f
tobacco, etc.

The demand for crops and their market value.

Facilities for getting crops to market, good or bad country roads,
railroads and water transportation.

The state of the land with respect to weeds, insect pests and plant
diseases.

GENERAL RULES

A few general rules may be made use of in arranging the order of the
crops in the rotation though they cannot always be strictly followed.

Crops that require the elements of plant food in the same proportion
should not follow each other.

Deep-rooted crops should alternate with shallow-rooted crops.

Humus makers should alternate with humus wasters.

Every well arranged rotation should have at least one crop grown for
its manurial effect on the soil, as a crop of cowpeas, or one of
clover, to be turned under.

The objection often made to this last rule is that, aside from the
increase in fertility, there is no direct return for the time, labor
and seed, and the land brings no crop for a year. It is not necessary
to use the entire crop for green manuring--a part of it may be used
for hay or for pasture with little loss of the manurial value of the
crop, provided the manure from that part of the crop taken off is
returned and the part of the crop not removed is turned under.

LENGTH OF THE ROTATION

The length of the rotation may vary from a two-course or two crop
rotation to one of several courses. Crimson clover may be alternated
with corn, both crops being grown within a year.

A three-course rotation, popular in some parts of the country, is
wheat, clover, and potatoes; potatoes being the money crop and
cleansing crop, wheat a secondary money crop or feeding crop, and
clover the manurial and feeding crop.

A popular four-course rotation is corn, potatoes or truck, small
grain, clover; the potatoes being the chief money crop, corn the
feeding crop, the small grain the secondary money or feeding crop, and
clover the manurial and feeding crop.

On many New England farms near towns, hay and straw are the chief
money crops. Here the rotation is grass two or more years, then a
cleansing crop and a grain crop. A Canadian rotation is wheat, hay,
pasture, oats, peas. A rotation for the South might be corn, crimson
clover, cotton, crimson clover; this rotation covering a period of two
years. A South Carolina rotation is oats, peas, cotton, corn--a
three-year rotation. It might be improved as follows: Oats, peas,
crimson clover, cotton, crimson cl