Applications of Calcium Sulfate in Agriculture

Applications of Calcium Sulfate

Applications of Calcium Sulfate in Agriculture – Benefits of agricultural gypsum

Indiscriminate and incorrect use of agricultural lands can lead to increased soil sodium content and soil salinity. Systematic use of calcium sulfate (CaSO4) is one of the important ways of improving field efficiency, especially in amending clay soils.

Besides preventing buildup of sodium in soil and amending sodic soils, the other advantages of using calcium sulfate in soil include improved stability of soil organic matter and soil aggregates, increased infiltration of water into soil and improved seed germination rate.

Together with water soluble polymers and nutrients, calcium sulfate provides better nutrition for plants and also plays an important role in creating a better environment for plant growth.

Calcium compounds are one of the popular minerals in the chemicals market, and fruits often face calcium deficiency when they are growing. Sufficient amount of calcium available to fruits that are growing is one of the factors that increase their quality. Calcium moves very slowly from one part of a plant to its other parts.

Therefore, fruits that receive it last in the calcium transport process usually experience its deficiency. Calcium must always be available to roots. It also improves nitrogen absorption by plants, especially when they are young.


Granules or powder?

It is noteworthy that the origin and particle size of calcium sulfate is very important in agriculture. In general, the smaller the particles of a mineral are the more available they will be to plants. Many calcium sulfate deposits are found on mountainsides.

These deposits are exploded during their extraction to separate calcium sulfate from other substances and powder it in specific sizes.

Calcium can also help in reducing evaporation of ammonia when ammonia, ammonium nitrate, urea, ammonium sulfate, and any ammonium phosphate are applied to soil. In soils with high pH values, calcium is not sufficiently available to plants.

Therefore, application of agricultural grade gypsum helps provide calcium. Calcium sulfate is also a source of sulfur, which is very important for plant growth. Sulfates that are absorbed and metabolized by plants release their oxygen. Nitrogen nitrate does the same thing with the difference that it releases more oxygen compared to sulfates. Calcium sulfate also prevents soil crusting on surfaces and thus helps seedling emergence. It can even prevent crusting in acidic soils.

Prevention of crust formation increases seed germination, accelerates seedling emergence, and allows farmers to harvest their crops earlier and send them to the markets. In such fields, seedling emergence percentage usually increases from 50% to 100%.

One of the mechanisms by which calcium sulfate can adjust soil pH for satisfactory plant growth is the replacement of hydroxyl ions by sulfate ions in some clay lattices. Agricultural grade calcium sulfate can reduce swelling and cracking in clay soils, which are related to the high sodium levels in these soils. Since sodium is replaced by calcium in clay soils, they become less swollen and hence the pore spaces through which air, water and roots move are not blocked.


Forms of calcium sulfate, dihydrate vs anhydrite

Various forms of calcium sulfate are found in the agricultural chemicals market. There are two molecules of water in every molecule of calcium sulfate dihydrate, whereas two formula units of the commercial form of gypsum, which is called calcium sulfate hemihydrate, share one molecule of water.

Anhydrite, or anhydrous calcium sulfate, has no water in its molecular structure. It must be mentioned that calcium sulfate dihydrate is the most reactive form of calcium sulfate in soil because of its water molecules that strongly increase its solubility, Anhydrite and calcium sulfate hemihydrate also have similar properties but they are much less reactive compared to calcium sulfate dihydrate and require much more time for exhibiting their effects.


Benefits of calcium sulfate in agriculture
  • Calcium sulfate is also used to increase concentrations of salts in soft water used in irrigation. Irrigation water from rivers that no longer have soluble salts does not infiltrate well into soil, or it degrades soil aggregates thereby reducing infiltration. Rainwater can behave in the same way and cause soil compaction. Applying calcium sulfate to soil surface, or using it in irrigation water, can solve this problem.
  • Calcium sulfate improves infiltration in compacted soils and decreases penetration resistance. If very wet soil is plowed by machinery, it will become compacted. Use of calcium sulfate can reduce soil compaction in many types of soil.
  • Soils treated with agricultural grade calcium sulfate have a broader spectrum of moisture content and can be planted without the danger of compaction. This is made possible because seedbed preparation is facilitated and accompanied by weed control. In addition, less energy is required for land preparation.
  • Calcium sulfate improves infiltration rate and soil hydraulic conductivity. Another advantage of using calcium sulfate in agriculture is that it protects soil against excessive runoff resulting from heavy rainstorms that are accompanied by erosion.
  • Calcium sulfate improves soil drainage and prevents its flooding caused by a combination of high sodium content, expansive clay soil and excessive rainwater. Increased infiltration rate and hydraulic conductivity caused by calcium sulfate application enable soils to have sufficient drainage.
  • Calcium sulfate can help in removing excess boron from sodic soils and increase stability of soil organic matter. Agricultural grade calcium sulfate also detoxifies the excess magnesium in soil. It can also improve the calcium/magnesium ratio in soils such as serpentine soils that lack a desirable calcium/magnesium ratio.


CalciSoil agricultural gypsum, is calcium sulfate dihydrate extracted from mineral deposits and is available for sale. For any inquiry or question do not hesitate to contact us.