David Kost

Predicting plant sulfur deficiency in soils: results from Ohio

We developed a model for plant available sulfur (S) in Ohio soils to predict potential crop plant S deficiency. The model includes inputs of plant available S due to atmospheric deposition and mineralization of soil organic S and output due to leaching. A leaching index was computed using data on annual precipitation; soil pH and clay content that influence sulfate adsorption; and pore water velocity based upon percent sand, silt, and clay. There are five categories of S status ranging from highly deficient to highly sufficient, and the categories are defined based on whether the crop S requirement was 15 or 30kg S ha−1 year−1. The final database derived from the model includes 1,473 soil samples representing 443 of the 475 soil series in Ohio. For a crop requiring 15kg S ha−1 year−1, most soils (68.6%) were classified as variably deficient, which implies that the response to S fertilization will be variable but often positive depending on specific crop conditions. For a crop requiring 30kg S ha−1 year−1, 43.2% of soils were classified as variably deficient, but 49.7% were classified as moderately or highly deficient, implying that a response to S fertilization will usually or always occur. The model predicts crop S status for a single state in the USA, but with proper inputs, it should be applicable to other areas.

Petroleum Coke Circulating Fluidized Bed Combustion Product Effects on Soil and Water Quality

The combustion of petroleum coke with limestone in a circulating fluidized bed (CFB) to remove SO2 from flue gas creates a product that may be used in agriculture. However, there are no reports on changes of soil chemical properties by application of petroleum coke CFB product. Two field experiments were conducted to determine elements in topsoil, subsoil, and soil water after CFB product application at 67.2 Mg/ha. Sulfur in the 0- to 60-cm and Ca, Mo, Ni, Sb, Sr, and V in the 0- to 15-cm soil layers were all increased 7 and 30 months after application. Concentrations of Ca, Mg, Ni, S, and Sr in soil water at the 60-cm depth were 2 to 4 times greater than control levels 6 months after treatment and 8 to 31 times greater 27 months after treatment. Concentrations of Al, As, Cd, Cr, Mn, and Sb were also increased in soil water 6 months after treatment at the 30-cm depth and 27 months after treatment at the 60-cm depth. Subsoil chemical properties and vadose water quality in this study were significantly changed by the surface application of petroleum coke CFB product, but the changes would not preclude the use of CFB product as a beneficial soil amendment.

Petroleum Coke Circulating Fluidized Bed Combustion Product as a Sulfur Source for Alfalfa

Abstract: Petroleum coke circulating fluidized bed (CFB) combustion product is created when petroleum coke is combusted with limestone in a circulating fluidized bed boiler. The CFB product contains high concentrations of sulfur (S), nickel (Ni), and vanadium (V). Using it as a S source is encouraged, but little information is available related to plant responses and environmental impact. The CFB product was applied at rates of 0, 11, 33, and 110 kg S ha−1 to two agricultural soils (Canfield silt loam and Wooster silt loam). Dry weight of alfalfa (Medicago sativa L.) and S in plant tissue was increased by the S treatments. Concentrations in alfalfa of V were increased but did not reach environmental concern levels. Concentrations in alfalfa of Ni were not increased. In the soils, only total S and plant available S were increased by these materials. No soil contamination problems were observed when CFB product was used as an S source.

Gypsum as a soil amendment to enhance water quality by reducing soluble phosphorus concentrations

It is said that lakes are born to die. As soon as a lake basin is formed, either slowly by glacial action as for the Great Lakes or rapidly by the New Madrid earthquake for Reelfoot Lake, Tennessee, in 1811 to 1812 (USGS 2012), it fills with water. It then begins to accumulate sediments and nutrients, including phosphorus (P), that increase productivity. This ultimately results in the lake basin filling with sediments and organic materials. The Maumee River drainage basin (area of 21,050 km2 [8,132 mi2]) on the western edge of Lake Erie occurs primarily in Ohio but also includes parts of Indiana and Michigan (figure 1). The basin has high agricultural productivity, with approximately 80% of the land devoted to row crop corn (Zea mays L.) and soybeans (Glycine max [L.] Merr.). The Maumee River drains into the shallow western basin of Lake Erie and contributes most of the sediment and one-third of soluble P that enters Lake Erie. Runoff from agricultural fields often contains excessive P that impacts water bodies in a process called cultural eutrophication (National Academy of Sciences 1969). Beginning in the 1950s, Lake Erie was strongly affected by cultural eutrophication (Verduin 1969). In the 1960s…

Meta-Analysis of Gypsum Effects on Crop Yields and Chemistry of Soils, Plant Tissues, and Vadose Water at Various Research Sites in the USA

Gypsum has a long history as a soil amendment. Information on how flue gas desulfurization (FGD) gypsum affects soil, water, and plant properties across a range of climates and soils is lacking. We conducted a meta-analysis using data from 10 field sites in the United States (Alabama, Arkansas, Indiana, New Mexico, North Dakota, Ohio, and Wisconsin). Each site used three rates each of mined and FGD gypsums plus an untreated control treatment. Gypsum rates included a presumed optimal agronomic rate plus one rate lower and one rate higher than the optimal. Gypsum was applied once at the beginning of each study, and then data were collected for 2 to 3 yr. The meta-analyses used response ratios () calculated by dividing the treatment value by the control value for crop yield or for each measured element in plant, soil, and vadose water. These values were tested for their significance with values. Most values varied only slightly from 1.00. Gypsum significantly changed more values from 1.00 for vadose water than for soil or crop tissue in terms of numbers of elements affected (11 for water, 7 for soil, and 8 for crop tissue). The highest value for soil was 1.57 (Ca) which was similar for both mined and FGD gypsum, for crop tissue was 1.46 (Sr) for mined gypsum, and for vadose water was 4.22 (S) for FGD gypsum. The large increase in Ca and S is often a desired response to gypsum application. Lowest values occurred in crop tissue for Mg (0.89) with FGD gypsum and for Ni (0.92 or 0.93) with both gypsums. Although some sites showed crop yield responses to gypsum, the overall mean values for mined gypsum (0.987) and for FGD gypsum (1.00) were not significantly different from 1.00 in this short-term study.