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

Abstract

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.