Potato Growing in Colorado 7 
and the rotation period may be shortened to four years. In this 
case, larger acreages may be planted to potatoes. Not only would 
the average yield of potatoes per acre be greatly increased, but a 
corrsponding increase in the yield of grain per acre would be at¬ 
tained following a crop of potatoes. 
If this system of crop rotation could be extended from six to 
eight, or even ten years, leaving the land in alfalfa for a longer 
period, even better results would be obtained. Long rotation period 
is only suited for large farms in combination with extensive live¬ 
stock operations. 
PREPARATION OF THE LAND 
The preparation of the land intended for potato growing should 
be thoro, as the potato develops its crop below the ground, and 
needs a loose, open soil so that the tubers can expand normally, 
and also to give the root system a chance to develop to its fullest 
extent. On the heavier soils, deep fall plowing is necessary, as it 
gives the elements a chance to act upon the land during the winter. 
Then again, the land should be plowed a couple of weeks before 
planting and kept cultivated so as to conserve the moisture stored in 
the soil during the winter months. When alfalfa is turned under, 
this may be done in the fall, but shallow plowing in this case is 
necessary, just deep enough to cut the crown of the alfalfa plants. 
Deep plowing will not kill all the alfalfa roots. The field should 
be cross-plowed again in the spring to the depth of eight to ten 
inches. Deep plowing is a very important factor in the preparation . 
of potato land, so as to give the roots the largest possible feeding 
area. Where the soil conditions are favorable, the potato plant 
will send its roots down to the depth of three feet, while if the soil 
conditions are unfavorable, the root system is confined to the top 
soil and the food supply curtailed, and the yield will correspond with 
the food supply. If the spring plowing is done early, the land should 
be kept harrowed to keep it in fine tilth until planting time. The 
preparation of the Hnd is really one of the most important factors 
in potato production, and unless a grower is willing to take the 
time and perform this work tlioroly, he cannot expect a large return. 
PLANTING 
The depth at which potatoes should be planted varies with the 
character of the soil, locality and method of culture. When high 
hilling or ridging is practiced, the planting is shallow—about two 
inches below the level of the field. On heavy soil the planting may 
be more shallow. When low hilling is practiced, the planting should 
be from, three to four inches deep, depending upon the character of 
the soil—the lighter the soil, the deeper the planting. 
The time of planting necessarily depends upon the season and 
