Testing Methods

SOIL TEST PACKAGE METHODS

Total Exchange Capacity (TEC by summation):

Ross, D. 1995. Recommended soil tests for determining exchange capacity. p. 62-69 In J.T. Sims and A. Wolf (eds.) Recommended soil testing procedures for the northeastern United States. Northeastern Regional Bulletin #493. Ag Experiment Station, University of Delaware, Newark, DE.

pH (1:1 in H2O):

McLean, E.O. 1982. Soil pH and lime requirement. p. 199-223. In A.L. Page et al. (ed.) Methods of soil analysis, part 2. Agronomy Monogr. 9, 2nd ed. ASA and SSSA, Madison, WI.

SMP/Sikora Buffer pH:

Shoemaker, H.E., E.O. McLean, and P.F. Pratt. 1961. Buffer methods for determining lime requirements of soils with appreciable amounts of extractable aluminum. Soil Sci. Soc. Am. Proc. 25:274-277.
Sikora, F. 2006. A buffer that mimics the SMP buffer for determining lime requirement of soil. Soil Sci. Soc. Am. J. 70:474-486.

Organic Matter (Loss on Ignition at 360 degrees C):

Schulte, E.E., and B.G. Hopkins. 1996. Estimation of soil organic matter by weight Loss-OnIgnition. p. 21-32. In: Soil organic matter: Analysis and interpretation. (ed.) F.R. Magdoff, M.A. Tabatabai, and E.A. Hanlon, Jr. Special publication No. 46. Soil Sci. Soc. Am. Madison, WI.

Estimated Nitrogen Release:

This number is a computed estimate of the nitrogen that may be released annually through organic matter decomposition. The calculation is based on the loss on ignition method previously listed.

Mehlich III Extractable S, Ca, Mg, K, Na, B, Fe, Mn, Cu, Zn, Al, and P:

Mehlich, A. 1984. Mehlich-3 soil test extractant: A modification of Mehlich-2 extractant. Commun. Soil Sci. Plant Anal. 15:1409-1416.

Inorganic Nitrogen (1 N KCl cadmium reduction):

Dahnke, W.C. 1990. Testing soils for available nitrogen. p. 120-140. In R.L. Westerman (ed.) Soil testing and plant analysis. Soil Sci. Soc. Am. Book Series 3, ASA, Madison, WI.

Total Carbon and Nitrogen (Combustion):

Nelson, D.W., and L.E. Sommers. 1996. Total carbon, organic carbon and organic matter. p. 961- 1010. In J.M. Bartels et al. (ed.) Methods of soil analysis: Part 3 Chemical methods. (3rd ed.) ASA and SSSA Book Series 5, Madison, WI.
McGeehan, S.L., and D.V. Naylor. 1988. Automated instrumental analysis of carbon and nitrogen in plant and soil samples. Commun. Soil Sci. Plant Anal. 19:493-505.

Total Organic Carbon -Acid Treated (Combustion):

Nelson, D.W.and Sommers, L.E. (1996).  total Carbon, Organic Carbon, and Organic Matter.  In Methods of Soil analysis (eds D. Sparks, A. Page, P. Heimke, R. Loeppert, P.N. Soltanpour, M.A. Tabatabai, C.T. Johnston and M.E. Sumner).

Soil Texture: Determination of Sand, Silt, and Clay:

Hydrometer Method. Soil, Plant, and Water Reference Methods for the Western Regions S – 14.10, 2003.

Bray I P:

Bray, H.R., and L.T. Kurtz. 1945. Determination of total, organic, and available forms of phosphorus in soils. Soil Science 59:39-45.

Bray II P:

Bray, H.R., and L.T. Kurtz. 1945. Determination of total, organic, and available forms of phosphorus in soils. Soil Science 59:39-45.

Olsen P:

Olsen, S.R. and L.E. Sommers. 1982. Phosphorus. p. 403-430. In A.L. Page et al. (eds.) Methods of soil analysis, part 2. Agron. Monogr. 9. 2nd ed. ASA and SSSA, Madison, WI.

Electrical Conductivity-Soluble Salts (1:2):

Soil, Plant, and Water Reference Methods for the Western Regions S – 2.10, 2003.

Saturated Paste Extract for pH, bicarbonate, nitrate, salts, chloride, cations, and minor nutrients:

Soil, Plant, and Water Reference Methods for the Western Regions S – 1.10, 1.30, 1.80, 1.20, 1.40, 1.50, 1.60, 2003.

Mineralization Nitrogen:

Dahnke, W.C. 1990. Testing soils for available nitrogen. p. 120-140. In R.L. Westerman (ed.) Soil testing and plant analysis. Soil Sci. Soc. Am. Book Series 3, ASA, Madison, WI.

Ammonium Acetate extractable cations (adjusted to a pH of 8.1):

Suarez, D.L. 1996. Beryllium, Magnesium, Calcium, Strontium, and Barium. p. 575-602. In D.L. Sparks (ed.) Methods of soil analysis Part 3: Chemical methods. Soil Sci. Soc. Am. Book Series 5, ASA, Madison, WI.

 Linsay, W.L., and W.A. Norvell. 1978. Development of a DTPA soil test for zinc, iron, manganese, and copper. Soil Sci. Soc. Am. J.  42:421-428.