Soil erosion rates under different tillage practices in central Belgium: New perspectives from a combined approach of rainfall simulations and 7Be measurements

The 7Be measurements confirmed overall trends observed during the rainfall simulations, with high soil losses in the conventional treatment (5.96 ± 1.37 kg-6.23 ± 2.36 kg) and a decrease in soil loss with the non-inversion (1.50 ± 0.34 kg-1.95 ± 0.54 kg) and the strip-till treatment (−0.19 ± 0.60 kg-0.10 ± 2.50 kg). However, 7Be-derived net erosion estimates overestimated total soil loss per plot compared to the direct measurements. The appropriateness of correction factors, like particle size correction and variations in relaxation mass depth, to improve the tracer based assessment of absolute soil loss values was evaluated. Spatial patterns in soil redistribution clearly reflected the sediment and runoff buffering capacity of the inter-row area in the strip-till treatment, while higher erosion rates were observed in the plant rows. Yet, sample representativeness to construct the soil erosion budget is a key consideration in light of discrepancies between tracer and rainfall simulation results. The different rainfall simulations support the preference of non-inversion tillage and strip-till over conventional tillage in order to reduce soil loss in the Belgian loess belt. The increased soil loss due to wheel track compaction implies the need to till favorable soil moisture conditions to avoid soil compaction.