The same is true with reference to home supplies. Very few vegetables are grown for the table and there is little milk, butter or eggs for home use or exchange for groceries or drygoods at the store.
Thus we see that the continuous growing of cotton on the soil, year after year, has a bad effect on conditions necessary to its best growth and development and also on the economics of the farm.
These facts are true to a greater or less degree in the case of nearly all of the farm crops. The grain crops are often considered as humus makers because of the stubble turned under, but Professor Snyder, of Minnesota, found that five years' continuous culture of wheat resulted in an annual loss of 171 pounds of nitrogen per acre, of which only 24.5 was taken by the crop, the remaining 146.5 pounds were lost through a waste of organic matter.
THE ROTATION OF CROPS
Now, suppose that instead of growing cotton on the same soil year after year, we select four crops—cotton, corn, oats and cowpea—and grow them in regular order, a rotation practiced in some parts of the South.
We will divide the farm into three fields and number them 1, 2 and 3, and will plant these crops as indicated by the following diagrams:
Plan of farm.
Plan for planting.