ISSUE #569

569 - Effective Nitrogen Management Strategies

7-25-12

NITROGEN MANAGEMENT WAS CRITICAL TO SUCCESSFUL SUGARBEET PRODUCTION SINCE THE CROP FIRST WAS GROWN IN THE RED RIVER Valley in 1918. Nitrogen management remains just as critical yet today. Many more tools are now available to fine tune your nitrogen management plan to maximize crop yield and quality, improve storage and increase factory efficiencies. Just as green manure crops and summer fallow disappeared as management options, fall applying 100% of your anticipated N needs may also have to change. You are strongly encouraged to carefully consider if change will benefit your farm business.

Utilize every option available to maximize your N fertilizer use efficiency. Precision N Management options include:

  • Soil testing to a 4-foot deep
  • Use of N stabilization and controlled release products
  • Zone soil testing
  • Variable rate N fertilization
  • SPLIT N applications with use of sidedressing equipment - This practice is common in corn production why not beets?

Refining Your N Management Plan

  • Obtain soil samples to an accurate 4' depth
  • Use a local soil testing lab with a reputation for quality service
  • Use satellite imagery or other reliable Precision Ag information to obtain soil samples by management zone
  • Review past history of N application rates versus yield and quality on your farm
  • Apply 65-75% of your anticipated N needs in the Fall of 2012
  • Sidedress additional N as needed by the 8-leaf stage of the crop in the Spring of 2013

Table 1: Effect of Total Available N, 0-4 ft. on Recoverable Sugar and Gross Revenue Per Acre. 6 Year Average (2006-2011)

Available N-lbs.
Factor0-100101-120121-140141-160161+
RSA (lbs.) 7986 8333 8059 8241 8143
Rev/A ($) 1330 1394 1351 1388 1359

Establish a target total available nitrogen level for each field. Consider soil test residual N, plus expected N mineralization from organic matter, plus added fertilizer. Then adjust the side-dress N rate up or down based on these factors.

How to Determine Amount of N to Sidedress in the Spring

FactorYield ImpactSidedress N Rate
Early Planting Increase Increase
Late Planting Decrease Decrease
Excellent Stand Establishment Increase Increase
Poor Stand Establishment Decrease Decrease
Low Stored Soil Water Decrease Decrease
Soils at Field Capacity in the Spring Increase Increase
Low Quality Beet History --------- Decrease
Low Yield History --------- Increase
Heavy Soil Type Decrease Increase
Light Soil Type Increase Decrease
High Organic Matter Increase Decrease
Low Organic Matter Decrease Increase

Zone soil testing and variable rate fertilization increases yield, quality and revenue per acre. Using multiple targets for zones for total available nitrogen increases revenue per acre compared to using only a single nitrogen rate target.

Table 2: Effect of Soil Test Type on Recoverable Sugar Per Acre and Gross Revenue Per Acre. 6 Year Average (2006-2011)

Soil Test TypeRSA (lbs.)Rev/A ($)
Not Tested 7237 1182
Conventional 8034 1329
Zone-Single Target 8198 1367
Zone-Multiple Target 8342 1388

Contact Your Agriculturist for assistance with maintaining a highly effective Cercospora management program.