14 



Campbell's 1902 Soil Culture Manual. 



In cut No. 1, we illustrate the common condition of ordinary plowed 

 fields. Note carefully the appearance underneath the portion of the fur- 

 row that has been thrown over by the mouldboard on to the side of the 

 next furrow. Here is the stubble, weeds, and clods that have rolled from 

 the next furrow, while right at the point where the furrow is tipped over 

 thesoil is firm from the bottom up. The usual manner of further fitting 

 thisjground is by the use of the harrow. This has a tendency to level, and, if 

 shallow plowed, to work the ground down fairly w^ell at the bottom of the 

 plowing, but in deep plowing, of five or more inches, the harrow has but 

 little effect upon these cavities underneath. This is a very serious propo- 



Cut No. 2. 



sition, and it is the source of many bad conditions, which have a direct 

 effect upon the final yield of the crops. First of all, it cuts off the seed or 

 root bed from the sub-soil below; thus preventing the movement of any 

 moisture from the sub-soil up into the root bed. It also forms air spaces 

 or cavities where a volume of air may exist, which aids in drying out the 

 soil immediately adjacent. It also prevents the lateral roots and feeders 

 from extending and permeating this portion of the soil, thus leaving a 

 large per cent, of our surface soil in a condition not at all beneficial to the 

 growing crop. 



In cut No. 2, we show the cross-section of the same two furrows 

 shown in cut No. 1. Here the cavities and loose condition of the soil at 



