effects of nitrogen different amounts, manure and irrigation water on yield and yield components of corn

in order to investigate effects of optimum use of manure and nitrogen fertilizer on yield and yield components of corn single cross 704 (late maturing, non-prolific and dent) in different levels of irrigation water. a field study was conducted in 2005 year in agriculture experiment station of college agriculture, arak university (34o 32′ n, 50o 31′ e; 1759 m above mean sea level). design of experiment was randomized complete block with factorial arrangement with three replications. nitrogen treatments were include 0, 92, 184 and 276 kg n ha-1, 46 kg n ha-1 + 2.5 ton ha-1 farm yard manure (fym), 92 kg n ha-1 + 5 ton ha-1 fym and 138 kg nha-1 +7.5 ton ha-1 fym and amounts 5, 10 and 15 ton ha-1 fym and water factor include 50%, 75% and 100 crop water requirement. results showed that with reducing nitrogen contents and irrigation water, yield and yield components reduced. maximum yield and yield components was produced when nitrogen and water used for plants sufficiently. chlorophyll content index increased when irrigation water amount was decreased. chlorophyll content index has direct relation with nitrogen and increased linear by nitrogen amount and this relationship was affected by water amounts. maximum grain yield of corn with nitrogen factor was produced with 138 kg n ha-1 + 7.5 ton ha-1 fym and average of grain yield was 7555 kg ha-1 and water factor at optimum irrigation was produced average of grain yield 8756 kg ha-1. maximum grain yield was produced with interaction effects of nitrogen and water in 138 kg n ha-1 + 7.5 ton ha-1 fym and optimum