ISBN 0-913107-05-0, Pub Regenerative Agriculture Association, 222 Main
Street, Emmaus, PA 18049. The Rodale people, obviously.
The book points out that entire fertilizer management question is an
Yes, according to the book, there can be great variability between labs.
The book strongly suggests you research your labs by asking users about
them, by seeing what industry credentials they have, and by asking how
they do their analysis. The book suggests you work with labs that are
either local or are persuasively competent in your soil and plant types.
They like the land-grant university labs best.
A lot of what is mystifying about fertilizer is sorting out the
difference between what you soil has, what your plant needs according to
yield goal and growing conditions, and the availability of the
fertilzier. If there is a word to put in capital letters, it's
availability. Obviously, you can grow in a limestone quarry, but if the
lime isn't in the form and the location that the plant can use it, you're
not going to benefit.
Some natural fertilizers are very good, but don't release when the plant
needs them. You might find plenty of N, but have to sidedress some at
planting time because the N is tied up in the carbon which is decomposing
You may also find you don't need very much of some kinds of fertilizer.
As a tip, for economical purposes, I'd suggest you put on basic
fertilizers like lime, NPK first, and do it on the land that gives the
best quick return, probably your poorest ground. Be careful about making
big commitments to "build" fertilizer like PK. It doesn't move, so you
could be just dumping a lot on where it's not going to be used.
Jim - Farmer - Iowa City, IA,