RESPONSE OF SOME WHEAT VRAIETIES TO MINERAL AND ORGANIC NITROGEN FERTILIZERS.

Two field experiments were conducted at the Experimental Research Station in El-Serw, Agricultural Research Center during 2011/2012 and 2012/2013 seasons to study the effect of inorganic nitrogen and organic nitrogen of compost combination treatments on grain and straw yield and N, P, K- uptake in grain and straw of some wheat varieties. The experiments were carried out in a split plot design with three replicates. Main plots were assigned to three wheat cultivars i.e., Sakha 93, Gemmiza 9 and Gemmiza 10. The sub main plots were devoted to nitrogen and compost combination treatments as follows: 100 % inorganic nitrogen (90 kg fed-1), 75 % inorganic nitrogen (67.5 kg fed-1) + 25 % organic nitrogen (22.5 kg fed-1), 50 % inorganic nitrogen (45.0 kg fed-1) + 50 % organic nitrogen (45.0 kg fed-1), 25 % inorganic nitrogen (22.5 kg fed-1) + 75 % organic nitrogen (67.5 kg fed-1) and 100 % organic nitrogen (90 kg fed-1). The results showed that the highest wheat grain and straw yields and N, P and K uptake in grain and straw were Gemmeza 10, Gemmeza 9 and Sakha 93, respectively and 100 % inorganic nitrogen, 75 % inorganic nitrogen + 25 % organic nitrogen, 50 % inorganic nitrogen + 50 % organic nitrogen, 25 % inorganic nitrogen + 75 % organic nitrogen and 100 % organic nitrogen, respectively. 100% inorganic nitrogen for Gemmiza 10 gave the highest wheat grain and straw yields and N, P, and K uptake in grain and straw. While, applying 75% inorganic nitrogen with 25% organic nitrogen could produce economic wheat grain and straw yields for Sakha 93 only. So, it may be saved 25% inorganic nitrogen when applying it as compost.