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United States Department of Agriculture

Agricultural Research Service

Related Topics

Research Project: Impact of Gypsum on Crop Yield, Soil Chemical Properties, and the Solubility of Phosphorus

Location: National Soil Dynamics Laboratory

2009 Annual Report


1a.Objectives (from AD-416)
1. To evaluate the impact soil amendments have on dry matter production and nutrient recovery in a bermudagrass pasture. 2. To evaluate the impact soil amendments have on soil chemical properties, specifically pH, SO4, exchangeable Ca, Al, Mg, trace metals, and electrical conductivity. 3. To evaluate the impact soil amendments have on available P in the soil.


1b.Approach (from AD-416)
Transport of P from land application of manure poses a major treat to accelerated eutrophication in surface water. Thus, evaluation of best management practices to minimize the environment the impact of P loss from animal waste is needed. The use of soil amendments such as FGD-gypsum seems to be a low-cost viable option. FGD-gypsum is a byproduct of the gas desulfurization systems used to reduce air pollution in coal burning power plants. The supply of FGD-gypsum is projected to increase in coming years as air quality standards continue to increase. Agricultural producers and stakeholder could benefit from the waste byproduct. Thus, research is needed to assess the environmental and plant productivity effects of FGD gypsum application to soils. Thus, the objective of this study is to evaluate the environmental and plant productivity effects of FGD gypsum application to soils.


3.Progress Report

Flue gas desulfurization (FGD gypsum) is a byproduct of scrubbers used to remove sulfur from the flue gas coal burning power plants during electricity production. This product is becoming available in large quantities. Presently, FGD gypsum is used primarily in the wallboard and cement industries. However, installation of FGD scrubbers is expected to increase significantly in response to new and existing air pollution regulations, with a concomitant increase in FGD gypsum. The current markets are not expected to be able to utilize all of the FGD gypsum produced. Agricultural land could benefit from the use of FGD gypsum, as low cost alternative to commercial gypsum. Thus, research is needed to adequately assess the environmental and plant productivity effects of FGD gypsum application to soils. To evaluate the potential benefits of FGD gypsum, an experiment was initiated in the spring of 2008 to determine its impact on biomass production in a Bermuda grass pasture. Treatments consisted of three different gypsum products (commercially available gypsum and FGD gypsum and FGD gypsum +fly ash from TVA) applied at three different rates (2, 10, and 20 Mg ha-1). Poultry litter was used as the fertilizer source. During the 2008 growing season (June-November), the Bermuda grass was harvested and biomass was collected three times throughout the growing season. Biomass yield was collected and the plant tissue was analyzed for nutrient content. An evaluation on the impact that FGD gypsum and FGD gypsum + fly ash has on the environment, plant productivity and soil fertility are in the process of being evaluated.


Last Modified: 10/1/2014
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