THE CAMPBELL SYSTEM 



more, the old idea of allowing the weeds 

 to grow in order to be turned under for 

 green manure, as commonly practised by 

 the summer-fallow system, is condemned 

 by Campbell, who lays special stress on 

 clean and continuous tillage for the con- 

 servation of moisture. His experiments 

 clearly show the marked difference in 

 yield between ground that has been sum- 

 mer tilled and land which has had its soil 

 moisture sapped to such a degree by 

 growing weeds that it breaks up on 

 plowing into a lumpy condition, and 

 cannot be made into a moist, mellow, seed- 

 bed. Mr. Campbell lays emphasis on the 

 need of local experience. He says : "The 

 mistake of the pioneer settlers was that 

 they tried to farm in the West as they 

 had done in the East, and the result was 

 disastrous failure." But he also insists 

 on the value of learning. "The ideal 

 farmer is first of all a student, then an 

 161 



