Superphosphates, 198.

Swamp muck, 30.

Sweet clover, 190.

Sweet potato roots, 13.
soils, 28, 160.

Sweet potatoes, 5.

Sylvinite, 199.

Systems of cropping, 119.


Tankage, 194.
as fertilizer, 194.
nitrogen in, 194.
phosphoric acid in, 194.

Temperature of soil, 57.

Tendrils, plants climb by, 122.

Testing seeds, 75.

Testing soils for water, 162.
for plant food, 215.