Agriculture Reference
In-Depth Information
Epsom salts (magnesium sulfate) are an easy-to-use amendment. If sulfur
and potassium are also low, sul-po-mag can be applied to add all three nutri-
ents. Your soil test should give you suggested application rates for magnesi-
of a particular fertilizer to add.
If both calcium and magnesium concentrations in the soil are low, dolo-
mitic limestone can supply both nutrients while raising the soil pH. Use the
amount of liming material recommended in your soil analyses. Do not apply
dolomitic limestone if the pH is 6.5 or above, or when soil calcium concentra-
tions are above 5,000 ppm.
Boron
Boron can be difficult for orchardists to work with because the trees need the
nutrient only in very small quantities. Unlike most other nutrients, however,
the adequate range of boron concentration within the tissues is very small,
and boron becomes toxic at extremely low concentrations. If your soil test
shows less than 0.5 ppm of boron, add 1 to 2 pounds of actual boron per acre.
Broadcast the boron amendment throughout the entire planting block.
Never apply boron-containing materials to the soil in bands. According to
the Organic Materials Research Institute, boric acid, hydrated forms of sodi-
um tetraborate, sodium borate derivatives, disodium octaborate and its hy-
drated forms, and hydrated forms of colemanite may be used to supply boron
but should be applied to the soil or plants only when you have a documented
deficiency, as shown in soil or foliar analyses. The OMRI website lists recom-
mended boron-containing amendments.
Organic Amendments
Organic amendments can improve water-holding capacity on droughty soils,
improve tilth, and help you get a start on building concentrations of soil or-
ganic matter.
The best materials to add are those that have already been composted,
for several reasons: Provided you have done the composting correctly, the
