has been used for more than 200 years as a soil amendment and
fertilizer. At least 30 benefits from it's use on land have been
1. Improves Soil Structure
Gypsum provides calcium, which is needed to flocculate clays in
soil. Flocculation is the process in which many individual small
clay particles are bound together in fewer but larger particles.
This allows root growth and air and water movement.
2. Reclaims Sodic Soils
Gypsum is the most economical way to reclaim sodic soils. The
calcium replaces the sodium held on the clay-binding sites. The
sodium can then be leached from the soil as sodium sulfate to an
appropriate sink. The sulfate is the residue from the gypsum.
3. Prevents Soil Crusting/Aids Seed Emergence
Gypsum can prevent crust formation on soil surfaces which result
from rain drops or sprinkler irrigation on unstable soil. The
gypsum is either surface applied or put in the irrigation system
(high grade gypsum). Prevention of crust formation means more
seed emergence, more rapid seed emergence, and easily a few days
sooner to harvest and market.
4. Improves Low-Solute Irrigation Water
Irrigation water from rivers that no longer have sources of
leachable salts either penetrates poorly into soil or causes
soil particles to degrade, which results in low water
penetration. This can be corrected with the use of gypsum.
5. Improves Compacted Soil
Soil compaction can be prevented by not plowing or driving
machinery on soil when it's too wet. The compaction in many
soils can be decreased with gypsum, especially when combined
with deep tillage. Combination with organic amendments also
helps, especially in preventing return of the compaction.
6. Makes Moist Soils Easier To Till
Soils that have been treated with gypsum have a wider range of
soil moisture levels where it is safe to till without danger of
compaction or deflocculation. This is accompanied with greater
ease of tillage and more effective seedbed preparation and weed
control. Less energy is needed for the tillage.
7. Stops Water Runoff and Erosion
Gypsum improves water infiltration rates into soils and the
hydraulic conductivity of the soil. It is protection against
excess water runoff from especially large storms that accompany
8. Decreases pH of Sodic Salts
Gypsum immediately decreases the pH of sodic soils and near
sodic soils from values often over 9 but usually over 8 to
values of from 7.5 to 7.8. These values are in the range of
acceptability for growth of most crop plants. The level of
exchangeable sodium is decreased, which lessens the hydrolysis
of clay to form hydroxides. Also there is release of the acid
9. Improves Swelling Clays
Gypsum can decrease the swelling and cracking associated with
high levels of exchangeable sodium on the montmorillonite-type
clays. as sodium is replaced by calcium on these clays, they
swell less and therefore do not easily clog the pore spaces
through which air, water and roots move.
10. Prevents Waterlogging of Soil
Gypsum improves the ability of soil to drain and not become
waterlogged due to a combination of high sodium, swelling clay
and excess water. Improvements of infiltration rate and
hydraulic conductivity with use of gypsum add to the ability of
soils to have adequate drainage.
11. Binds Organic Matter To Clay
Gypsum is a source of calcium which is a major mechanism that
binds organic matter to clay in soil. This gives stability to
soil aggregates. The value of organic matter is increased when
it is applied with gypsum.
12. Makes Polymer Soil Conditioners More Effective
Gypsum increases the beneficial effects of water-soluble
polymers used as amendments to improve soil structure. Just as
with organic matter, the calcium in the gypsum is the mechanism
which binds the water-soluble polymers to the clay in soil.
13. Makes Magnesium Non-Toxic
In soils having unfavorable calcium : magnesium ratios, such as
serpentine soils, gypsum can create a more favorable ratio.
14. Corrects Subsoil Acidity
Gypsum can improve some acid soils even more then lime. Surface
crusting can be prevented. The effects of toxic soluble aluminum
can be decreased, even in the subsoil where lime will not
penetrate. It is then possible to have deeper rooting with
resulting benefits to the crops. Gypsum is now being widely used
on acid soils.
15. Improves Water Use Efficiency
Gypsum increases water-use efficiency of crops. In times of
drought, this is extremely important. Improved water
infiltration rates, improved hydraulic conductivity of soil and
better water storage in the soil all lead to deeper rooting and
better water-use efficiency. From 25 to 100 percent more water
is available in gypsum-treated soils due to less runoff.
16. Creates Favorable Soil EC
Because it is readily soluble, gypsum results in a proper solute
concentration (EC) in soil to maintain it in a flocculated
state. It is better environmentally and cost-wise to maintain
the needed EC with gypsum than with excess application of
fertilizers. Regular annual applications of gypsum are needed
for this purpose.
17. Makes It Possible To Use Low Quality Irrigation Water
Gypsum is essential when low quality irrigation water must be
used. The effective sodium absorption ratio (SAR) of irrigation
water should be less than 6 for some crops and less than 9 for
others. When it exceeds these limits, gypsum should be applied.
18. Decreases Dust Erosion
The use of gypsum can decrease wind and water erosion of soil.
Severe dust problems can be decreased, especially when combined
with the use of water-soluble polymers.
19. Helps Plants Absorb Nutrients
Calcium, which is supplied in gypsum, is essential to the
mechanisms by which most plant nutrients are absorbed by roots.
20. Prevents Heavy Metal Toxicity
Calcium acts as a regulator of the balance of particularly the
micro nutrients, such as iron, zinc, manganese and copper in
plants. It also regulates non-essential trace elements. Calcium
prevents excess uptake of many of then, and, once they are in
the plant, calcium keeps them from having adverse effects when
their levels get high.
21. Increases Value Of Organics
Gypsum adds to the value of organic amendments. Blends of gypsum
and organics increase the value of each other as a soil
amendment. Gypsum decreases burn out of soil organic matter when
soils are cultivated.
22. Improves Fruit Quality; Prevents Some Diseases
Good fruit quality requires an adequate amount of calcium.
Calcium moves very slowly, if at all, and fruits at the end of
the transport system get too little. Calcium must be constantly
available to the roots. This is especially true in very high pH
soils. Gypsum is also known to prevent disease: it is used for
peanuts, which develop below ground, to keep them disease free.
Gypsum helps prevent blossom-end rot of tomatoes and bitter pit
in apples. Gypsum is preferred over lime for potatoes grown in
acid soils so that scab may be controlled. Root rot of avocado
trees caused by Phytophthora is partially controlled by gypsum.
23. Provides A Source of Sulfur
Gypsum contains sulfate, a natural form of sulfur which is
readily available for soil needs and plant up-take. This
replenishes the sulfur which is no longer being added to the
soil due to the use of high-analysis fertilizers, which contain
very little, if any, sulfur.
24. Helps Prepare Soil For No-Till Management
A liberal application of gypsum is a good procedure when
starting a piece of land into no-till soil management or into
pasture crops. Improved soil aggregation and permeability will
last for years and surface-applied fertilizers will more easily
penetrate into the soil.
25. Decreases Bulk Density of Soil
Gypsum-treated soil has a lower bulk density compared with
untreated soil. Organics can decrease it even more when both are
used. The softer soil is easier to till and crops respond
26. Multiplies The Value of Other Inputs
Gypsum can improve the response to all other inputs, including
fertilizers. It more than adds to their beneficial effects - it
27. Improves pH of Rhizoshere
Increased calcium uptake by roots when gypsum is applied can
decrease the pH of the rhizosphere adjacent to plant roots. In
high pH soils, the added availability of especially iron and
zinc is very important to some plant species.
28. Keeps Clay Off Roots
Gypsum can help keep clay particles from adhering to the roots
of crops like potatoes, carrots, garlic and beets. This is
cost-saving especially at harvest time.
29. Decreases Loss of Nitrogen to the Air
Calcium from gypsum can help decrease volatilization loss of
ammonium nitrogen from applications of ammonia, ammonium
nitrate, UAN, urea, ammonium sulfate, or any of the ammonium
phosphates. Calcium can decrease the effective pH by
precipitating carbonates and also prevent ammonia loss to the
atmosphere by forming a complex calcium salt with ammonium
30. Increases Crop Yields
Gypsum-for various combinations of the above effects-can
substantially increase crop yields. From 10 to 50 percent is
very common. Gypsum can be a farmer's friend.
The Holloway distributor network can deliver and spread gypsum,
compost and other soil amendments quickly and efficiently. For
more information on Holloway soil amendments, call toll-free
1-800-441-7887 or e-mail Vard Terry at
About Us |
How Does It Work?