Soil Testing and Nitrogen Critical to Quality

Soil testing is a critical component to ultimately delivering a high quality sugarbeet crop. Sugarbeets are good scavengers of nitrogen, so any excess “N” available in the soil profile, even down to 6′ can have a negative impact on crop quality.

Basic Guidelines to Conventional Soil Testing preceding Sugarbeets:

  1. 15-20 soil cores per field.
  2. Sample the uniform areas: Sampling from uniform areas will give you the most representative sample results. If large areas of the field differ due to crop history, soil type, topography, etc., you should sample them separately or avoid them.
  3. Following Small Grain: Soil sampling can begin as early as August 15. Add ½ lb of N per day to the soil test for each day before September 15 for an accurate measurement of nitrogen. Some advantages of early sampling include a more uniform sample from an untilled soil profile, being able to see and avoid problem areas and growers will have results in time for fertilizer spreading.
  4. Following edible beans or field peas: Soil sampling should be delayed until after September 15.
  5. Following corn, sunflowers and soybeans: Soil sampling can begin immediately after harvest.

Zone sampling

Soil sampling based on nitrogen contributed from previous beets tops, topography or soil type are all examples of zone sampling. All of these reasons warrant dividing a field into areas of different fertility requirements. One common method is to sample fields in zones the second year after sugarbeets, using the sugarbeet canopy images as a guide.

Grid sampling

This method requires that you divide the field into 1 to 5 acre blocks with 8-12 soil core samples collected within a 10-20′ radius in each block. Fields showing a lot of variability in crop yield, crop growth, etc. may be good candidates for grid sampling.