NUTRIÇÃO E CRESCIMENTO DA ERVA-MATE SUBMETIDA À CALAGEM

Mate tea trees are native of south Brazil, growing on acid soils. However, small farmers intercrop this species with agricultural crops, which usually require liming to reduce the soil acidity. Therefore, this study aimed to verify the liming effect on Mate tea seedling growth and nutritional status. Samples of an acidic soil (pH = 4.2, Al3+ = 3.9 cmolc dm-3) were incubated with increased rates (0.0, 0.7, 1.8, 2.5, 3.4, 4.3 and 5.2 g dm-3) of a liming material for 21 days. Then mate tea seedlings were transplanted to the pots containing 3 dm3 of soil, grown for 210 days. At the end of this period, seedlings were harvested, split into leaf plants, stem, and roots for determining the foliar area, root length and volume, dry matter production and levels of N, P, K, Ca, Mg, Fe, Cu, Zn, Mn and Al as well as the efficiency of the usage of Ca and Mg by the plant. The soil was analyzed chemically. Calcareous elevated the values of Ca, Mg and K in the soil and stimulated a little increase in the aerial parts of the plants. Seedling maximum dry matter production was obtained at low rates of liming and drastically decreased at high liming rates. Micronutrients and Al seedling decreased with lime rate. Calcium and Mg utilization efficiency reduced with increasing availability of these nutrients in the soil. It can be concluded that mate tea plants are tolerant to soil acidity and the lime is needed only to supply Ca and Mg nutritional requirements.