Olaf C. Soine, Soil Scientist
Zinc trials on sugarbeets have been conducted for three years at Crookston and for two years at East Grand Forks, Sabin-Glyndon, and Auburn-Cavalier areas. The average yields are given in Table 1. The highest yields were at Crooks ton for 1968-70 and at East Grand Forks for 1969-70. The late spring seeding and the summer drought effected the 1970 yields. The drought was more severe at Glyndon and Cavalier. Broadcasting 10 pounds of zinc (30 lbs. zinc sulphate) per acre was the best treatment at two locations, but at E. Grand Forks, the unfertilized check plot had the highest beet yield.
Samples of the blade, petiole and roots were taken in mid-July for zinc analysis at Crookston and East Grand Forks. These two plots have had the same land and crop management for the past two years. The data is given in Table 2. There were some increases in zinc content of the blade, petiole, and root when compared to the check plot. In general, the two broadcast treatments supplied more zinc to the beet plants than the band treatments
The soil analysis for each location is given in Table 3. The soils are all typical of the Red River Valley, being alkaline, high in organic mater, exchangeable potash and high in sulfur. The extractable phosphorus was high to very high, except at East Grand Forks where the test was low. The zinc test was medium at three locations and high at Crookston.
Summary: Variable increases up to one ton of beets per acre were obtained from the application of zinc. Broadcasting 10 pounds of zinc per acre gave the best results at two locations. At East Grand Forks, the check plot had the highest yield. The two broadcast treatments produced a slight increase in zinc content of the blade, petiole and root.
This experiment, which consists of six 4-year rotations, was started in 1967, and data is now available for the 4-year period. The rotations and average yields are given in Table 4. Sugarbeets follow the last crop in each rotation (e.g., Rotation 1, beets follow legume fallow; Rotation 2, beets follow oats, etc.). Rotation 1 is the most common cropping system used in this area. In Rotation 4, the first crop of alfalfa is removed and the land is fallowed the remainder of that year. The black fallow in Rotation 5 is used for weed control, and sometimes the legume seeding may fail. This area is not too well adapted for soybeans, but the yields have been good, as shown in Rotation 6.
The effect of the 1967-69 crop on the 3-year average yield of beets, percent sugar, impurity index, and pounds of sugar per acre is given in Table 5. There are some interesting variations in the percent sugar for the various rotations. The black, sweet clover, and alfalfa fallow rotations have the lowest percent sugar, while Rotations 2 and 6 have the highest.
The impurity index gives some indication of the quality of the beets and the lower this figure is the better the processing quality. The three fallow rotations have the highest impurity indexes while the oats and soybean rotations, Rotations 2 and 6, have the lowest.
It is interesting to note that the amounts of sugar per acre for Rotations 2 and 6 are higher than those from the three fallow rotations.
Table 6 gives the average net income for 1967-68. These figures include a land cost of $20.00 per acre and $5.00 per acre for taxes. If a grower owns his land, these costs would not be "out of pocket" costs.
The calculations for all crops and the rates for all farm operations are based on two publications1 by the Extension Service, University of Minnesota, and North Dakota Crop and Livestock Reporting Service. The highest income came from Rotation 3 which included potatoes, while the lowest came from Rotation 4. In general, the net returns from the three fallow rotations were the lowest.
1Custom Rates for Farm Operation. Extension Pamphlet 134-Revised 1969-Agricultural Extension Service, University of Minnesota.
Custom Farm Work Rates. Jan. 8, 1969. North Dakota Crop and Livestock Reporting Service, North Dakota State University. Fargo, North Dakota.
1973 Sugarbeet Research and Extension Reports, Volume 1, pg. 1 -3