Ammonium sulfate Ammonium sulfate [(NH4)2SO4] supplies
all of its N in the NH4
+ form. It contains 21% N and
24% S. This may be of particular advantage to hybrids requiring
enhanced NH4
+ nutrition, but the effect is shortlived
as NH4
+ is rapidly nitrified (converted to NO3
-) in the
soil over the course of several weeks. In contrast to urea,
there is little risk of NH3 volatilization when surface applied.
Ammonium sulfate also supplies S. It is available in
both dry granular (21-0-0-24) and liquid (8-0-0-9) forms.