Soil Amendment Benefits2017-04-26T09:36:12+00:00

Soil Amendment Benefits

Gypsum and limestone are recognized soil amendments applied to promote healthy soils. ACG Materials has high grade gypsum and limestone solutions specifically designed for agricultural application.

Gypsum, anhydrite, and limestone are recognized soil amendments applied to promote healthy soils. ACG Materials has high grade gypsum, anhydrite, and limestone solutions specifically designed for agricultural application.

Why Gypsum?

Natural gypsum can correct soil issues that many other soil amendments can’t. Gypsum is used to balance soil properties, correct aluminum toxicity, leach harmful salts from the root zone, improve water infiltration and retention, improve soil structure and reduces soil crusting, improve nutrient uptake and is a bio-available source of elemental calcium and sulfur.

The Many Benefits of Gypsum, Anhydrite, and Limestone:

Corrects Aluminum Toxicity – Gypsum binds with aluminum to move it deeper in the soil column, it and in turn, temporarily corrects pH levels. Aluminum toxicity can occur in soils that have large amounts of aluminum containing minerals. Excessive amounts of aluminum can inhibit root development and limit crop growth.

Improved Soil Structure – Gypsum and limestone provide calcium, which can flocculate clay soils and reduce the swelling of smectite and open pore spaces improving the penetration of water, air, and roots into the soil.

Increased Water Infiltration – As the soil structure improves, the water infiltration rate and hydraulic conductivity of the soil increases.

Crust Prevention – Using gypsum and limestone to increase the electrolyte concentration of the irrigation water can prevent depositional crusts on soil surfaces, which can adversely affect water infiltration rates and seed emergence.

Better Moisture Retention – Gypsum and limestone help the soil take in and retain moisture, improving the soil’s water-use efficiency, which is especially critical in times of drought.

Fertilization – Gypsum supplies bio-available calcium and sulfur, elements vital to proper plant growth and development.

Enhanced Nutrient Absorption – The calcium supplied in gypsum and limestone is essential to the biochemical mechanisms by which most nutrients are absorbed. It regulates the balance of micronutrients in grass plants and optimizes the calcium to magnesium ratio in soils.

Environmentally Safe – Lawn and garden gypsum and limestone are inert and non-toxic.

Irrigation Effect – Controlling soil salinity with appropriate water management is especially important because soils with high sodium content perform poorly compared to calcium rich soils. Many irrigation sources contain excess salt, which in turn increase the salinity of soils.

Soluble Application  – Soil performance can be improved by including gypsum and limestone with irrigation water because the calcium found in those minerals compete with other applications for binding sites in the soil.

Manure Treatment – Gypsum can be mixed with animal waste to combine with ammonium (NH4) to form ammonium sulfate to prevent loss of nitrogen and thus reduce odors.  Ammonium sulfate is odor free.

Benefits of Gypsum, Anhydrite, & Limestone

Limestone and gypsum have been used for centuries as an additive to enrich the soil with missing minerals and correct pH values. Gypsum can be used for all crops that requires calcium, especially on alkaline soils where they cannot withstand the pH adjustment from limestone. While we normally associate gypsum as a soil amendment, it’s an excellent source of elemental Calcium and Sulfur.

Crops that Benefit from Gypsum, Anhydrite, & Limestone

Alfalfa – Gypsum is a source of sulfur. Alfalfa needs 25-50 pounds per acre of actual sulfur to make a good crop.  Another report indicated that it helped grow stronger healthier stems.

Alliums – increased growth rates and bulb size

Almonds – increased growth and yields

Barley – increased yields

Citrus – significantly reduced root rot caused by Phytophthora parasitica, reduced salinity effects of  salts and improved plant growth (citrus is salt sensitive)

Coffee – increased yields

Corn – 25% higher yields, corn needs about 25-50 pounds of actual sulfur per acre that gypsum can provide

Cranberries – increased yields, less disease

Desert Salt Grass (Distichilis spicata var. stricta) – gypsum increased growth rates and increased biomass, corrected nutrient imbalances due to sodium.

Ginseng – did not affect tissue calcium but a significant increase in both shoot growth and root dry weight.

Grapes – in California gypsum has been used for over 25 years.  Used by many wineries to increase production.

Lawns – 50 pounds per 1,000 square feet or one ton/acre

Lilium sp. – reduced upper leaf necrosis (associated with a calcium deficiency)

– Marsh vegetation and wetlands remediation – had significantly higher dry matter production than the control without gypsum

Papaw – increased total lateral branching by 60-73% as compared to unamended control and total dry matter accumulation and net uptake of N, P, and K per tree was 100% greater

Peanuts – 600-880 pounds per acre have been used

– The peanuts grown had higher calcium content but less zinc. All peanuts grown in gypsum treated fields had less Aflatoxin produced on them when compared to unsupplemented peanuts.

Legumes – require lots of sulfur to form nitrogen fixing nodules on the roots.

– Gypsum has been particularly useful to peanut farmers and to some extent to watermelon farmers.


  • Significantly reduced incidence of internal brown spot and soft rot, in several locations around the country.
  • The best control of the disease of common scab of potato (S. aureofaciens) was obtained by soil application of gypsum (25 g and 12.5 g/pot), and a corresponding increase in yield
  • The mean tuber yield response due to sulfur addition was 1.1 t/ha. Addition of sulfur (S) by gypsum was effective in overcoming the sulfur deficiency symptoms and in increasing the sulfur concentration in the leaves.
  • One study found that growers using 500-1,200 pounds of gypsum per acre had potatoes with stronger cells, they were more uniform in appearance, a decrease in internal brown spotting, and increased storage time


Strawberries – increased yield and reduced soil disease


  • earlier ripened fruit with larger fruit
  • the fruit also had higher levels of some nutrients
  • worked better in reducing blossom end rot as compared to other calcium sources calcium chloride (CaCl2), calcium nitrate (Ca(NO3)2,), etc.

Raspberries – it controlled Phytophthora root rot better, significantly increased plant growth, fruit yield, and root growth compared to other methods and control

Sugarcane – increased growth rates

Vegetables – cabbage, broccoli, cauliflower, radishes, turnips, kale and onions have all been shown to benefit from gypsum

Wheat – increased yields

Wheatgrass (Agropyron elongatum) – gypsum increased growth rates and increased biomass, corrected nutrient imbalances due to sodium.


Plants that can benefit from gypsum include:

Flowers – clematis, lilacs, irises, delphiniums, alyssum stock, candy-tuft, nasturtium, tulips, gladioli, roses, camellias and gardenias

Landscape plants – evergreens, rhododendrons, mountain laurel, pin oak, sweet gum and flowering dogwood


Arbuscular mycorrhizal fungi – increased colonization and growth rates of these beneficial fungi


Cal-CM products

CALCIUM SULFATE – Cal-CM Plus Calcium Sulfate is a blend of two forms of Calcium Sulfate: Anhydrite and Dihydrate (gypsum).

Cal-CM Plus + Calcium Sulfate (available in mini or standard sized prill)

  • Supplies essential calcium for cellular strength and plant vigor.
  • May make 25%-96% more water available to plants depending on the soil type and soil management practices while simultaneously improving drainage through particle flocculation.
  • Reduces excessive runoff and erosion.
  • Fights nutrient tie-up, making many essential nutrients more available.
  • Reduces and retards soil cracking and crusting
  • Improves, amends and reclaims soils high in destructive sodium and magnesium that is present in low quality irrigation water and soil.
  • Helps improve soil structure and decreases compaction, providing optimum air and water availability for plant root growth.
  • Enhances positive bacterial action and discourages plant diseases related to poor soil aeration.
  • Performs as an amendment, conditioner and fertilizer.

Cal-CM Plus + Limestone (available in mini or standard sized prill)

  • Cal-CM Plus Limestone products can be widely used to improve the fertility and functioning of productive soils as follows:
  • Adjusts low pH levels.
  • Neutralizes acidic soils, improving solubility of many essential plant nutrients influenced by soil pH.
  • Features Rapid-Releases technology. The finely ground, uniform particle size is more rapidly released into the soil, which increases the availability of nutrients.
  • Time of Application
  • Causes a reduction in aluminum, which may be toxic and restrict root and associated top growth. Restricted root growth also reduces drought tolerance.
  • Allows for more efficient use of fertilizer-supplied phosphorus (P). Aluminum, particularly at a low pH, is chemically active and combines with fertilizer phosphorus, causing it to become insoluble.
  • Reduces leaching of potassium. On the soil’s exchange complex there are a limited number of sites that can hold nutrients such as potassium. When these sites are occupied by strongly attached aluminum (low pH), any potassium added in fertilizer is more susceptible to leaching.
  • Supplies calcium, an essential plant nutrient.

Cal-CM Plus + Iron (50%)  (available in standard sized prill)

  • Cal-CM Plus Calcium Sulfate + Iron (50%) is an all natural plant food source, with benefits that include the following:
  • Contains 50% Iron, which promotes deep green color in turf and improved root structure.
  • Essential in maintaining good levels of chlorophyll, which promotes optimum plant growth and reproduction.
  • Contains 21% Calcium, for plant strength and soil conditioning.
  • Improves soil structure, making water more available to plants.
  • Promotes strong plant cell wall structure for better transport and retention of other elements to the plant.
  • Contains 16% Sulfur, an essential plant food for production of protein.
  • Promotes the development and activity of enzymes and vitamins.
  • Helps in chlorophyll formation.
  • Improves root growth and seed production.
  • Helps with vigorous plant growth and resistance to cold.


Bulk ag fines products

There are several natural soil amendments that are available for bulk purchase and application.

Our bulk ground gypsum and limestone products are:

  • Solution Grade Gypsum
  • Solution Grade Anhydrite
  • Ag Grade Gypsum 1/4″ Minus Ag fines
  • Ag Grade Gypsum 1/8″ Ag fines
  • Ag Grade Anhydrite 1/4″ Minus Ag fines
  • Ag Grade Anhydrite 1/8″ Ag fines
  • Ag Grade Limestone 1/4″ Minus Ag fines
  • Ag Grade Limestone 1/8″ Ag fines










Cal-CM Sulfate Calculator

Thank you for using the Cal-CM Sulfate Calculator. This is a simple and easy-to-use tool that will allow anyone to compare the calcium values and cost of usage between Cal-CM (with its 100% gypsum guarantee), and any other source of calcium sulfate. The Cal-CM Sulfate Calculator works equally well for comparing agricultural grade, prilled, or solution grade material. Once you input your specific information into the yellow shaded areas, a cost comparison and tonnage requirement will calculate automatically. You will be able to print this complete analysis for future reference.

One helpful hint: If you do not know or have readily available the “lbs. of calcium required per acre”, simply use the following formula for the calculation:

Example 1: If you usually use Gypsum A at a rate of 1 ton (2000 lbs.) per acre, and the calcium percentage of the gypsum is 17%, your calcium requirement per acre would be 2000 x .17= 340 lbs.

Example 2: If you usually use Gypsum B at a rate of 2.5 tons (5000 lbs.) per acre, and the calcium percentage of the gypsum is 14%, your calcium requirement per acre would be 5000 x .14= 700 lbs.

CLICK HERE to download the Cal-CM Sulfate Calculator as an Excel Workbook.

Akhovan-Kharazian, M., W.F. Campbell, J.J. Jurinak, and L.M. Dudley, 199 1. Effects of calcium sulfate, calcium chloride, and sodium chloride on leaf nitrogen, nodule weight, and acetylene reduction activity in Phaseolus vulgaris L. Arid Soil Res. Rehabil. 5:97-103.

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Scott, W.D., B.D. McCraw, J.E. Motes, and M.W. Smith. 1993. Application of calcium to soil and cultivar affect elemental concentration of watermelon leaf and rind tissue. J. Amer. Soc. Hort. Sci. 118:201-206.

Shainberg, I., M.E. Sumner, W.P. Miller, M.P.W. Farina, M.A. Pavan, and M.V Fey, 1989. Use of gypsum on soils: A review, pp. 1-1 I 1. IN: B.A. Stewart (ed.), Advances in Soil Science, Vol. 9, Springer-Verlag New York.

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How to Take Control of Your Soil

The Benefits of Low-cost Soil Amendments

Find out all the ways that applying a simple and low cost soil amendment can improve your yields and lower your overall costs.



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