EFFECT OF ALFALFA ON YIELDS OF FIELD CROPS. 11 
ative rows, to record the percentage of sugar in the beets as reported 
by the local sugar factory upon the samples from each plat, and to 
determine the proportion of the weight of the tops to the combined 
weight of beets and tops. This last determination is important not 
only as showing something of the vigor of growth of the sugar beets, 
but also as indicating the quantity of feed available as a by-product 
of the beet crop. 
The facts for each of the three stations regarding the effect of 
alfalfa in stimulating the yield of subsequent crops of sugar beets, as 
shown in Table IV, and also as to its effect on the size of beets, the 
percentage of sugar in the beets, and the percentage of tops are sum- 
marized below. 
At Scottsbluff the yield of beets from the 44 plat years averaged 
13.8 tons per acre, while the mean annual difference in favor of 
those following alfalfa (second and third year) was 3.4 ±0.5. The 
size of beets from the same plats averaged 1.53 pounds, with a mean 
annual difference in favor of those following alfalfa of 0.39 ±0.032. 
The sugar content of the beets for the 44 plat years averaged 17 per 
cent, with a mean annual difference against the plats following 
alfalfa of 0.5 ±0.15. The proportion of the weight of tops to the 
combined weight of beets and tops for the 44 plat years is 27 per 
cent, with a mean annual difference in favor of the beets following 
alfalfa of 2.3 ±0.6. 
At Belle Fourche the yield of beets for the 44 plat years averaged 
9.9 tons per acre, with a mean annual difference in favor of the plats 
following alfalfa (second and third year) of 0.64 ±0.36. The size of 
the beets from the same plats averaged 0.78 pound, with a mean 
annual difference in favor of the plats following alfalfa of 0.08 ±0.035. 
The percentage of sugar in the beets averaged 19.7 per cent, while 
the mean annual difference in favor of the plats following alfalfa is 
0.5 ±0.19. The records as to percentage of tops are incomplete. 
At Huntley the yield of beets for the 36 plat years averaged 10.7 
tons per acre, with a mean annual difference in favor of the plats 
following alfalfa of 1.5 ±0.6. The size of beets from the same plats 
averaged 0.96 pounds, with a mean annual difference in favor of those 
following alfalfa of 0.17 ±0.05. The sugar in the beets averaged 17 
per cent, with a mean annual difference against the plats following 
alfalfa of 1.3 ±0.22. The proportion of the weight of tops to the 
combined weight of beets and tops, omitting 1918, when the records 
were not made, has averaged 38 per cent, with a mean annual dif- 
ference in favor of the plats following alfalfa of 8± 1.8. 
It is possible to make a comparison between the effect of alfalfa 
on the subsequent yield of beets and the effect of the application of 
farm manure at the rate of 12 tons per acre, as was done with the 
potato crop. The chief difference in the two comparisons is that 
