Effect of calcium/potassium ratio ammonium supply on nutrition and yields of cucumber plants

A greenhouse experiment was conducted in order to study the influence of two calcium/potassium (Ca/K) ratios (0.75 and 0.33) and ammonium supply (0 and 1 mmol/L) in the nutrient solution on nutrient uptake, mineral composition, and productivity of cucumber plants grown in sand culture. There were not significant differences in nitrate consumption between the four treatments. Calcium and potassium consumptions were directly related with the Ca/K ratio in the nutrient solution. The treatment with Ca/K = 0.75 and ammonium supply, that showed the lowest potassium and nitrogen plant levels and the highest calcium uptake and concentration in plant, offered the highest yields.