TY - BK AU - The,C. AU - Calba,H. AU - Friesen,D.K.|Palmer,A.F.E. AU - Horts,W.J. AU - Zonkeng,C. ED - Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT) Kenya ED - 7. Proceedings of the Eastern and Southern Africa Regional Maize Conference TI - Maize grain yield correlated responses to change in acid soil characteristics after 3 years of soil amendments SN - 970-648-120-6 U1 - 338.16 PY - 2002/// CY - Nairobi (Kenya) PB - KARI|CIMMYT KW - Acid soils KW - Agricultural economics KW - Chemical soil types KW - Cropping systems KW - AGROVOC KW - Cultivation KW - Maize KW - Small farms KW - Zea mays KW - CIMMYT KW - KARI N2 - A long-term agronomic experiment was conducted from 1996 to 2000 in Cameroon, on acid soil with low ph (4.63), high Al supply, low Mg and low P. The objective was to assess the relative advantages of the use of acid tolerant maize (Zea mays L.) cultivars compared to the use of fertilizers and organic manure to correct soil acidity. On acid soil, maize grain yield of the soil acidity-tolerant cultivar ATP-SR-Y was 61% higher compared to the sensitive cultivar Tuxpeño Sequia. The application of 60 kgha-1 of P yearly for 3 consecutive years did not significantly increase the grain yield of the acidity-tolerant cultivar. Lime except in the first year resulted in a significant increase in grain yield of both the tolerant (82%) and particularly the susceptible cultivar (208%). This corresponded to a significant decrease in exchangeable Al and to a significant increase in pH and available Ca and Mg contents of the soil. The application of chicken manure or green manure (Senna septabilis leaves) significantly increased maize grain yield. These increases were partly attributed to an increase of available Ca and P of the soil for chicken manure application and to a decrease of exchangeable Al and a small increase in pH and Mg for Senna septabilis leaves application. It was concluded that the best correction factor was lime. However, organic amendments which are within reach of small farmers can at least substitute for lime application particularly for soil acidity- sensitive maize cultivars. Furthermore, the use of soil acidity-tolerant cultivars can greatly reduce the need for lime application and thus contribute to overall sustainability ER -