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.

 

Canada Prairies and Northern Plains

Nitrogen management presents numerous challenges. Crops require relatively high N rates, but most of the N fertilizer is applied in advance of peak crop demand. Precipitation during fall and winter and especially during early spring, produces potential for N loss by leaching and denitrification. ESN provides greater protection against N loss than conventional N sources.
 

ESN Spring Application

ESN as 100% of a spring N source is not recommended for top-dressing on winter wheat in this environment. This is a crop with immediate N demand that will not be fully met by using a controlled release N source.

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.

 

ESN Fall Application at Seeding

  • 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. As such, greater seed row safety can be achieved when using ESN as opposed to 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.
  • Pre-plant broadcast unincorporated, using the seeding operation for 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.
  • Under average conditions in these areas, 35 - 50% of ESN-N will be released in 25 to 30 days after application. The balance of ESN-N will be released over the following 30 to 40 days.
  • Impregnating crop protection chemicals on ESN has not been evaluated.

 

Winter Wheat 

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.
 

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 sufficient release from ESN. Supplying 70 to 80% of the N as a conventional N source, such as ammonium sulfate or urea is recommended to provide the immediate N needs of the wheat crop. ESN blends easily with conventional N fertilizers such as ammonium sulfate, urea, phosphates, and potash. 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.

 

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%

 

 

 

 

 

 

 

 

 

Winter Wheat - Eastern Geographies

Fall Applications:

In most eastern geographies, the majority of the N should be applied as a spring top-dress to reduce 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
 

General conditions:

  • Relatively dry fall and winter 
  • Precipitation increases west to east
  • Soils freeze in winter in north, do not freeze in south
  • Soil warms quickly in spring

 

Risk of winter and early spring N loss:  

Low to moderate

 

Recommended ESN use:

Fall - preferred  

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.

Spring - acceptable

ESN may be applied on dormant wheat as a blend with other soluble N sources such as urea and/or ammonium sulfate. A blend of 60-70% ESN and 40-30% soluble N is suggested for late winter/early spring application. For later spring applications, a blend of 40% ESN and 60% soluble N is suggested. ESN is not recommended after the 5-leaf stage.

 

Winter Wheat - Pacific Northwest
 

General conditions:

  • Highly variable local temperature and moisture conditions
  • Mix of dryland and irrigated crops

 

Risk of winter and early spring N loss:  

Low to high

 

Recommended ESN use (consult your ESN representative for specific local use):

Areas with low N loss potential
Fall - preferred
 

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.

Spring - acceptable

ESN may be applied on dormant wheat as a blend with other soluble N sources such as urea and/or ammonium sulfate. A blend of 60-70% ESN and 40-30% soluble N is suggested for late winter/early spring application. For later spring applications, a blend of 40% ESN and 60% soluble N is suggested. ESN is not recommended after the 5-leaf stage.

 

Areas with high N loss potential
Spring – preferred

ESN may be applied on dormant wheat as a blend with other soluble N sources such as urea and/or ammonium sulfate. A blend of 60-70% ESN and 40-30% soluble N is suggested for late winter/early spring application. For later spring applications, a blend of 40% ESN and 60% soluble N is suggested. ESN is not recommended after the 5-leaf stage.

 

Fall – acceptable

ESN should be applied in late fall when soils are cool.

 

Winter Wheat - Southwest

Consult your ESN representative for recommendations in this region.