ons they will suffice to keep it
amply supplied for ordinary production. Because of this it is usually
considered more profitable to cut both the crops which medium red clover
produces in one season, or to pasture off one or both, than to plow
under either as green manure. But when soils are too stiff or too open
in character it may be advantageous to bury clover to restore the
equilibrium. It may also be necessary to bury an occasional crop in
order to put the land quickly in a condition to produce some desired
crop, the growth of which calls for large supplies of humus. When clover
is plowed under it will usually be found more profitable to bury the
second growth of the season than the first. The crop is in the best
condition for being plowed under when the plants are coming into bloom.
If left until the stems lose their succulence the slow decay following
in conjunction with the bulkiness of the mass plowed under might prove
harmful to the crop following the clover. The influence of the roots
upon the mechanical condition of the soil is most beneficial. The roots
go down deep into the subsoil and also abound in fibrous growth. The tap
roots in their decay furnish openings through which the superfluous
water may go down into the subsoil. The fibers adhering to the main
roots so ramify through the soil that when even stiff land is filled
with them it is rendered friable, and is consequently brought into a
good mechanical condition.

While all varieties of clover may be utilized in producing food and in
enriching land, none is equal to the medium red for the two purposes
combined. This arises from the fact that none save the medium red grows
two crops in one season under ordinary conditions. Though the first crop
should be taken for food, as it generally is, there is still ample time
for a second crop to grow for plowing under the same season. This second
growth is ready for being plowed under when time is less valuable than
it would be when the mammoth or alsike varieties would be in season for
being thus covered. And yet the work may be done sufficiently early to
admit of sowing fall or winter crops on the land which produced the
clover.

CHAPTER IV

ALFALFA

Alfalfa (_Medicago sativa_) previous to its introduction into
California, from Chili, about the middle of the last century, was
usually known by the French name Lucerne. The name Alfalfa is probably
Arabic in its origin, and the term Lucerne has prob