CHAPTER XV. 
cotton unique: a self-supporting crop 
Cotton, like other plants, gets its food for life 
and growth from the soil, the water, and the air. 
Strange as it may seem on first blush, it is from air 
and from water that all plants are chiefly derived. 
From the air carbon enters the leaves and there 
forms the so-called carbonaceous matter of the 
plant. Cotton lint is pure cellulose, a material 
made from the carbonic acid of the air. From the 
air, too, comes a large part of the oxygen which, 
next to carbon, is the predominant constituent of 
the dry matter in the cotton plant, as well as in 
other plants. Other elements found in cotton are 
hydrogen, nitrogen, sulphur, calcium, sodium, 
magnesium, chlorine, iron, aluminum, potassium, 
phosphorus, and silicon. 
what is a fertile soil? 
A fertile cotton soil must contain all the elements 
of plant food in sufficient quantities and in available 
form to produce productive crops. As a rule, the 
soil elements are present in sufficient quantities to 
produce paying crops. Nitrogen, phosphorus and 
potassium, however, may be deficient, and if so, 
must be added through other means, or the crop 
will manifest its loss by making small growth and 
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