Response of groundnut grown on acidic soil to rice-husk ash applied at 0, 1, 2, 3 and 4 t ha -1 was studied in two field experiments in 2005 and 2006 at Ishiagu in the derived savanna zone of southeast Nigeria. Treatments were fitted in a randomized complete block design (RCBD) replicated three times. Effects of treatments on some soil fertility and productivity parameters were evaluated. The rice-husk ash used contain 64.00 g kg -1 Ca, 12.20 g kg -1 Mg, 12.50 g kg -1 P, 9.00 g kg -1 K, 2.10 g

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... g -1 N, 1.23 g kg -1 organic carbon and had a pH of 10.86. Soil pH increased from initial values of 5.16 to 6.20, while levels of exchangeable acidity correspondingly decreased from initial values of 0.80 to 0.26 cmol kg -1 with 3 t ha -1 applied rice-husk ash. Estimation of linear and quadratic curves respectively for soil pH and exchange acidity show values of r 2 = 0.95 for soil pH and R 2 = 0.98 for exchange acidity. Significant increases (P < 0.01) in soil P, K and Ca status relate significantly (P = 0.05) to patterns of growth and kernel yield of the crop. The 3 t ha -1 rice-husk ash is recommended. No significant yield advantage was observed at 4 t ha -1 .