The effects of increasing doses of magnesian lime, phosphorus and potassium on the yield of soybeans were studied during two years on a red-yellow podzolic soil with pH 5,5, fertilized with phosphorus in the previous three crops. No response to potassium was obtained. The effect of lime manifested only in the second year, when the smaller dose, of 1 metric ton per hectare, caused an yield increase of 9 per cent. The responses to phosphorus were linear; however, the increase due to the larger dose, of 100 kg/ha of P2O5, corresponded to 9 per cent only.