Gypsum, the naturally occurring mineral that makes up 90% of the drywall manufactured around the country, is getting a new lease on life, thanks to the growing popularity of drywall recycling. Reclaimed gypsum can be used in the production of new drywall, which means less new gypsum needs to be mined, saving our natural resources. However, there are many ways to use recycled gypsum that are far more significant.
Here are just some of the ways recycled gypsum is being used to improve crops, protect our environment, improve animal living conditions, revitalize contaminated industrial sites, and much more.
1. A Great Source of Valuable Plant Nutrients
Gypsum has been used as a fertilizer to improve agricultural soil for more than 250 years, providing a moderately soluble source of calcium and sulfur that are essential to overall plant growth and increased crop yield.
Now, with the availability of recycled gypsum, it’s less expensive and more environmentally friendly than ever to use this valuable, naturally occurring mineral.
“Because gypsum solubilizes rather slowly, gypsum can provide continual release of sulfur to the soil for more than just the year it is applied. Use of gypsum as a sulfur fertilizer to enhance crop production in sulfur deficient soils has been proved for many crops such as corn, soybean, canola, and alfalfa.” – Gypsum as an Agricultural Amendment – Bulletin 945
Gypsum also provides beneficial calcium that improves crop production and prevents disease in many plants such as peanuts, watermelon, tomatoes and apples.
2. Improve Soil Properties
In addition to improving plant growth and increasing crop yields, recycled gypsum can also be used to condition the soil to improve conditions for optimal growth.
For example, sub-soil acidity can prevent plant roots from utilizing available nutrients and water in the soil, adversely affecting plant growth. Agricultural lime is often used to correct soil acidity and lower soil pH. But calcitic lime’s effectiveness is limited to the zone of incorporation.
Gypsum is often a better alternative to calcitic lime, since its solubility promotes greater penetration of the calcium throughout the soil, controlling acidic soil more effectively.
“Soil scientists note that this material [gypsum] is not only important as a source of sulfur and calcium, but it also may promote changes in soil structure that facilitates better water management and plant growth.” – 2015 Journal of ASFMRA
3. Reduce Toxins in Agricultural Runoff
One of the biggest sources of pollution to our waterways and critical drinking water resources is nutrient runoff from agricultural fields. Nitrogen and phosphorous, commonly found in fertilizers and animal manure used to supply vital nutrients to crops, adversely affect the environment and threaten wildlife when they enter rivers, lakes and streams.
This environmental damage can be clearly seen, particularly in watershed areas such as the Maumee River watershed in Indiana and Ohio, where annual algae blooms have become the norm on Lake Erie. These conditions kill wildlife, introduce toxins into drinking water and disrupt economic growth in the surrounding areas.
While it is necessary to sustain fruitful and reliable agriculture, the need to safeguard our water resources is also a pressing problem that threatens our future. Fortunately, promising research is underway that could turn the tide, allowing farmers to continue supporting their livelihoods, while acting as responsible stewards of the land and the water.
A study is being conducted at Ohio State University to test the effects of using recycled gypsum as a soil amendment in the Maumee River watershed area in an effort to reduce the levels soluble reactive phosphorus (SRP) in the runoff water that enters area waterways.
The earliest results have shown a 55% reduction of SRP in runoff water in gypsum-treated plots of land, when compared with untreated plots. These findings show a significant potential to improve water quality in agricultural areas around the country from the Great Lakes to the Gulf of Mexico.
Data collected from drainage tiles on multiple farms in the Maumee River watershed
While recycled gypsum is already being used to improve soil quality on many farms, this research demonstrates the added environmental benefits of using gypsum to reduce SRP levels and preserve waterways and aquatic life, as well.
4. Additive for Animal Bedding
While gypsum’s solubility makes it the perfect mineral for increasing crop yields, conditioning soil and preventing toxic run-off, gypsum’s absorbency also makes it a great additive for animal bedding.
Organic materials, such as sawdust, shavings, straw and corn fodder are widely used as bedding materials for dairy cows. However, these materials often support conditions such as moisture, nutrients, and rich pH, which are ideal for pathogenic growth. Adding gypsum additives to dairy bedding keeps bedding dryer, while decreasing teat end exposure to environmental mastitis pathogens and reducing somatic cell counts. The result is healthier cows and safer milk production.
Gypsum additives are also useful in chicken houses to promote healthier chickens.
“Ammonia concentration, litter moisture and pH were significantly lower in the gypsum treatment than the shavings treatment at both 21 and 40 day of age. No differences in broiler performance, livability or paw score were observed” – University of Georgia, Athens, GA
Horse boarding facilities and equine enthusiasts can also benefit from using a gypsum additive in their horse bedding. Gypsum additives absorb, neutralize and trap ammonia odors, extending bedding life. Unlike other bedding additives, like lime, gypsum will not burn or crack horse hooves. In fact, gypsum additives are natural, non-toxic and safe for humans and animals. Gypsum additives also aid in composting manure and improve manure value.
5. Soil Remediation and Stabilization
Another useful application for recycled gypsum is in the area of soil remediation or stabilization in industrial sites such as hard rock mining, coal mining, smelting and refining and construction and mixed-contaminant areas.
Gypsum, combined with other soil amendments, can address a variety of soil issues including:
- Aluminum (Al) toxicity
- Poor soil aggregation
- High sodic levels
- Lead stabilization
- Hydrocarbon contaminated soils
Gypsum is a great choice for soil remediation because it is inexpensive, non-toxic, safe to handle and relatively soluble.
6. Bulk Waste Solidifiers & Stabilizers
To minimize the release of harmful chemicals from industrial waste sites, liquid waste if often converted into solids for proper storage or disposal. Due to its absorbent properties, gypsum powder is an ideal choice to convert semi-solid slurries that represent a significant volume of most waste. Recycled gypsum, in particular, is more absorbent and provides superior solubility when compared to mined gypsum products, for faster waste cleanup and remediation.
7. Fillers & Diluents
Recycled gypsum can be successfully substituted in many products that have traditionally used mined gypsum products. Cement and specialty ready-mix concrete manufacturers have already begun using recycled gypsum in many of their products. Recycled gypsum is also used in a wide range of plastics, caulks, adhesives, sealants and specialty cements.
Due to its lack of abrasiveness and inert properties, recycled gypsum is also an ideal filler or diluent for a variety of products including:
- Wood Filler
- Tile Grout
- Body Putty
- Modeling Clays
Recycled gypsum also improves fire retardancy, tensile strength and translucency of polymers, particularly thermoplastics, thermosets and coatings, while reducing production costs at the same time.
8. Water Clarification
Cloudy or muddy water in ponds is not aesthetically pleasing and can be potentially dangerous. Muddy water reduces sunlight penetration which can be detrimental to aquatic life, by limiting food production for game fish and other animals. Cloudy water can also interfere with the ability of many species of fish to see and capture prey. Cloudy water conditions can also promote the growth of undesirable blue-green algae and bacteria.
The most common cause of cloudy ponds and lakes is the presence of suspended particles, mainly clay. Soil erosion, rain runoff, animal activity and the food-seeking actions of bottom-feeding fish like carp and bullheads can all contribute to suspended clay particles in ponds and lakes.
The addition of gypsum into muddy ponds helps to clarify the water by attracting clay particles together to form clumps. As the clay particles clump together, their weight increases and the clumps settle to the bottom. Since gypsum is a neutral salt, adding it to the water will not affect the pH of the pond or lake.
9. Compost Additive
Recycled gypsum is an all-natural way to enhance compost, whether you’re a backyard gardener or a commercial composter. Gypsum naturally reduces nitrogen losses which improves compost aeration, increases heat, enhances microbial growth and reduces unpleasant odors. The addition of a gypsum additive also provides calcium, sulfur, nitrogen and trace minerals to the basic compost, making it more valuable.
10. Lawn & Garden
Everyone wants the rich, green lawns they see on TV. But many of the products on the market, such as weed and feed or garden fertilizers, may not produce results homeowners expect because poor soil quality is the real problem.
The key to lush, green grass and blooming gardens is proper soil conditioning. Just as farmers use recycled gypsum to enhance crop growth and improve agricultural soil, the same techniques can be applied to residential lawns and gardens. The addition of recycled gypsum soil amendments loosens clay soils, naturally aerating soil and improving water and air penetration. This encourages the production of early roots. Recycled gypsum can also improve acidic, sodic or erosion-prone soil conditions.
Recycled gypsum soil amendments are cost effective and safe for pets, people and plants.
When you consider all the beneficial uses for recycled gypsum, it’s no wonder that recycled gypsum production is on the rise. The use of recycled gypsum not only preserves natural resources by reducing the need for additional gypsum mining. It also keeps waste drywall out of landfills and provides many ways to safeguard our environment, sustain our crops, and revitalize contaminated sites to provide additional resources for the future.
To find out more about drywall recycling in your area or to purchase recycled gypsum products, visit USA Gypsum, the largest drywall recycler and gypsum products producer in the United States.