KINDS OF SOILS— THEIR CHARACTERISTICS 55 



work up well." They are usually not too wet nor too dry. 

 They do not bake and crack so badly as the heavy clay soils 

 do. Clods are less hkely to form. They hold moisture better 

 than light sandy soils. Corn, cotton, potatoes, fruits, vege- 

 tables, grains, and grasses all do well on the medium loams. 

 Texture of Soil. — The texture of soil is determined by the 

 size and shape of the particles of which it is composed and 

 the way in which these particles are grouped in kernels or 

 crumbs or larger masses. The texture determines to a large 



Fig. 31. — Soils of different texture. The coarse or open te.xture may be improved 

 by tillage and by packing with roller or planker. 



extent the agricultural value of soil (Fig. 31). It is a fac- 

 tor to consider when studying the composition of soil, as it 

 determines largely the capacity of soil to retain such foods as 

 may become available for plants. 



Soil such as sand is open in texture and freely admits 

 water, which quickly passes downward, carrying soil fertil- 

 ity with it. Open soil is more hkely to lose its plant food 

 than a soil that is fairly close in texture. Clay loams, in re- 

 taining water, also retain their plant-food better. We call 

 them close in texture. An open texture also allows too rapid 

 decay of vegetable matter. On the other hand, a very com- 

 pact soil such as clay is undesirable. When there is rain it 

 puddles, and neither air nor water can enter and circulate. 



