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.

What is ESN?

ESN is a controlled release nitrogen fertilizer. It consists of a quality urea granule contained within a unique polymer coating. The analysis of ESN is 44-0-0.

Does ESN stay soft for the entire growing season? 

ESN stays soft if there is moisture to diffuse into the coating and maintain the urea solution inside.  Under conditions of severe, extended drought where ESN is left on the soil surface, it may slowly dry out and may become hard.  It will rehydrate and become soft, once moisture is present again.

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 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.

How is ESN different from Agrotain and other similar products?

ESN is a controlled-release nitrogen fertilizer.  ESN encapsulates the nitrogen and controls all N losses by regulating the exposure of N to the environment while it gradually feeds the crop.  Nitrogen in ESN remains encapsulated and releases N over a period of about 50-80 days protecting that N during the periods of generally greatest losses.  Agrotain and other “look-a-like” urease inhibitors are chemical additives, called stabilizers, added to urea to reduce volatilization only and are effective for about 7-14 days after application.  Urea treated with these additives is immediately water soluble.   

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.

Is ESN recommended for use on all acres?

ESN is designed for soil and environments that are at risk for N-loss and where nitrogen is a limiting factor for growth. The added value of ESN may not be realized in soils that have other limiting factors such as compaction, drought, flooding, imbalance of other nutrients and excessively high or low pH. ESN does not correct existing problems in the soil other than the loss of N from traditional sources.  ESN may have some benefits not related to N loss that results from continuous feeding and controlled-release nitrogen supply.

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.

How should ESN be spread?

ESN can be applied using either spinner or air flow machines. ESN should be double spread for uniformity when using a spinner because fertilizer tapers off at the edges of the spread pattern. Always ensure the spreader is properly calibrated to deliver the desired N rate.

See Use Recommendations for more information.

How should ESN be handled?

Care should be taken to minimize granule abrasion that results from excessive handling. Belt conveyors are preferred.  Moving ESN with screw augers, especially when operated at high speeds and low volumes, should be minimized.

See Use Recommendations for more information.