KINDS OF SOIL 57 



On the other hand, clay soils are usually rich in 

 plant food, especially in potash. Plants onc$ 

 established in them, particularly deep-rooting 

 plants, are carried ahead vigorously. The farm 

 crops that succeed most generally on clay soils are 

 the cereals, grasses and some tree fruits, notably 

 the apple, pear and plum. Clay land is especially 

 valuable for hay. 



The treatment of a clay soil should be that which 

 will remedy its chief defect heaviness. Under- 

 drainage will do much to accomplish this result. 

 Underdrainage removes the surplus water in a dry 

 time and promotes aeration and warmth in these 

 soils, many of which are sadly deficient in these 

 respects. The fine particles of clay may be 

 separated from each other and the soil loosened 

 and lightened by mixing them with particles of 

 humus or sand. Barnyard manure or a green 

 manure crop will lighten a heavy clay soil, 

 as well as give body to a light sandy soil. Man- 

 ures applied to clay soils in the fall lose but 

 little of their plant food by leaching. It is 

 rarely practicable to haul sand upon a clay soil and 

 plow it under, because of the expense, but if this 

 can be done expediently the result will be gratifying. 

 It often happens that a muck bed, marking the 

 place where a small swamp formerly existed, is 

 adjacent to clay land. Three or four inches of 

 muck spread upon clay soil is of immediate and 

 lasting benefit. 



Extreme caution should be used in plowing and 

 tilling clay soils. If plowed when too wet they 

 become cloddy. There is a certain point between 

 wetness and dryness when a clay soil crumbles 

 quite readily; it should be tilled only at this time, 

 so far as is possible. The texture of a clay soil 



