In this study, alfalfa production fields were used to study the effect of removing the first crop for hay versus plowing down the first crop for beet production. In 1967, the first crop of alfalfa was cut and removed on June 29. These plots and the plots with alfalfa were plowed and fallowed the remainder of that year. Beets were planted on these plots in 1968. In 1970, the alfalfa was cut and removed on June 17, but the plots weren't plowed until July 8 because of excessive rainfall. These plots were planted to beets in 1971.
Fertilizer 0-46-0 at 250 lbs per acre was broadcast the previous fall and 6-42-0 at 100 lbs per acre was drill applied at seeding time. The beet field in 1968 was mechanically thinned and weeded and no hand labor was used.
The beets were harvested on September 20, 1968, and October 11, 1971.
The experimental data is given in Table 1 for 1968 and 1971.
In 1968, the beets on the plow-down plots yielded .45 tons more than the alfalfa removal plots. In 1971, the opposite was true--the alfalfa removal plots yielded .39 tons more than the plow-down. The alfalfa removal plots had higher percent sugar and lower impurity indexes. The sugar yield was very similar for both treatments.
Table 2 gives information about the yield and value of the alfalfa hay. The alfalfa was weighed and calculated to 15.5% moisture basis and is reported on this basis in Table 2. The yield in 1970 was very good and the price was $20.00 compared to $18.00 per ton in 1968. The growers in the Crookston area have a market for this crop, which is an asset for this type of sugarbeet production.
1971 Sugarbeet Research and Extension Reports. Volume 2, page 85.