ISSUE #386

386 - Shareholder Records Support Reduced N Use

9-13-00

The grower practices data summary for 1999 supports reduced N use to maximize recoverable sugar per acre. The data in Table 1 indicates a total of about 113 pounds of soil test plus added fertilizer N gave maximum recoverable sugar per acre in 1999. This data agrees very closely with Dr. Larry Smith, U of MN Research recommendations to reduce N use.

American Crystal Sugar Co. – 1999 Crop Year Soil Tested Fields 0-2 ft by Red River Valley

Table 1.

Soil Test N03 0-2 ftAvg. N AppliedAvg. Total NFieldsHarvested AcresTons Per AcreSugar %SLM %Rec. Sugar Per TonRec. Sugar Per Acre
0-20 85 97 383 27632.2 19.6 17.47 1.36 322 6311
21-40 88 120 1543 110044.1 20.2 17.41 1.37 321 6484
41-60 65 115 1603 113685.0 20.1 17.40 1.38 320 6432
61-80 43 113 1127 78423.2 20.4 17.39 1.40 320 6528
81-100 23 113 607 41755.9 20.4 17.48 1.44 321 6548
101-120 11 120 315 21611.1 19.9 17.31 1.47 317 6308
121-140 6 136 190 12525.4 20.1 17.31 1.51 316 6352
141+ 3 191 226 16282.1 20.4 17.17 1.59 312 6365

2000 N Management Recommendations

  • If past N use was greater than 120 lbs. available reduce use to 120-lb. level.
  • If past N use was about 120 available – reduce use by 10 lbs./acre. 
  • Reduce N use on headlands and strikeouts when possible.
  • Consider zone management strategies for N. Research by Dr. Larry Smith at the U of MN Northwest 

Research and Outreach Center supports these recommendations. See the 1999 Sugarbeet Research and Extension Reports pages 105-116.

Precision Farming Strategies Provide Increased Profit Opportunity

Utilization of satellite imagery data, yield monitor maps, or topographic maps of fields, and variable rate N application can benefit shareholders by:

  • Increasing yields
  • Improving crop quality
  • Sometimes reducing fertilizer costs
  • Enhancing environmental protection

Zone management of fields enables shareholders to put the right amount of fertilizer in the right place in the field at the right time. A summary of grower practice record data (Table 2) from the 1999 production season shows:

  • Soil testing pays
  • Highest recoverable sugar per acre was achieved on fields using zone soil (or other zoning methods) testing based on satellite imagery

Table 2: Effect of soil testing method on sugarbeet yield and quality in 1999.*

Soil Testing MethodYield T/ASugar %SLM %Sugar/TonRecoverable Sugar/Acre Lbs
No Soil Testing 15.8 17.13 1.47 313 4945
All Methods 19.8 17.38 1.40 320 6336
Grid Tested 21.0 17.27 1.38 318 6678
Zone Tested 21.2 17.38 1.36 320 6784

* Five year agreement requires soil testing

Use of variable rate fertilizer application equipment enables shareholders to apply the right amount of fertilizer N where it’s needed. Effect of variable rate fertilizer application versus crop yield and quality on the 1999 American Crystal Sugar Co. crop based on grower practice records is shown in Table 3.

Table 3: Effect of method of fertilizer application on 1999 American Crystal Sugar Co. crop yield and quality.

Fertilizer Application Method Yield T/A Sugar % SLM % Recoverable Sugar/Ton Recoverable Sugar/Acre Lbs 
Conventional Spreading  19.7  17.16  1.36  316  6225 
Variable Rate Spreading  22.4  17.22  1.37  317  7101 

How can a shareholder get started in precision N management on his farm?

  • Review your field satellite imagery at crystalsugar.com
  • Visit with your agriculturist
  • Study research data from NDSU and U of MN
  • Contact your soil sampling agronomist
  • Make arrangements with your fertilizer dealer