Agriculture Reference
In-Depth Information
10
Quantifying the Effects of
Earthworms on Soil
Aggregation and Porosity
Martin J. Shipitalo
North Appalachian Experimental Watershed, U.S. Department of Agriculture,
Agricultural Research Service, Coshocton, Ohio, U.S.A.
Reneé-Claire Le Bayon
Department of Plant Ecology, Neuchâtel University, Neuchâtel, Switzerland
CONTENTS
Stabilization of Aggregates in Casts: Physical, Chemical,
INTRODUCTION
The potential for earthworms to improve soil aggregation and porosity and the subsequent effects
of these changes in soil structure on plant growth and soil hydrology were perhaps first recognized
by Gilbert White in 1777 when he wrote Ñworms seem to be great promoters of vegetation, which
would proceed but lamely without them; by boring, perforating, and loosening the soil, and
rendering it pervious to rains and the fibres of plants; by drawing straws and stalks of leaves and
twigs into it; and, most of all, by throwing up such infinite numbers of lumps of earth called worm-
casts, which, being their excrement, is a fine manure for grain and grassÒ (White 1789). Before
these observations, earthworms were often regarded as pests by farmers and detrimental to crop
growth.
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