292 



SOILS AND FERTILIZERS 



been inverted, subsequent harrowing and cultivation fail 

 to pulverize and loosen the tough sod in the lower part 

 of the furrow slice. A good seed bed cannot be made 

 upon such a foundation. When the land is plowed so 

 the furrow slice is left at an angle of 30 to 45, the sur- 



FlG. 47. Complete Inversion of the Furrow Slice (after Roberts) . A poor way 



of plowing sod land. 



face is corrugated and all vegetation is buried in loose 

 soil. When land that has been plowed in this way is 

 cultivated and harrowed, a better seed bed is formed 

 than is possible on a completely inverted furrow slice. 



The plowing should thoroughly pulverize the soil, 

 completely bury all surface vegetation, and leave the 

 land in a corrugated condition with the furrow slice at 



