Frequently Asked Questions

The following is not intended to be complete or detailed use recommendations for all geographies, crops, or applications.  User assumes all responsibility for proper use and handling of specific geographies, crops, and applications.  Please consult ESN recommendations and/or your Nutrien ESN representative for complete recommendations for use.  Consult ESN recommendations for more information.

At what temperature does ESN begin to release? Does ESN release N below 50 degrees F?

The release of N from ESN is temperature dependent, but there is not a specific “on-off” temperature.  Practically, ESN can start releasing N at temperatures above the freezing temperature of water, since liquid water is necessary for the diffusion process, but ESN releases very slowly at cold temperatures to protect the N when crops are growing slowly.  ESN release does not start at 50 degrees F, but the release is very slow at lower temperatures and increases gradually as temperature increases to better match crop N demand.

See figure/fact sheet illustrating ESN release at different temperatures for more information.

Can ESN be applied in a growing crop? Will it release fast enough to meet crop N demand?

Yes, much research has demonstrated ESN performs excellently as a top-dress application in many crops, including corn, soybeans, cotton, potatoes, winter wheat, and others depending on geography and soil and environmental conditions.  Because later applications, such as top-dressing corn, are made in warmer temperatures, ESN’s release will accelerate more quickly.  In some cases, such as full-season potato varieties in long growing seasons or very sandy soils with high leaching potential, applying a few weeks after planting may actually perform better than ESN applied before planting.  On cool-season crops in cold areas, such as W. Canada and the No. Great Plains, fall or spring pre-plant is the preferred application timing; top-dress applications are usually not recommended for these situations.  If ESN is to be applied in a growing crop, blending ESN with an immediately available N source, such as urea or ammonium sulfate, will provide for the immediate crop N needs until ESN release begins.  It is ultimately important to match N supply to crop N demand, and ESN has been proven a useful tool in achieving this objective.  Consult your ESN dealer or Nutrien representative for specific recommendations for specific crops and application times.

See Use Recommendations for more information.

Can ESN be applied in the fall?

Fall nitrogen application may increase the risk of N loss in some environments and is therefore not recommended in those areas.  Spring N application is usually a preferred practice in many regions. Where fall N application is an acceptable practice according to soil type, environmental conditions, and cropping system, ESN is a great alternative to other N sources.  In dryland cropping systems in arid and semi-arid areas, such as W. Canada and the Great Plains, fall may be the preferred application time for ESN.  For these geographies, cool, dry conditions in late spring and early summer, may inhibit release from ESN unless it is incorporated.  Because the N in ESN remains protected thru cold winter periods, it reduces the risk of N loss and can improve N-use efficiency over conventional N sources that pose a greater risk.  Areas that remain warm and wet through winter and early spring may not be suitable for fall ESN application.  In these areas, ESN or ESN blends may be appropriate for some fall-seeded or winter crops.  Consult your ESN dealer or Nutrien representative to discuss fall ESN applications.

Can ESN be blended with other fertilizers? Does blending destroy the ESN coating?

Yes, ESN can be blended with other fertilizers.  In fact, it blends well with other fertilizers. ESN is designed to withstand normal handling processes. Proper handling and blending will not destroy the coating.  Excessive blending may damage the coating and reduce ESN’s effectiveness.  To help avoid abrasion of the coating, add ESN to the blend last and mix for the minimum time required to achieve uniformity.  The blend will remain dry and flowable.  ESN is the perfect product to improve any nitrogen program.  Ask your retailer how it can help you.

See Use Recommendations for more information.

Can I be more profitable by saving money and using a lower percentage of ESN in my blends?

Some ESN users attempt to cut costs by reducing the portion of ESN in the blend and therefore do not realize ESN’s optimum performance and full benefits.  ESN recommendations are based on hundreds of studies in many environments and designed to produce the best possible performance.  These studies show that best results and greater profitability are achieved using the amount of ESN recommended for each crop and time of application.  In most cases this is at least 50% to as much as 100% of the total crop N needs as ESN.  Remember that the portion of N applied as conventional, immediately available N sources is fertilizer N that is unprotected.  ESN is designed to release in synchronization with crop demand, so only a small amount of immediately available N is typically needed.  Using ESN as recommended produces greater yields and profitability than lower-cost alternatives that may appear to be a bargain but fail to provide the performance and profitability of ESN.

Can I just use a urease inhibitor or nitrification inhibitor instead of ESN? They’re the same thing at a lower price, aren’t they?

ESN is different from other enhanced-efficiency nitrogen fertilizers; it is not the same as urease and nitrification inhibitors; it works by a different mode of action; ESN provides additional benefits inhibitors cannot, and ESN provides these benefits for a longer time than is common for inhibitors and stabilizers.

Currently, ESN is the only polymer-coated controlled-release N fertilizer widely available in broadacre agriculture.  There are many enhanced-efficiency nitrogen product choices on the market with different modes of action and different benefits.  There is also a lot of misunderstanding and misinformation.  Many of these products are effective for specific problems.  Some are not as effective as others.  It is essential to understand each product, its mode of action, the N-loss mechanisms it controls, the time for which it is effective, and what its benefits are.

Most other products in agriculture are either additives or contain additives, called stabilizers, which inhibit nitrogen transformations. These inhibitor, or stabilizer, products are water soluble.  They are not controlled- or slow-release fertilizers like ESN.  In the same way, one would not use a grass herbicide to control broadleaf weeds, one should not use a urease inhibitor to reduce leaching loss or a nitrification inhibitor to control volatilization.  Because ESN truly controls the exposure of N to all loss mechanisms and controls N supply to the crop, it can provide benefits the stabilizers cannot. ESN protects against all N loss mechanisms for a longer time than the stabilizer products.

ESN is unique among enhanced-efficiency fertilizers in agriculture.  It provides longer-lasting protection, better performance, greater benefits, and, we believe, greater value than other available options.

See the EEF guide fact sheet for more specific information.

Do fertilizer spreaders damage the ESN coating?

ESN is designed to be applied using the same application equipment that is used for other dry fertilizers, including both spinner and air-flow type applicators.  While some effect of handling and spreading is unavoidable, granules can be damaged by improper handling, proper procedures and adjustment of spreaders will assure damage is minimized, and ESN retains its protective coating and performs as it should.  Where possible, air-flow spreaders should be adjusted to use slower air speeds, to minimize impact on ESN.

Please consult ESN Handling Recommendations for guidelines on proper handling and application procedures.

Does ESN float? Will ESN granules wash away in heavy rain?

A small percentage of ESN granules are buoyant and may float in water.  Some surface movement is possible if surface water flow is strong enough to erode soil in conventional-till, or erode residue in no-till. Significant movement of ESN offsite is rare and results from the combination of recently applied ESN, sloping topography, bare soil, and sufficient rainfall for erosion, a combination that should be avoided.  ESN may be less prone to floating and movement if the fields previously received a moderate rain that firmed soil or residue contact with the granules.  Light incorporation is preferred where possible to prevent the possibility of granule movement.

Does ESN need to be soil incorporated to work effectively?

No. Research and grower experience show that ESN works very well when surface applied in many geographies where intermittent moisture or even heavy dew is present.  Many users have had great results top-dressing winter wheat and no-till corn.  To maintain a more predictable N release rate, it is advisable to incorporate ESN where possible.  Surface application without incorporation is generally not recommended in semi-arid and arid areas without irrigation.  When surface applied to very dry soil, ESN granules have difficulty absorbing water and may be slow to release nitrogen. Some moisture is required to initiate and maintain that process. In arid and semi-arid areas without irrigation, incorporation is recommended.

Does ESN release N thru coating failures or fractures?

ESN’s primary release mechanism is by diffusion thru tiny, molecular-size pores in the polymer coating.  A few granules may contain tiny flaws from the coating process, or may be damaged by normal handling processes.  These granules release N quickly on contact with water.  While a small portion of the N in ESN may be released quickly thru these imperfections, the primary release mechanism is by diffusion thru intact coatings.   Sulfur-coated urea, an older technology, does release N through fractures or degradation of the sulfur coating.

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