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2019 Myth Busters

Reference: Nutrien ESN - Rosie Thoni

Busting the Myths Around ESN: Part 2

Last year, we shared a few of the most common myths around ESN and gave you the facts, straight from the source. This time, we’re tackling more myths, like how ESN is released into the soil, what happens to ESN in heavy rainfall, and if the urea in ESN will volatilize as it releases. Read on to learn the facts about these common misconceptions and more.

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 for specific geographies, crops, and applications. Please consult ESN recommendations and/or your Nutrien ESN representative for complete recommendations for use.

Myth #1: ESN releases nitrogen when the coating breaks down in the soil

ESN’s coating encapsulates a soluble nitrogen fertilizer. The coating forms a protective barrier that acts as a semi-permeable membrane surrounding the fertilizer granule. Tiny, molecular-size pores in the polymer coating allow water to slowly enter the granule, dissolving the soluble fertilizer which then diffuses out through the coating into the soil. The rate of the process is controlled by soil temperature. ESN’s coating remains intact through the release process, maintaining the protective barrier and controlling N supply to the crop. ESN does not release N by swelling, rupture, or “breakdown” of the coating.

ESN’s coating is a biodegradable polymer that decomposes in in the soil in about 18-24 months. The end products of ESN decomposition are carbon dioxide, ammonia, and water. However, this “breakdown” is not the mechanism of N release. ESN’s primary release mechanism is by diffusion through tiny, molecular-size pores in the polymer coating.

Myth #2: Since the N in ESN releases as urea, it will volatilize the same way when left on the surface

ESN protects against volatilization even more effectively than urease inhibitors and for a longer time. Urea released from ESN is less susceptible to volatilization because only a small amount is released at a time, which maintains a lower urea concentration and prevents the temporary rise in pH around the fertilizer granule that is responsible for causing ammonia volatilization.

Myth #3: ESN cannot release quickly enough if applied in a growing crop

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, top-dress ESN may be preferred over ESN applied before planting. On cool-season crops in cold areas, such as Western Canada and the Northern 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 crop’s immediate N needs until ESN release begins. Consult your ESN dealer or Nutrien representative for specific recommendations for crops and application times.

Myth #4: My regular fertilizer application equipment will 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, proper procedures and adjustment of spreaders will assure damage is minimized, ESN retains its protective coating and performs as it should.   

Myth #5: ESN will float and 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. Light incorporation is preferred where possible to prevent the possibility of granule movement.

Myth #6: ESN is similar to a nitrogen stabilizer or urease inhibitor

ESN is 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 when greatest losses generally occur. Urease inhibitors and other similar additives, called stabilizers, are 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.

To see a time-lapse video of how ESN releases in the soil, click here.

For ESN use recommendations, including proper handling and application procedures, click here.

For questions or comments, tweet us  @SmartNitrogen.

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