258 CROP PRODUCTION 



Improving Clay Soils 



In many parts of the United States clay soils predomi- 

 nate in a large proportion of the farms. Such soils are 

 likely to be so firmly compacted that crops do not thrive. 

 This is because the particles which make up the soil are 

 in so finely powdered condition that they collect together, 

 prevent the easy growth of roots, retain moisture in wet 

 weather, and bake solid in dry weather. To remedy 

 this condition it is necessary to treat the soil by such 

 methods as will either change its texture or increase the 

 size of the spaces between the soil particles. 



One of the most effective ways of improving a clay 

 soil is by a thorough system of drainage. This permits 

 the surplus water to run away rapidly, thus allowing the 

 air freer access from above. It is likely to decrease 

 the injury from surface baking in dry weather, and 

 enables the owner to till the soil oftener and to secure 

 better results by means of such tillage. 



Frequent tillage when a clay soil is in a proper condi- 

 tion to work is very helpful in improving its texture. 

 It breaks up the large lumps and greatly increases the 

 amount of air between the soil particles, thus enabling 

 the root hairs to penetrate more freely and the various 

 micro-organisms in the soil to work more effectively. 



It is very injurious, however, to plow, spade, or even hoe 

 a clay soil when it is too wet. Such treatment compacts 

 the soil particles so firmly that they harden into solid 

 clumps which plant roots are not able to penetrate. 

 When a clay soil is too dry, tillage can be done only 

 under great disadvantage, as the operation becomes 

 very difficult, and the soil is likely to separate into large 

 lumps which are hard to pulverize. 



