8 
Colorado Experiment Station 
but from the higher yield of small grains planted on the land. 
Clover lends itself better to short crop rotation than alfalfa, and, 
for this reason, the farmers in the higher mountain valleys can 
place their farms on a four-year system of rotation, while in the 
warmer valleys and in the irrigated sections of the plains, a five- 
or perhaps six-year rotation is better. 
While at present the plowing under of alfalfa and clover has 
been a main source of soil fertility, the time will undoubtedly 
come when this will have to be supplemented with the application 
of stable manures, and this is already done to a great extent by 
our best growers. 
SEED 
During the last two years, more attention has been devoted 
to the question of seed selection and type than to any other phase 
of potato growing. . Gratifying results, both in yield and quality, 
have been obtained. While seed selection is important to success, 
it is only one of the grower’s problems. No matter how good 
the seed may be, the returns will not be satisfactory unless thq 
grower is willing and able to perform the cultural work, and 
provide the right kind of soil conditions to enable the plant to 
make a satisfactory growth. The grower must first see to it that 
Perfect type of Rural seed. The kind to plant 
