SOME 15 years ago an aquaintance of mine who makes a high-quality compost had some of his product tested by the appropriate authorities. When it was analyzed it didn't rate too highly as a fertilizer. But then something interesting happened. In greenhouse tests it produced plant growth rates considerably higher than its N-P-K (nitrogen-phosphorous-potassium) content indicated was possible. Around the same period some impressive growth rates were being achieved with processed cow manures, even though at the time one newly published gardening book said of manure: ``It ain't worth the hauling.''
Nowadays such results would no longer be considered surprising. The benefits of organic matter in soil, though not fully understood, are much more widely appreciated.
Among other things, manures and composts are generally rich in enzymes, a bacteria-produced chemical, to be more exact, that is fundamental to life on earth. The agricultural enzyme is not a plant food in itself, but it is the key to the pantry door, so to speak. It is the catalyst that prompts chemical reactions that literally unlock the soil, releasing nutrients that might otherwise remain chemically bound and unavailable to the probing plant roots.
Recognizing the importance of enzymes to a vibrant soil, laboratories now produce them in brewing vats for inclusion in biological fertilizers and compost activators and for direct application to the soil. Researchers have identified some 8,000 separate species or types of enzymes, each one serving a different purpose. Many are being put to work in industry, but this column will deal only with agricultural enzymes.
When agricultural enzymes are applied to the soil, millions -- perhaps billions -- of chemical reactions begin taking place immediately, within a matter of seconds, in fact. In the process they detoxify soils that have been poisoned by excessive applications of chemical fertilizers, herbicides, and pesticides; neutralize both acid and alkaline soils; loosen heavy clay soils; and even penetrate hard pan. They stimulate the nitrogen-fixing bacteria, which take nitrogen from the air and ``fix'' it into the
soil, that exist in all soils.
Back in the late 1950s Dr. K. K. Richardson developed a soil-enzyme formula that contained 13 ``families.'' Most important, he hit on a way to stabilize the enzymes so that his Formula A-35 has a shelf life of up to 20 years.
His formula was tested over many years by Frank and Gay Finger on their Kansas farm with such satisfying results that they bought the formula from Dr. Richardson. For several years they have been manufacturing Formula A-35 from a plant in Fayetteville, Ark., for sale to gardeners under the label Nitron.
Under normal circumstances, compost or manure in the soil contains bacteria that slowly release enzymes as part of the decay process which, in turn, stimulates their own ability to reproduce still more enzyme-producing bacteria. So the idea of applying enzymes directly to the soil is to give the whole process a boost and set it on track without delay.
Remember, though, while the enzyme makes plant nutrients readily available, it does not manufacture them. Simply applying enzymes to soil without replenishing its organic content would eventually deplete the soil totally.
Formula-35 can be applied with any organic fertilizer on the same day but not with artificials. If you are using a chemical fertilizer, it is suggested that it be applied three or more days before or after the application of enzymes.
Another enzyme-related product has recently come onto the market, developed over 14 years by Ford Staffel, a biochemist and horticulturist in Houston. His Spray-N-Grow product is a cultured foliar spray that in technical terms is described as a kinase -- a substance capable of converting the precursor of an enzyme into an active enzyme.
Once sprayed on the leaves, the active ingredient is transferred to the roots where it stimulates enzyme production in the immediate root zone. It, too, has yielded promising test results.
For more information on these soil conditioners write to: Nitron, PO Box 400, Fayetteville, Ark. 72702, and Spray-N-Grow, PO Box 722038, Houston, Texas 77272.