John T. Moraghan
Professor of Soils
At last year's conference the effect of population and nitrogen fertilizer on the yield and performance of sugarbeets at the James Link farm, Mooreton, North Dakota during 1969 was evaluated. The work this year was expanded and was conducted on the Main Station at Fargo.
The objectives were:
The populations in 1970 were 0, 45, 70, 95, 120 plants per 100 feet of row, and each population was evaluated at nitrogen fertilizer levels of 0, 50,100 and 200 pounds per acre of N. The soil nitrate-N in the upper 2 feet of soil in early May was approximately 50 pounds per acre. The soil at the experimental site was sown to small grains in 1969. The 1970 planting date was May 13th.
At each of seven harvests (spaced at 2-week intervals) between July 14 and October 6, the effect of treatment on the yields of roots and tops, the leaf area, the number of leaves, the percentage sucrose in the roots, the moisture content in the roots, the root Impurity Index, the nitrate content of recently matured petioles and the soil water content was evaluated. The soil nitrate-N in the top 5-feet of soil was estimated soon after planting and after the final harvest.
As in 1969 a prolonged dry period was encountered. Between June 20 and August 28 only 0.89 inches of precipitation were recorded at the experimental site. However, the yield averaged over population and nitrogen treatments on October 6 was 20 tons per acre. A rain of 3.52 inches was recorded on September 20 and the effect of this precipitation on the Impurity Index and sugar levels is of interest. Extensive use of sub-soil moisture was noted during the growing season. The 45 plants per 100 feet of row population tended to produce lower root yields. The use of nitrogen fertilizer resulted in root yield increases.
1973 Sugarbeet Research and Extension Reports, Volume 1, pg. 13