5. Conclusion
The results of this 5-year field experiment undertaken on a meadow red clover/grass mixture on loamy sand soil have demonstrated that straw and biochar amendments significantly affect root system morphology. The soil amendments applied resulted in higher root length, surface area, volume and mean root diameter. However, the differences for most of the root morphometric parameters were noticed mainly between the control, which did not have any amendments, and the other treatments where straw or biochar produced from miscanthus or wheat were applied. There were no differences between the treatments with different feedstock types (miscanthus vs. wheat), materials (straw vs. biochar) or amendment rates (5 vs. 2.25 t ha-1). The results of the root system characteristics were reflected in the aboveground biomass productivity. The soil amendments, i.e., straw and biochar, significantly increased the productivity in comparison with that of the control treatment. However, these differences were noticed only during the first and second cuts.