112 COTTON 
Why is this true? 
Because it does the following things: 
1. It injures the texture of the soil by making 
light soils loose and open, and heavy soils dead and 
lifeless. 
2. It destroys the humus of the soil; and no 
soil can remain fertile if it contains little or no 
organic matter. 
3. It influences unfavorably the water content 
of the soil: light sandy soils with little vegetable 
matter are loose and open, and_ soon lose the 
moisture in them; heavy clay soils robbed of their 
vegetable matter quickly dry out and bake. 
4. It influences unfavorably the amount of 
available plant food in the soil. Vegetable matter 
itself contains plant food and when used up, with 
no additional amount to replace it, the loss is soon 
felt. Plant food is lost also by leaching away in 
loose soils or by becoming insoluble in stiff heavy 
lands. 
5. It draws too constantly on that special ratio 
of fertilizing ingredients most needed by the cotton 
plant. A crop following after one requiringasome- 
what different proportion of nitrogen, potash and 
phosphoric acid, does much to restore the proper 
‘ balance required for the most profitable cotton 
production. 
Continuous culture of cotton on any land, then, 
is undesirable. Its harmful influence may be over- 
come only by a system that involves a change of 
crops. 
Such a change of crops is suggested by nature 
herself. Cut a forest growth and a change of trees 
comes on. Pasture lands give way to many weeds 
and thistles; bluegrass and Bermuda drive out the 
clovers and timothy. Crops do better when fur- 
