Transmissible Effects of a Biochar Amendment to an Upper Soil Zone Upon an Associated Lower Zone, Including Attenuation of Soybean Cyst Nematode (Heterodera glycines)

Mung bean residues stimulate the hatching of soybean cyst nematode (SCN). In our previous study, combined incorporation mung and biochar into soil can be effective in suppression (SCN), Heterodera glycines, upper layer soil. However, there are no data available as to whether such effects transmissible, could for example manifest subsoil zones where is confined topsoils, via water-based pathways. We evaluated leachate passage from a biochar-amended an zone lower microcosm-based system, upon range physicochemical properties density SCN. Disturbed was filled total 9 cylindrical cores with two layers. The (0–15 cm) amended at rates equivalent 0, 0.3% or 1.8%, bulk set 1.1 g cm−3. (15–25 without amendment compacted 1.2 beans were grown weeks incorporated layer. Water surface-applied 4, 6, 8 after incorporation. After 16 weeks, soils separately collected assayed. presence reduced abundance free-living nematodes, mainly bacterivorous, but increased that predator genus Ecumenicus this zone. under layer, P soluble cations abundances nematodes including Ecumenicus, resulting greater maturity index, basal structure indices. Notably, SCN decreased by more than 90% compared zero-biochar controls. This demonstrates properties, impacts on biota plant pathogens, transmissible.