Data underlying the research article: "Bokashi als bodemverbeteraar"

Abstract<br>
A decrease in organic matter negatively impacts soil quality, leading to lower yields and greater dependence on fertilization and irrigation. At the same time drought periods are increasing and fertiliser application becomes more restricted. Bokashi could prove as a valuable addition to help mitigate these trends. Bokashi is produced from fermented organic residual streams, such as leaf and mowing residues. This allows organic material to be added to the soil, creating possibilities for soil improvement, and currently falls outside of fertilizer regulations. In this study, the effect of repeated bokashi application on organic matter content, waterretention capacity, penetration resistance, and nitrogen content was measured. Additionally, the chemical quality of the bokashi was determined, and weed pressure and germination were examined for their effect on crop growth. This took place on three sandy soils in the Netherlands from spring 2024 to spring 2025. The results show no effect of bokashi application over the research period as a whole; however, in 2025, a higher organic matter content was found in the bokashi treatment within Sint Joost. There were no differences observed between bokashi and control treatments for other parameters tested. Previous research suggest that bokashi application may have a cumulative effect as application occurs over a longer period; although this was not seen in current study and bokashi may prove effective after longer application. The study demonstrates that, for the parameters tested, bokashi has no negative effect and, on a location-specific basis, can have positive effects. This emphasizes the need for further research into location-specific application of bokashi.