Initial growth and root surface properties of dicotyledonous plants in structurally intact field soil and compacted headland soil

Abstract The root surface physicochemical properties affect the ratio and uptake of cations by plants and are influenced by environmental threats. In this study, we examine the effect of soil compaction on the root surface properties and growth of dicotyledonous plants including Fabaceae: lupine, pea, soybean and Brassicaceae: mustard and rape. Undisturbed samples from a Haplic Luvisol derived from loess were taken in cores at 5–15 cm depth from a structurally intact area in the centre of a field (reference R) vs. repeatedly and intensively compacted headland area of the same field (compacted C). The soil dry bulk densities were 1.29 and 1.61 Mg m−3, respectively. Plants were grown in these soil cores for 11 days in a controlled environment chamber. Based on the curves of potentiometric titration, the cation exchange capacity (CEC), the total negative charge (Qtot) and the acid strength of the surface groups responsible for surface charging were determined. The apparent surface area (S) was calculated using the adsorption of water vapour method. Soil compaction resulted in a reduced fraction of strongly acidic groups (pKapp