Key Technical Points for Mixed Culture of Snails and Earthworms

In order to improve the economic benefits and biological conversion of snail farming, many places are now adopting the method of mixed culture of snails and earthworms. Using this rearing method can increase the production of both earthworms and snails at the same time. This is because the excrement of the giant African snail (Achatina fulica) is rich in organic matter and can serve as excellent food for earthworms. According to calculations, an adult snail weighing 32.75 grams on average excretes about 1.5 grams of droppings within 1 day, while a young snail weighing 0.45 grams excretes about 0.09 grams of droppings within 1 day. After adopting mixed culture, not only are the organic matter and food residues in the snail excrement fully utilized, but the weekly work of cleaning and sweeping the excrement from the boxes and pools can also be eliminated.

In addition, tests in Guangdong and other places have shown that although the giant African snail can feed on dead earthworms, when feed is sufficient it will not attack earthworms living in the soil, and there is no phenomenon of mutual killing between the two. During the mixed culture process, both grow and reproduce fairly normally, and the snails grow better than those fed alone.

The ratio for mixed culture of the giant African snail and earthworms should be such that the earthworms introduced can basically clear and digest the snail excrement, and both grow fairly normally. When mixing, the amount introduced can be calculated by weight; generally the introduction ratio of snails to earthworms is 11:1 to 15:1. At the beginning of rearing, the number of earthworms introduced can be somewhat smaller. Because during the mixed culture process, the earthworms will also grow and reproduce, so during the rearing process the growth and reproduction of the snails and earthworms should be observed and the ratio adjusted at any time. If too much earthworm excrement is found, some earthworms can be removed and some new soil replaced. Recently, some farmers have also carried out comprehensive farming on the basis of mixed culture of earthworms and snails. That is, the residue left after cultivating mushrooms is used as earthworm feed to raise earthworms, and then snails are raised on the feed bed used for raising earthworms. The snail excrement and leftover food residues are in turn feed for the earthworms, and the earthworm excrement in turn becomes high-quality organic fertilizer for crops and flowers. In this way, mushrooms—earthworms—snails—crops and flowers form a small cycle of comprehensive biological utilization, which can further improve economic benefits.