THE INTENSIVE PRODUCTION OF LUMBRICUS-TERRESTRIS L FOR SOIL AMELIORATION

The benefits of earthworm inoculation in improving soil conditions are now well established. The main problem with this technique is that it is difficult to obtain large numbers of the most appropriate species at an economic price. At present, the only way of obtaining earthworms for soil improvement is from large scale field collection and this is laborious and expensive. Research at the Open University aims to overcome these problems by investigating ways of intensively producing Lumbricus terrestris. This paper identifies the key variables in the process and presents experimental evidence that L. terrestris can grow and reproduce all year round. Initial results indicate that by optimising the key variables of temperature and nutrition this species can be grown from cocoon to sexual maturity in less than half the time taken in the field. Furthermore, the rate of reproduction can be increased to twice the maximum rate reported by other researchers, even when the earthworms are kept at densities much higher than found in the field. It is concluded that continuous, intensive production of L. terrestris is possible and that this method of supplying earthworms for soil improvement has many advantages compared to field collection.