| Abstract: | Soil samples were collected from topsoil and subsoil beneath secondary coastal rainforest and from areas which had undergone forest clearance over periods from less than one year to five years. Soils are characterized using total element, particle size and mineralogical analyses and fertility studies examined parameters associated with the exchange complex of the topsoil horizon. Changes in these parameters less than one year after forest clearance are shown as significant increases in pH, organic carbon, available cations (Ca, Mg, Na, K), available P, total N and effective CEC with exchangeable Al being reduced to zero concentration. However, two and five years after clearance, nutrient concentrations decreased to deficient levels and low pH and organic matter resulted in Al and Mn being potentially toxic to plant growth. Brief reference is made to the Fertility Capability Soil Classification System (FCC) as a means of assessing fertility status. © 1998 John Wiley & Sons, Ltd. |
