EVALUATION OF LITHOTHAMNIUM AS CORRECTIVE OF SOIL ACIDITY AND SOURCE OF NUTRIENTS FOR BEAN PLANTS

With the objective of evaluating the efficiency of lithothamnium in the correction of the soil acidity and as source of nutrients for bean plants, an experiment was conducted in vases, in greenhouse conditions. The experimental design was a complete randomized one, with nine treatments: control, four doses of lithothamnium (1/4, 1/2, 1 and 2 times the dose for V at 70%), commercial dolomite limestone as reference pattern (dose for V at 70%), lithothamnium (V at 70%) without micronutrients, lithothamnium (V at 70%) with reduction of 20% of NPK and lithothamnium (V at 70%) plus Mg. Three soil classes were evaluated, Quartzarenic (NQ), Yellow Red Latossol (LV) and Red Argissol (AV), with four repetitions for each treatment. Four bean plants were cultivated in vases with three dm(3). Two of these plants were harvested in the flowering period, with both the macro and micronutrients concentrations being evaluated. The other two plants were harvested at the end of the cycle, when the productions of grain and vegetable dry matter (aerial parts, root, grain and total) were evaluated. Lithothamnium showed practically the same effect of the commercial dolomite limestone in the correction of the acidity and in the saturation for bases being used the dose to reach a V at 70%. Lithothamnium promoted in the three soils, the elevation of calcium and magnesium levels, increasing the pH values and saturation for bases, and consequently, reduction in the saturation for aluminum, accrediting the product to be used as corrective and fertilizer. Those effects promoted better nutrition conditions, growth and production of the bean plant. The doses to reach 90% of the maximum production of grains in the NQ and LV soils were 610 and 1.090 kg ha(-1), respectively, these doses being lower than those required to reach a V at 70%. In NQ soil, without lithothamnium, and also in the treatment with lithothamnium (dose for V at 70%) without micronutrients, plants did not produce grains. In a general way, it was observed that the smallest doses of lithothamnium, in the three soils, were the ones that presented better results in the appraised characteristics and that the best results were found in LV.