Available boron and correlation with soil properties in Rio de Janeiro State, Brazil

To correlate extractable boron (B), clay and organic carbon (C) content and soil pH, the contents of available B were determinated in 103 soil samples of surface soil horizons from soils of Rio de Janeiro State, Brazil, using azomethin-H after extraction by hot water method. The average content was 2.43 +/- 0.67 mg kg(-1) of B with a variation from 1.31 to 4.50 mg kg(-1). The correlation values between B and organic C (r = 0.29**) and B and clay (r = 0.27**) were both significant. The highest correlation was found betwe en B and pH (r = -0.41**). The amount of available B was influenced by clay and organic C contents.