SO HARNESSING THE EARTHWORM 



riously reducing the fertility of the topsoil for immediate crop- 

 ping. When subsoils are brought to the surface, especially from 

 depths ranging from eighteen inches to two feet downward, they 

 should be "weathered" for months and mixed sparingly into the 

 topsoil before they become fully available for best results. How- 

 ever, in the translocation of the subsoil by earthworms, the neces- 

 sity for leaving the land fallow for months of weathering is 

 avoided. The soil undergoes the necessary changes in the ali- 

 mentary canals of the earthworms, preparing it, as has been 

 stated, for immediate use. 



The earthworms do not simply swallow the subsoil, bring it 

 to the surface and deposit it. It is thoroughly mixed with the 

 surface topsoil, so that the whole becomes one uniform, homo- 

 genized layer. To determine, as well as to illustrate, the mixing 

 action of earthworms, we prepared a culture box of carefully 

 stratified layers of materials. Layers of granulated peat moss, 

 mixed horse manure, rabbit manure, and chicken manure, with 

 layers of good topsoil, were alternated. We then added several 

 hundred earthworms on top of the stratified compost, allowing 

 them to burrow down into the mix. After four months, we 

 dumped the box for examination. We found no sign of stratifica- 

 tion, the entire contents of the box having been converted into 

 one homogenized mixture of fine, crumbly soil. 



In our lath house, where we had established our experi- 

 mental culture beds, great numbers of earthworms had burrowed 

 into the earth from the culture boxes and other beds. We were 

 using an old cement mixing box for compost mixing. This box 

 is about five feet long, thirty inches wide and twelve inches deep, 

 with a galvanized iron bottom that had finally rusted into many 

 holes. This box had been filled with rabbit manure and thor- 

 oughly wet down, preparatory to mixing the earthworm compost. 

 However, we had neglected the task of mixing compost for a 

 period of several weeks. Upon examination of the manure, we 

 found that many earthworms had moved into the box from the 

 damp earth beneath it and were producing many egg-capsules. 



