Several layers of certifications or validations may be in place to ensure data quality for commercial analytical labs. For example, the Agricultural Laboratory Proficiency (ALP) Program provides soil samples to laboratories for analysis and then assesses that laboratory’s results relative to the test soil’s known properties. In turn, the ALP program is accredited by the American National Standards Institute/American Society of Quality Control National Accrediting Board (ANAB) through testing of ISO/IEC 17043, itself an international standard of the International Organization for Standardization and the International Electrotechnical Commission for laboratory proficiency testing that determines the performance of individual laboratories for specific tests or measurements and is used to monitor laboratories’ continuing performance through interlaboratory comparisons. Thus, commercial laboratories conducting analyses for soil health indicators select measurements and indicators that are understood in the research community to relate to processes in soil important to soil health; and methods that are affordable to the farming community, as well as verifiable for accuracy and precision (= reliability to the producer) by independent tests.
Summary and Conclusions
This introduction to Volume II provides those interested in soil health assessment methods a brief background regarding identification and selection of the indicators within this volume and to provide context regarding current and future soil health assessment efforts. It also demonstrates that multiple groups (i.e., SHI and the NRCS‐SHD) that engaged in workshops and conferences during 2013 to 2015 continue to coordinate soil health assessments to protect and enhance our fragile, yet life‐sustaining soil resource for current and future generations.
References
1 Acosta‐Martínez, V., and Tabatabai, M.A. (2011). Phosphorus cycle enzymes. In R.P. Dick, (ed.), Methods of soil enzymology. Madison, WI: SSSA. doi:10.2136/sssabookser9.c8.
2 Blake, G.R., and Hartge, K.H. (1986). Bulk density. In: A. Klute (ed.), Methods of soil analysis: Part 1. Physical and mineralogical methods (p. 363–382). 2nd ed. Madison, WI: ASA and SSSA.
3 Brevik, E.C. (2018). A brief history of the soil health concept. The Profile. Madison, WI: Soil Science Society of America. Posted 18 Dec. https://profile.soils.org/files/soil‐communication/documents/95_document1_d50a8524‐dbf4‐4856‐8c62‐4a03ede6c3d4.pdf (Accessed 20 Feb. 2020).
4 Bundy, L.G., and Meisinger, J.J. (1994). Nitrogen availability indices. In R.W. Weaver, S. Angle, P. Bottomley, D. Bezdicek, S. Smith, A. Tabatabai, and A. Wollum, (eds.), Methods of soil analysis. Part 2 (p. 951–984). SSSA Book Ser. 5. SSSA, Madison, WI.
5 Buyer, J.S., and Sasser, M. (2012). High throughput phospholipid fatty acid analysis of soils. Appl. Soil Ecol. 61, 127–130. doi:10.1016/j.apsoil.2012.06.005
6 Deng, S., and Popova, I. (2011). Carbohydrate hydrolases. In R.P. Dick, (ed.), Methods of soil enzymology (p. 185–209). SSSA, Madison, WI.
7 Emerson, W.W. (1995). Water retention, organic‐C, and soil texture. Aust. J. Soil Res. 33, 241–251. doi:10.1071/SR9950241
8 Fajardo, M., McBratney, A.B., Field, D.J., and Minasny, B. (2016). Soil slaking assessment using image recognition. Soil Tillage Res. 163, 119–129. doi:10.1016/j.still.2016.05.018
9 Franzluebbers, A.J., Wright, S.F., and Stuedemann, J.A. (2000). Soil aggregation and glomalin under pastures in the Southern Piedmont USA. Soil Sci. Soc. Am. J. 64, 1018–1026. doi:10.2136/sssaj2000.6431018x
10 Gee, G.W., and Bauder, J.W. (1986). Particle‐size analysis. In A. Klute, (ed.), Methods of soil analysis. Part 1– Physical and mineralogical methods (p. 493–544). 2nd ed. Madison, WI: ASA and SSSA.
11 Hudson, B.D. (1994). Soil organic matter and available water capacity. J. Soil Water Conserv. 49, 189–194.
12 Ismail, I., Blevins, R.L., and Frye, W.W. (1994). Long‐term notillage effects on soil properties and continuous corn yields. Soil Sci. Soc. Am. J. 58:193–198. doi:10.2136/sssaj1994.03615995005800010028x
13 Karlen, D.L., Wollenhaupt, N.C., Erbach, D.C., Berry, E.C., Swan, J.B., Eash, N.S., and Jordahl, J.L. (1994). Long‐term tillage effects on soil quality. Soil Tillage Res. 32, 313–327. doi:10.1016/0167‐1987(94)00427‐G
14 Karlen, D.L., Stott, D.E., Cambardella, C.A., Kremer, R.J., King, K.W., and McCarty, G.W. (2014). Surface soil quality in five midwestern cropland Conservation Effects Assessment Project watersheds. J. Soil Water Conserv. 69, 393–401. doi:10.2489/jswc.69.5.393
15 Kemper, W.D., and Roseneau, R.C. (1986). Aggregate stability and size distribution. In: A. Klute, editor, Methods of soil analysis: Part I. Physical and mineralogical methods (p. 425–442). 2nd ed. Madison, WI: ASA and SSSA.
16 Klute, A. (1986). Water retention: Laboratory methods. In: A. Klute, editor, Methods of soil analysis: Part 1. Physical and mineralogical methods (p. 635–662). 2nd ed. Madison, WI: ASA and SSSA. doi:10.2136/sssabookser5.1.2ed
17 Klose, S., Bilen, S., Tabatabai, M.A., and Dick, W.A. (2011). Sulfur cycle enzymes. In R.P. Dick, (ed.), Methods of soil enzymology (p. 125–159). Madison, WI: SSSA.
18 Knudsen, D., Peterson, G.A., and Pratt, P.F. (1982). Lithium, sodium and potassium. In A.L. Page (ed.), Methods of soil analysis. Part 2. 2nd ed. Madison, WI: ASA and SSSA.
19 Langdale, G.W., Leonard, R.A., and Thomas, A.W. (1985). Conservation practice effects on phosphorus losses from Southern Piedmont watersheds. J. Soil Water Conserv. 40, 157–161.
20 Lindsay, W.L., and Norvell, W.A. (1978). Development of a DTPA soil test for zinc, iron, manganese, and copper. Soil Sci. Soc. Am. J. 42, 421–428. doi:10.2136/sssaj1978.03615995004200030009x
21 Marotz, C., Amir, A., Humphrey, G., Gaffney, J., Gogul, G., and Knight, R. (2017). DNA extraction for streamlined metagenomics of diverse environmental samples. Biotech. 62, 290–293. doi:10.2144/000114559
22 Miller, R.O., Gavlak, R., and Horneck, D. (2013). Saturated paste extract for calcium, magnesium, sodium and SAR. In Soil, plant and water methods for the western region (p. 21‐22). 4th ed. WREP‐125. Washington, D.C.: Wetlands Reserve Enhancement Program.
23 Mikha, M.M., and