University of Wisconsin - Madison | Department of Soil Science

Department of Soil Science
University of Wisconsin - Madison
608.262.2633

Agronomy Abstracts 2000

SUBDIVISION A-1a - STUDENT ACTIVITIES

Streamlining Nitrogen Fertilization in Tree Nursery Production. J. Dobrahner, B. Lowery, J.G. Iyer, Univ. Wisconsin-Madison.

DIVISION A-5 - ENVIRONMENTAL QUALITY

Use of the Internet as an Innovative Teaching Tool. P. Barak, Univ. Wisconsin-Madison.

A Redox-Based Ecophysiological Framework for Linking Microbial Communities and Biogeochemical Cycles. R.F. Harris, Univ. Wisconsin-Madison.

DIVISION A-6 - INTERNATIONAL AGRONOMY

Environmental Issues Facing Industrial Agriculture in the 21st Century. J.M. Powell, USDA-ARS; L.E. Lanyon, Pennsylvania State Univ.; P.W. Barak, Univ. Wisconsin-Madison.

DIVISION A-7 - AGRICULTURAL RESEARCH STATION MANAGEMENT

The Wisconsin Agricultural Research Station GIS: Arlington. D.H. Mueller, S.G. Mukhtyar, P.R. Nichols, R.F. Harris, S.J. Ventura, Univ. Wisconsin-Madison.

The Wisconsin Agricultural Research Station GIS: Marshfield. D. Wiersma, S.G. Mukhtyar, P.R. Nichols, R.F. Harris, S.J. Ventura, Univ. Wisconsin-Madison.

DIVISION A-8 - INTEGRATED AGRICULTURAL SYSTEMS

Estimating Livestock-Related Nutrient Fluxes from Limited Census Data. W.L. Bland, Univ. Wisconsin-Madison.

Collaborative Development of an Agricultural Systems Model. M.C. Anderson, W.L. Bland, Univ. Wisconsin-Madison.

Impact of Annual Organic Amendment on Disease Incidence in a Three Year Vegetable Rotation. A.G. Stone, Oregon State University; G.E. Vallad, L.R. Cooperband, W.R. Stevenson, R.D. Goodman, Univ. Wisconsin-Madison.

Paper Mill Sludge and Compost Effects on Plant Available Water and Soil Carbon Over Time. B.J. Foley and L.R. Cooperband, Univ. Wisconsin-Madison.

DIVISION C-3 - CROP ECOLOGY, MANAGEMENT AND QUALITY

Are Depleted Soils Causing a Reduction in the Mineral Content of Food Crops? J.W. Lyne, P. Barak, Univ. Wisconsin-Madison.

DIVISION S-1 - SOIL PHYSICS

Carbon Leaching and its Role in the Carbon Budgets of Natural and Managed Ecosystems. K.R. Brye, J.M. Norman, L.G. Bundy, and S.T. Gower, Univ. Wisconsin-Madison.

Determining Particle Size Using a Laser Light Diffraction Technique. F.J. Arriaga, B. Lowery, S. Parks, and D.W. Mays, Univ. Wisconsin-Madison.

Applying Electrical Conductivity Measurements to Model Corn Yield Distributions. C.L.S. Morgan, J.M. Norman, R.P. Wolkowski, R.T. Schuler, and B. Lowery, Univ. Wisconsin-Madison.

DIVISION S-2 - SOIL CHEMISTRY

Lead Adsorption on Kaolin. T.D. Ranatunga, R.M. Taylor, Alabama A&M Univ.; W.F. Bleam, Univ. Wisconsin-Madison; H.G. McWhinney, Prairie View A&M Univ.

Reduced Sulfur in Organic Horizons and Humic Acid from Northern Forest Soils and the Strong Retention of Mercury. C. Lin, P.R. Bloom, E.A. Nater, Univ. Minnesota; S.J. Yoon, W.F. Bleam, Univ. Wisconsin-Madison.

Enzyme Hydrolyzable Organic Phosphorus in Soils and Manures. T.J. Boerth, P.A. Helmke, Univ. Wisconsin-Madison.

Activity of Phytase and Phosphatase in the Rhizosphere of Lupinus albus L. J.A. Howe, P.A. Helmke, Univ. Wisconsin-Madison.

Binding of Cd, Cu, Zn, H, and Ca to Dissolved Humic Substances at Indigenous Concentrations. P.A. Helmke and P.A.V. Escosteguy, Univ. Wisconsin-Madison.

Which Cd Solution Species Influences Cd Bioavailability in Sludge-Amended Soils?P.A.V. Escosteguy and P.A. Helmke, Univ. Wisconsin-Madison.

DIVISION S-3 - SOIL BIOLOGY AND BIOCHEMISTRY

Effect of Compost on Soil Properties and Woody Ornamentals Production. R.F Gonzalez, L.R. Cooperband, Univ. Wisconsin-Madison.

DIVISION S-4 - SOIL FERTILITY AND PLANT NUTRITION

Coupling of H and N Cycles in Several Common Agroecosystems of Midwestern United States. M. Avila-Segura, P. Barak, J.L. Posner, Univ. Wisconsin-Madison; D.A. Laird, USDA-National Soil Tilth Lab.

Whole-farm Phosphorus Management on Dairy Farms. J.M. Powell, USDA-ARS; L.G. Bundy, D. Jackson-Smith, Univ. Wisconsin-Madison.

Nutrient Management Program in Wisconsin. L.G. Bundy, Univ. Wisconsin-Madison.

Current Status of Soil Test P on U.S. Dairies. S E. Feagley, Texas A & M Univ.; J.B. Peters, Univ. Wisconsin-Madison; T.C. Daniel, Univ. of Arkansas.

Forages Show Little Response to High Soil Test P. M.P. Russelle, USDA-ARS-USDFRC; M.A. Schmitt, Univ. Minnesota; J.M. Powell, Univ. Wisconsin-Madison; C.A. Hasthorpe.

Turnover of Dairy Manure N Fractions in Soil. J.M. Powell and K.A. Kelling, Univ. Wisconsin-Madison.

Effect of Manure Application Timing on Relative Nitrogen Availability.K.A. Talarczyk, K.A. Kelling, T.M. Wood, and P.E. Speth, Univ. Wisconsin-Madison.

DIVISION S-5 - PEDOLOGY

Virtual Soil Landscapes: A New Paradigm. S. Grunwald, Water Quality Laboratory; P. Barak, K. McSweeney, D.J. Rooney, B. Lowery, Univ. Wisconsin-Madison.

The Present, Past, and Future of the Catena Concept. D.J. Brown, K. McSweeney, V.T. Holliday, M.K. Clayton, Univ. Wisconsin-Madison.

A Re-examination of the Catena Concept on the Landscape of Origin in East Africa. D.J. Brown, K. McSweeney, M.K. Clayton, V.T. Holliday, Univ. Wisconsin-Madison.

Application of Neural Networks for the Prediction of Soil Attributes over the Landscape. S.J. Park, Center for Development Research, Bonn, Germany; K. McSweeney, B. Lowery, Univ. Wisconsin-Madison.

Identification of Pedogeomorphological Processes on a Hillslope, Somerset, England. S.J. Park, Center for Development Research, Bonn, Germany; K. McSweeney, B. Lowery, Univ. Wisconsin-Madison.

DIVISION S-6 - SOIL AND WATER MANAGEMENT AND CONSERVATION

Phosphorus Indexes: The Midwest Experience. B.C. Joern, Purdue Univ.; A.P. Mallarino, Iowa State Univ.; L.G. Bundy, Univ. Wisconsin-Madison; T. Bailey, B.M. Stewart, J. Kaap, NRCS.

Mapping an Eroded Dubuque Soil Using a Constant Rate Penetrometer. B. Lowery, F.J. Arriaga, D.J. Reinert, and K. McSweeney, Univ. Wisconsin-Madison.

DIVISION S-7 - FOREST AND RANGE SOILS

Papermill Sludge Slows Growth of Young Pinus resinosa in Plantations. W. Stites, J.G. Bockheim, Univ. Wisconsin-Madison.

DIVISION S-8 - NUTRIENT MANAGEMENT AND SOIL AND PLANT ANALYSIS

Approach for the Elemental Concentrations in Plant Tissue by ICP-MS and ICP-OES. L.S. Zhang, S.M. Combs, Univ. Wisconsin-Madison.

Analysis of Dissolved Iodide by Gaseous Sample Introduction ICP-MS. L. S. Zhang, Univ. Wisconsin-Madison.

Phosphorus, Potassium and pH in Wisconsin Soils: A 25 Year Review of Public and Private Laboratory Data. S.M. Combs, J.B. Peters, K.A. Kelling, Univ. Wisconsin-Madison.

Simulated Rainfall Duration and Soil Sampling Depth Effects on Interpretation of Phosphorus Runoff Data. T.W. Andraski, L.G. Bundy, J.S. Studnicka, and J.M. Powell, Univ. Wisconsin-Madison.

Phosphorus Forms, Amounts, and Movement in Biosolids-Treated Soils. J.S. Studnicka, T.W. Andraski, L.G. Bundy, Univ. Wisconsin-Madison; D.S. Taylor, Madison Metropolitan Sewerage District.

Evaluation of Variable-Rate Lime Application for a Corn-Soybean Rotation. R.L. Zogbaum, R.P. Wolkowski, and L.G. Bundy, Univ. Wisconsin-Madison.

Management Practice Effects on Phosphorus Losses in Runoff in Corn Production Systems. L.G. Bundy, T.W. Andraski, J.S. Studnicka, J.M. Powell, Univ. Wisconsin-Madison.

Dairy Diet Phosphorus Effects on Phosphorus Losses in Runoff from Land-Applied Manure. A.M. Ebeling, L.G. Bundy, T.W. Andraski, and J.M. Powell, Univ. Wisconsin-Madison.

DIVISION S-11 - SOILS AND ENVIRONMENTAL QUALITY

Availability of Phosphorus for Transport by Water following Manure Application to Soils. L.W. Good, L.R. Cooperband, Univ. Wisconsin-Madison.

Alachlor Leaching Under Aerobic vs. Anaerobic Conditions in Soil Microlysimeters. H.W. Read, Univ. Wisconsin-Madison.

Land Application of Crushed Drywall Waste for Field Crops. R.P. Wolkowski. Univ. Wisconsin-Madison.

Computer Software Application

The Wisconsin Agricultural Research Station GIS: Overview. R.F. Harris, S.G. Mukhtyar, D. Wiersma, D.H. Mueller, S.J. Ventura, Univ. Wisconsin-Madison.

SUBDIVISION A-1a - STUDENT ACTIVITIES

Streamlining Nitrogen Fertilization in Tree Nursery Production. J. Dobrahner, B. Lowery, J.G. Iyer, Univ. Wisconsin-Madison.
Groundwater contamination by agricultural fertilizers has become one of the nations most pressing environmental concerns. Nitrate, one of the most abundant components of agricultural fertilizers, has been detected in drinking water at concentrations in excess of the acceptable limits defined by the Environmental Protection Agency. The objective of this trial was to compare a slow-release and conventional fertilization method in reducing nitrate loss in a tree nursery. Leachate and tissue samples from plots of red oak and white pine were collected for comparison. Results indicate that leachate nitrate concentrations were significantly reduced by slow-release fertilization compared to conventional methods. Tissue sampling revealed that slow-release was unable to provide sufficient nutrient to red oak seedlings. This deficiency was not observed in white pine seedlings. From our observations we may conclude that nitrate loss to the environment is reduced by slow-release fertilization. However, adequate nutrient delivery to sustain normal growth may be species specific. Ultimately, the purpose of this research was to investigate fertilization methods that effectively provide nutrients to tree nursery seedlings while minimizing losses to the environment.
Jaslyn Dobrahner

DIVISION A-5 - ENVIRONMENTAL QUALITY

Use of the Internet as an Innovative Teaching Tool. P. Barak, Univ. Wisconsin-Madison.
The advent of widespread connectivity and interplatform operability has created new opportunities in science education. However, there is no evidence that current students learn in a manner that is fundamentally different than their pre-computer predecessors. Teacher-student interactions that foster curiosity, discovery, and critical thinking must be retained if higher education is to retain its quality. First-tier residence education institutions should be cautious about reinventing themselves as correspondence schools of the electronic type. The widespread availability of the internet at universities offers all-hours, all-point, cross-platform student access to teaching tools--hypertext-linked notes, threaded asynchronous discussion, and scientific visualization in the form of slides, video, and multimedia--to enhance science education, yet the hallmark of the successful use of the internet as a teaching tool should be productive classrooms.
Phillip Barak, 608-263-5450, pwbarak@facstaff.wisc.edu

A Redox-Based Ecophysiological Framework for Linking Microbial Communities and Biogeochemical Cycles. R.F. Harris, Univ. Wisconsin-Madison.
The standard, box chart-based, periodic table characterization of each element according to 1) atomic number, symbol, weight, electron configuration of the neutral atom in the ground state, and 2) oxidation states/numbers of the element in combined form, is expanded to characterization of the biochemical forms of a given element according to 1) name, physical state, formula structure and weight, outer shell electrons assigned to each atom, 2) average oxidation number of the element, related biologically available electrons, standard Gibbs energy of formation of the compound, and 4) standard biological (pH 7) electron transfer potential for oxidative conversion/reductive formation of the compound to/from the element's most oxidized biological form. The resultant macro and microelement database focuses on simple compounds containing the element with/without H and/or 0, but also includes appropriately qualified multielement compounds and materials. Use of the database for teaching redox and energy concepts at introductory through advanced levels is illustrated with diagrams of increasing conceptual complexity. Applicability to interpretation and prediction of interrelationships between environmental factors, microbial community structure and trophic function, and biogeochemical cycles is reviewed.
Robin F. Harris, 608-265-0677, rfharris@facstaff.wisc.edu

DIVISION A-6 - INTERNATIONAL AGRONOMY

Environmental Issues Facing Industrial Agriculture in the 21st Century. J.M. Powell, USDA-ARS; L.E. Lanyon, Pennsylvania State Univ.; P.W. Barak, Univ. Wisconsin-Madison.
Intensive high input/output modes of agricultural production can have numerous adverse environmental impacts, such as gaseous emissions that contribute to global climate changes and pollution of land and water. This paper begins with a brief description of the evolution and typology of global, industrial agricultural systems, followed by an overview of the principal environmental impact domains at various scales. It then focuses on the main biophysical and socioeconomic determinants of environmental outcomes that are associated with industrial agriculture with a focus on nutrient management in crop and animal production. The paper proceeds with a discussion of technology and policy options for improving environmental performance. It concludes with a call for more integrated development approaches that improve the capacity of policy makers, extension programs, farmers, future land mangers and agribusiness to make integrated nutrient management decisions that consider all components of an agricultural system and associated environmental impacts.
J. Mark Powell, 608-264-5044, jmpowel2@facstaff.wisc.edu

DIVISION A-7 - AGRICULTURAL RESEARCH STATION MANAGEMENT

The Wisconsin Agricultural Research Station GIS: Arlington. D.H. Mueller, S.G. Mukhtyar, P.R. Nichols, R.F. Harris, S.J. Ventura, Univ. Wisconsin-Madison.
The Arlington Agricultural Research Station (ARS) is the prototype for application of the Wisconsin ARS GIS to management of a historically well established experiment station. MS Access and ArcView databases are managed by customized ArcView extension and Visual Basic query programs and connections to other software programs. The Access database consists of farm records organized within standard (field boundary, management, analyses, and lookup ID) and project specific categories. The ArcView database consists of 1) state agency-derived coverages such as soils, topography, and groundwater contamination susceptibility (1:250,000 to 1:500,000 scale); and watersheds (1:24,000); 2) Station-digitized Soil Survey Geographic Database coverages including soil name, slope, and drainage (<1: 20,000); 3) standard farm coverages such as orthophotos, DEM (4 m), and GPS-derived field (<1:1,000) and annually-updated subfield boundaries integrated with selected Access records such as crop planting, chemical and fertilizer application, irrigation and tillage; and 4) project-specific coverages such as high resolution DEM (1 m) and DEM-derived slopes and depressions for selected fields. Applications to day-by-day farm management and development of a Wisconsin NRCS 590 nutrient management plan are demonstrated.
Robin F. Harris, 608-265-0677

The Wisconsin Agricultural Research Station GIS: Marshfield. D. Wiersma, S.G. Mukhtyar, P.R. Nichols, R.F. Harris, S.J. Ventura, Univ. Wisconsin-Madison.
The Marshfield Agricultural Research Station (ARS) is the prototype for application of the Wisconsin ARS GIS to management of newly acquired research station land. MS Access and ArcView databases are managed by customized ArcView extension and Visual Basic query programs and connections to other software programs. The Access database consists of farm records organized within standard (field boundary, management, analyses, and lookup ID) and project-specific categories. The ArcView database consists of 1) state agency-derived coverages such as soils, topography, and groundwater contamination susceptibility (1:250,000 to 1:500,000 scale); and watersheds (1:24,000); 2) Marathon county agency-digitized Soil Survey Geographic Database coverages including soil name, slope, and drainage (<1: 20,000); 3) standard farm coverages such as GPS-derived field (<1: 1,000) and annually-updated subfield boundaries integrated with selected Access records such as field management; and 4) project-specific coverages such as high resolution DEM (1 m), DEM-derived slopes and depressions, land survey, and grid-sampled soil nutrients for selected fields. Applications to design of a surface water drainage system and identification of water quality protected agricultural and ecological management zones, are demonstrated.
Robin F. Harris, 608-265-0677, rfharris@wisc.edu

DIVISION A-8 - INTEGRATED AGRICULTURAL SYSTEMS

Estimating Livestock-Related Nutrient Fluxes from Limited Census Data. W.L. Bland, Univ. Wisconsin-Madison.
Spatially concentrated livestock production may lead to localized accumulations of plant nutrients, with deleterious effects on water quality. Analysis of such agricultural systems requires estimation of regional nutrient fluxes in fertilizer, feed and animal products. Unfortunately, data are generally limited at the spatial scales of interest. Such scales include drainage basins of modest rivers or lakes or distances over which manure might be transported. Existing USDA reporting systems are oriented toward market information and follow restrictive confidentiality rules. These data are also largely instantaneous census values which may not reflect the number of animals that annually pass through a regional system. From knowledge of nominal practices we developed rules to interpret readily available data to yield the more complete set needed to estimate animal feed requirements, manure production and exports of nutrients in animal products and carcasses. For example, the annual cull rate of dairy cows in WI is now about 30%, so feed demand of and manure production by replacements significantly impact local nutrients balances. The number of replacement heifers in a county is not reported, but can be estimated from assumptions about calf births, growth rates, time to freshening.
William L. Bland, 608-262-0221, wlbland@wisc.edu

Collaborative Development of an Agricultural Systems Model. M.C. Anderson, W.L. Bland, Univ. Wisconsin-Madison.
Tensions are growing in the WI Central Sands concerning the impacts of irrigated agriculture on local groundwater quality. While recent expansions in irrigated acreage have profited the region economically, groundwater nitrate levels are increasing at alarming rates. County officials are revising landuse plans to protect municipal and domestic wellheads, but lack information on the ramifications of possible regulatory paths. To assist this policy development process, we are constructing an Integrated Assessment Model (IAM) for the region; this model will provide first order estimates of impacts on water quality and local revenue streams under various land management scenarios. It is our hope that in exercising the IAM, diverse stakeholders will develop a shared insight into how the system functions, and how changes to one part affect the rest of the system. We seek to avoid the "black box" paradigm; collaborative IAM development between scientists and stakeholders often results in a broader acceptance and a deeper understanding on the part of all parties. Here, we report on a pilot study of collaborative model development conducted last winter with small groups of growers and citizens. During a series of meetings, we worked together with the stakeholders to iteratively construct a mutually acceptable picture of nitrogen cycling in an irrigated field. Based on this experience, we are revising plans for broader collaboration in 2001.
Martha Anderson, 608-265-3288, anderson@emily.soils.wisc.edu

Impact of Annual Organic Amendment on Disease Incidence in a Three Year Vegetable Rotation. A.G. Stone, Oregon State Univ.; G.E. Vallad, L.R. Cooperband, W.R. Stevenson, R.D. Goodman, Univ. Wisconsin-Madison.
In this project we investigated the effect of serial organic amendment on disease incidence in a vegetable rotation. Paper mill sludge (PS), composted PS (PSC) and PS composted with bark (PSB) were amended to a sandy soil in Hancock, W1 at low (L) and high (H) rates (PS, 22/44 Mg/ha; others, 38/76 Mg/ha) annually in 1998-2000. Potato, snap bean and pickling cucumber were grown in 1998, 1999, and 2000, respectively, and all naturally occurring disease incidence was assessed. In 1998, only PSB L increased the proportion of potatoes with commercially damaging levels of scab incidence relative to the unamended control. Silver scurf incidence was higher than the control in PS L and H, PSC H, and PSB H. Pythium leak incidence was lower than the control in PSB L, PSC H, and PS H. Early blight incidence was higher than the control in PS L and H and PSC H. Aerial black leg incidence was higher than the control in PS H and lower in PSB H. In 1999, all amended treatments increased emergence and reduced aerial Pythium incidence and foliar brown spot severity in snap bean relative to the control. However, only PSC L and H reduced pod brown spot incidence. Field disease incidence in the 2000 pickling cucumber crop will also be presented. The potential for organic matter-mediated suppression of specific disease types will be discussed.
Alexandra G. Stone, 541-737-5461, stonea@bcc.orst.edu

Paper Mill Sludge and Compost Effects on Plant Available Water and Soil Carbon Over Time. B.J. Foley and L.R. Cooperband, Univ. Wisconsin-Madison.
Use of paper mill sludge (PS) or PS compost in annual crop production systems holds promise as a means to improve soil quality. This study determined effects of amending sandy soil with PS and PS composts on soil water dynamics and soil C and effects on vegetable production from 1998-2000. Treatment plots were amended every spring with either raw PS or two PS composts at two application rates (22.4 and 44.8 Mg/ha for raw PS and 38 and 78.4 Mg/ha for composts). Soil cores (7.5 cm) were collected pre- and post-amendment application, mid-season during crop growth, and post-harvest. Water retention was determined at low tension (0 to 33 J/kg) with porous plates and from 200 to 2500 J/kg with a thermocouple psychrometer. Plant-available water (PAW) was calculated as the difference in volumetric water content between 33 and 2500 J/kg. Bulk soil samples (0 to 75 cm), collected at the same time frequency, were analyzed for total C. Regression analysis between total soil C and PAW revealed a positive linear relationship after 1 yr following amendment application. There were significant differences between PS and PS composts and application rate. Compost-amended soils contained higher total soil C and hence greater PAW than the non-amended control soil. The relationship between soil C and PAW also changed as a function of time after amendment application.
Leslie R. Cooperband, 608-265-4654, lrcooperband@facstaff.wisc.edu

DIVISION C-3 - CROP ECOLOGY, MANAGEMENT AND QUALITY

Are Depleted Soils Causing a Reduction in the Mineral Content of Food Crops. J.W. Lyne, P. Barak, Univ. of Wisconsin-Madison.
With sufficient quantities of food in an affluent society and raised public awareness of environmental quality, there is growing concern about the quality of food and demand for more accountability of how food is grown. Several studies of historical food composition tables show an apparent decline in food nutrient content over the past 70 years. This decline has been attributed to soil degradation and the "mining" of soil fertility by industrial agriculture. In this presentation, USDA food composition tables are reexamined and factors of food nutrient content will be related to soil quality. Plant nutritional needs are determined and links to soil fertility management and land use patterns are discussed. For major cations of selected fresh produce crops, ternary diagrams show no real loss in the balance of mineral nutrition in food crops. Although it may be hypothesized that a decline in soil quality has lead to an apparent decline in food nutrition, more controlled studies are needed to factor out the many variables associated with the food composition tables and this type of analysis.
Phillip Barak, 608-263-5450, pwbarak@wisc.edu

DIVISION S-1 - SOIL PHYSICS

Carbon Leaching and its Role in the Carbon Budgets of Natural and Managed Ecosystems. K.R. Brye, J.M. Norman, L.G. Bundy, and S.T. Gower, Univ. Wisconsin-Madison.
Carbon (C) leaching is important in natural and managed ecosystems because it represents a mechanism for C loss. Equilibrium-tension lysimeters (ETLs) were used beneath 1.4 m undisturbed soil columns of Plano silt loam (Typic Argiudoll) to quantify soluble C leaching for a 4-yr period from 1996 through 1999 in a natural tallgrass prairie and N-fertilized no-tillage and chisel plowed maize ( Zea mays L.) agroecosystems. Total drainage was greatest for the chisel plowed agroecosystem and smallest for the prairie during the 4-yr period. Total C concentrations averaged 27, 54, and 50 mg/L and organic C concentrations averaged 13, 16, and 17 mg/L for the prairie, no-tillage, and chisel plowed agroecosystem, respectively. Cumulative total C leaching losses were 124, 472, and 548 kg/ha for the prairie, no-tillage, and chisel plowed agroecosystem, respectively. The organic C fraction was 58, 31, and 36% of total leached C for the prairie, no-tillage, and chisel plowed agroecosystem, respectively. Though the magnitude of C leaching is relatively minor compared to the magnitude of other components of the C budget, the presence of soluble organic C at depth in a soil profile also represents an important source of C that could potentially support subsoil denitrification.
K.R. Brye

Application of a Spatial Runoff/Infiltration Model to Trafficability Decision-Making. J.M. Norman, B. Lowery, J. Mecikalski, C. Molling, C. Morgan, C. Rodgers, D.J. Rooney, Univ. of Wisconsin-Madison; and M. Stelford, Case Corp. Advanced Farming Systems, De Kalb, IL.
A Precision Agricultural Landscape Model (PALM) has been developed and used to simulate soil wetness in the plow layer on a daily basis in several fields in northern Illinois in collaboration with Case Corp. Advanced Farming Systems. The objective of the PALM is to assist farmers in management decisions related to mechanized activities. The PALM is a terrain- and weather-driven, distributed-parameter, hydrological-biophysical model that considers runoff, infiltration, surface energy exchanges, compaction, plant growth, and yield on a fine grid (e.g. 10 m) over individual fields. Spatially distributed (10- to 20-m grid) soil input information is obtained using a combination of topography from GPS, A-horizon thickness, and field-capacity estimates based on electrical conductivity surveys with an EM-38, soil texture in the top meter using penetrometer measurements, and 10 to 20 soil cores. Predictions of daily soil water content in the top 15 cm depend strongly on the validity of runoff estimates so special efforts have been made to incorporate tillage type, row direction, surface roughness variation with rainfall, surface sealing, and re-infiltration in the two-dimensional diffusive-wave runoff model. Results show field variability comparable to measurements.
John M. Norman, 608-262-4576, jmnorman@wisc.edu

Determining Particle Size Using a Laser Light Diffraction Technique. F.J. Arriaga, B. Lowery, S. Parks, and D.W. Mays, Univ. Wisconsin-Madison.
Traditional particle size analysis techniques, such as pipette and hydrometer, are relatively easy to conduct, but usually take a long time. Alternative particle size methods have emerged but have not been fully accepted in soil science. One of these, a laser light diffraction technique for determining particle size, was compared with pipette and hydrometer methods. The laser instrument uses 132 light detectors and an optical mathematical model to measure particles with a mean diameter between 0.04 and 2000 micrometers. We developed a reproducible procedure for analyzing soil samples with the laser diffractor, which requires 8 min per sample, compared to about 8 h with traditional methods. This does not include sample preparation time, which is the same as traditional methods. Additionally, the laser technique provides a continuous particle size distribution curve. Particle size data from the laser technique correlated well with pipette and hydrometer methods for the range of soils tested. However, optical model output data from the laser required additional processing to obtain comparable values to the pipette method. The laser light diffraction technique produced quick, reliable, and reproducible data, making this technique very valuable in soil science.
B. Lowery, 608 263-5691, blowery@wisc.edu

Applying Electrical Conductivity Measurements to Model Corn Yield Distributions. C.L.S. Morgan, J.M. Norman, R.P. Wolkowski, R.T. Schuler, and B. Lowery, Univ. Wisconsin-Madison.
Spatial distribution of plant-available water is one of the most important factors influencing variability of yield across seemingly uniform fields. Midwestern agricultural soils, which typically are loess caps over glacial till or outwash, can have a wide range of water holding capacities in individual fields because of landscape processes and management (erosion, deposition, tillage). If robust methods can be developed to map plant-available water over individual fields, these maps can be used to improve management options for many years. Recent measurements on several agricultural fields in Wisconsin and Illinois have demonstrated that electrical conductivity measurements from the EM-38 instrument, made before planting, can be related to maximum soil moisture storage. A spatial map of field plant-available water, created by the EM-38, is used to initialize a simple water-budget model based on measurements of solar radiation, precipitation and vapor pressure deficit. Corn yield resulting from this model will be compared to the actual yield maps of the fields.
C.L.S. Morgan

DIVISION S-2 - SOIL CHEMISTRY

Lead Adsorption on Kaolin. T.D. Ranatunga, R.M. Taylor, Alabama A&M Univ.; W.F. Bleam, Univ. Wisconsin-Madison; H.G. McWhinney, Prairie View A&M Univ.
Lead pollution is a serious problem in many superfund waste sites. Thus, a better understanding of the kinetics and mechanism of lead interaction with soil surfaces is of paramount importance. Focusing on this objective, the nature of interaction of lead with kaolin as well as the factors effecting the sorption on pristine kaolin and also phosphate treated kaolin surfaces were investigated. Batch equilibrium studies indicated that sorption on these surfaces was pH dependent. The sorption process was observed to be rapid, and sorption equilibrium was attained within 10 minutes for both surfaces. Lead sorption was significantly increased when phosphate was present on the clay surface. Experimental data for lead sorption on both surfaces fitted a Freundlich much better than a Langmuir isotherm. Increasing the ionic strength of the electrolyte decreased lead sorption on kaolin suggesting an outer sphere sorption mechanism. X-ray Photoelectron Spectroscopy (XPS) on kaolin and phosphate adsorbed kaolin indicated that the lead on these surfaces existed not only as single ionic species but as a complex form of lead.
Robert W. Taylor, 256-858-4187, rwtaylor@aamu.edu

Reduced Sulfur in Organic Horizons and Humic Acid from Northern Forest Soils and the Strong Retention of Mercury. C. Lin, P.R. Bloom, E.A. Nater Univ. Minnesota; S.J. Yoon, W.F. Bleam, Univ. Wisconsin.
This study examined the relationship of sulfur (S) chemistry in soil organic matter (SOM) to the S chemistry in humic acid (HA) and the quantity of native mercury (Hg) retained in extracted HA. Soil samples were taken from 0 horizons and peat soils along upland to wetland transects at the Marcell Experiment Forest in northern Minnesota. The relative oxidation states of S were determined by x-ray adsorption near edge spectroscopy and the contents of organic bound Hg in SOM and HA were determined by cold vapor atomic fluorescence spectroscopy. The data showed that the most poorly drained soils have the lowest fraction of oxidized S (sulfonate and sulfate) and the highest fraction of reduced S (thiol and disulfide) in both SOM and HA. The S/OC ratio in SOM showed a strong linear relationship with the S/OC in HA. Much of the Hg in soils is extracted along with HA but the Hg/OC ratio is poorly correlated with the Hg/OC ratio in the source SOM. In contrast, the Hg/reduced S ratio in HA is well correlated with the ratio in SOM. The treatment with strong base extraction and acid washing during the preparation of HA does not remove Hg from the reduced S functional groups in SOM.
CHUNG-MING LIN, 612-625-7050, clin@soils.umn.edu

Enzyme Hydrolyzable Organic Phosphorus in Soils and Manures. T.J. Boerth, PA. Helmke, Univ. Wisconsin-Madison.
The effects of metal chelators on the efficacy of enzyme hydrolysis of organic phosphorus compounds in soils and manures were investigated. Increasing amounts of citrate or EDTA were added to soils and manures, followed by incubation with phosphatase or phytase. Orthophosphate was determined colorimetrically to measure the amount of organic phosphate hydrolyzed. Results indicate that enzymes mineralize more organic phosphorus as the concentration of metal chelators increases. Removal of metals bound to the organic phosphorus compounds enhances their susceptibility to hydrolysis by enzymes.
Thomas J. Boerth

Activity of Phytase and Phosphatase in the Rhizosphere of Lupinus albus L. J.A. Howe, P.A. Helmke, Univ. Wisconsin-Madison.
Acid phosphatase and phytase activities were measured in the rhizosphere soil of white lupin ( Lupinus albus L.) in order to evaluate their significance in the phosphorus nutrition of the plant. White lupin seedlings were grown in a Plano silt loam soil (pH 5.8) with a low available phosphorus content. Phosphorus was added to the soil as diammonium phosphate applied at 0, 10, or 20 mg P/kg. Acid phosphatase and phytase activities were measured in rhizosphere and bulk soil samples using p-nitrophenyl phosphate and phyate as substrates, respectively. Results indicated that acid phosphatase and phytase release increased with decreasing available phosphorus in the soil, indicating that the enzymes play a role in phosphorus acquisition under phosphorus-deficient conditions in the soil.
Julie Howe, 608-262-0397, jhowe@wisc.edu

Evidence for the Binding of Methyl Mercury to Reduced Sulphur Groups in Soil Organic Matter. J. Qian, U. Skyllberg, Swedish Univ. of Agricultural Sciences; P.R. Bloom, Univ. Minnesota; W.F. Bleam, S. Yoon, Univ. Wisconsin; W. Frech, Umea Univ.
Atmospheric deposition of anthropogenic mercury (Hg) is a large-scale environmental problem at northern latitudes. An accumulation of the highly toxic form of mercury, methyl mercury (CH3Hg+), in higher biota has led authorities to discourage people to eat fish from more than 10000 lakes in Sweden alone. Despite extensive environmental research, little is known about mechanisms behind the bioaccumulation of Hg. Partly this can be explained by limited knowledge about the binding of Hg2+ and CH3Hg+ to natural organic matter (NOM) which has hampered mechanistic research about central processes such as methylation of Hg2+ (or HgO) to CH3Hg+ and demethylation of CH3Hg+ to Hg2+ (or HgO). Using extended x-ray absorption fine structure spectroscopy (EXAFS), xray absorption near edge spectroscopy (XANES) and macroscopic equilibrium studies we show that CH3Hg+ is complexed by reduced organic sulphur groups in NOM from soils. These results will lay a new basis for further mechanistic research on the biogeochemistry of CH3Hg+ in soils and waters.
Jin Qian, +46-90-7866647, jin.qian@sek.slu.se

Binding of Cd, Cu, Zn, H, and Ca to Dissolved Humic Substances at Indigenous Concentrations. P.A. Helmke and P.A.V. Escosteguy, Univ. Wisconsin-Madison.
The competitive exchange behavior of indigenous levels of Cd, Cu, Zn, H, and Ca bound to water-soluble humic substances was studied in humic solutions. The humic solutions were extracted with cation-chelating resin, Chelex-20, from a Plano silt loam (Typic Argiudolls) treated with a high Cd sewage sludge in 1976. The humic solutions were titrated with additions of Cu2+, Ca2+, and Zn2+. The activities of free cations of all metals were determined by Donnan membrane equilibrium analysis after each addition of metals. No significant competition for binding sites between the free Cd, Zn, Cu, H, and Ca in response to changes in total dissolved and free metal activities were observed. The exchangeability of Cd, Cu, Zn, H, and Ca bound to water-soluble humid substances was compared to the results predicted by computer-implemented models.
Philip A. Helmke, 608-263-4947, pahelmke@wisc.edu

Which Cd Solution Species Influences Cd Bioavailability in Sludge-Amended Soils. P.A.V. Escosteguy and P.A. Helmke, Univ. Wisconsin-Madison.
The indigenous levels of Cd activity and the total Cd concentration were compared as an index of Cd availability to plants. Such comparison was studied by growing seedling plants in soil water saturation extracts containing the same total Cd concentration but different free Cd activities. The soil solutions were obtained from a Plano silt loam (Typic Argiudolls) treated with a high Cd sewage sludge in 1976. The activities of free cations were determined by Donnan membrane equilibrium analysis after the growth cycle. Total Cd was analyzed in root parts and correlated with its indigenous levels in the soil solution.
Pedro Escosteguy, 608-263-0397, paescosteguy@students.wisc.edu

DIVISION S-3 - SOIL BIOLOGY AND BIOCHEMISTRY

Effect of Compost on Soil Properties and Woody Ornamentals Production. R.F Gonzalez, L.R. Cooperband, Univ. Wisconsin-Madison.
We investigated the use of wood residue-based composts in field nursery crop (woody ornamental) production. Project objectives were to evaluate the effect of compost use on nutrient availability, soil physical properties and plant growth. We established a field trial at West Madison Agricultural Research Station, UW-Madison consisting of four replicates of three shrub species (Spirea japonicum gumball, Berberis thunbergia atropurpurea, and Juniper chinensis pfitzeriana) with three composts types (duck manure-sawdust, potato cull-sawdust and paper mill sludge-bark) at two application rates (2.5 cm layer of compost incorporated into the top 15 cm of top soil, and 2.5 cm incorporated + 2.5 cm surface applied as a mulch) and a no-compost control. The field trial was established in late May 1998 on a single soil type (silt loam) and ran for two growing seasons. We measured changes in cation exchange capacity; pH; % organic matter; and plant available P, K, Ca, Mg; micronutrients; bulk density; water retention; and hydraulic conductivity over the course of the experiment. We also measured biweekly gravimetric water content as well as ammonium-N, nitrate N and P using ion exchange membranes. Preliminary results indicate that duck manure-sawdust compost increased biomass production, and available P, and decreased soil bulk density while the other compost types had no effect on these properties.
Leslie R. Cooperband, 608-265-4654, lrcooperband@facstaff.wis.edu

DIVISION S-4 - SOIL FERTILITY AND PLANT NUTRITION

Coupling of H and N Cycles in Several Common Agroecosystems of Midwestern United States. M. Avila-Segura, P. Barak, J.L. Posner, Univ. Wisconsin-Madison; D.A. Laird, USDA-National Soil Tilth Lab.
In modern agroecosystems, acidification of soils results mainly from nitrification of excess ammoniacal nitrogen inputs. Leaching of nitrate due to excess N inputs also leaches base cations, primarily Ca and Mg, by virtue of charge balance. In addition to acidification from excess N inputs, soil acidification may be induced by crops by imbalance in the extraction of cations vs anions, requiring plants to produce organic anions by deprotonating organic acids. After long periods of acidification, loss of cations by leaching and reduction of CEC by acidification can account for a large fraction of the total exchangeable base cations in the soil. The Wisconsin Cropping Systems Trial, located at the Arlington Research Station of the University of Wisconsin-Madison, has archived soil samples and performed plant analysis since 1989 for soils managed under common cropping systems of Midwestern United States. This trial represents a prime opportunity for studying the coupling of N and H cycles and to evaluate the acidification potential of these agricultural agroecosystems. Soil acidification and leaching of base cations will be considered as fingerprints of the long term effects of agroecosystems on soil chemical properties.
Phillip Barak, 608-263-5450, pwbarak@wisc.edu

Whole-farm Phosphorus Management on Dairy Farms. J.M. Powell, USDA-ARS; L.G. Bundy, D. Jackson-Smith, Univ. Wisconsin-Madison.
Unlike other regions that import significant amounts of their feed, most dairy farms in the Northcentral and Northeastern U.S. continue to be integrated crop-livestock farms that produce most of their own feed and recycle manure nutrients through crops. To remain economically viable, however, many dairy farms in this region are increasing herd size and importing more and more feed. Excessive nutrient imports resulting in soil nutrient accumulation, runoff and the pollution of surface and ground waters are pressing environmental challenges facing many dairy systems. This paper examines key factors that affect phosphorus (P) inputs and outputs, pathways, and flow rates on dairy farms in the U.S. Specifically, the paper elucidates key relationships between feed, land management and P recycling, such as (1) between feed sufficiency and the ability of a farm's land base to recycle manure P; (2) between the feed P and the amount and forms of P excreted in manure; (3) between manure P excretion and the buildup of soil test P; and (4) between manure application, tillage and P runoff. We show how improved P management in one production component (e.g., feed) affects P cycling in other production components (e.g., soils and crops) and the relative impact of each component's management on profitability and the environment.
J. Mark Powell, 608-264-5044, jmpowel2@wisc.edu

Nutrient Management Program in Wisconsin. L.G. Bundy, Univ. Wisconsin-Madison.
Recent Natural Resource Conservation Service nutrient management policy specifies use of a phosphorus index (PI) strategy in developing nutrient management plans. A draft PI for assessing the risk of P losses in runoff from cropland was developed for Wisconsin following published approaches. The Wisconsin PI recognizes the interaction of P source and transport factors by utilizing a multiplicative calculation of the sum of P transport and P source factors to assess P losses. P source factors include Bray P1 soil test, fertilizer P application rate and organic P application rate. P transport factors include soil erosion, runoff curve number, field slope, and distance to concentrated flow. The PI is structured to assess the risk of soluble P loss and will require modification to assess total P losses. The PI was applied to 11 farm fields yielding a range of values from 28 to 248. Calibration of the PI with measured P losses is needed.
J.D. Kaap, 608-276-8732, jim.kaap@wi.usda.gov

Current Status of Soil Test P on U.S. Dairies. S E. Feagley, Texas A & M Univ.; J.B. Peters, Univ. Wisconsin-Madison; T.C. Daniel, Univ. Arkansas.
There are numerous extraction methods for soil test phosphorus (P) used across the nation. These methods were developed to estimate the plant available P in relation to application rates of commercial inorganic sources of P. Over the last ten to fifteen years, some surface waters have had sufficient quantities of P introduced into them through runoff to cause eutrophication. There are'various sources of the runoff P such as, municipal sewage treatment plants, storm water runoff from urban areas, and agricultural lands where animal manures and inorganic fertilizers have been applied. Due to these water quality problems, USEPA and state regulatory agencies are implementing regulations and rules to reduce P runoff. This presentation will concentrate on extractable P from soils where dairy manure has been applied. The objectives are to a) demonstrate differences in P distribution on a manured field, b) discuss differences in extractable P from several studies across the US, and c) discuss difference between seven P extraction methods from selected soils across the US where dairy manure has been applied.
Sam Feagley, 979-845-1460, sfeagley@tamu.edu

Forages Show Little Response to High Soil Test P. M.P. Russelle, USDA-ARS-USDFRC; M.A. Schmitt, Univ. Minnesota; J.M. Powell, Univ. Wisconsin-Madison; C.A. Hasthorpe.
Soils on many dairy farms have increasing levels of soil test phosphorus (STP), caused by repeated fertilizer and manure P applications in excess ol crop P removal. We determined STP levels in several areas within dairy farm fields in MN and WI that have received manure, and measured apparent alfalfa and com response to STP during the 1999 growing season. STP levels varied widely both among and within fields. Variation increased as the mean STP level increased. Sitespecific manure applications may be acceptable even in high-STP fields, because they contain many low-testing areas. Corn yield, corn P uptake, and first cut alfalfa yield were not related to STP, whereas second and third cut alfalfa yields increased slightly as STP rose from low to optimum. Tissue P concentration in first cut alfalfa increased with STP, but not in second nor third cut alfalfa. Relatively little P wasremoved in forage, indicating that STP reductions will be slow. Soil test potassium (STK) was highly correlated with STP, and alfalfa K concentration increased with greater STP. Therefore, in addition to potential adverse environmental affects, high P testing soils on dairy farms may also produce forage that contains too much K to be fed safely to dry or closeup cows.
Michael P. Russelle, 612-625-8145, russelle@soils.umn.edu

Turnover of Dairy Manure N Fractions in Soil. J.M. Powell and K.A. Kelling, Univ. Wisconsin-Madison.
Nitrogen excretion in dairy manure can be divided into three pools: urinary N (UN), fecal endogenous N of microbial and gut origin (FEN), and fecal undigested feed N (FUFN). Each pool of manure N has a different potential to be recycled after its application to cropland. The rate and extent of manure N recycling depends on soil physical and chemical properties and the relative proportion of each manure component. Each of the manure components (UN, FEN, and FUFN) was labeled with 15N and applied in equivalents of 0 and 160 kg/ha of available N to 16 prominent agricultural soils of Wisconsin (four silt loams, four loams, four sandy loams, and four sands) of various fertility levels within a textural class. The soil manure mixtures were incubated at constant temperature and moisture, and sampled at weekly intervals for 24 wk. Data on N mineralization rates (k) and cumulative manure N mineralization (Nmin) of each manure N component were determined and related to soil properties.
J. Mark Powell, 608-264-5044, jmpowel2@wisc.edu

Effect of Manure Application Timing on Relative Nitrogen Availability. K.A. Talarczyk, K.A. Kelling, T.M. Wood, and P.E. Speth, Univ. of Wisconsin-Madison.
To determine the effect of application time on manurial N availability, solid dairy manure was applied at 32 Mg/ha in November, January, March, or just before spring tillage (April) in each of 4 yr in southwest Wisconsin. Separate fields were used each year. The manures contained oat-straw bedding and had an average C:N of 15.6. Plots receiving several rates of fertilizer N provided a basis of comparison. Corn grain yield, whole plant yield, and whole plant N uptake from the manure plots tended to be highest with the November application. In spite of no incorporation of any of the manure treatments until mid-April, based on fertilizer equivalence, manurial N availability ranged from 11 to 43% with the fall applications, typically about 8% higher than the availability from the winter or spring applications. Averaged across all application times and years, apparent N availability was 27% of the total manure N applied. This value may be somewhat low because of the cool, wet second year of the study. These data suggest that benefits associated with allowing time for adequate manure N mineralization may be more important than the risk of N losses from the manure during the late fall or winter.
Keith A. Kelling, 608 263-2795, kkelling@wisc.edu

DIVISION S-5 - PEDOLOGY

Virtual Soil Landscapes: A New Paradigm. S. Grunwald, Water Quality Laboratory; P. Barak, K. McSweeney, D.J. Rooney, B. Lowery, Univ. Wisconsin-Madison.
Pedology has evolved from mental, factorial concepts to complex, quantitative, pedodynamic modeling. Methods used in soil landscape modeling range from conceptual (e.g. regressions) to geostatistical approaches. New technologies such as Virtual Reality Modeling Language (VRML) provide opportunities for appreciably enhancing display of soil landscape information. We introduce a new VRML-based approach to soil landscape modeling addressing four different realms: (i) character space to express the statistical relationship between soil and topographic attributes, (ii) geographic space to describe the extent, continuity and spatial distribution of soil and topographic attributes in the x, y, and z directions using geostatistics, (iii) time space to describe changes in soil attributes over time, and (iv) abstract space to describe the organizational structure abstracting real soil landscapes to portray virtual soil landscapes. We present selected virtual soil landscapes implemented in VRML visualizing and characterizing a "real world" in southern Wisconsin to mirror our understanding of soils and our three-dimensional perception of the environment. This new paradigm attempts to improve communication of soil and landscape information to the research community, educators and any other user of soil information.
Sabine Grunwald, 419-448-2089, sgrunwal@heidelberg.edu

Mapping Subsurface Strata Using a Soil Imaging Penetrometer (SIP). D.J. Rooney, J.M. Norman, F.L. Scarpace, M. Dudka, Univ. Wisconsin-Madison; R.L. McLeese, USDA-NRCS; S.H. Lieberman, U.S. Navy; S. Grunwald, Heidelberg College.
The mapping of subsurface soil strata involves the visual inspection of core samples or pit faces for the determination of layer boundaries. The current best available technology requires the removal of the soil media from in situ environmental conditions and the subsequent exposure of the sample to ex situ conditions. Removing or exposing the sample to ex situ conditions not only disturbs the samples, but is very time and labor intensive. Additionally, it is difficult to optimize and direct sample placement in both the x, y, and z dimension with little or no preliminary soil information. A Soil Imaging Penetrometer (SIP) system has been developed to provide a first order inspection capability for subsurface mapping applications. The SIP has a diameter of 2.85 cm and is inserted into the soil using a truck-mounted hydraulic push system. A miniature solid-state digital video camera in conjunction with a white-light source images the soil strata through a sapphire window located in the side of the probe. The soil imagery can be used to optimize sample placement and provide a valuable decision support tool to field personnel. linage processing techniques can be applied to the digital images or movies to aid in the analysis of the data collected. The imagery can be transferred to any location via the Internet or posted on the World Wide Web.
Daniel J. Rooney, 608-265-5350, djrooney@wisc.edu

The Present, Past, and Future of the Catena Concept. D.J. Brown, K. McSweeney, V.T. Holliday, M.K. Clayton, Univ. Wisconsin-Madison.
While the catena concept enjoys wide recognition among environmental scientists, there is little consensus on the precise meaning of the term. The U.S. Soil Survey, while making little use of the concept, considers the catena a restricted sort of association, a sequence of soils down a hillslope with decreasing drainage on uniform parent material. The editors of Catena take a more process-oriented view, dedicating their journal to research at the disciplinary intersection of geomorphology, hydrology and pedology. Between these two poles, there exist a wide variety of vague and conflicting interpretations of the catena-the most troubling of which is the synonymous use of "catena" and "toposequence." Historical research into the development of the concept of the catena in 1930's East Africa shows that the idea originated in Uganda as a soil mapping technique, to which Geoffrey Milne later attached a name and explanatory soil-landscape processes. Much of the current confusion can be traced to subsequent attempts by U.S. pedologists to force the catena into the dominant "natural body" paradigm. Drawing on this historical context and contemporary environmental research requirements, we propose a revitalized catena to better link the practice of soil mapping with the study of soil formation.
Kevin McSweeney, 608-262-6968, kmcsween@wisc.edu

A Re-examination of the Catena Concept on the Landscape of Origin in East Africa. D.J. Brown, K. McSweeney, M.K. Clayton, V.T. Holliday, Univ. Wisconsin-Madison.
Inspired by Geoffrey Milne's synthesis of soil-landscape patterns and processes through the catena concept, we apply quantitative soil-landscape modeling methods to selected soil formation questions on the landscape of origin for the catena concept in central Uganda. Tremendous advances have been made in the last few decades in the use of terrain models and multivariate spatial statistics to improve soil mapping. In this case study, we use these techniques- complemented with traditional soil genesis research techniques-to investigate the formation of stone lines, texture-contrast soils, particle-size gradients in depositional zones, and other questions relevant to both this specific landscape and the theory of soil formation more generally. In so doing, we not only approach old questions in a new way, but also suggest a model for our larger goal of rendering soil formation research more directly and explicitly relevant to the practice of soil mapping. This preliminary report focuses largely on the novel methodological approach employed, but also includes a description of the study area, hypotheses to be tested, and early results on stone line formation.
Kevin McSweeney, 608-262-6968, kmcsween@wisc.edu

Application of Neural Networks for the Prediction of Soil Attributes over the Landscape. S.J. Park, Center for Development Research, Bonn, Germany; K. McSweeney, B. Lowery, Univ. Wisconsin-Madison.
Artificial neural networks were applied to characterize the spatial distribution of soil attributes at the catena and catchment scale. More specific research questions were 1) to compare different algorithms of neural networks in the framework of soil-landscape analysis; 2) to compare the results between neural networks and regression analyses; and 3) to identify the optimum number of soil samples needed to characterize the spatial variance of soil attributes. Two research sites under different environmental conditions were selected, and 220 and 504 soils samples from each slope were collected and analysed. Digital elevation models were first constructed, from which eight terrain indices were calculated. Among many other algorithms compared, a multilayer perceptron with two hidden layers showed the best performance for predicting soil attributes at the study sites. Multilayer perceptron outperformed multiple regression analyses for both variance explained (0. 1 >R2) and prediction error. Both in the neural networks and regression analyses, 5075 samples were sufficient to identify the relationship between landform configuration and individual soil attributes at the observed spatial scale.
S.J.Park, 44-228-734926, spark@ unibonn.de

Identification of Pedogeomorphological Processes on a Hillslope, Somerset, England. S.J. Park, Center for Development Research, Bonn, Germany; K. McSweeney, B. Lowery, Univ. Wisconsin-Madison.
Thirty-two physicochemical attributes of 502 soil samples on a hillslope were analyzed using ordination techniques to identify process-response relationships between the distribution of soil attributes and slope configuration. A principal component analysis was applied and extracted components were regressed with terrain index. The five components explaining 80% of the total variance were interpreted as 'podzolization effect', 'nutrient system effect', 'solute leaching effect', 'erosion-weathering effect', and 'soil acidification effect'. There is a varying degree of success in modeling soil distribution using terrain attributes not only in the amount of variance explained, but also in terrain attributes brought into regression models. Topsoil attributes are better correlated with terrain attributes than subsoil attributes, due to their more active involvement in contemporary pedological and geomorphological processes. For subsurface soils, only few soil attributes (secondary Mn and soil pH) were successfully modeled by terrain attributes. The others show poor model fits, due to complex responses to pedogeomorphological processes. This research suggests that soil-landscape modeling in hillslopes with complex histories requires greater attention to interpreting subsoil patterns.
S.J.Park, 44-228-734926, spark@ unibonn.de

DIVISION S-6 - SOIL AND WATER MANAGEMENT AND CONSERVTION

Phosphorus Indexes: The Midwest Experience. B.C. Joern, Purdue University; A.P. Mallarino, Iowa State University; L.G. Bundy, University of Wisconsin; T. Bailey, B.M. Stewart, J. Kaap, NRCS.
Phosphorus Index (PI) assessment tools are being developed throughout the US to identify individual fields or management units with high P loss potential. In addition to the common PI approach of identifying P loss potential via soil erosion and runoff, P export via field tile effluent can be a significant transport pathway in some soils of the Midwestern US. In this presentation we will compare how Indiana, Iowa, and Wisconsin are approaching PI development and implementation. Each state has significant variations in crop, soil, resource utilization, and climatic variables that can pose significant scientific and political challenges to the individuals charged with developing PIs. We will also discuss the issues of regional/national normalization of PI values, the importance of PIs as part of CNMPs, and the relevance if PIs in the coming era of TMDLs and other "ambient" water quality initiatives.
Brad C. Joern, 765-494-9767, bjoem@purdue.edu

Mapping an Eroded Dubuque Soil Using a Constant Rate Penetrometer. B. Lowery, F.J. Arriaga, D.J. Reinert, and K. McSweeney, Univ. of Wisconsin-Madison.
Soil erosion not only reduces crop production, but it also impacts the environment. Fast and reliable tools are needed to develop spatial maps of eroded land. A constant rate penetrometer was used to determine erosion levels of an eroded Dubuque silt loam soil. The penetrometer was pushed with a hydraulic cylinder mounted on a probe truck to a depth of 1 m where possible. Data were collected continuously with a datalogger connected to a load cell and a string potentiometer depth gauge. The penetrometer had a 30 o tip. Penetrometer data correlates well with previously available soil erosion maps of the site, where depth to clay residuum (2Bt2 horizon) was used to determine erosion severity. Depth to clay residuum averaged 0.95, 0.74, and 0.45 m for the slight, moderate, and severe erosion levels, respectively. Connected with digital elevation models, the penetrometer can be used to map eroded soil and can provide useful data for soil and land management.
F.J. Arriaga, 608 262-0221, farriaga@wisc.edu

DIVISION S-7 - FOREST AND RANGE SOILS

Papermill Sludge Slows Growth of Young Pinus resinosa in Plantations. W. Stites, J.G. Bockheim, Univ. Wisconsin-Madison.
Red pine in two central Wisconsin plantations (ages 3 and 5 with initial average heights of 0.6 and 1.4 m) received 0, 10, 20, or 40 dry Mg/ha of surface-applied papermill wastewater-treatment sludge. Soil and foliar nutrient concentrations, foliar mass, and height and diameter growth were measured for up to 3 yr. Sludge lowered acidity and increased N, Ca, Mg, Na, and K in the upper 0. 15 m of soil. First-year foliar concentrations of N, P, Mg, S, and in some cases K, Fe, and Zn increased with sludge, whereas Al and B decreased. These changes would appear beneficial or neutral, yet needle mass, height growth, and diameter growth decreased significantly with sludge. It was not possible to tell exactly why sludge curtailed growth, because sludge affected many soil and plant properties simultaneously. Possible mechanisms for the decreased growth include increased competition from herbaceous plants, induced B deficiency, decreased drought tolerance, or evaporation of rainfall from the sludge layer. Dry weather prevailing during the study could have aggravated any of these. Further studies should investigate whether these effects persist with normal precipitation, whether adding supplemental P, K, or B to papermill sludge would benefit red pine, and whether a more nutrient-demanding tree species is more suited than red pine to benefit from sludge nutrients.
Will Stites, 715-345-7065, wstites@coredcs.com

DIVISION S-8 - NUTRIENT MANAGEMENT AND SOIL AND PLANT ANALYSIS

Approach for the Elemental Concentrations in Plant Tissue by ICP-MS and ICP-OES. L.S. Zhang, S.M. Combs, Univ. Wisconsin-Madison.
Inductively coupled plasma optical emission spectrometry (ICPOES) is extensively used for the simultaneous analysis of major, minor and trace metals in plant tissues. However, it is not without challenges. With a limited sample preparation work, the major components may be over the linear range of "routine" calibration, but the minor or the trace components may be far below the "detection limits". A simultaneous analysis becomes a simultaneous compromising. ICP mass spectrometry (ICP-MS) is increasingly available. ICP-OES and ICP-MS can and should be used to meet the challenge of 14 "simultaneous" analysis of metals in plant tissue samples. An approach was proposed, including the sample preparation, list of elements by ICP-OES, list of elements by ICP-MS, and procedures for "special" elements such as chromium, arsenic, selenium, and iodine.
Ling S. Zhang, 608-262-4364x106, lzhang3@wisc.edu

Analysis of Dissolved Iodide by Gaseous Sample Introduction ICP-MS. L. S. Zhang, Univ. of Wisconsin-Madison.
For the analysis of iodide by inductively coupled plasma mass spectrometry (or optical emission spectrometry), a gaseous sample introduction is very efficient and possesses several advantages over a conventional nebulizer sample introduction. In the currently available gaseous sample introduction methods, iodide in aqueous samples is oxidized to iodine by some form of oxidant (e.g. nitrite at low pH) and iodine is separated from aqueous phase via a gas-liquid-separator. Since both iodide and iodate exist in natural water samples, the iodate in original aqueous samples could also oxidize iodide to iodine when the samples are acidified, resulting in a positively biased iodide result. It was proposed that a solution of iodate and nitric acid might be used as an oxidant. In this way, iodide would be oxidized to iodine by iodate, no matter whether the original samples contain iodate or not. The iodide result would not be positively biased.
Ling S. Zhang, 608-262-4364x106, lzhang3@wisc.edu

Phosphorus, Potassium and pH in Wisconsin Soils: A 25 Year Review of Public and Private Laboratory Data. S.M. Combs, J.B. Peters, K.A. Kelling, Univ. Wisconsin-Madison.
Wisconsin farm soil test data from public and private FSA certified soil testing laboratories has been summarized since 1974. Soil P values for all Wisconsin farm soils and the number of counties having average soil P values greater than where response to phosphate application is expected have increased. Highest levels (> 100 ppm) and steepest increases (approximately 20 to 40 ppm) occurred in counties having extensive acreage of coarse-textured soils managed for potato and vegetable production. Applying no more than recommended rates of phosphate fertilizer and/or appropriate crediting of manure nutrients appears to have become more common on Wisconsin farms and is reflected by the slowed rate of increase in soil P. Soil K has increased for all soils and most counties have shown an increase from below optimum for most crops (80 to 120 ppm) to optimum for com and alfalfa. Soil pH has either remained the same or increased, indicating that forage producers recognize the importance of liming to maintain optimum alfalfa yields. Increased soil P, K and pH show widespread adoption of fertility management practices necessary for profitable crop production. Trends in soil P show that while average values are below the environmental critical levels, no additional phosphate is being recommended on an increasing number of samples because profitable crop response is not expected.
Sherry Combs

Simulated Rainfall Duration and Soil Sampling Depth Effects on Interpretation of Phosphorus Runoff Data. T.W. Andraski, L.G. Bundy, J.S. Studnicka, and J.M. Powell, Univ. Wisconsin-Madison.
Simulated rainfall is widely used to determine phosphorus (P) loss in surface runoff. We determined runoff sampling time, soil test P, soil sampling depth, and corn management practice effects on dissolved reactive P (DRP) and biologically available P (BAP) concentrations and loads in runoff. Management practices included two tillage systems (chisel plow and no-till) with and without dairy manure. Runoff was collected 30 min following runoff initiation (T30) and following 60 min of simulated rainfall (T60) applied at 75 mm/hr. Runoff sampling time and soil sampling depth did not influence the interpretation of soil test P effects on P concentrations in runoff; however, concentrations were lower at T60 and had generally higher r-square values for soil P-runoff P relationships at shallower sampling depths. Time affected BAP concentrations and loads, but not DRP in runoff from recently established management practices (established <5 months prior to rainfall simulation). The significant time x management practice interaction on BAP in runoff resulted from greater treatment differences with higher rainfall amounts applied at T60 rather than differences in the amount of time until runoff initiation at T30. These results indicate that the T60 sampling time was a better indicator of the potential effects of recently established management practices on P losses in runoff.
Todd Andraski, (608) 265-5370, andraski@wisc.edu

Phosphorus Forms, Amounts, and Movement in Biosolids-Treated Soils. J.S. Studnicka, T.W. Andraski, L.G. Bundy, Univ. Wisconsin-Madison; D.S. Taylor, Madison Metropolitan Sewerage District.
Phosphorus (P) accumulation in soils receiving long-term applications of biosolids is a potential source of pollution if this P is lost to natural waters. The objective of this study was to determine effects of biosolids P rate on P in soils and to evaluate the extent of P movement at various soil depths. We collected soil samples at depths of 0-90 cm in 15-cm increments from 29 fields near Madison, WI, which had received various applications (1-17 yr) and amounts (187-2306 kg P/ha) of biosolids P during 1979-1998. Soils were analyzed for P using distilled water extraction, Mehlich III, Bray-1, and iron-oxide paper strip methods. Bray-1 soil test values at 0-3, 0-15, and 15-30 cm were positively correlated with biosolids P applied. At 0-15 cm, Bray-1 values ranged from 27-201 mg/kg across the sites. There was little or no relationship between Bray-1 P values at 30-90 cm and biosolids P loading. Results from all P tests were similarly related to biosolids P applied, but none was better correlated than Bray-1. Degree of P saturation at 0-15 cm across biosolids P rates ranged from 9-29%. No evidence of substantial P movement below 30 cm was found even at the highest biosolids P rates. Both agronomic and environmental P tests were good indicators of the P status of biosolids-treated soils.
Julie Studnicka, (608) 263-3878, jsstudnicka@wisc.edu

Management Practice Effects on Phosphorus Losses in Runoff in Corn Production Systems. L.G. Bundy, T.W. Andraski, J.S. Studnicka, J.M. Powell, Univ. Wisconsin-Madison.
Phosphorus (P) losses in runoff from cropland can contribute to pollution of surface waters. This study was conducted to determine the influence of management practices used in corn production on P losses in runoff. Field experiments with variables including soil test P level (STP), tillage and manure application combinations, and manure and biosolids application histories were subjected to simulated rainfall, and runoff collected for 1 hr after rainfall initiation was analyzed for dissolved reactive P (DRP), bioavailable P, total P (TP), and sediment. In no-till corn, DRP concentration and load increased as STP increased from 8 to 62 mg/kg. No tillage and unincorporated manure increased DRP concentrations, did not consistently affect DRP loads, and decreased TP concentration and loads in runoff. Tillage to incorporate manure generally lowered runoff DRP concentration but increased TP concentration and loads due to increased sediment loss. Management practices have a major influence on runoff P losses that exceeds the effects of STP alone. Results emphasize the need to design management recommendations to minimize losses of those P forms with the greatest pollution potential.
Larry Bundy, (608) 263-2889, lgbundy@wisc.edu

Evaluation of Variable-Rate Lime Application for a Corn-Soybean Rotation. R.L. Zogbaum, R.P. Wolkowski, and L.G. Bundy, Univ. Wisconsin-Madison.
Variable-rate technology has been used in Wisconsin for fertilizer application for some time. This study is being conducted to evaluate the efficacy of variable-rate compared to field average liming. Four fields in southern Wisconsin managed in a corn ( Zea mays L.)/soybean [Glycinemax L. (Merr.)] rotation were chosen to conduct the study. Replicated field length strip treatments were installed using a commercial variable-rate lime spreader based on a 0.4 ha grid-sampling in spring 1999. Strip treatments include: no lime, lime applied at the field average rate, and lime applied according to site-specific need. In addition, three standard small plot studies were sited in each field. Treatments consist of no lime 1/3, 2/3, 1, and 1-1/3 lime requirement. Soil pH showed modest change in 1999, presumably because of the short time after application. Significant yield response to lime treatment was observed at all small plots in one field, and one of three plots in the other field planted to soybean in 1999. Corn yield responses to liming were not significant. Yield monitor data obtained from the cooperators showed response to lime only in one field planted to soybean in 1999. Results evaluated to date demonstrate the variability of the lime requirement of the selected fields.
R.L. Zogbaum, 608 263-4529, rzogbaum@wisc.edu

Dairy Diet Phosphorus Effects on Phosphorus Losses in Runoff from Land-Applied Manure. A.M. Ebeling, L.G. Bundy, T.W. Andraski, and J.M. Powell, Univ. Wisconsin-Madison.
Phosphorus (P) losses from land-applied manure can contribute to nonpoint source pollution of surface waters. Dietary P levels influence P concentrations in animal manures and may affect P losses from land-applied manure. The objective of this study was to determine the effects of dairy diet P concentration on P losses in runoff from land-applied manure. Manures with P concentrations of 4.8 and 12.8 g/kg from two dietary P levels were applied to a silt loam soil at 56 wet Mg/ha (40 and 108 kg P/ha, respectively). The high P manure was also applied at a P rate equivalent to low P manure (40 kg P/ha). Plots were subjected to simulated rainfall (75 mm/hr) in June and again in October. Runoff was analyzed for dissolved reactive P (DRP), bioavailable P, total P, and sediment concentration. Natural runoff from the same plots was collected from November-May and analyzed for P as described above. At equivalent manure rates, DRP in June runoff from the high P manure was about 10 times higher (0.27 vs. 2.87 mg/L) than the low P manure, and 4 times higher (0.27 vs. 1.20 mg/L) when applied at equivalent P rates. Phosphorus concentrations in October runoff and in natural runoff were lower (0.02 to 1.69 mg/L), but treatment effects were the same as for June runoff. These results suggest that excess P in dairy diets increases the potential for P loss in runoff from land-applied manure.
Angela Ebeling, (608) 263-3878, amebeling@wisc.edu

DIVISION S-11 - SOILS AND ENVIRONMENTAL QUALITY

Availability of Phosphorus for Transport by Water following Manure Application to Soils. L.W. Good, L.R. Cooperband, Univ. Wisconsin-Madison.
Two Plano silt loam soils with the same cropping history but different soil test P levels were obtained from a long-term fertilizer trial. The soils were mixed with fresh dairy manure and poultry litter at rate of 80 kg/Ha total P applied to the top five cm of soil and incubated for 36 weeks. Water-extractable P from the amended soils stabilized after two weeks of incubation, with levels in the high P soil amended with dairy manure > high P soil with broiler litter > low P soil with broiler litter > low P soil with dairy manure > high P soil > low P soil. Water-extractable P in the soil-dairy manure mixtures showed a significant interaction between soil P test level and manure, while those from poultry litter-amended soils did not. The organic portion of water-extractable P in the incubated mixtures increased from 2 weeks to 36 weeks, but remained less than 10 % for the poultry litter-amended soils. In contrast, dissolved organic P was 26% - 36% of the total water-extractable P for the dairy manure amended soils after 36 weeks. Data will be presented to test the hypothesis that dissolution of a calcium-phosphate mineral is controlling the solubility of P from the soil amended with poultry litter.
Leslie R. Cooperband, 608-265-4654, lrcooperband@facstaff.wis.edu

Alachlor Leaching Under Aerobic vs. Anaerobic Conditions in Soil Microlysimeters. H.W. Read, Univ. Wisconsin-Madison.
The acetanilide herbicide alachlor is degraded in soil to a dechlorinated metabolite, particularly under reducing conditions. The Nmethoxymethyl moiety, present on both alachlor and the metabolite may be responsible for the carcinogenic properties of alachlor, hence the dechlorinated metabolite is of toxicological significance and leaching of this compound to groundwater is a concern. Alachlor was applied at normal field rates to undisturbed soil column microlysimeters containing Plano Silt Loam. Leaching under saturated conditions was compared with that occurring under unsaturated conditions. Both alachlor and its dechlorinated metabolite (2-,6-diethyl-N-(methoxymethyl) acetanilide) were monitored. Both alachlor and the metabolite were detected at far higher levels in the saturated columns than in the unsaturated columns. In both the saturated and unsaturated columns, the metabolite was detected more frequently than the parent compound, although at generally low levels, except when significant amounts of alachlor were also present. In those instances, levels of the parent were generally greater than the metabolite, but concentrations of the two were correlated.
Harry W. Read, 608-265-4848, hwread@wisc.edu

Land Application of Crushed Drywall Waste for Field Crops. R.P. Wolkowski, Univ. Wisconsin-Madison.
Land application of certain solid waste materials may be a pathway to slow the construction of new landfills, while providing a cost savings to businesses and essential plant nutrients to crop producers. Before such practices can be accepted, field research should be conducted to evaluate potential benefits and concerns relative to crop growth and the environment. Eighteen site years of research were conducted in Wisconsin, examining the response of alfalfa (12 yr) and potato (6 yr) to treatment with crushed gypsum drywall waste. Rates of application on alfalfa ranged between 2.2 and 36 Mg/ha of material, and 112 and 560 kg/ha of actual Ca on potato. Commercial gypsum fertilizer and an untreated control treatment were included. The highest application of drywall increased alfalfa yield at two locations that were historically responsive to S fertilization. Potato yield was not affected by drywall or gypsum fertilizer treatment. Soil water pH decreased slightly, soil test Ca and S increased, and Mg decreased where high rates of drywall were applied. Potato tuber Ca level was increased by wallboard and gypsum application. No phytotoxic effects from direct application of drywall were noted. Land application of clean, crushed gypsum drywall is a reasonable alternative to land filling and provides a response equal to that expected from gypsum fertilizer.
R.P. Wolkowski, 608/263-3913, rpwolkow@facstaff.wisc.edu

Computer Software Application

The Wisconsin Agricultural Research Station GIS: Overview. R.F. Harris, S.G. Mukhtyar, D. Wiersma, D.H. Mueller, S.J. Ventura, Univ. Wisconsin-Madison.
The GIS focuses on temporal MS Access and ArcView databases managed by customized ArcView extension and Visual Basic query programs and connections to other software programs. The Access database consists of farm records organized within standard (field boundary, management, analyses, and lookup ID) and project-specific categories. The ArcView database (Wisconsin Transverse Mercator coordinates) consists of 1) state agency-derived coverages such as bedrock, surficial deposits, and groundwater contamination susceptibility (1:500,000 scale); soils, ecoregions and original vegetation (1:250,000); DEM (75 m); and watersheds (1:24,000); 2) county agency- or station-digitized Soil Survey Geographic Database coverages including soil name, slope, and drainage (<1:20,000); 3) standard farm coverages such as orthophotos, DEM (4 m), and GPS-derived field (<1: 1,000) and annually-updated subfield boundaries integrated with selected Access records such as crop planting, chemical and fertilizer application, irrigation and tillage field management; and 4) project-specific coverages such as high resolution DEM (1 m) and DEM-derived slopes and depressions for selected fields. Applications to general farm management and specific integrated crop production/ water quality protection projects are demonstrated.
Robin F. Harris, 608-265-0677, rfharris@wisc.edu

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