|Fageria, N - EMBRAPA, BRAZIL|
|Castro, E - EMBRAPA, BRAZIL|
Submitted to: The International Workshop on Characterization Management and Utilization of Red Soils
Publication Type: Proceedings
Publication Acceptance Date: November 2, 2002
Publication Date: N/A
Interpretive Summary: In many parts of the world soil acidity is a major yield-limiting factor for upland rice production. A greenhouse experiment was conducted to evaluate the productivity response of several upland rice types to varying soil acidity. Soil acidity effects on growth and grain yield for a number of upland rice types were determined. Upland rice types used in this study differed in grain yield. Acid soil-tolerant upland rice types identified in this study appear to be excellent plant materials to overcome the soil acidity constraints. Superior upland rice types identified in this study could be used in the breeding program to produce high-yielding upland rice cultivars suitable for improving yield potentials on infertile, acidic soils.
Technical Abstract: In many parts of the world on highly weathered Oxisols, acidity is one of the major factors that contributes to the reduction of crop yields. In addition to liming, use of acid tolerant crop species or cultivars within species, is a complimentary solution to improve crop production on such soils. A greenhouse experiment was conducted to evaluate the growth, grain yield, yield components and nutrient use efficiency response of 20 upland rice (Oryza sativa L.) genotypes to two levels of soil acidity. Oxisols (Typic Haplustox) were amended with and without dolomitic lime (6g /kg soil) to achieve pH of 4.5 (High soil acidity) and 6.4 (Low soil acidity). At both soil acidity levels, genotypes differed significantly in growth, grain yield and yield components. Grain yield, and most of the yield components, were significantly decreased at low soil acidity as compared with high soil acidity, demonstrating the tolerance of upland rice genotypes to soil acidity. Genotypes differed significantly in macro-micro nutrient use efficiency. Additionally, there was significant acidity x genotype interactions observed for almost all nutrient use efficiency for grain production. Grain yield gave significant negative correlation with soil pH, Ca saturation, and base saturation. Grain yield gave significant positive correlations with soil Al, H+Al, and CEC, confirming that upland rice genotypes are tolerant to soil acidity.