40 SOILS AND PLANT LIFE 



group, add enough water to make the soil sticky. To the 

 third group, add water until the whole is a saturated mass. 

 In this case, the clay, the silt, and the sand, of which the 

 different pies are made should be thoroughly worked in 

 your hands. Set the pies in the oven or on the back of 

 the stove to bake. 



Conclusion. — After baking, crumble each pie care- 

 fully in your hands, making note of how hard each one 

 is to crush. Would you say that plowing or trampling a 

 sandy soil would puddle it as much as it would a clay 

 soil? Would it puddle a silt soil as readily as a clay 

 soil? What effect would the addition of organic matter 

 have on each of these soils? 



27. Covering, or Working into the Soil, Organic Matter. 

 — As already stated, the second object of tillage is to 

 cover or work into the soil any organic matter which may 

 be on the surface. This may be accomplished by using 

 the plow or disc. 



With the plow, a narrow strip of land is turned up, 

 twisted over and laid bottom side up. Where there is 

 any great amount of trash or straw on the ground, a roll- 

 ing cutter, or coulter, as it is called, is used. This rolling 

 knife cuts through the trash so that it can not gather, and 

 Uft or clog the plow. 



If tall weeds, green manuring crops, or any other plants 

 are plowed under, some means must be employed to 

 draw them down to the bottom of the furrow, allowing 

 the dirt to cover them completely. A chain or a bent 

 rod is commonly used to draw the heavy plant growth 

 under the overturning furrow slice. 



28. Putting Seed into the Seed Bed. — The operation 

 of seeding will be studied again in connection with certain 



