152 ALFALFA. 
the accumulation of roots, it leaves the soil richer in this 
element than it was before producing the crop. Professor 
Davenport, when speaking of the members of this important 
family, says: ‘‘They not only work for nothing and board 
themselves, but they pay for the privilege.’’ These plants 
are the only ones of any agricultural importance that can 
use the atmospheric nitrogen, and they can do it only with 
the aid of certain bacteria. 
Figure 3 is typical of the alfalfa plant in blossom, and 
shows its peculiar habit of bearing the flowers all along the 
stem and not simply at the tips as the clover blossoms are 
borne. The seed is formed in spiral pods as shown in the 
illustration Fig. 4. Unlike red clover, alfalfa is a perennial 
and lives for an indefinite period. Near Lake Minnetonka, 
fields have been producing alfalfa for thirty years continu- 
ously. 
Seeding.—The young alfalfa plant is rather delicate and 
a weak feeder consequently the seed bed must be carefully 
prepared, with a good supply of plant food readily avail- 
able. The ground should be plowed rather deeply and the 
surface brought into a fine condition as in the sowing of 
clover or other small seeds. From ten to fifteen pounds 
should be sown per acre, preferably without a narse crop, 
and as early as possible in the spring without danger of 
frost which may kill the young plants. As soon as the first 
blossoms appear or whenever the plant shows signs of los- 
ing thriftiness, it should be mowed as this stimulates stronger 
growth. It can usually be cut three times during the sea- 
son, and after it has become well established, it will yield 
from three to five tons of cured hay per acre. 
Soil.—Alfalfa seems to do best on sandy loam soils that 
have a good supply of plant food and are well drained 
though it has been known to have grown ina heavy clay 
soil. It will do well on any soil that will produce wheat or 
coin. The field designed for alfalfa should be selected with 
the view of leaving it for several years. The plant seems to 
reach its prime in four years and can as a rule be leftina 
field profitably for seven or eight years. No difficulty is ex- 
perienced in getting alfalfa out of a field if it is plowed in 
mid-summer and kept well cultivated. 
