Official Series Description


Lab Data Summary

Aggregate lab data for the KNIFFIN soil series. This aggregation is based on all pedons with a current taxon name of KNIFFIN, and applied along 1-cm thick depth slices. Solid lines are the slice-wise median, bounded on either side by the interval defined by the slice-wise 5th and 95th percentiles. The median is the value that splits the data in half. Five percent of the data are less than the 5th percentile, and five percent of the data are greater than the 95th percentile. Values along the right hand side y-axis describe the proportion of pedon data that contribute to aggregate values at this depth. For example, a value of "90%" at 25cm means that 90% of the pedons correlated to KNIFFIN were used in the calculation. Source: KSSL snapshot . Methods used to assemble the KSSL snapshot used by SoilWeb / SDE

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Pedons used in the lab summary:

MLRALab IDPedon IDTaxonnameCINSSL / NASIS ReportsLink To SoilWeb GMap
10940A14871969IA007002Kniffin7Primary | Supplementary | Taxonomy | Pedon | Water Retention | Correlation | Andic Soil Properties40.6450005,-93.015274
10986P041585IA1850054Kniffin5Primary | Supplementary | Taxonomy | Pedon | Water Retention | Correlation | Andic Soil Properties40.8916664,-93.1755524
10986P041685IA1850055Kniffin5Primary | Supplementary | Taxonomy | Pedon | Water Retention | Correlation | Andic Soil Properties40.8919449,-93.1747208
10986P041785IA1850056Kniffin5Primary | Supplementary | Taxonomy | Pedon | Water Retention | Correlation | Andic Soil Properties40.8919449,-93.1755524
10940A1488S1969IA185001Kniffin6Primary | Supplementary | Taxonomy | Pedon | Water Retention | Correlation | Andic Soil Properties40.5944443,-93.3955536

Water Balance

Monthly water balance estimated using a leaky-bucket style model for the KNIFFIN soil series. Monthly precipitation (PPT) and potential evapotranspiration (PET) have been estimated from the 50th percentile of gridded values (PRISM 1981-2010) overlapping with the extent of SSURGO map units containing each series as a major component. Monthly PET values were estimated using the method of Thornthwaite (1948). These (and other) climatic parameters are calculated with each SSURGO refresh and provided by the fetchOSD function of the soilDB package. Representative water storage values (“AWC” in the figures) were derived from SSURGO by taking the 50th percentile of profile-total water storage (sum[awc_r * horizon thickness]) for each soil series. Note that this representation of “water storage” is based on the average ability of most plants to extract soil water between 15 bar (“permanent wilting point”) and 1/3 bar (“field capacity”) matric potential. Soil moisture state can be roughly interpreted as “dry” when storage is depleted, “moist” when storage is between 0mm and AWC, and “wet” when there is a surplus. Clearly there are a lot of assumptions baked into this kind of monthly water balance. This is still a work in progress.

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Sibling Summary

Siblings are those soil series that occur together in map units, in this case with the KNIFFIN series. Sketches are arranged according to their subgroup-level taxonomic structure. Source: SSURGO snapshot , parsed OSD records and snapshot of SC database .

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Select annual climate data summaries for the KNIFFIN series and siblings. Series are sorted according to hierarchical clustering of median values. Source: SSURGO map unit geometry and 1981-2010, 800m PRISM data .

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Geomorphic description summaries for the KNIFFIN series and siblings. Series are sorted according to hierarchical clustering of proportions and relative hydrologic position within an idealized landform (e.g. top to bottom). Most soil series (SSURGO components) are associated with a hillslope position and one or more landform-specific positions: hills, mountain slopes, terraces, and/or flats. Proportions can be interpreted as an aggregate representation of geomorphic membership. The values printed to the left (number of component records) and right (Shannon entropy) of stacked bars can be used to judge the reliability of trends. Small Shannon entropy values suggest relatively consistent geomorphic association, while larger values suggest lack thereof. Source: SSURGO component records .

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There are insufficient data to create the 3D mountains figure.

There are insufficient data to create the 3D terrace figure.

There are insufficient data to create the 3D flats position figure.

Competing Series

Soil series competing with KNIFFIN share the same family level classification in Soil Taxonomy. Source: parsed OSD records and snapshot of the SC database .

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Select annual climate data summaries for the KNIFFIN series and competing. Series are sorted according to hierarchical clustering of median values. Source: SSURGO map unit geometry and 1981-2010, 800m PRISM data .

Click the image to view it full size.

Geomorphic description summaries for the KNIFFIN series and competing. Series are sorted according to hierarchical clustering of proportions and relative hydrologic position within an idealized landform (e.g. top to bottom). Proportions can be interpreted as an aggregate representation of geomorphic membership. Most soil series (SSURGO components) are associated with a hillslope position and one or more landform-specific positions: hills, mountain slopes, terraces, and/or flats. The values printed to the left (number of component records) and right (Shannon entropy) of stacked bars can be used to judge the reliability of trends. Shannon entropy values close to 0 represent soil series with relatively consistent geomorphic association, while values close to 1 suggest lack thereof. Source: SSURGO component records .

Click the image to view it full size.

Click the image to view it full size.

There are insufficient data to create the 3D mountains figure.

Click the image to view it full size.

There are insufficient data to create the 3D flats position figure.

Soil series sharing subgroup-level classification with KNIFFIN, arranged according to family differentiae. Hovering over a series name will print full classification and a small sketch from the OSD. Source: snapshot of SC database .

Block Diagrams

Click a link below to display the diagram. Note that these diagrams may be from multiple survey areas.

  1. IA-2010-09-03-03 | Van Buren County - 2004

    Typical pattern of soils and parent material in the Edina-Seymour-Clarinda association (Soil Survey of Van Buren County, Iowa; 2004).

  2. IA-2010-09-03-04 | Van Buren County - 2004

    Typical pattern of soils and parent material in the Kniffin-Rinda-Gara association (Soil Survey of Van Buren County, Iowa; 2004).

  3. IA-2011-05-31-09 | Davis County - 1991

    Typical pattern of soils and parent material in the Edina-Seymour-Clarinda association (Soil Survey of Davis County, Iowa; 1991).

  4. IA-2011-05-31-10 | Davis County - 1991

    Typical pattern of soils and parent material in the Armstrong-Gara-Kniffin association (Soil Survey of Davis County, Iowa; 1991).

Map Units

Map units containing KNIFFIN as a major component. Limited to 250 records.

Map Unit Name Symbol Map Unit Area (ac) Map Unit Key National Map Unit Symbol Soil Survey Area Publication Date Map Scale
Kniffin silt loam, 2 to 5 percent slopes531B124514027002tfzfia00719701:15840
Kniffin silt loam, 5 to 9 percent slopes, moderately eroded531C21881402702fj1dia00719701:15840
Kniffin silt loam, 5 to 9 percent slopes531C9734027012tfzgia00719701:15840
Kniffin silt loam, 2 to 5 percent slopes531B180304047092tfzfia05119881:15840
Kniffin silty clay loam, 5 to 9 percent slopes, moderately eroded531C235604047112tfzhia05119881:15840
Kniffin silt loam, 5 to 9 percent slopes531C4314047102tfzgia05119881:15840
Kniffin silty clay loam, 5 to 9 percent slopes, moderately eroded531C225434048192tfzhia05319861:15840
Kniffin silt loam, 5 to 9 percent slopes531C6694048182tfzgia05319861:15840
Kniffin silt loam, 2 to 5 percent slopes531B6174048172tfzfia05319861:15840
Kniffin silty clay loam, 5 to 9 percent slopes, moderately eroded531C210726476392tfzhia11719911:15840
Kniffin silt loam, 5 to 9 percent slopes531C9726476382tfzgia11719911:15840
Kniffin silt loam, 2 to 5 percent slopes531B3226476372tfzfia11719911:15840
Kniffin silty clay loam, 5 to 9 percent slopes, moderately eroded531C296944131172tfzhia17719941:12000
Kniffin silt loam, 2 to 5 percent slopes531B68164131152tfzfia17719941:12000
Kniffin silty clay loam, 2 to 5 percent slopes, moderately eroded531B21927413116fvwbia17719941:12000
Kniffin silt loam, 5 to 9 percent slopes531C259218607862tfzgia18519661:15840
Kniffin silty clay loam, 5 to 9 percent slopes, moderately eroded531C2241518607872tfzhia18519661:15840
Kniffin silt loam, 2 to 5 percent slopes531B95418607852tfzfia18519661:15840

Map of Series Extent

Approximate geographic distribution of the KNIFFIN soil series. To learn more about how this distribution was mapped, or to compare this soil series extent to others, use the Series Extent Explorer (SEE) application. Source: generalization of SSURGO geometry .