364 DRY-FARMING 
face packing, are sound and in harmony with the 
experience of the great dry-farm sections and with 
the principles that are being developed by scientific 
investigation. The ‘‘Campbell system”’ as it stands 
to-day is not the system first advocated by him. 
For instance, in the beginning of his work he advo- 
cated sowing grain in April and in rows so far apart 
that spring tooth harrows could be used for culti- 
vating between the rows. This method, though 
successful in conserving moisture, is too expensive 
and is therefore superseded by the present methods. 
Moreover, his farm paper of 1896, containing a full 
statement of the ‘‘Campbell method,” makes abso- 
lutely no mention of ‘summer tillage,” which is 
now the very keystone of the system. These and 
other facts make it evident that Mr. Campbell has 
very properly modified his methods to harmonize . 
with the best experience, but also invalidate the 
claim that he is the author of the dry-farm system. 
A weakness of the ‘‘Campbell system”’ is the contin- 
ual insistence upon the use of the subsurface packer. 
As has already been shown, subsurface packing is of 
questionable value for successful crop production, 
and if valuable, the results may be much more easily 
and successfully obtained by the use of the disk and 
harrow and other similar implements now on the 
market. Perhaps the one great weakness in the 
work of Campbell is that he has not explained the 
principles underlying his practices. His publica- 
