Bio-Drilling, Compaction Alleviation, and Fate of Stormwater Management

Compaction due to urbanization and farm operations disrupt natural soil profiles, increase impervious surface areas, and decrease vegetative cover. These disruptions increase storm-water runoff at the expense of ground water recharge, degrading water quality, and impairing aquatic habitats. A completely randomized experiment was conducted at the OSU/South Centers, Piketon, OH, to assess the effect of Daikon radish (Raphanus sativus, L. var. oleiferus) on alleviating compaction. Treatments included long-term tillage, long-term no-till, and a fallow soil compacted with farm equipment with and without Daikon radish. Radish was sown in mid-August and plants were winter-killed at the onset of first frost when the temperature dropped to -2.22°C (28°F). To assess progress in compaction alleviation, a model was developed to extrapolate information on soil porosity as an indicator of hydrological properties of soils. Earthworm population dynamics were also considered as a bio-indicator of compaction alleviation. The adoption of radish, used as bio-drilling, alleviated overall compaction by 40% with reductions ranging from 90% at 0–13 cm to 30% at 56–64 cm depth. The fallow compacted soil with radish had the highest population of earthworm with total body mass of 3.6 kg m^-3, followed by NT at 0.8 kg m^-3, and till at 0.4 kg m^-3 (p <0.05). Mean values of soil porosity were increased by 44% with radish compared to the fields without radish. This increase ranged from 71% in the upper soil depths (0–13 cm depth) to 25% in the lower depths (56–64 cm depths). Use of bio-drilling has potential to synergistically alleviate the effect of compaction, minimize flash-flooding, and improve water quality.