Abstract
The pot-grown experiment of sudangrass (Sorghum sudanense [Piper] Stapf cv. Rich sudan, Sg), signalgrass (Brachiaria decumbens Stapf cv. Basilisk, Bd), and pangolagrass (Digitaria eriantha Steud. cv. Transvala, Tr) was conducted to determine the optimum application rate of lime (calcium carbonate) and phosphorous fertilizer in red-yellow acid soil in Okinawa, Japan. As the application rate of calcium carbonate increased, the concentration of exchangeable aluminum significantly decreased in the soil. Lime application was highly effective in the growth for Sg, while not for Bd or Tr. The critical level of phosphoric acid application in the soil is required for more than 2.3 and 2.1mg P_2O_5/100 g dry soil for Bd and Tr, respectively.
