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Introduction:

    Executive Summary

    Research Goals

Executive Summary

The first several weeks of the semester, our Soils class spent lab time at the Hartnett site in southern Dunn County.  The Hartnett site landscape includes a steeply sloping interface between the high, sandy glaciofluvial, Wissota Terrace of the lower Chippewa River Valley (see Andrews 1965) and a narrow, deeply incised stream valley inset into the Wissota Terrace.   The low order stream that flows through the property is a tributary to the Chippewa River. 

The class was divided into groups of three to four students, and each group was assigned an area in which to dig a soil pit.  This website is a compilation of the results of that fieldwork and additional research.  The purpose of this website is to present the results of our research to determine the genesis of the soils in the study area, and to provide the landowner with recommendations for suitable land uses based on the knowledge we have gained about soils on his property.   

Eight pits were excavated.  Pits were excavated in representative landscape positions with respect to slope aspect and position.  This allowed us to gain an understanding of how landscape position influences soil development.  Each group of students studied the soil profiles exposed in their pits and described and recorded their findings.  The pits were also photographed.  Information gathered in the field includes depth, color, structure, consistence, boundary, and other phenomena present for each master horizon. 

The soils across the site are sandy and appear to be derived from glaciofluvial outwash.   Evidence that the upland portion of this site was used for farming is found in the pits located on level portions of the site (Ap horizon, or plow zone).  This evidence is confirmed by current land-use in the surrounding area.  Elsewhere, on less level and poorly drained areas the site is wooded.  Climate, natural vegetation, and other soil forming factors are fairly consistent across the study area.  The bedrock in Dunn County consists of Pre-Cambrian crystalline rocks overlain by Cambrian sedimentary units.  The sub-crop at the Hartnett site study specifically is the Cambrian-age Mount Simon Sandstone Formation, a medium to coarse-grained quartz-rich sandstone.  This bedrock unit is overlain by at least 10 meters of glaciofluvial outwash of the Wissota Terrace in upland settings and les than two meters of younger, sandy alluvium in lowland positions.  The major factor contributing to variability in soil characteristics is slope and position on the landscape. 

Soils in the lowland portions of the site are distinguishable from soils on the upland and steeply sloping portions of the site.  All soils observed in pits (1, 6, and 7) located on steep slopes fit the Finchford Series soil description, and correlate to the Hubbard series soils in the most current edition of the Dunn County Soil Survey (the exact map unit, HuA or HuB is dependent upon slope).  Similarly, the pit located in the upland portion of the site, currently mapped as Finchford Series, corresponds to the Hubbard Series (HuA) in the Dunn County Soil Survey.  There is more variation in the lowland soils, which are consistent with the Scotah Series for pits 2 and 4, and the Finchford Series for pits 3 and 8.  Pit 2 appears most like the Plainbo Series and pit 4 is most similar to the Morocco Series as described in the Dunn County Soil Survey.  Pits 3 and 8 are both similar to the Hubbard Series as described in the Dunn County Soil Survey.    

The most significant factors in terms of land use are slope characteristics and a seasonally high water table in the lower portion of the study area (especially near the stream).  The sandy texture of these soils make the area susceptible to wind and water erosion.  Thin autochthonous glacial outwash in the upland and sloping portions of the study area already exhibit erosional characteristics.  Consequently, soils in the lowland areas are thickened, suggesting materials have eroded down from upslope and accumulated at the bottom.   

Much can be done with soils in the upland portion of the site.  The sloping portions of the area are more susceptible to erosion, and should probably not be disturbed.  The lowland area also has many possibilities for land use, but structures with basements should not be constructed because of shallow bedrock and seasonally high water table.  If construction is to occur on any portion of the study area, soil berms should be in place, and vegetative buffers should be left.   

Mitigation against future soil erosion is suggested for this study area.   Soils in this area may be moderately fertile and suitable for cultivation, especially in the upland regions.  Zero-tillage and contour plowing should be implemented if sustainable cultivation is to be performed.  Soils in this area are best suited for “low impact” activities such as pasture or recreation areas.         

Group #7     

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Research Goals/Objectives

Research Goal

Our goal is to be able to make recommendations for appropriate land uses based on the soil morphology we observed at the Hartnett Site.  This site was selected for study for two reasons.  First, the landowner graciously granted access permission to their property.   Second, The study site occupies a landscape position commonly observed in Dunn County and surrounding counties.  This landscape position encompasses the steeply sloping interface between bedrock-controlled uplands and the adjacent high, sandy glaciofluvial Wissota terrace within the lower Chippewa River Valley (after Andrews 1965).  A more thorough understanding of soil formation processes and variability across this landscape position has been identified as an important research goal by NRCS personnel responsible for providing updated soil maps and interpretive classifications for land use and resource management.  

Research Objectives

1) Characterize the catenary relationship between soil profiles across the study site.

A. Select eight (8) pedons at representative landscape positions

B. Describe the soil profiles, including the depth, color, structure, consistence, boundary, and other phenomena for each master horizon

C. Photograph the described profile face of each pit

2) Determine factors that have contributed to soil genesis, using the descriptions of site profiles and existing map units.

3) Make interpretations about landscape history and evolution, using the CLORPT model and our understanding of catenary relationships.

4) Make recommendations for appropriate land uses by identifying limiting soil, geomorphic and climatic factors, and including specific recommendations for:

A. Native Prairie, Grasses and Terrestrial Life

B. Wetland Mitigation or Restoration and Migratory Waterfowl Habitat

C. Outdoor Recreation

D. Agriculture

E. Residential Development

F. Commercial and Industrial Development

G. Construction and Fill

H. Trees and Shrubs Suitable for Planting

Group #2

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