Comparing the Missouri Gravel Bed and a Wood Chip Production Method for Tree Growth

Abstract

Tree root defects from current nursery production practices influence short- and long-term tree performance and survivability. The Missouri Gravel Bed (MGB) system, a production method using gravel as a substrate, has been used to prevent many of these defects from occurring. MGB production involves planting bare root stock into a bed of gravel with frequent drip irrigation in order to produce a root system with relatively few defects. MGB production methods have also been purported to allow for summer transplanting of many species, as opposed to traditional dormant transplanting.Because gravel has low water- and nutrient-holding capacity, biochar (5% by volume) was incorporated into one plot as a possible means of improving both water- and nutrient-holding capacity over gravel alone. Wood chip mulch was also investigated as a growing substrate in place of the gravel in a growing system. In 2015, three species, Quercus bicolor (swamp white oak), Taxodium distichum (baldcypress), and Tilia cordata (littleleaf linden), were studied in pea gravel (PG), biochar-amended pea gravel (BC), and wood chip mulch bed (MB) growing environments. Very few differences occurred over the growing season with above- or belowground parameters indicating that the minimal-to-no-cost, more readily available substrate of wood chip mulch should be considered in these growing systems.

The Influence of Biochar Soil Amendment on Tree Growth and Soil Quality: A Review for the Arboricultural Industry

“…Water content at field capacity in the sandy soil resulting from the addition of biochar could explain the increased growth response in the Coral gum-treated trees. When incorporating pine waste biochar to improve root regeneration, significantly higher root biomass was observed when planting Small-leaved lime (Tilia cordata) in late Spring (Fite et al, 2019). Total above and below-ground biomass production and foliar magnesium (Mg) concentrations of peach trees were significantly higher following biochar amendment at all harvesting dates compared to control trees (Atucha and Litus, 2015).…”