Bicarbonate Accumulation and pH Changes at the Soybean (Glycine max (L.) Merr.) Root‐Soil Interface

Abstract

Investigation of the root‐soil interface environment of soybean roots showed an accumulation of HCO₃ and an increase in pH as compared to the original soil. The magnitude of the HCO₃ accumulation and pH increases was related to the NO₃ level of the soil solution. This effect was attributed to a greater uptake of anions than cations by the plant so that HCO₃ release maintained electrical neutrality. The pH increased by as much as one unit and HCO₃ accumulation was as great as 35 meq/100 g of dry roots.