The Colorado Potato Industry. 
7 
the Billings loam and does not pack or become lumpy so easily as 
the latter but on the other hand it contains less gravel. These 
two soils, constitute by far the larger part of the successful po¬ 
tato district north and east of the town of Greeley. 
The Billings clay loam is finer than either of the others. It 
has less gravel and is so deep that the under drainage is not good. 
This soil occupies narrow strips in the creek bottoms and while 
it often produces good crops of potatoes it is liable to serious 
attacts of fungous diseases. 
The Colorado sand is coarser in texture, contains less nitro¬ 
genous matter and requires more water to produce a crop but 
where proper rotation of crops and cultural methods have been 
employed, good results are obtained. 
The Laurel sand loam, which is the first bottom land of the 
Poudre River Valley, is not very different from the other sandy 
loams but in most places the water table is close to the surface 
and potato growing on this soil in not uniformly successful. 
All these soils contain more or less alkali but not enough in 
most cases to prevent the development of plants except where 
water stands and evaporates. 
Preparation oe Potato Land. The preparation of the land 
for potato growing is probably the most important item of the 
work. The difference between new land broken for potatoes, old 
land and alfalfa land is most marked. The new land produces a 
very clean grade of potatoes but does not give so good a yield as 
land either preceeded by potatoes or alfalfa. Alfalfa land gives 
the largest yields and is less liable to disease than where potatoes 
succeed potatoes. The universal practice is to rotate so as to 
preceed potatoes with alfalfa. 
Rotation oe Crops. The most common rotation is alfalfa two 
or three years, potatoes two years or where beets are grown, pota¬ 
toes one year, and beets one year, then grain two years. Sometimes 
wheat or oats are only grown one year but experience has shown 
that in the majority of cases, the first year of grain following 
potatoes or beets produces so much straw that the young alfalfa 
is smothered out if grown. The grain, owing to the reduced 
fertility of the soil, is not so large the second year and makes 
a better nurse crop for the alfalfa. Another rotation practiced to 
some extent is alfalfa two years, potatoes one year, wheat one 
year, potatoes one year, grain, then alfalfa again. This system 
while not very generally practiced has some possibilities in the way 
of blight control which will be spoken of later in this report. 
The number of years alfalfa should be allowed to grow to get the 
land in the best condition for potatoes is an open question. 
While by far the majority of growers allow it to stand but 
