Liming Effects On Soils Cultivated with Sugar Beet (Beta vulgaris L.) Under Greenhouse Conditions In Brazil.

Liming is an essential practice for tropical soils to correct acidity and improve soil fertility, allowing the crops to achieve the maximum potential yield. The goal of this study was to evaluate the effects of lime on chemical attributes of soil and on initial development of sugar beet under greenhouse conditions in two different textured soils: sandy and clayey. The experiment was carried out in Pirassununga, Sao Paulo State, Brazil from July/2009 to October/2009 in pots containing 15 dm³ of soil samples. The completely randomized experimental design was adopted with five treatments and eight repetitions, totaling 40 experimental units for each type of soil. The treatments consisted of five rates of limestone for the sandy soil: 0, 1.22, 2.27, 3.31, 4.31 t ha^-1 and for the clayey soil: 0, 1.35, 2.78, 4.13, 5.56 t ha^-1; the rates was chosen according the base saturation method. After limestone application the soil samples were incubated for 30 days before sugar beet sowing. The root phytomass measurements were made at 20, 40 and 60 days after sowing; soil samples were collected before limestone application, after the incubation period and at the end of the trials for soil fertility measurements. The lime effectivelly modified the chemical attributes, with linear response to the pH in CaCl_2, base saturation, Ca, Mg e sum bases, for both soils. The root phytomass increased with limestone rates during the plant development; this increase was more evident in plants grown on the clay textured soil, in which the base saturation achieved around 80%, the recommended level for sugar beet crop, which resulted in the production of shoot phytomass, showing the effects of pH on the development of sugar beet. Liming showed to be essential for sugar beet production under acid tropical soils.