Two field experiments were conducted at the Experimental Research Station in El-Serw, AgriculturalResearchCenter during 2010/2011 and 2011/2012 seasons to study the effect of nitrogen and compost combination treatments and potassium fertilizer levels on growth, yield and its components as well as grain quality of some wheat cultivars. The experiments were carried out in a strip-split plot design with three replicates. The vertical plots were assigned to wheat cultivars (Sakha 93, Gemmiza 9 and Gemmiza 10). The Horizontal plots were devoted to nitrogen and compost combination treatments as follows: 1) 100 % mineral nitrogen (90 kg/fed). 2) 75 % mineral nitrogen (67.5 kg/fed) + 25 % organic nitrogen "compost" (22.5 kg/fed). 3) 50 % mineral nitrogen (45.0 kg/fed) + 50 % organic nitrogen "compost" (45.0 kg/fed). 4) 25 % mineral nitrogen (22.5 kg/fed) + 75 % organic nitrogen "compost" (67.5 kg/fed). 5) 100 % organic nitrogen "compost" (90 kg/fed). While, the sub – plots were allocated to potassium fertilizer levels (0 and 48 kg K2O/fed).
Results showed that Gemmiza 10 cultivar surpassed other studied cultivars in number of days to heading, flag leaf area, plant height, number of spikes/m2, number of spikelets/spike, number of grains/spike, grains weight/spike, grain and straw yields/fed, potassium content in grains in both seasons. However, Gemmiza 9 cultivar produced the longest spikes and the highest values of protein percentage in grains in both seasons. Whereas, Sakha 93 cultivar recorded the highest values of 1000 – grain weight at the same time the lowest values of other studied characters in both seasons.
Application of 100 % mineral nitrogen fertilizer alone produced the highest values of all studied characters. Application of 75 % mineral nitrogen (67.5 kg/fed) + 25 % organic nitrogen "compost" (22.5 kg/fed) came in the second rank after application of 100 % mineral nitrogen alone without significant differences between them in some studied characters in both seasons.
All studied characters of wheat plants gradually increased as a result of increasing potassium fertilizer levels from 0 to 48 kg K2O/fed in both seasons. Generally, maximum means of all studied characters were produced from fertilizing wheat plants with 48 kg K2O/fed in both seasons.
It could be recommended that fertilizing Gemmiza 10 cultivar plants with mineral nitrogen (67.5 kg N/fed) + compost (22.5 kg N/fed) + 48 kg K2O/fed to enhance wheat productivity and also to reduce sources of environmental pollution and maintain human health.