Members

Members are needed for participation in a Network Research Project on agricultural uses of FGD gypsum and other FGD products. The goal is to demonstrate the agronomic value and environmental acceptability of FGD products in each participant's geographic area.

There are Network research sites in North Dakota, New Mexico, Indiana, Arkansas, Alabama, and Ohio. Descriptions of these sites are below.

NORTH DAKOTA

Coal Creek Generating Station – Great River Energy

The Coal Creek Generating Station of Great River Energy (headquarters in Elk River, MN) is located near Underwood, ND. It is supporting research at two sites located about 8 miles south of Dickinson, ND. The soil at #1 ( wayne) is classified as Lawther silty clay from the White River formation. This site has a slope of 0 to 2 percent and has been in wheat-fallow for greater than 20 years. The soil at #2 ( gary) is classified as a Belfield-Daglum silt loam from the Golden Valley formation. This site has a slope of 0 to 2 percent and has been in a wheat-fallow rotation for greater than 10 years. Wheat crops were grown at both sites in 2007 and 2008 using no-till management. Yields, and soil and grain samples for chemical quality measurements were collected each year. Gypsum rates for both FGD gypsum and commercial gypsum were 0, 1, 5, and 10 tons/acre (0, 2.24. 11.2, and 22.4 Mg/ha).

NEW MEXICO

San Juan Generating Station – Public Service Company of New Mexico

The San Juan Generating Station of Public Service Company of New Mexico is a coal-fired power plant located about 15 miles west of Farmington, NM. It is supporting research at a site northeast of Aztec, NM. The soil at the site is a Werlog loam (Aquic Ustifluvents, fine-loamy, mixed [calcareous] mesic) with a 0 to 1 percent slope. This deep, somewhat poorly drained soil is on the Animas River floodplain and has been in permanent pasture or alfalfa for at least the past 20 years. Crop growth is restricted in some areas of the site due to low soil permeability caused in part by high soil salinity and/or sodicity. It is suspected that gypsum might improve these conditions by decreasing soil dispersion and increasing hydraulic conductivity. FGD and commercial gypsum treatments were applied in mid-April 2008 at rates of 0, 1, 5, and 10 tons/acre (0, 2.24, 11.2, and 22.4 Mg/ha). Alfalfa was planted the first week of June, 2008, but poor stand establishment due to cold weather required replanting in August, 2008.

A second New Mexico study was started in August 2008 on a field at the New Mexico State University Agricultural Science Center in Farmington. The purpose of this study is to evaluate gypsum as a sulfur source for alfalfa nutrition. Alfalfa has a high S requirement and will remove 30 kg S/ha per year as hay. FGD and commercial gypsum treatments were applied at rates of 0, 0.045, 0.13, and 0.45 tons/acre (0, 0.10, 0.30, and 1.0 Mg/ha). Preliminary (pre-treatment) soil samples were collected, the gypsum treatments were applied, alfalfa was planted, and initial irrigation water was applied between August 8 and August 14, 2008. The first cutting for alfalfa yield was made in May, 2009. The soil in the experimental field is Kinnear very fine sandy loam.

ARKANSAS

White Bluff Generating Station - Entergy

Entergy’s White Bluff Generating Station near Redfield, AR (30 miles south of Little Rock) is supporting research that began in 2008. Because the White Bluff plant did not currently produce gypsum, substitute FGD gypsum was obtained from We Energies Pleasant Prairie Power Plant in Wisconsin that burns primarily Powder River Basin coal—as does the White Bluff Plant. The research objectives are to evaluate the effects of gypsum applications on water infiltration and stand establishment of cotton, and on aluminum solubility and cotton root growth. One goal is to use gypsum application to reduce the soil crusting that often requires planting of 3 or 4 cotton ( Gossypium hirsutum ) seeds in one place to insure an adequate stand. This high rate of seed planting has a seed cost of approximately $75 per acre.

Soil samples collected as part of another study showed a significant degree of pH stratification in the top 45 cm of the soil profile in several fields in Central Arkansas. Observed soil pH levels were in the 6-7 range in the first 15 cm and decreased to a 4-5 pH range for samples collected deeper than 30 cm. It is well known that increased aluminum solubility under acidic soil pH inhibits proper root growth, restricting root development to the first 45 cm of soil. Such situation increases the probability of fruit shade as a result of wide fluctuations in moisture conditions in such soil volume.

A test site at the University of Arkansas’s Lon Mann Cotton Research Station near Marianna, AR was selected to conduct the tests on a soil mapped as a Memphis silt loam (fine-silty, mixed, active, thermic Typic Hapludalfs). Memphis silt loam is a very deep, moderately permeable, well drained soil that developed in deposits of loess (wind-blown silt) more than 4 feet thick. The soil is moderately to very strongly acid throughout the profile, except where limed. The Memphis series is of large extent in the Southern Mississippi Valley Silty Uplands (Major Land Resource Area 134) in Arkansas, Kentucky, Louisiana, Mississippi, Missouri, and Tennessee.

Pelletized (commercial) gypsum and FGD gypsum were applied in April 2008 at rates equivalent to 0, 1, 2, and 3 ton/acre (0, 2.24, 4.48, and 6.72 Mg/ha) to plots ≈ 4 m x 15 m (i.e. four 38-in wide beds, 50 ft long). A rainfall simulator was to be used to induce the formation of a crust the day after planting, but excessive extended rainfall prevented crust formation and caused poor stand establishment unrelated to crust formation.

In 2009, FGD gypsum at rates equivalent to 0, 0.4, 0.8, and 1.0 ton/acre (0, 0.9, 1.8, and 2.3 Mg/ha) will be applied ahead of planting to plots ≈ 4 m x 2 m (i.e. four 38-in wide beds, 6 ft long). Treatments will be replicated 4-5 times in a randomized complete block design. Planting will be done by hand to ensure a consistent seed population. A rainfall simulator will be used to induce the formation of a crust the day after planting. Plant emergence and stand counts will be collected. A tension infiltrometer (Decagon devices, Pullman, WA) will be used to assess infiltration rates according to gypsum application rates.

A 40 ha field was selected to assess the effect of FGD gypsum applications on aluminum solubility, cotton root growth and water infiltration. Treatments consist of FGD gypsum at rates of 0, 0.4, and 0.8 ton/acre (0, 0.9, and 1.8 Mg/ha), with treatments replicated 3 times. Plot dimensions are ≈ 25 m x 125 m (24, 38-in wide beds, 400 ft long). Deep soil samples (0-60 cm, on 15 cm increments) were collected prior to gypsum applications and will be collected after crop removal. Soil pH was measured in the samples collected, with pH stratification being significant. Samples will be analyzed for nutrient content, and soluble aluminum. Soil moisture, at 15 and 45 cm deep, will be monitored through the season with ECH 2O probes (Decagon devices, Pullman, WA) attached to a data logger for continued measurement. Water advancement will be measured on each plot with temperature sensors (www.ibtag.com) located every 30 meters. Root growth development will be monitored through the growing season and will be assessed at peak bloom.

INDIANA

Cayuga Generating Plant - Duke Energy

The Cayuga Generating Plant of Duke Energy is supporting research on agricultural use of FGD gypsum in western Indiana. The Cayuga Plant did not produce FGD gypsum when the study was being established, so substitute FGD gypsum was provided by Duke Energy’s Gibson Power Plant in Gibson County in southwestern Indiana. The hypothesis of this research is that a surface application of FGD gypsum will serve as an electrolyte source for low electrolyte rainwater and improve water entry and surface water quality and provide Ca and S fertility for plants in a conservation tillage system. A rainfall simulation study in the second year will quantify the effect of application of FGD gypsum on soil loss and surface water quantity and quality especially with respect to Hg in the runoff waters.

The field for study is in western Indiana near Kingman ( Fountain County) and has been in long-term conservation tillage in a corn ( Zea mays)/soybean ( Glycine max) rotation. Soils in the field are predominately Russell silt loam (fine-silty, mixed, superactive, mesic Typic Hapludalfs) and Ragsdale silty clay loam (fine-silty, mixed, superactive, mesic Typic Argiaquolls). These are very deep soils that developed in deposits of loess (wind-deposited silt). Russell silt loam has an acid subsoil and is of large extent in Indiana, Illinois, and Ohio. Ragsdale silty clay loam is of moderate extent in Indiana and Illinois. These soils have problems of runoff, erosion, water entry, and drainage typical of many soils in the Midwest corn-belt.

The experimental design is a completely randomized design with four replications randomly assigned to strips across the field. Each treatment plot is 60 feet (18.3 m) wide by 1850 feet (564 m) long (2.55 acres or 1.03 ha) in size. FGD gypsum is being compared to a commercially-available pelletized gypsum product (provided by Mineral Processing, Inc) that is widely sold in the corn-belt and other areas. The FGD gypsum was applied by a normal lime spreader and calibrated to deliver an accurate amount. Rates of FGD gypsum and commercial gypsum applied to the soil on May 29, 2008 were 0, 300, 750 and 2000 lb /acre. Corn was planted late (June 20) in 2008 because of excessive rains. Soybean will be grown in 2009. Planting of the plots is done with Real Time Kinematic (RTK) satellite navigation and yield is determined using a calibrated yield monitor equipped with a very accurate Global Positioning System (GPS) to construct a yield map. The harvester records the entire yield of the treated strips, which are farmed in a controlled traffic scheme.

Rainfall simulator experiments will be conducted on small 1 m by 6 m plots within the larger plots in 2009. A portable rainfall simulator will be used to apply a 2 inch /hr intensity rainfall until steady state runoff conditions are established and then samples will be taken every five minutes for runoff, sediment, nutrient and pesticide production and heavy metal concentrations.

ALABAMA

Widows Creek Fossil Plant - Tennessee Valley Authority

Tennessee Valley Authority is supporting research in northern Alabama that will evaluate the potential agricultural use of two FGD gypsums (with or without admixtures of fly ash) in comparison to commercial gypsum. An FGD gypsum containing fly ash is produced at Unit 8 of the Widows Creek Fossil Plant in Alabama. Unit 8 produces a mixture of gypsum plus fly ash from the unit. The FGD gypsum without fly ash is from the Cumberland City Fossil Plant in Tennessee. This study seeks to determine the rate of gypsum that is needed to increase plant yield in forage grasses, decrease the solubility of excess P (available P in the soil), and to assess the use of FGD gypsum as an alternative, low-cost, effective amendment that provides the same or better benefits as commercial gypsum.

A field experiment was established on a Hartsells fine sandy loam (fine-loamy, siliceous, subactive, thermic Typic Hapludults) at the Sand Mountain Research and Extension Center in Crossville, AL. The Hartsells soil is moderately deep, well drained, and moderately permeable . It developed in loamy residue weathered from acid sandstone containing thin strata of shale or siltstone. The soil is extremely acid to strongly acid throughout the profile, except where limed in surface layers. This soil is an excellent candidate for evaluating gypsum’s ability to ameliorate the subsoil acidity. The Hartsells series is of large extent in northern Alabama and also occurs in Georgia, Kentucky, Tennessee, and Arkansas.

The experiment consists of 3.6 m by 6 m plots in four blocked sections on an established bermudagrass (Cynodon dactylon L.) field that is managed as a pasture for hay production. Poultry litter will be used as the nitrogen source and applied each year at 4 tons /acre (maximum 1 time application rate for Alabama). The experimental treatments consist of three gypsum products (commercially-available gypsum, FGD gypsum, and FGD gypsum + fly ash) applied at rates of 0, 0.892, 4.46, and 8.92 tons/acre (0, 2, 10, and 20 Mg /ha. The gypsum materials were applied on May 21, 2008. Pasture yields were measured in July, August, and September of 2008 by clipping a sample in each plot. Pasture biomass samples for quality analysis were collected from control, high rate FGD gypsum, and high rate agricultural gypsum treatments during each yield cutting in 2008. Pasture yields will be measured at 6-week intervals in 2009. The goals of this study are to evaluate the impacts of FGD gypsum and FGD gypsum + fly ash on improving soil quality, soil fertility, and plant yield, while minimizing soluble P in the soil resulting from poultry litter amendment.

OHIO

Cardinal Plant - Buckeye Power

Buckeye Power Inc. is supporting research on agricultural use of FGD gypsum in eastern Ohio. The objective is to evaluate FGD gypsum as a soil amendment for improving crop yields by ameliorating subsoil acidity on soils typical of eastern Ohio.

Two experiments were established at the Mill Creek MetroParks Farm at Canfield (Mahoning County), OH. The experiments are identical in design except for crop type (established mixed grass pasture versus corn crop) and use a randomized complete block design with four blocks (replications) of seven soil amendment treatments. Treatment plots measure 6 m by 6 m. FGD gypsum from the Cardinal Power Plant at Brilliant, OH and a commercially-available agricultural gypsum (brand name Nutrasoft) were each applied at rates of 0, 0.089, 0.892, and 8.92 ton/acre (0, 0.2, 2, and 20 Mg/ha.

The mixed grass pasture experiment was started in 2008 on an east-facing slope that is primarily Wooster silt loam soil (fine-loamy, mixed, active, mesic Oxyaquic Fragiudalfs). Wooster soil is deep, well drained and formed in low-lime loamy glacial till with a thin mantle of loess (up to 16 inches thick) in some places. It is very strongly acid to medium acid in the upper soil horizons unless limed, and very strongly acid to neutral in the lower horizons and substratum. Vegetation in the pasture is predominately reed canarygrass (Phalaris arundinacea) in the lower, wetter block of the study. Upper blocks are not dominated by any species but contain localized areas of tall fescue (Festuca arundinacea), timothy (Phleum pratense), and orchardgrass (Dactylis glomerata) with a thin scattering of legumes [birdsfoot trefoil (Lotus corniculatus), white clover (Trifolium repens)]. Gypsum treatments for the pasture study were applied on May 23, 2008. Pasture yield from all plots was measured in July and September, 2008 by cutting two strips in each plot for each measurement. Pasture biomass for quality analysis was sampled from control, high rate FGD gypsum, and high rate agricultural gypsum treatments during the September yield cutting in 2008. Yield and quality sampling will be repeated in 2009, and yield sampling only in 2010.

The corn crop experiment was started in a different field on the Mill Creek Farm in 2009. Gypsum treatments at the rates specified above were applied on May 7, 2009. Corn was planted in May, 2009. Corn yield and grain quality will be measured in 2009 and 2010.

WISCONSIN

Pleasant Prairie Power Plant - We Energies

The Pleasant Prairie Power Plant of We Energies is supporting research on agricultural use of FGD gypsum in southern Wisconsin. The purpose of the research is to investigate the potential use of FGD gypsum on agricultural soils that are negatively affected by soil surface sealing and crusting problems and compaction in alfalfa farming.

The hypothesis of this research is that a surface application of FGD gypsum will serve as an electrolyte source and release the electrolytes in rainwater, thus improving water entry with positive effects on surface water quality. The gypsum will also provide Ca and S fertility for plants in an alfalfa production system. The specific goals of this experiment are to assess FGD gypsum application to soil and determine its impacts on soil physical and chemical properties, plant yields, and biomass and soil quality (heavy metal concentrations).

In a two-year field study starting in 2009, FGD gypsum will be compared to a commercially available gypsum product widely sold in the Midwest USA and other areas. The field for study is Field #295 at the University of Wisconsin Arlington Field Station, north of DeForest, WI near the intersection of Meek Rd and Ramsey Rd. The field was planted to corn in 2008. The soils in the field site are predominately Ringwood and Huntsville silt loams. They are very deep and well drained. Ringwood silt loam (fine-loamy, mixed, superactive, mesic Typic Argiudolls) formed in loess or other silty material and in the underlying loamy till on till plains. It is of moderate extent in northern Illinois and southern Wisconsin. Huntsville silt loam (fine-silty, mixed, superactive, mesic cumulic Hapludolls) formed in alluvium on flood plains. It is of large extent in Illinois and parts of Iowa, Minnesota, Wisconsin, Missouri, and Indiana. These soils have problems of runoff, erosion, and water entry typical of many soils in the central Wisconsin Dairy Region.

The experimental design will be a completely randomized design with four replications randomly assigned to strips across the field. The treatments (n = 7) will include the two gypsum products (FGD gypsum and the commercially-available gypsum) applied at three rates each while one control plot will receive no gypsum. Rates of gypsum applied to the soil will be 0, 2,000, 4,000 and 8,000 lb acre ‑1. The FGD and commercial gypsums will be applied by hand to treatment plots that are 15 feet wide x 25 feet long in size. Plots will be planted to alfalfa the first year (2009) using standard University of Wisconsin Recommendations for establishing new alfalfa. Alfalfa will be harvested when appropriate with a small plot harvester.

Suction lysimeters will be installed to a depth of 60 cm in both the control plots and plots receiving the highest application rate of each gypsum material (total of 12 lysimeters) following planting and removed following the last harvest. In both years, water samples from these lysimeters will be taken weekly after installation when the water table is sufficiently high to obtain samples. Water samples will be analyzed for pH, mercury, anions, cations, and nitrate-nitrogen.

The results of this research will be used to develop guidelines for applying FGD gypsum in typical alfalfa production agriculture in the Midwest to improve yield and soil and water quality.