Kenyan Highlands versus Brazilian Cerrado Acid Soils:Chemistry, Mineralogy, and Phosphorus Sorption and Availability

摘要

We characterized the chemistry and mineralogy of selected acid soils from the maize growing areas of the Kenyan Highlands and the Cerrado Region of Central Brazil. In general, the Kenyan soils from west of the Rift Valley are similar to or slightly better than the Brazilian soils in terms of P fixation capacity and other chemical and mineralogical properties that most impact plant growth. On the other hand, the Kenyan soils east of the Rift Valley have ～3 times greater P fixation capacity and higher Al saturation than the other Kenyan soils and thus present more severe constraints on crop production. 20 μmol citrate per gram soil released ～3. 5 times more P from the Kenyan surface soils than did a 0.01 M NaCl solution alone.