Draft ring of plow, 93.

Draining, need of, 235.

Drains, 158-239.
and capillary water, 237.
covered, 237.

Drains, effect on film water, 237.
effect on plant food, 238.
effect on soil temperature, 238.
effect on soil water, 237.
grade of, 239.
lateral, 239.
location of, 238.
main, 239.
open ditch, 237.
surface, 237.
tile, 239.

Dried blood, 194.
as a fertilizer, 194.
nitrogen in, 194.


Early crops, soils for, 27, 28.

Egg experiments to show osmose, 18, 19.

Egg plant, soil for, 28.