Agronomically
and Environmentally Sound Fertilizers
Sulphur is an integral part of plant nutrition and is used
by all plant types in varying quantities. The primary source
of plant available sulphur comes from the soil's organic matter.
Organic matter mineralizes into plant-available sulphate sulphur.
As such, every year that a crop is harvested, a portion of
the available soil sulphur is depleted and a portion is returned
to the soil as crop residue that is recycled back into organic
matter.
As the years go by without supplementing the soil with sulphur
fertilizer, the cropping systems tend to remove more sulphur
than is being replaced, leaving many soils worldwide in a
sulphur deficient scenario.
Another significant factor affecting soil sulphur levels are
environmental concerns. sulphur is being continually "cleaned"
from fuels such as gasoline and diesel fuel, coal burning
plants have become more efficient and emitting less sulphur
into the atmosphere. Due to these two major factors, atmospheric
sulphur being returned to the soil by way of acid rain has
been reduced globally.
Elemental sulphur has the potential to be a very large and
effective product for satisfying global plant nutrient sulphur
requirements. Elemental sulphur fertilizers' agronomic availability
(conversion from S to SO4) is dependent on soil moisture,
bacterial activity, temperature, and particle size.
Particle size may be most crucial. Elemental sulphur can be
easily converted to plant available sulphate sulphur if the
particle sizing is in the 50 to 200 mesh range. Particle size
can be controlled via operational procedures and swelling
clay selection, and as such, rate of conversion from S to
SO4 can be controlled.
R&D Research Farm – Washington, Louisiana
Alberta Agriculture, Alberta Canada
Controlled Release
Controls are widespread in Europe to control volumes of water
soluble fertilizer leaching losses. North America and other
parts of the world are heading in the same direction. The
Mississippi and Rhine river watershed are two good examples
of major agricultural regions environmentalists are targeting
fertilizer leaching losses. Much attention is being paid to
the 'dead zone' in the Gulf of Mexico - which in part is attributed
to fertilizer leaching losses.
Because elemental sulphur bentonite formulations convert to
plant available and water soluble sulphate sulphur over a
period of time, the sulphur is available to the crop throughout
the growing season and is much less likely to be lost due
to leaching.
Most elemental sulphur formulations can be certified as Organic
as well.
