EFFECT OF NITROGEN AND WATER REGIME ON SPINACH YIELD AND WATER CONSUMPTION USING NEUTRON SCATERRING TECHNIQUES

Field experiment was conducted at the Farm of soil and Water Research Department,Nuclear Research Center,Atomic Energy Authority,Inshas,Egypt to evaluate the role of nitrogen fertilizer and water regime on spinash yield,water consumption and actual evapotraspiration(ETc) under drip irrigation system hold on virgin sandy soil.Data indicated that the 40% ETc treatment resulted in spinash yield of 3.31,5.41 and 3.898 ton ha-1,while 60% ETc induced 3.41.6.026 and 5.88 ton ha-1for one,two and four splitting nitrogen doses,respectively.The other two water regimes i.e 80% and 100% ETc yielded 4.217,11.004,7.762 and 4.099,6.955,6.821ton ha-1respectively.Statistically,high significant differences were noticed between N splitting treatments while the difference between water regime treatments was only significant at P≤0.05.Polynominal functions used to predict the best nitrogen splitting dose indicated that the maximum spinash yield were 5.755,6.852,12.42 and 7.862 ton fresh yield ha-1 at 2.6.2.96,2.7 and 2.966 nitrogen doses for 40,60,80 and 100% ETc,respectively.This indicated that 80% ETc treatment was the best one.Also,the best nitrogen splitting dose for 40,60,80 and 100% ETc treatments was around 3 doses that induced high spinash yield.The treatment 80% ETc saved about 20% from the water consumptive use.The data also showed that the two splitting nitrogen dose had the highest ETa values over four and full one nitrogen dose