jerry floren minnesota department of agriculture jerry...

Jerry Floren

Minnesota Department of Agriculture jerry.floren@state.mn.us

(651) 201-6642

Robert O. Miller Colorado State University

¨  Types of MDA Laboratory Programs ¨  Manure testing manuals ¨  Changes in the 2012 manure

laboratory evaluation ¨  Encourage you to submit client

reports ¨  Additional reference samples ¨  Using the MAP reports

Manure Analysis Proficiency (MAP) Program

Certified Manure Testing Laboratory Program

Certified Soil Testing Laboratory Program

The standard methods manual, published in 2003.

Published in 2010 and adds some tests to those in the 2003 manual. It also has suggestions for equipment to homogenize manure samples.

¨  We evaluate both accuracy and precision. ¨  Because the data are typically not normally

distributed, we evaluate accuracy using Median and Median Absolute Deviation (MAD) rather than mean and standard deviation.

¨  Five points are deducted for each accuracy flag and three points are deducted for each precision flag (8 possible points for each sample).

¨  We calculate the percent not flagged for each sample and test and sort the scores from highest to lowest. The top 80% is passing.

Lab Score Percent Flags 56007 48 100.00% 0 56023 48 100.00% 0 56009 48 100.00% 0 56011 45 93.80% *P 56005 45 93.80% *P 56003 43 89.60% *L 56012 43 89.60% **H 56015 40 83.30% *H *P 56001 37 77.10% **L *P *P 56014 37 77.10% *H *P *P 56016 32 66.70% *H **H *P *P 56018 29 60.40% *H **H *P *P *P

¨  Bob Miller’s Method Two runs – remove outliers > 4.0 MAD units Flag results more than 2.9 MAD unit from the

median ¨  MDA Method

Traditionally, we flagged results more than 2.5 MAD units from the median

In 2012, we combined both methods. Labs were flagged for accuracy if they were 2.5 MAD units from the median and 2.9 MAD units from the median after removing the outliers.

¨  Intentionally left blank.

Median 95% CL Rd Rep1 Rep2 Rep3 Rp P-Flag Rep Mean A-Flag 1.883 ± 0.277 1.9 0.01 0.02 0.02 24.0 *P 0.014 *L 0.170 ± 0.030 2.2 0.000 0.002 0.002 79.2 *P 0.001 *L 1.616 ± 0.218 1.5 0.01 0.01 0.01 28.5 *P 0.013 *L

¨  MAP labs received an email from MDA with a graphical report for each of the tests they ran for the second exchange in 2012.

R reads the Excel files into a data file used to calculate medians, MADs, and precision indicators (Rp and Rd).

¨  Laboratories must have acceptable results for both total phosphorus and for total nitrogen (by TKN or N-Combustion).

¨  The other 14 tests are evaluated individually.

¨  Points are deducted for poor accuracy compared to other labs in the MAP Program and for poor precision within an individual lab.

¨  If we produced capsules, what sizes would work best for your lab?

¨  72 Samples ¨  36 Liquid Manure ¨  36 Solid Manure

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         N-­‐C  median  vs.  No  Flag%  

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                 TKN  median  vs.  No  Flag%              

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1   2   3   4   5   6   7   8   9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  

TKN

N-C

Liquid Manure

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N-C Solid Manure

TKN

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TKN 0  

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Solid Manure

Liquid Manure

N-C

Jerry Floren

Minnesota Department of Agriculture jerry.floren@state.mn.us

(651) 201-6642