Agriculture Reference
In-Depth Information
Ammonium Sulfate 21-0-0 (24% Sulfur)
In the long term, the focus should be on compost and cover crops for nitrogen, but this
product can be helpful during the transition. It's especially useful on farms where it's diffi-
cult to make or buy enough compost, but if you're composting at home, you should be
okay for nitrogen. Remember, plants will pass up chemically produced nitrogen in favor of
amino acid or protein-based nitrogen any time they're available, so our focus is still on or-
ganic matter.
The sulfur in ammonium sulfate does a better job than gypsum to counteract an imbal-
anced soil by leaching excessive cations, and can make the calcium more available. The
ammonium is also slower to release than nitrate fertilizers, which is great, but you need to
have sufficient calcium in the soil in order for ammonium sulfate to work.
The best kind to use is the dark gray colored form, a by-product of the nylon industry.
Since sulfur works right along with nitrogen to form proteins and makes nitrogen use more
efficient, this is a pretty good match. One of the other most important uses is to raise the
energy of the soil, the ERGS, which we'll look at in the energy chapter. This product is one
of the best for raising the ERGS mid-season when you want to promote fruiting in the
plant. The cost is $0.20-$3.00 per pound, and this product is easier to find than the others
mentioned in this chapter.
Of course, you should only use extremely small amounts. Otherwise, it reacts with water
to create sulfuric acid, depletes too many cations, and oxidizes the organic matter. Person-
ally, I don't use it often, but both of my soil labs often recommend it at low doses, not at
the high amounts that conventional farming uses. The rate is two to four pounds per 1,000
square feet on the lawn and in the garden. I use only the lower end of this recommendation.
This low amount should not leach and cause problems, especially if you're working on
building organic matter.
