Fine and coarse straw-, husk- and bran-char were thoroughly
homogenized with the contaminated soils (5% biochar by weight),
flooded with deionized water and incubated for two weeks. An
addition of 5% was chosen because it is a typical addition based
on previous work on biochar. Pore water was collected with a soil
moisture sampler (Rhizosphere Research Products, Netherlands)
inserted into each pot prior to transplanting rice seedlings. Basal