Seed & Chemical
Alternatives to 34-0-0 nitrogen fertilizer
By Rosalie I. Tennison
Is the loss of ammonium nitrate as a nitrogen source really a crisis?
By Rosalie I. Tennison
Ever since the Oklahoma bombing when ammonium nitrate (AN) was used to create
an explosive that brought down a building and killed and injured hundreds, it
has been a product under siege. For growers, AN has been a good source of inexpensive
nitrogen, easy to apply with low volatilization losses and safe for the crop.
But, government regulations on restricted sale of the product and an industry
concerned about safety meant the gradual withdrawal of a product that was deemed
'not worth the trouble'. With the announcement that Simplot will stop manufacturing
AN at its Brandon facility, there are no North American manufacturers of agricultural
grade AN left. Off-shore manufacturing continues for the time being, but the
cost to import AN means it would no longer be a reasonably priced source of
While some growers who have come to depend on AN as their preferred nitrogen
source bemoan this loss, others are switching to the many alternatives that
are available. In fact, most crop inputs retailers have a list of alternatives
that growers can use and some may be a better choice than AN. As always, what
is required in crop production is flexibility and a willingness to adjust.
Depending on the needs of your crop, growers can choose anhydrous ammonia (NH3),
urea, calcium nitrate*, ammonium sulphate
or UAN liquid as a source of nitrogen. Another option is the addition of Agrotain
to UAN or urea; it is a nitrogen stabilizer marketed by Philom Bios which adds
the functionality of ammonium nitrate to urea and UAN by stabilizing the volatility
of urea. Nitrogain, a product that comprises urea or UAN pre-treated with Agrotain,
is also available through the Mosaic Company. In addition, Agrium of Calgary,
Alberta, is hoping to have a polymer-coated nitrogen product available for food
grade use in 2006.
"The reality is that having AN available became a safety factor and despite
concern over the loss of this product, sales have been declining anyway,"
says Howie Heinrichs, an account manager in western Canada with Agrico Canada.
"This isn't a disaster for agriculture because there are alternatives.
There are all kinds of ways to fertilize a crop and, while growers may have
to make adjustments to equipment to accommodate other nitrogen sources, it's
a one time cost." He says any qualified dealer can help growers make the
Broadcast applications most at risk
Scott Day, a diversification specialist for Manitoba Agriculture, Food and Rural
Initiatives in Melita, says that AN had a nice fit, especially in broadcast
situations. He adds that not all forms of nitrogen will work in all situations.
"Farmers certainly won't stop fertilizing because of this loss, but they
will have to make adjustments," he admits.
As is the case when products get removed from the market for safety reasons
– remember rolling baby walkers and countless recalled food items –
industry improves the product, reducing risk, or develops a better product.
Such is the case with the polymer-coated nitrogen developed by Agrium and the
products Agrotain and Nitrogain. In broadcast applications, their use may be
critical to improving nitrogen use efficiency of alternative products like urea.
"Agrotain can be used to stabilize urea," explains Day. "But,
it isn't commonly used in my area." The patented stabilization that the
product offers prevents volatilization of nitrogen for 12 to 14 days reducing
urea and UAN losses. Of course, using the product adds some cost to the fertilizer,
but growers get the value of a stable product.
Garry Hnatowich, a senior research agronomist with Philom Bios, says Agrotain
is an effective urease inhibitor, which growers need to consider if they want
to get all the benefits from a urea or UAN broadcast application. "Growers
need to consider the cost of a 30 percent loss of nitrogen and balance that
against the cost of urea plus Agrotain. I believe this combination is still
in a price range growers are used to for ammonium nitrate," he says.
Price is always a factor, comments Day. However, Heinrichs believes that growers
do not want to use products that are unsafe and will pay a small amount extra
for the comfort of safety. "Paying more money for a safe product is a choice
most growers make," adds Heinrichs.
The introduction of ESN, a controlled release, polymer-coated nitrogen product
developed by Agrium is keenly anticipated by the company. "Proper management
of urea is something growers need to do and ESN can help with that management,"
says Ray Dowbenko, a senior agronomy specialist with the company. Standing for
'effective, efficient, environmentally smart nitrogen', ESN, when available
for general use, could be another answer to growers' nitrogen woes.
"Much depends on growers' expectations and what their fertility needs
are," continues Dowbenko. "What are their expected results? If only
three to four percent of nutrient loss occurs when using urea, then maybe there
is no concern. If the loss nears 30 to 40 percent, then maybe another nitrogen
source should be considered. Of course, growers are at the mercy of the weather
but they know when there is a higher danger for losses."
ESN is referred to as a controlled release product, not a slow release product.
According to Dowbenko it can take up to two weeks to get 20 to 30 percent of
the nitrogen released to the seed. "This control will reduce losses and
protect the environment," explains Dowbenko. He says it may not release
quickly enough to be a top dress product for the spring. But, there could be
savings in time and costs by using ESN in winter wheat because all the fertilizer
needs can be applied at once in the fall to release gradually over the season.
With respect to nitrogen release, management of ESN for all crops will depend
upon prevailing environmental conditions. The downside is that the product is
currently only registered for non-food crops.
No one ever said choosing a fertilizer program is easy. Since growers moved
away from using only manure to commercial fertilizer products, the number of
sources of nitrogen has increased and the means to apply it to the crop has
been fine-tuned. As in all cases, growers need to plan their fertility program
in tandem with their choice of crop and method to grow it. For example, Day
says calcium nitrate is perhaps not a good choice in his area because the soil
already is high in calcium and the additional cost for calcium nitrate, which
would add unneeded calcium, would not be justified. In another area, however,
where soil test results recommend an application of calcium, this product would
be a good fit.
Heinrichs reminds growers their local retailer will have all the options available
and growers who are unsure what product would be the best choice need only ask.
It is the level of expertise that resides with the local agri-retailer that
growers need to draw on when making their decisions on fertility. While the
loss of AN may be a concern, there are many alternatives and others are in the
development stages, all that is needed is an understanding of them and a willingness
to adjust. -30-
The loss of ammonium nitrate is no big deal. Many growers simply balance the
likelihood of environmental conditions leading to large losses of urea with
the additional cost of a product like Agrotain. If conditions are cold and dry
losses are not expect to be significant, then they go with straight urea. If
conditions are variable or potentially conducive to volatilization, then the
grower has to balance the threat of losing some N with the additional cost.
In general broadcast urea is about 80 percent as effective as urea treated with
Agrotain, so the math is pretty easy. John Waterer,
In this area, 34-0-0 was the preferred fertilizer for broadcasting on grass
seed crops and hayland. Over time, the availability and price have moved farmers
to more uses of 46-0-0. To reduce the risk of loss, many farmers have attempted
to do more fall application, often broadcasting after a snowfall.
Broadcasting urea on three or four inches of snow or just before a rain seems
to reduce loss. The idea of coating is good as long as the weather co-operates
in the 12 to 14 days before. Cost is always a consideration, so most growers
in this area will opt to use the weather to their advantage as much as possible.
Dave Hegland, Wembley, Alberta.