TYPES OF FARMING 



319 



Fig. 211. — " Hungry soil.'* Sand. To' left, unfertilized. Yield of potatoes, thirteen 

 bushels per acre. Yield of corn, three bushels per acre. (Wisconsin Station.) 



Fia. 212. — Profitable sand. Corn on7clover sod, manured. (Wisconsin Station.) 



are easy to build and dairy cows will turn into profit large quanti- 

 ties of roughage that can be produced so readily on sands. Further- 

 more, the manure produced can be used to good advantage in soil 

 improvement (contrast Figures 211 and 212). An extra silo for 



