Geoderma, 46 (1990) 73-84 73 Elsevier Science Publishers B.V., Amsterdam -- Printed in The Netherlands Effect of Lumbricus Terrestris L. Burrows on Hydrology of Continuous No-Till Corn Fields W.M. EDWARDS 1, M.J. SHIPITALO', L.B. OWENS' and L.D. NORTON 2 1 United States Department of Agriculture, Agricultural Research Service, Coshocton, OH 43812 (U.S.A.) 2United States Department of Agriculture, Agricultural Research Service, West Lafayette, IN 47907 (U.S.A.) (Received May 29, 1989; accepted after revision August 25, 1989) ABSTRACT Edwards, W.M., Shipitalo, M.J., Owens, L.B. and Norton, L.D., 1990. Effect of Lumbricus ter- restris L. burrows on hydrology of continuous no-tiU corn fields. Geoderma, 46: 73-84. This paper reviews research performed at the USDA-Agricultural Research Service, North Ap- palachian Experimental Watershed, Coshocton, Ohio into the importance of earthworm burrows, primarily those made by Lumbricus terrestris L., on the hydrology of no-till corn fields.Long- term runoff records showed that infiltrationand therefore, potential ground water recharge, could increase by more than 100 mm yr-' in watersheds farmed with no-tillpractices as compared to similar fieldsthat were conventionally tilled.T h e difference in hydrologic response appeared to be due to differences in soilphysical properties, possibly those attributable to earthworm activity. When crop residues were lefton the surface under continuous no-tillcorn management, earth- worms thrived and their large, nearly vertical burrows persisted. Field studies showed that dye and chemical tracers applied in simulated rainfallmoved in the earthworm burrows. The number and sizes of burrows and other macropores were determined and water and nitrate movement in > 5 m m diameter burrows were measured. Flow in these earthworm burrows during 12 growing season storms accounted for an average of 4% of rainfall, (range 1-10%) or 13 times more than would be predicted based solely on their cross-sectional area. Total movement of nitrate in the burrows during these 12 storms was estimated to be < 1 kg ha- i. BACKGROUND At the USDA-ARS North Appalachian Experimental Watershed near Cosh- octon, Ohio, small, gaged watersheds have been used for 50 years to evaluate the effects of management on infiltration, runoff and erosion from sloping residual soils of the unglaciated uplands of the Allegheny Plateau. Some of the first studies conducted revealed that intense, summer storms produce surface crusts on conventionally tilled top soils that reduce infiltration, thereby in- creasing runoff and erosion. Similar storms on the same watersheds in years 0016-7061/90/$03.50 © 1990 Elsevier Science Publishers B.V.