THE BENEFITS OF GYPSUM
Gypsum deposits are found in sedimentary rock on all five continents of the world. Precipitation in
vast inland seas during prehistoric times has produced gypsum deposits from Canada to Texas and throughout
the Western States of the US.
The chemical name for gypsum is Calcium Sulfate Dihydrate; it's simply Calcium Sulfate with two water molecules attached.
The earliest evidence of gypsum's use is found in the mortar and plaster of the ancient pyramids of Egypt. Even today, eighty per cent of gypsum mined in the US is destined for the construction industry, making up the major component of drywall. An inexpensive, non-toxic and inert substance, gypsum is also used as a filler in many foods, in the brewing industry, by the cosmetic industry, as a binding agent in pharmaceuticals and a major component of kitty litter.
For over 200 years farmers have used Gypsum as an effective and cost efficient soil conditioner. It is highly versatile, with a huge array of benefits that can be broken down into four main categories.
- Soil Conditioner
- Water Efficiency
- Gypsum as a fertilizer
- Gypsum in soil amendment
The free calcium ions in gypsum flocculate soil particles, opening up the soil and making it more porous.
As a result, soil becomes more friable allowing better root growth and greater movement of air and water in
the root zone.
Gypsum is particularly effective in breaking up compacted soil caused by sodium and clay. Crusting, cracking, panning, slaking and compaction are reduced, which promotes better seed emergence. Less tillage may be needed and gypsum helps build a deeper top soil. The soil dries more easily so that it is easier to till after rain or irrigation. Gypsum binds organic matter to clay, giving stability and checking erosion. Good aeration enhances friendly bacterial action and discourages up to thirty plant diseases such as blossom end rot and bitter pit.
Gypsum promotes water infiltration, retention and conservation and the water becomes 'more available'
in chemical terms. Acting as a 'wetting agent', gypsum allows water to penetrate soil without run-off, ponding
or waterlogging. Some studies have found that the application of gypsum can half the amount of run-off by increasing
surface roughness and flow path tortuosity. Better penetration allows longer intervals between irrigations. Tests show
farmland treated with gypsum can require up to 33% less water. In most cases the money saved in water costs will more
than pay for the gypsum used. Lower quality water can be used for irrigation after treatment with gypsum. Examples are
river water with low solute levels which are sometimes too pure to give good water infiltration, or recycled water
with high salt levels.
Gypsum supplies calcium and sulfur, both essential nutrients for plants. Calcium promotes the uptake mechanism for many other minerals - nitrogen, phosphates, potassium, iron and zinc.
Very alkaline soils are buffered by gypsum, and the low pH in acidic soils will be increased. The calcium in gypsum also counteracts sodic soils by replacing the sodium ions on clay-binding sites, allowing excess sodium to leach out.
Other elements that are considered toxic in high amounts become chemically bound by gypsum (e.g. aluminum and magnesium).
The overriding value of gypsum is that the benefits compound and the effects of any additional chemical products used on the crop may be magnified. As a soil conditioner, the distribution of water, oxygen and minerals is improved. As a chemical, soil conditions are balanced and the uptake of nutrients by the root system is enhanced. As a fertilizer, gypsum provides the vital calcium and sulfur essential for growth.
Better soil conditions, improved root growth and increased water and mineral uptake promote healthier plants, increased growth and bigger yields.