Agricultural Service Laboratory
Clemson University

November 29, 2004

Quality Control

     To ensure accuracy with results, the Agricultural Service Laboratory is
     involved in four different sample exchange programs:

     A.  The National Forage Testing Association (NFTA) submits one sample 
         quarterly for analysis of dry matter, protein, minerals, acid 
         detergent fiber, and neutral detergent fiber.
 
     B.  The Association of American Feed Control Officials submits one sample 
         monthly for analysis of protein, minerals, fat, ash, acid detergent fiber
         and neutral detergent fiber.

     C.  The National Manure Analysis Proficiency Program submits samples
         quarterly for analysis of NH4-N, total N, minerals, and dry matter.
 
     D.  The Agricultural Service Laboratory is a member of the North American
         Proficiency Testing Program for Soil, Plant, and Water Analysis Laboratories
         which provides quarterly exchanges of plant, soil, and water samples.

     Reports from each of these groups are evaluated and kept on file at the
     Agricultural Service Laboratory.


     The Agricultural Service Laboratory follows several established procedures to
     ensure quality control on a daily basis:

     A.  A tissue sample purchased from the National Institute of Standards and
         Technology is dry or wet ashed and analyzed on the ICP on a daily basis 
         along with the feed and forage, plant tissue, and animal waste samples.  
         Solution standards are run at the beginning, midpoints, and end of each 
         set. 

     B.  A glycine standard is digested and analyzed daily, and a standard solution
         of ammonium sulfate is distilled daily to ensure quality control for
         analysis of Kjeldahl nitrogen in feed and forage and animal waste samples.

     C.  An orchard leaf or peach sample from NIST is analyzed every 15 samples for
	   feed and forage, plant tissue, and animal waste being analyzed for
         total nitrogen.

     D.  A sample provided by the Association of American Feed Control Officials is
         analyzed with each set of feed samples requiring percent fat to ensure
         quality control for fat.

     E.  A sample provided by NFTA is analyzed with each set of feed samples
         requiring fiber to ensure quality control for fiber.

     F.  Two check soil samples with established results are analyzed daily along
         with each set of 100 soil samples.  The check soils are used with the
         mineral analysis and pH determination.

     G.  Solution standards are analyzed on the ICP for each set of 100 soil samples
         at the beginning, mid-point, and end of each set.

     H.  For pH, along with the two check soil samples, samples at the beginning, 
         middle, and end of every set are rescooped and checked at the end of the run.

     I.  Quality control soil samples are analyzed along with soil samples requiring 
         nitrate nitrogen.

     J. An NIST orchard leaf standard is analyzed along with the feed, plant, and
	  manure samples for nitrogen.

     The procedures used at the Agricultural Service Laboratory are referenced
     and documented in the literature.