ANYONE TRYING to salvage fertilizer potency may be interested in a newer product. Developed by IMC-Agrico, Agrotain inhibits the break-down of urea into ammonia gas. By slowing the rate of break-down, urea is kept fresh and, thus, more beneficial to plants.
“Using this product, you just get more efficiency out of fertilizer,” says Chuck Wilson, Arkansas Extension rice specialist.
A liquid, Agrotain is used as a coating on urea. Despite this, the weight of urea isn't impacted — growers still put out the same amount of Agrotain-treated urea as untreated.
Wilson says the product fits well in situations where nitrogen is put out pre-flood and it takes a week or so to get flooded up.
“Normally, urea begins breaking down after application,” he says. “Laying on the soil surface, it will convert to ammonia gas and much of its value is lost to the atmosphere. By stabilizing the urea with Agrotain, a producer is given more time to get a flood established. When that flood is established, the Agrotain-treated urea is incorporated into the soil and when it breaks down, the urea's benefits are at a higher level.”
Another application for this material is with preflood fertilizer and wet soils. “Our recommendation is to try and delay the fertilizer and flood until the soil dries out. But you can't always do that because the weather is going to do what it wants. Eventually, you'll have to fertilize and flood.
“If I'm in a situation where I'm going to put fertilizer on wet soils, Agrotain definitely has some benefit. Volatilization is the same loss mechanism, but it's normally magnified when untreated urea is put on wet soil compared to dry. In that situation, if it's my field, I'm going to use Agrotain to help stabilize my fertilizer.”
Wilson and fellow researchers now have two years of data from studying Agrotain. He says it looks to be very effective for about 10 days.
“We've done many tests with Agrotain. We've seen some rather dramatic differences in small plots. We've also done strip trials in large fields and have seen similar, although not quite as dramatic, results. In large fields, though, there will be areas that will flood up within 24 hours and other areas that aren't flooded for 10 days. So in large fields, the bottom end of the field will see Agrotain's benefits more than areas closer to the well.”
In tests where half a field is treated with Agrotain and half without, differences in yield can swing 8 to 10 bushels in the product's favor. In plots, Wilson has seen as much as a 30 bushel yield difference consistently.
The cost for Agrotain is about 2.25 cents per pound of urea. If you're treating 200 pounds of urea, it'll cost about $4 to $5 per acre over the cost of straight urea.
“We've had no problems coating urea with Agrotain. Instinct says that if you put a liquid on urea, it will gum up. But that isn't the case with this product — it doesn't cake or anything. Agrotain has some spreader-type material that helps with the coating. It also has a green dye to help show treated urea. Field application isn't a problem either.”
However, there is sometimes an issue with fertilizer dealers having to handle the product. “Treating urea requires an extra step,” says Wilson.
Normally, urea goes from barge to dealer storage to air strip.
“With Agrotain, though, urea's got to be put through a blender or treater of some type. That's time prohibitive — and time is money. That said, there are dealers across the state that have used it and are pleased with the results. Most of the farmers who have used it and I've spoken to have been very pleased as well.”