The purpose of this manual is to document methodology and to serve as a reference for the laboratory analyst. The standard methods described in this SSIR No. 42, Soil Survey Laboratory Methods Manual, Version 4.0 replaces as a methods reference all earlier versions of the SSIR No. 42 (1989, 1992, and 1996, respectively) and SSIR No. 1, Procedures for Collecting Soil Samples and Methods of Analysis for Soil Survey (1972, 1982, and 1984). All SSL methods are performed with methodologies appropriate for the specific purpose. The SSL SOP's are standard methods, peer-recognized methods, SSL-developed methods, and/or specified methods in soil taxonomy (Soil Survey Staff, 1999). An earlier version of this manual (1996) also served as the primary document from which a companion manual, Soil Survey Laboratory Information Manual (SSIR No. 45, 1995), was developed. The SSIR No. 45 describes in greater detail the application of SSL data.

Trade names are used in the manual solely for the purpose of providing specific information. Mention of a trade name does not constitute a guarantee of the product by USDA nor does it imply an endorsement by USDA.

METHODS OF ANALYSIS FOR SOILS, WATER, AND BIOLOGICAL MATERIALS

1. SAMPLE COLLECTION AND PREPARATION

2. CONVENTIONS

3. SOIL PHYSICAL AND FABRIC-RELATED ANALYSES

4. SOIL AND WATER CHEMICAL EXTRACTIONS AND ANALYSES

5. ANALYSIS OF ORGANIC SOILS OR MATERIALS

6. SOIL BIOLOGICAL AND PLANT ANALYSES

7. MINERALOGY

SOIL SURVEY LABORATORY METHODS (Obsolete Methods with Old Method Codes)

8. SAMPLE COLLECTION AND PREPARATION

9. PARTICLE-SIZE ANALYSIS

10. FABRIC-RELATED ANALYSES

11. ION EXCHANGE ANALYSES

12. CHEMICAL ANALYSES

13. MINERALOGY

14. MISCELLANEOUS