Limnic Materials Study Purpose: Show that Limnic materials are not "O" or "C" materials. Provide support for Proposal to Soil Taxonomy concerning reintroducton of "L" master horizon designation and suffixes "ca", "co", and "di". Dates: 21 - 23 October 1997 People: Robert J. Ahrens, Lead Scientist, Soil Taxonomy, Lincoln, NE Charles Love, SDQS, Indianapolis, IN Wade Bott, MLRAPL, Winamac, IN Rex Brock, SS, Winamac, IN Shane McBurnett, SS, Winamac, IN Franklin Furr, RSS, Winamac, IN Don Ruesch, RSS, Columbia City, In Jerry Larson, SDQS, Indianapolis, IN Don Franzmeier, Agronomy Dept., Purdue University Bill Hosteter, Soil Liaison, Indianapolis, IN Other Potential Participants: Jerry Thomas, RSS, Greencastle, IN Scot Haley, RSS, Indianapolis, IN Larry Huber, Soil Consultant, Valparaiso, IN Tom Ziegler, Soil consultant, Lafayette, IN Background: 21 October 1997 Briefing on Past Studies and Sites 1975 visit by Bill McKinzie and Warren Lynn Sites visited were in the following counties: Montgomery - muck/coprogenous earth/sand/coprogenous earth Stuben - muck/coprogenous earth/sand Stuben - muck/coprogenous earth/sand White - muck/coprogenous earth La Porte - muck/coprogenous earth Cass - thin muck/coprogenous earth/sand (11 inches muck) Elkhart County has Edwards and Muskego muck Starke County has Toto muck (OSD site) La Porte County has Edwards and Muskego muck Pulaski County has Edwards and Muskego muck It would be good to sample the coprogenous earth and marl for lab analysis. We do not have diatomaceous earth in this area. Importance of special designations for limnic layers or horizons: Marl is difficult to consider as a "C" horizon. Marl may have some plant parts present, but not enough to be an "O" horizon. It may also have staining from organic materials that make it darker than normally defined. Coprogenous earth is also difficult to consider as a "C" horizon. Some coprogenous earth has enough plant parts and organic materials to be considered as "O", but it is vastly different from our normal mucky materials. It reacts entirely different upon drying and does not rewet. Also it creates problems in farming when exposed on the surface. Both marl and coprogenous earth present problems with underground drain tiles. Both materials coat the tile and stop or greatly reduce the amount of water entering the tile. This often happens within a year of the time the tile is installed. Using an "O" or a "C" designation definitely does not provide needed information for land owners or drainage contractors who are working with these materials. Also this would be helpful for assessments as the organic materials on the surface subside. The soils with marl and coprogenous earth have little or no value for cropping as soon as the organic surface is gone. In Elkhart County, IN, Muskego muck presented some difficulties in horizon designations in the coprogenous earth materials. The organic carbon content fluctuated in the layers and the designations fluctuated between "O" and "C" horizons. As limnic layers the designation would remain constant and it would present a warning that these materials would not react like normal "C" materials that can be brought to the surface. The proposal to use the designations found in Soil Taxonomy, 1975, would still do the job. These designations are: Lca for marl (calcium) Lco for coprogenous earth Ldi for diatomaceous earth Special designations are used for all kinds of inclusions in horizons or special properties of horizons. In organic soils we designate the types of organic materials by using "a", "e", or "i". None of these fit the coprogenous earth materials when the organic content is great enough to be called an "O" horizon under the present thinking. Procedure: The investigation will involve studying Limnic materials in La Porte, Pulaski, and Starke Counties and possibly Elkhart County in Indiana. Soils to be investigated will include the Edwards, Muskego, Martisco, and possibly the Toto series. If other muck soils underlain with Limnic materials are near, they may also be investigated. Arrangements will be made to excavate and sample 3 of the Limnic soils to determine the composition of the Limnic layers. This study should show that Limnic materials are better defined with an "L" horizon designation rather than the currently inconsistently used "O" or "C" designations. The present method of horizon designation allows for confusion in the terminology of the horizons. Designations can change between "O" and "C" due to a slight change in organic carbon content of the coprogenous earth materials. Marl has historically been considered "C" material, but is an accumulation of calcium carbonates and is not parent material to any other horizons.