Temperature and soil. moisture content effects on the growth of Lumbricus terrestris (Oligochaeta: Lumbricidae) under laboratory conditions

The growth of Lumbricus terrestris was determined under varying temperature and soil moisture contents under laboratory conditions Our objective was to identify the optimum soil moisture or temperature that would aid in the reproduction of L. terrestris for inoculations in areas devoid of this species. A laboratory experiment using different growth chambers for temperature control with varying soil moisture contents was conducted at the National Soil Tilth Laboratory in Ames, LA. Five temperatures, three different soil moisture contents, and horse manure as a food source were selected and replicated 10 times. It was found that 30 degreesC were fatal to L. terrestris after 14 d and 25 degreesC after 182 d. Regardless of temperature, worms reared under high soil moisture content (30%) developed faster and increased in mass than those reared at 20 or 25% soil moisture content over 266 d. Optimum temperature and soil moisture content for mass rearing of L. terrestris was identified at 20 degreesC and at 30% soil moisture content for these Iowa soils. (C) 2001 Elsevier Science Ltd. All rights reserved.