The objective of this study was to evaluate the effects of soil (Ca+Mg)/K ratio on nutrient uptake, development and bulb yield of vernalized garlic (Allium sativum L.) grown in 50 liter pots, under greenhouse conditions. Rates of potassium were applied to an allic dark red latosol (Oxisol) in order to obtain soil (Ca+Mg)/K ratios of approximately to 170; 50; 35; 20; 12.5; 7.5; 3.5 and 2.0. The increase of potassium rates influenced the soil solution, increasing directly the K, Ca and Mg concentrations. The contents of K and Mn in the leaves decreased with the increment of the soil (Ca+Mg)/K ratio, while the opposite occurred with the Ca and Mg content. Other nutrients uptake were not influenced by the treatments. The soil (Ca+Mg)/K ratio influenced bulb yield and plant height at the lowest ratios, and potassium excess decreased plant yield and weight. The best correlation with bulb yield was observed between potassium saturation (%K), followed by K/(Ca+Mg)1/2 ratio and exchangeable potassium in the soil.
garlic; potassic fertilization; cationic nutrition; Ca:Mg:K ratio