The present investigation was conducted during the two seasons of 2006/2007 and 2007/2008 at Arab El-Awammer Research Station (A.R.C.); Assiut, Egypt to study the effect of N application, compost and bio-fertilization on soil and nitrate concentration of leaves of Romaine cv.grown in sandy soil.The results indicated the effectiveness of N application 120 N level and 6 ton of organic fertilizer in ...