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MINING PHOSPHATE NEAR COLUMBIA, TENN.

Farming is no longer a haphazard business. It is now a high-class science as well as a fine art. When the land was new, it was not necessary to pay so much attention to its fertility. Crop after crop of the same kind was planted in the same field, year after year. After a while the richest land became poor. The same substances had been drawn from the soil so often there was not enough left to grow even fair crops. This happened in the South, and in the East. Farms were given up as too poor to be profitable.

Now we know how to overcome this difficulty in farming. One way is by rotating crops, the other is by direct fertilization. Both methods worked together will build up the poorest soil. By rotating crops, we mean, for example, raising corn in a field one year, oats the next year, and clover the next. Each crop takes a different substance from the ground. Some crops add fer-

Lat. 37° N.; Long. 85° W.

stility. A good rotation will improve the soil.

Direct fertilization is putting manures of various kinds in the soil. These manures may be the droppings of animals, ground bone, offal, or minerals. A study of the soils of every farm should be made to find out what the proper fertilizer is. Sometimes, for instance, lime is needed most.

Phosphates are extensively used as fertilizers. Phosphates are formed about decayed organic bodies in layers of rocks. In Tennessee the phosphate deposit is in limestone. Beds of this mineral are found in many places in the South, especially in Florida, South Carolina, Kentucky and Tennessee. Here you see how phosphate is dug out and loaded on cars. These cars are run to a nearby factory, where the mined material is manufactured into fertilizer.

*Explain rotation of crops.*

Copyright by The Keystone View Company.

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