COTTON 
121 
diminutive returns in seed and lint. By a de- 
ficiency is meant, in this case, an insufficient 
amount of plant food available for the use of the 
plants. 
Really, as we have already seen, there is no such 
thing as worn-out cotton soils. There are poor 
cotton soils, unproductive cotton soils, infertile cot- 
ton soils, but they are so because of improper man- 
agement; because the humus has been destroyed; 
shallow plowing has been followed; plant food has 
been lost or locked up. 
Tillage and humus — and these alone — unlock 
the door to this treasure-house of old Mother 
Earth. The addition of nitrogen, phosphorus and 
potassium in chemical forms is only a temporary 
arrangement to make better crops for the time 
being. No permanent improvement of the soil will 
result unless tillage and an abundant amount of 
humus become the basis of such improvement. 
Chemical fertilizers are to be used, therefore, as 
supplementary helps, rather than as primary con- 
ditions. 
We are now ready to consider the feeding de- 
mands of the cotton plant in reference to the forms 
of plant food usually purchased — nitrogen, phos- 
phorus, and potassium. 
But first, let us divide the cotton plant into its 
parts that we may clearly know the relative quan- 
tities of each. 
PARTS OF AN AVERAGE COTTON PLANT 
Part Per cent. 
Roots 8.80 
Lint. . . . 10.56 
Bolls 14.21 
Leaves 20.25 
