The legacy of biomass burning during conversion for both oil palm
and rubber plantations coupled with the subsequent agricultural management
practices associated with monoculture plantations strongly influenced
soil pH, base saturation and extractable P in the converted land
uses (Figs. 1a, b, d; Tables A.3 and A.4). Soil pH, which was the only
chemical property to exhibit land-use change effects at all depth intervals
in both landscapes, was highest in the converted land uses in the
clay Acrisol soil (Fig. 1a). This is most likely due to ashes from biomass
burning of which effects on increasing soil pH can last for many years
(Markewitz et al., 2001; van Straaten et al., 2015) aswell as limingpractices
in oil palmplantations in this landscape and kieserite fertilizer application
prior to our study. Furthermore, the increased base saturation
in the top 0.5mdepth in the oil palmplantations in both soil landscapes
was also influenced by legacy effects of biomass burning and liming
(Fig. 1b). However, this increased base saturation was only surficial
and the lower depths reflected the typically low base saturation of
Acrisol soils (Fig. 1b). From an ancillary study conducted in the same
plots during the same year, oil palm plantations showed increased
leaching fluxes of Na, Ca andMg at 1.5mdepth compared to the forests