Agriculture Reference
In-Depth Information
Chapter 15
Supplementing Nutrients
STEP 4
The next step is fertilization. Microbes and plants need nutrients. We can supply most of
these nutrients through good mulches and well-made compost, but not only do we need the
nutrients, we need them in specific amounts in relation to each other. That's were a small
amount of specific fertilizers come in, to move towards these ratios. Organic matter gener-
ally can't do it alone, so this is a vital step.
There are several definitions of the word fertilizer . In many countries, in order to be con-
sidered a fertilizer, a product must have a certain amount of total nitrogen, available phos-
phate and soluble potash, often written as NPK.
Notice that it's available phosphate and soluble potash, not total. This has an unfortunate
consequence for organic fertilizers. Nutrients in organic fertilizers are wrapped up in vari-
ous organic compounds that need to be broken down by microbes before they become
available to plants, as nature intended. This means an organic fertilizer will not qualify as a
fertilizer and will look like poor value when compared to the high numbers of a chemical
fertilizer. It will be sold as a soil amendment or perhaps a specialty fertilizer.
Further, the law says a “complete fertilizer” only has to supply the three nutrients listed
above. We know, of course, that plants need many dozens of nutrients, so it makes no sense
to apply only three. In fact, applying any of these three indiscriminately often causes more
problems than benefits.
Also, fertilizers don't have to list how much salt they have in them, or how much chlor-
ine, or how much of any other nutrient we may not want. For example, muriate of potash,
also known as 0-0-60, contains almost as much chlorine as potassium. It's one of the most
common fertilizers worldwide, is used in many NPK fertilizers, and may have caused more
damage to our soils than any other fertilizer. Additionally, chemical fertilizers often include
a slew of heavy metals, sewage sludge and toxic waste that don't have to be listed on the
label. This is a great way for industry to get rid of its toxins — right in your backyard, and
you even get to pay them for the privilege.
Search WWH ::




Custom Search