Effect of Different Levels of Magnesium and Potassium Fertilizers on the Grain Yield and Components of Maize in Calcareous Soils

The study aims to investigate the response of corn (Variety Veto) to different levels of Magnesium and Potassium fertilizers in calcareous soil. A field experiment was conducted during the Season 2015 at north of Iraq /Irbil . The experiment was designed as(RCBD) with two factors. The first was magnesium fertilizer which was added at four levels (0,60,120,180 kg mg.ha-1)as  Magnesium sulfate (Mgso4.7H2o) .while The second factor was Potassium fertilizer was added at four levels (0,80,160,240 kg k.ha-1) as potassium sulfate (K2so4). Addition of Mg and K-fertilizer significantly  increased dry weight .The highest value of dry weight was at Mg3K2 (22.37 g.plant-1) Results indicated That application of Mg and K-fertilizers significantly increased the grain yield .The percentage of increase were 22.27% , 39.56% and 20.22% at levels Mg1 ,Mg2 and Mg3 respectively compared with control Mg0  the effect of K-fertilizer was significant and the percentage of increase compared with control K0 were 33.61% , 54.35% and 50.65% at levels K1 ,K2 and K3 respectively . The highest value of grain yield was at Mg2K2(5544.16 Kg.ha-1) The increase in grain yield was mainly due to the number of grain .cob-1  and secondly to the weight of 100 grains.