Use in Winter Wheat

Every type of nitrogen (N) fertilizer is applied and handled differently. These general use recommendations for ESN are based on optimal growing conditions. Your specific conditions and goals should be considered to achieve best results. 

Proper N nutrition of wheat is critical to high yields and quality. Nitrogen stimulates tillering, head development, and protein storage in the grain. Nitrogen sufficiency at tillering is crucial, because potential head number is influenced by tillering success. Excessive N early can cause excessive vegetative growth and lodging. Head size can suffer if N deficiency occurs before stem elongation. Winter wheat uses about 30-40% of its N by the five to six leaf stage (start of stem elongation) and about 60-70% from the start of stem elongation to maturity. Controlling the timing of N supply can also increase grain protein by providing greater N availability during heading. The controlled N release of ESN can help produce high yields and quality while reducing excessive vegetative growth.

Interactions of weather conditions, timing of N demands, and potential for N loss should be considered in determining the most appropriate ESN application for different geographies and uses. Recommendations are the result of field-testing over several years at many locations. Actual results may vary depending on weather and soil conditions.

Canadian Prairies and Northern Plains

ESN’s controlled nitrogen release provides flexibility in nitrogen (N) application timing. It can be used to enhance nitrogen-use efficiency and crop performance in a variety of cultural practices. The options in this document give general guidelines for preferred use in wheat under different nitrogen-management strategies for the Canadian Prairies and Nothern Plains. The potential for winter N-loss is generally low to moderate in this environment. ESN performs best on winter wheat when applied in the fall at seeding. For fall applications, ESN is recommended as a single N source to provide controlled feeding during the fall establishment period and rapid growth the following spring. ESN blends easily with other granular fertilizers and provides convenient one-pass fertilization. Spring top-dress applications on winter wheat or spring pre-plant applications on spring wheat usually perform best if blended with soluble N sources, such as ammonium sulfate or urea.

ESN Fall Application at Seeding (preferred):

On the Canadian Prairies and the Northern Great Plains full value of ESN is derived from fall application at time of seeding winter wheat. Applying ESN at seeding means no need to top-dress in spring…meaning no extra time, application costs, or wondering if you will get to the field in time to meet the crop’s peak N demand – takes the risk and cost out of spring top-dressing.

 

  • Pre-plant band, side/mid-row band.
  • Pre-plant broadcast and incorporated.
  • Seed-row placed ESN provides a physical barrier between the seed and the urea within the coating and greater seed-row safety than urea or ammonium sulphate nitrogen sources. Within the Canadian Prairie provinces, safe rate guidelines exist for seed placed N on the provincial agricultural websites. ESN can be used at 3X indicated rates when it is 100% of the N source, ESN can be used at 2X the existing safe rate when it is 70% of the N source and at 1.5X the safe rate indicated, when it is 50% of the total N source. Tables for seed-safe rates of ESN for soil type and planter configurations can be found here.
  • Pre-plant broadcast unincorporated, using the seeding operation or incorporation.
  • Crop residue is necessary to hold ESN in place (broadcast applications).
  • Heavy crop residue may restrict ESN - soil contact, and potentially affect N release from ESN due to poor ESN to soil moisture contact.
  • Impregnating crop protection chemicals on ESN has not been evaluated.

ESN Spring Application (acceptable):

ESN as 100% of a spring N application is not recommended for top-dressing on winter wheat in this environment primarily for reasons of the sometimes-limited rainfall to move nitrogen into the crop root zone and early nitrogen demand of the crop. This is a crop with early spring N demand that may not be fully met by using a controlled release N source. Performance of spring ESN application often improves when blended with a conventional N source. Winter wheat breaks dormancy and takes up N at soil temperatures that may be too cool for adequate release from ESN. ESN top-dressed in spring on winter wheat in this region should be blended with a soluble nitrogen source such as urea or ammonium sulfate. For best results, blends should be applied early in the spring before or at “green-up” in order to assure adequate soil moisture and meet early demand of the wheat. The later the N application occurs, the greater the demand for immediate N supply and the lower the percentage of ESN recommended in the blend. ESN is not recommended after the five-leaf stage.

Winter Wheat development and ESN nitrogen management for Canadian Prairies and Northern Great Plains

Region N-Loss Potential Recommended Use
Western Canada and the
Semi-arid Great
Low to High Fall: Preferred
Recommended Blend
Time of Application ESN Conventional N
Fall: at seeding 100% Not needed
Spring: on actively growing
wheat (2 to 5 leaves)
0% 100%

 

 

 

 

 

 

ESN Spring Wheat:

ESN may be applied in fall for spring wheat similar to recommendations for application at planting on winter wheat. These applications should comprise a high percentage of the total N as ESN, preferably 100% ESN to protect against over-winter and early spring nitrogen loss. Fall-applied ESN should be incorporated. Spring ESN application is preferred and should be incorporated before or at planting to ensure good contact with soil moisture. Seed-placed or banded ESN is optimal where possible and where safe rates can be used. Blends supplying 50-75% of the N as ESN are appropriate for preplant applications on spring wheat. This blend should be sufficient to optimize yields and protein. For greater protein benefit, use the greater percentage of ESN. Post-emergent top-dress applications on spring wheat are less effective in this region and are not  recommended.

Winter Wheat - Eastern Geographies

ESN’s controlled nitrogen release provides flexibility in nitrogen application timing. It can be used to enhance nitrogen-use efficiency and crop performance in a variety of cultural practices. The options below give general guidelines for preferred use in wheat under different nitrogen-management strategies for eastern geographies.

Fall Applications:

• In most eastern geographies, the majority of the N should be applied as a spring top-dress to prevent potential N losses over winter and early spring. Typically less than one-third of the total N needs should be applied in the fall at seeding.
• For the portion of N applied in the fall, use ESN in a blend for 50-75% of the total recommended fall N at planting to promote early tillering and continued plant health thru the winter.
• If more than one-third of total nitrogen needs are applied in the fall, apply a blend comprised of 80-100% ESN late in the fall after soil temperatures are cool.

Spring Applications:

• ESN can be top-dressed in the spring on winter wheat as a blend with a soluble nitrogen source such as urea or ammonium sulfate
• A blend supplying75-100% of the spring N needs as ESN is recommended for late winter/early spring application prior to green-up.
• A blend supplying 50-75% of the N as ESN is suitable for applications at green-up.
• For applications after green-up thru the five-leaf stage, use a blend comprised of 30-50% ESN.
• ESN is not recommended after the 5 leaf stage.

Winter Wheat - Central and Southern Plains

ESN’s controlled nitrogen release provides flexibility in nitrogen application timing. It can be used to enhance nitrogen-use efficiency and crop performance in a variety of cultural practices. The options in this document give general guidelines for preferred use in wheat under different
nitrogen-management strategies for the Central and Southern Plains. The potential for winter N-loss is generallylow to moderate in this environment, and rainfall increasesfrom west to east. Soils in the northern parts of the region generally freeze during winter; soil in the southern plains generally do  not freeze over winter.

Fall Application (preferred):

Best results are achieved in this region when ESN is applied in the fall at time of seeding winter wheat. For fall applications, ESN is recommended as a single N source to provide controlled feeding during the fall establishment period and rapid growth the following spring. Fall ESN application eliminates the risk and cost of spring top-dressing. Spring top-dress applications on winter wheat or spring pre-plant applications on spring wheat usually perform best if blended with soluble N sources, such as ammonium sulfate or urea.

  • ESN should comprise a high percentage of the total nitrogen, typically 80-100%.
  • ESN may be applied pre-plant banded, pre-plant broadcast and incorporated, as a side band application, or in seed-row following suggested seed-safe N rates for placement.
  • Seed-row placed ESN provides a physical barrier between the seed and the urea within the coating and greater seed- row safety than urea or ammonium sulfate.
  • ESN can be used at up to 3X the indicated safe rates of urea when it is 100% of the N source, ESN can be used at 2X the safe rate of urea when it is 70-75% of the N source and at 1.5X the safe rate indicated, when it is 50% of the total N source. Tables for seed-safe rates of ESN for soil type and planter configurations can be found here
  • Small amounts of other N sources may be blended to supply some immediately available nitrogen to stimulate tillering along with other elements such as sulfur or phosphate.

Spring Application (accetable):

ESN as 100% of a spring N application is not recommended for top-dressing on winter wheat in this environment primarily because of early nitrogen demand of the crop and sometimes-limited rainfall to move nitrogen into the crop root zone. Early spring N demand that may not be fully met by using a controlled-release N source. Performance of spring ESN application often improves when blended with a conventional N source. Winter wheat breaks dormancy and takes up N at soil temperatures that may be too cool for adequate release from ESN.
ESN top-dressed in spring on winter wheat in this region should be blended with a soluble nitrogen source such as urea or ammonium sulfate. For best results, blends should be applied early in the spring before or at “green-up” to assure adequate soil moisture and meet early demand of the wheat. The later the N application occurs, the greater the demand for immediate N supply and the lower the percentage of ESN recommended in the blend.

• For late winter to early spring applications (dormant wheat to green-up), ESN should comprise 50-75% of the total nitrogen to be applied in a blend with another soluble nitrogen source.
• From green-up to five-leaf growth stage, ESN percentage should be reduced to 30-50% of the total N as ESN.
• ESN is not recommended after the five-leaf stage.

Winter Wheat - Pacific Northwest

In areas of low to moderate nitrogen loss potential, best results are often achieved when ESN is applied in the fall at time of seeding winter wheat. For fall applications, ESN is recommended as a primary N source to provide controlled feeding during the fall establishment period and rapid growth the following spring. Fall ESN application eliminates the risk and cost of spring top-dressing.
For areas of high N-loss potential, early spring ESN application is preferred. Spring application reduces the risk of over-winter loss and applies N closer to the time of peak crop uptake. Fall ESN application may be acceptable in these areas and provide better performance than soluble fertilizers, but ESN should be applied when soils are cool to slow nitrogen release from ESN.

Fall Application:

  • ESN should comprise a high percentage of the nitrogen, typically 80-100%.
  • ESN may be applied pre-plant banded, pre-plant broadcast and incorporated, as a side band application, or in seed-row following suggested seed-safe N rates for ESN placement.
  • ESN can be used at up to 3X the indicated safe rates of urea when it is 100% of the N source, ESN can be used at 2X the safe rate of urea when it is 70-75% of the N source and at 1.5X the safe rate indicated, when it is 50% of the total N source. Tables for seed-safe rates of ESN for soil type and planter configurations can be found here.
  • Small amounts of other nitrogen sources may be blended to supply some immediately available nitrogen to stimulate tillering along with other elements such as sulfur or phosphate.

Spring Application:

ESN top-dressed in spring on winter wheat in this region should be blended with a soluble nitrogen source such as urea or ammonium sulfate. Early spring top-dress ESN performs very well under sprinkler-irrigated conditions. ESN may be applied from dormancy up to five-leaf stage as a blend with other soluble N sources such as urea and/or ammonium sulfate. Suggested portion of ESN in the blend is shown in the table below. Irrigated cropping systems should use the high end of the blend ranges shown. Low rainfall, dryland areas should use a lower ESN percentage in the blend. ESN is not recommended after the 5-leaf stage.

ESN as 100% of a spring N application is not recommended for top-dressing on winter wheat in low-rainfall dryland production because of early nitrogen demand of the crop and sometimes-limited rainfall to move nitrogen into the crop root zone. Early spring N demand that may not be fully met by using a controlled-release N source. Winter wheat breaks dormancy and takes up N at soil temperatures that may be too cool for adequate release from ESN.

For best results, blends should be applied early in the spring before or at “green-up” in order to assure adequate soil moisture and meet early demand of the wheat. The later the N application occurs, the greater the demand for immediate N supply and the lower the percentage of ESN recommended in the blend. ESN is not recommended after the five-leaf stage.

Nitrogen-Loss Potential Application Timing Recommended Blend %
of N as ESN
Low Preferred: Fall (time of seeding) 80-100%
  Early spring:dormancy until green-up 50-75%
  Spring: green-up to 5 leaves 30-50%
High or Irrigated Fall (time of seeding) 80-100%
  Preferred: Early spring dormancy
until green-up
60-90%
  Spring: Green-up to 5 leaves 40-60%

 

Spring Wheat:

Spring pre-plant ESN application is preferred for spring wheat and should be incorporated before or at planting to ensure good contact with soil moisture. Seed-placed or banded ESN is optimal where possible and where safe rates can be used. Blends supplying 50-75% of the N as ESN are appropriate for pre-plant applications on spring wheat. This blend should be sufficient to maximize both yields and protein. For greater protein benefit, use the greater percentage of ESN. Post-emergent top-dress applications on spring wheat are less effective in this region and are not recommended.