Evaluation of growth characteristicsthe and changes in the concentration of macro and micro nutrients of garlic affected by alkalinity and nitrogen sources in hydroponic culture

Soil and water alkalinity are limiting factors of agricultural products in arid and semi-arid areas especially in Iran. An experiment was carried out as factorial base on completely randomize desigen with three factors; sodium bicarbonate at three levels (0, 10 and 20 mM), nitrogen sources (5 mM ammonium sulfate, ammonium nitrate and calcium nitrate in nutrient soulotion) and garlic genotypes (white and purple) with three replications. The results showed that shoot and root fresh and dry weight decreased by increasing sodium bicarbonate from 10 mM to 20 mM in nutrient solution and application of ammonium nitrate and ammonium sulfate sources decreased the negative effect of sodium bicarbonate on shoot and root fresh and dry weights. The results showed that nitrogen and potassium concentration in both garlic genotypes which nourished with ammonium nitrate and ammonium sulfate were increased by increasing alkalinity stress intensity. Calcium and magnesium concentrations in the plants that treated by calcium nitrate and ammonium sulfate sources increased by increasing alkalinity intensity in both genotypes. while iron concentration in all of nitrogen sources decreased under alkalinity stress. Conclution: According to the results of this experiment, the use of ammonium sulfate and ammonium nitrate sources has a better performance on nutrients absorption and nutrient concentration in shoot of garlic under bicarbonate stress conditions.