Two field experiments were conducted at El-Kassasin Farm, Ismailia Governorate, Egypt, (30º 33 ״ 31 ׳ N-30°56 ״ 7 ׳ E, elev. 15.8 m) during the summer seasons of 2014 and 2015 on maize plants (c.v. single hybrid 30K8) grown on a sandy loam soil to study the effect of applying different sources of N-fertilization alone and in combination with foliar application of humate potassium on yield and its components and quality of maize grains. Different sources of N-fertilization caused significant increases in yield and its components and mineral uptake. Meanwhile, application of 50% N- mineral as ammonium sulphate (75kg N fed.-1) +50% organic N (75 kg N fed.-1) (5.3 t compost fed-1) achieved the highest values of all aforementioned parameters followed by the application of 100% of the recommended mineral N (150 kg N/fed.) then 100 % organic N (150 kg N fed.-1) (10.6 t compost fed-1), in a descending order. Spraying maize plants with potassium humate significantly enhanced plant growth, yield and its components as well as N, P and K uptake, total protein and oil in grains. In this respect, spraying plants with 4 L/fed potassium humate attained the superiority impacts comparing the other treatments. Hence, it can be concluded that fertilizing maize plants with 50% N- mineral (75 kg N fed.-1) +50% organic N (75 kg N fed.-1) (5.3 t compost fed-1) in combined with spraying plants at rate 4 L/fed potassium humate gave the highest values of yield and its components and NPK uptake as well as protein and oil content in grains as compared to other interaction treatments.