Agriculture Reference
In-Depth Information
while supplying magnesium. Because this is a natural product, the percent-
ages and chemical compositions of calcium and magnesium vary, as does
its calcium carbonate equivalent value (liming ability). As we discussed in
and pH are both low. Excessive amounts of magnesium can interfere with
calcium uptake and increase bitter pit problems in apples.
Enzymes.
Various organic products containing enzymes, often combined
with supposedly beneficial microbes and plant nutrients, are marketed as
fertilizers and soil amendments. According to the U.S. National Organic Pro-
gram, enzymes are acceptable if derived microbiologically from natural ma-
terials and not fortified with synthetic plant nutrients. In actual practice, it
is extremely difficult to understand how applying enzymes to the soil would
benefit orchard crops.
Enzymes are chemically complex biochemicals that carry out or regulate
very specific chemical reactions. Microbes, soil macroorganisms, plants, and
all other living things produce the enzymes they need for their life processes.
While adding enzymes to the soil or spraying them on your fruit crops is not
likely to cause any damage, you will earn much greater returns on your in-
vestments of time and money by focusing on creating the conditions needed
for a biologically rich and active soil containing adequate amounts of plant
nutrients. We have covered many such practices, such as correcting soil
drainage problems, adjusting soil pH, incorporating green manure crops, ap-
plying compost, and adding optimal amounts of plant nutrients.
Epsom salts or magnesium sulfate.
Epsom salts are a rich source of mag-
nesium and are best applied before planting orchard crops. They are much
more rapidly available than dolomite, however. According to the U.S. Nation-
al Organic Program, they may be used when you can document a soil mag-
nesium deficiency. Base your application rates on soil or tissue analyses. Do
not apply to apples when soil calcium concentrations are also low. Kieserite
