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United States Department of Agriculture

Agricultural Research Service


Location: National Soil Dynamics Laboratory

Title: Cost Assessment of Standard Soil Sampling

item Torbert, Henry

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: January 19, 2006
Publication Date: January 19, 2006
Citation: Torbert III, H.A. 2006. Cost assessment of standard soil sampling. In: Wielopolski, L., editor. Proceedings of Emerging Modalities for Soil Carbon Analysis: Sampling Statistics and Economics Workshop, January 19-20, 2006, Upton, New York. BNL-75762-2006 formal Report 29. p. 57-59.

Interpretive Summary: Recently, due to concerns regarding the potential for global change due to increased atmospheric CO2 levels there has been increased interest in evaluating the potential for C sequestration in soil. This has lead to interest in measuring changes in soil C due to changes in land management practices. In this paper the potential costs of standard soil sampling and analysis for this purpose is discussed. Conclusion indicate that soil sampling and analysis for C sequestration will require increased expense because it will require sampling of several soil depths and precision laboratory techniques. Inclusion of more soil depths will significantly increase sample numbers and sample collection expense. Precision laboratory techniques will significantly increase cost of equipment and sample processing.

Technical Abstract: Recently, there has been increased interest in determining the potential for C sequestration with changes in land management. This paper will discuss the potential cost of standard soil sampling for this purpose. To determine the potential cost of soil C analysis on a field scale, many of the methods developed for traditional soil testing for soil fertility status can be used. This would include methods to determine the places to sample and the number of sub-samples needed. However, additional considerations will be required (compared to traditional soil testing) to fully asses soil C levels for the purposes of determining C sequestration. Of primarily concern would be the need for increased sampling depth and the inclusion of separate soil depths in the sampling scheme. This will require additional equipment that can sample deeper and additional processing cost to cut and maintain separation of the soil cores by soil depth. A typical farm of 700 ha was considered for estimation of sampling cost, with a sampling depth of 30 cm divided into 6 - 5 cm separate soil increments. While the cost of traditional soil sampling would be considered negligible (absorbed by the farmer), the cost of soil sampling for soil C assessment was estimated to be $4.90/sample. This would be a minimum cost, not considering overhead and maintenance expenses. In the laboratory, measurement by traditional wet chemistry or loss on ignition would not have sufficient precision and accuracy for analysis of soil C sequestration. An instrument that can accurately measure C levels in samples would be required for this purpose. The cost of laboratory preparation and processing and the minimum cost of supplies for processing samples through a C analyzer were estimated to be $2.94/sample. However, this does not consider overhead cost of marinating laboratory facilities. An informal survey of soil testing laboratories across the USA found that most did not offer soil C analysis of this type. The laboratories that did offer soil C analysis, the cost for analysis varied widely with cost ranging from $3.75 to $ 22.00/sample, with a medium of $10.00/sample. Using the minimum cost estimates, the cost for sampling the 700 ha farm would be approximately $1650.

Last Modified: 4/23/2014
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