Grain farmers prefer to grow cover crops outside of the actual grain-growing season. Surface composting is a relatively new method of terminating a cover crop with minimal tillage and without using glyphosate or other herbicides. In this project, we investigated the effect of the Norwegian biostimulant Terra Biosa by surface composting an undercrop on a grain farm in Skjeberg in southeastern Norway in May 2022. Terra Biosa is a further development of EM(Effective microorganisms). The project aims to investigate if the addition of the biostimulant improves the effect of surface composting on soil fertility by stimulating a faster and more controlled decomposition of organic matter. We will study the effect of Terra Biosa application on soil structure, soil biology, soil mineral nitrogen content, plant nutrient uptake and plant growth. The project report will be published in late 2022 or early 2023.

NORSØK’s role in the project is to provide scientific advice. Furthermore, NORSØK was involved in project planning, performed some soil sampling and analyses, and will co-author the report.