Soil classification and phosphorus relationships as influenced by soil iron and manganese in soils of the Mbo Plain in Cameroon.

摘要

Decreasing yield of crops grown in soils of the Mbo Plain has been attributed to deficiencies of soil P. The objectives of this study were to classify these soils using the United States Soil Taxonomy System and to determine P, Fe, and Mn status at four sublocations (Nzock5, Mbomi4, Mbomi2 and Mbomi10) of the Mbo Plain. Two pedons were described at each sublocation. Phosphate rates (0, 25, 50, and 75 mg P kg;Properties of the Mbo Plain soils were similar in all sublocations. The texture alternated between clay and clay loam. Base saturation was low and ranged from 4 to 52%. Soils are acidic with a water pH range of 3.8 to 5.0. Aluminum saturation percentage varied from 16 to 92%. Clay mineralogy was kaolinitic and ECEC ranged from 2.3 to 11.4 cmol kg;The main P fractions were Al- and Fe-bound P. Sorption isotherms indicated 50 to 439 mg P kg;Iron and Mn in plant tissue were present in apparent toxic concentrations (