From Farmer to Shrimper: The Dead Zone
(pg 5 of 8)
Together, corn and soybean fields account for
about half the nitrogen that reaches the Gulf.
In recent decades, farmers have also confined
larger numbers of livestock to smaller parcels of
land, with less land available for the distribution
of manure. Animal manure accounts for about 15
percent of the nitrogen load reaching the Gulf.
In all, nearly 90 percent of the nitrogen bound
for the Gulf of Mexico originates from nonpoint
sources. The remainder comes from municipal and
industrial point sources (such as municipal sewage