The 17 essential elements
Form used by plants:
Both solution- and adsorbed- sulfate are forms available for plant use.
Ideal foliage range for apple
250-600 mg sulfate-S/kg
S tests are typically NOT performed with most analytical
P or Mg, approximately 15-35 pounds per acre per year are
taken up by the crop.
Ideal soil range:
low: < 2
sufficient: > 10
relatively mobile in soils
information exists about sulfur in orchard nutrition. Immature
shoot tip leaves are the preferred tissue for diagnosing
S deficiency. Sulfate-S
concentrations of 100 ppm or less are associated with S
Mobility in plant:
to N deficiency except younger leaves are affected first.
Increased risk of S deficiencies
soils that have low organic matter content, shallow soils
or soils in which the topsoil has been removed by erosion. When
in the sulfate form (SO42-), it may
be readily lost via leaching through coarse-textured soils.
Excess problems/Interactions with
- Excess sulfate reduces molybdenum
July 13, 2004