But manure alone doesn’t cut it. "'There just aren’t enough organic sources of fertilizer [i.e. manure] to raise the crops that we raise today," said Ferguson. "The foods that we eat are all primarily reliant on inorganic fertilizers ... Our society today would not be where it is without inorganic fertilizer."
One of the more popular synthetic options is urea, an ammonium-based compound that is safer to transport, handle and disperse than anhydrous ammonia and ammonium nitrate. But it is a bit more complicated to manufacture, and also works less efficiently than ammonium nitrate, because when it hits the soil, the resulting reaction lets a lot of nitrogen escape into the atmosphere.
This "volatile loss," as it’s called, is amplified in soils with a low acidity. And as a general rule, soil in the western part of the U.S. tends to be more alkaline (the opposite of acidic), meaning urea is a less effective fertilizer in parts of Texas.
Another option is ammonium sulfate. This is the substance primarily used at the American Plant Food Corporation, a producer and marketer of fertilizer based in Houston. Ammonium sulfate is well-suited to alkaline soils, and is less flammable, but it offers fewer nutrients for its weight than ammonium nitrate.
The West, Texas, disaster will, if anything, only accelerate the declining usage of ammonium nitrate as a fertilizer, Ferguson said. But because of its low price, effectiveness and relative ease of transport, ammonium nitrate will probably still be in use — and still pose a danger — for some time.
Copyright 2013 TechNewsDaily, a TechMediaNetwork company. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.