Agriculture Reference
In-Depth Information
8
Effects of Earthworms on Soil
Organic Matter and Nutrient
Dynamics at a Landscape Scale
over Decades
Patrick Lavelle,
1
Fabienne Charpentier,
1
Cécile Villenave,
1
Jean-Pierre Rossi,
1
Laurent Derouard,
1
Beto Pashanasi,
2
Jean Andre,
3
Jean-François Ponge,
4
and Nicolas Bernier
4
Laboratoire d'Ecologie des Sols Tropicaux,
Bondy Cedex, France;
1
Estacion Experimental San Ramon, INIAA, Yurimaguas, Loreto, Peru;
2
Université de Savoie, France;
MNHN, Brunoy, France
3
4
CONTENTS
Medium-Term Effects: Experiments Inoculating Earthworms into Cropping
Long-Term Effects of Earthworms: Modeling and Observation of
After several decades of unquestioned success, agriculture is now facing important global problems.
Huge increases in productivity in developed countries have been accompanied by a severe depletion
of Ñsoil qualityÒ in terms of resistance to erosion, organic contents, concentrations of heavy metals,
and pesticide residues. Agricultural intensification in developing countries has been less successful
because of various socioeconomic limitations. Nevertheless, traditional agricultural practices do not
conserve the quality of soils; stocks of organic matter are rapidly becoming depleted, and erosion
removes fine particles from the soil surface horizons. In a context of increasing human population
pressures, particularly in developing countries, this degradation of soils results in many social and
environmental problems (Eswaran 1994; FAO 2000). Features common to all kinds of soil degradation
are a significant decrease in organic reserves, degradation of the soil structure, and severe depletion of
soil invertebrate communities, especially earthworms (Decans et al. 1994; Lavelle et al. 1994).
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