SOIL MANAGEMENT 53 



clay is neither too wet nor too dry to work to advantage.' 

 If handled when too wet it puddles or runs together; if too 

 dry, it forms clods. In either case the harmful effects may 

 extend over a period of several years. It is therefore a serious 

 matter to decide just when to plow or work such soils. A 

 good deal of experience is necessary in order to recognize 

 the right time. Even then it is not always possible to do the 

 work at the time when it is most needed. The successful 

 handling of clay soils depends upon using the period in which 

 they can be safely worked. 



How clay may be made easier to work. - The fact that 

 clay becomes sticky when wet and hard when dry is due 

 largely to its very fine particles. If these particles can in 

 some way be brought together into small groups or granules, 

 the clay will lose to some extent, these objectionable features 

 and may be much more easily handled. Furthermore, when 

 it is in a granular condition, it is easier for roots to penetrate 

 it, and it will also retain most of its water-holding power. 



A granular condition of clay may be brought about by the 

 addition of lime or finely-ground limestone. In some way 

 lime causes the fine particles of clay to mass together into 

 small granules. The effect of lime on clay may be illustrated 

 by making one ball of wet clay and another of clay mixed 

 with a small quantity of lime. When both balls are dry, 

 it will be found that the one mixed with lime will break more 

 easily than the one made of pure clay. 



Another method of improving clay soils and making them 

 easier to handle is by applying coarse organic matter, such 

 as straw or coarse manure, or by growing plants having large 

 root systems. When either material is thoroughly mixed 

 with the soil by plowing and disking, it tends to separate 

 the fine particles and produce granulation. 



