The Soil: Its Use and Abuse 



1363 



method of determining this point is by trying different fertilizer materials 

 on plots of the soil in the field. 



OBJECTS OF tillage 



A crop enjoys good quarters as much as does a cow or a man. Good 

 quarters for the plant means good physical condition of the soil, good 

 tihh. Good physical condition rests upon two things: the texture, or 

 fineness, of the soil, and the structure, or state of aggregation. A sand 



Fig. II. — A heavy soil in bad tilth due to lunvise handling. Tramping or plowing when 

 too wet is generally the cause of this condition. A poor place Jor plant growth 



or gravel soil has a coarse, open texture that may be so porous as to be 

 leachy and not hold enough water for crop use. A clay soil is fine tex- 

 tured and may be too compact and hard. The farmer cannot change the 

 texture of the soil. He must make the best of it. 



But the farmer can do good work in changing the structure of the soil. 

 One cannot greatly alter the structure of sand and gravel soils. The 

 chief aim in their tillage is to maintain as compact a structure as pos- 

 sible, and to keep a thin surface mulch. Clay soil, on the other hand, 

 is troublesome because of the bad structure it tends to assume. It will 

 puddle, bake, and then break up in great clods. In this condition it is 



