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 temperatures 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, IA. 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°C were fatal to L. terrestris after 14 d and 25°C 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°C and at 30% soil moisture content for these Iowa soils.