at 40m3 fed.-1. Water stressed cowpeas fertilized by 40 m3 fed.-1 of POC gave the highest values of water use efficiency (0.86and 0.87 kg m-3). The lowest total consumed water was recorded with 20 and 40 m3 fed.-1 of ChM–fertilized plantsunder normal and drought conditions. The content of biochemical compounds and macro-elements as well asmeasurements of some important tissues in leaflet of 3rd leaf related to drought and organic fertilizers were also studied.It was concluded that application of 20 m3fed.-1 of ChM gave the highest yield in well irrigated-cowpea. Doubledamount of organic fertilizers reduced the deleterious effect of drought especially POC and CwM by saving irrigationwater.
