Post on 22-Feb-2016
description
Median
Median Absolute DeviationMAD
% Relative Median Absolute Deviation%RMAD = MAD / median x 100
Intralaboratory precision
Interlaboratory precision
Within
Between
ICP vs colorimetry to analyze P
Calculated CEC
Salt pH
Combustion C and CaCO3
Nitrate analysis
Scooping versus weighing
Hot-water and Mehlich-3 B
Micropipette method for soil texture
ICP vs colorimetry to analyze P
0
10
20
30
40
50
60
70
80
90
0 10 20 30 40 50 60 70
colorimetric-P, mg/kg
ICP-
P, m
g/kg
ICP vs colorimetric P
ICP labs = 39
colorimetric labs = 21
0 10 20 30 40 50 60 7005
1015202530354045
colorimetric ICP
P conc, mg/kg
%RM
AD (M
AD/M
ED x
100
)
ICP vs colorimetric P
0
2
4
6
8
10
12
0 2 4 6 8 10 12
colorimetric-P MAD, mg/kg
ICP-
P M
AD
, mg/
kgICP vs colorimetric P
Calculated CEC
1 M NH4OAcCEC at pH 7 = sum of bases + acidity
Calculated CEC
?
4 5 6 7 8 9-5
0
5
10
15
20
25
30
35
1:1 soil pH
M3
Ca -
Amm
Acc C
a
4 5 6 7 8 9-1
0
1
2
3
4
5
6
7
1:1 soil pH
M3
Mg
- Am
mAc
c Mg
4 5 6 7 8 9-0.2
-0.1
0.0
0.1
0.2
0.3
0.4
1:1 soil pH
M3
K - A
mm
Acc K
Ca Mg K
4 5 6 7 8 9-10
-5
0
5
10
15
20
25
1:1 soil pH
calc
CEC
- Am
m A
ceta
te C
EC
0 5 10 15 20 25 30 35 400
10
20
30
40
f(x) = NaN x + NaNR² = 0 Northeastern Region Methods Manual
NAPT NH4OAc CEC median +- MAD, meq/100g
Calc
CEC
, meq
/100
g
1:1 line
Exchangeable acidity =12.6 – (1.64 x soil pH) – (0.48 SMP buffer pH)
0 5 10 15 20 25 30 35 400
10
20
30
40
f(x) = NaN x + NaNR² = 0 Northcentral Region Methods Manual
NAPT NH4OAc CEC median +- MAD, meq/100g
Calc
CEC
, meq
/100
g
1:1 line
Exchangeable acidity =12 x (7 – SMP buffer pH)
0 5 10 15 20 25 30 35 400
10
20
30
40
f(x) = NaN x + NaNR² = 0 Current calculation at Univ. Kentucky
NAPT NH4OAc CEC median +- MAD, meq/100g
Calc
CEC
, meq
/100
g
1:1 line
Acidity =8 x (7.5 – SMP buffer pH)
0 5 10 15 20 25 30 35 400
10
20
30
40
f(x) = NaN x + NaNR² = 0 Using 1 M KCl soil pH &
Sikora-2 soil-buffer pH
NAPT NH4OAc CEC median +- MAD, meq/100g
Calc
CEC
, meq
/100
g
1:1 line
Salt pH
4 5 6 7 8 93
4
5
6
7
8
9
soil water pH
0.01
M C
aCl2
soil
pH
1:1 line
0.0 0.5 1.0 1.5 2.0 2.5 3.00.0
0.2
0.4
0.6
0.8
1.0
1.2
1:1 EC, dS/m
soil
wat
er p
H - 0
.01
M C
aCl2
pH
Nitrate analysis
0 10 20 30 40 50 60 70 800
10
20
30
40
50
60
70
80Ion selective electrode
nitrate reduction
NO3-N conc., mg/kg
%RM
AD (M
AD/M
ED x
100
)
criti
cal v
alue
Combustion C and CaCO3
4 5 6 7 8 9 100.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
1:1 soil pH
% C
from
CaC
O3
4 5 6 7 8 9 100.001
0.01
0.1
1
10
1:1 soil pH
% C
from
CaC
O3
Scooping versus weighing
0 10 20 30 40 50 60 70 80 90 1000.6
0.8
1
1.2
1.4
1.6
1.8
2
f(x) = 0.00590390922708225 x + 0.975504432009451R² = 0.466092123713754
% sand
soil
dens
ity, g
/cm
3
M3 assumes 1.18 g / cm3
M1 assumes 1.25 g / cm3
% sand% OM
g / cm3g / cm3
0 10 20 30 40 50 60 70 80 90 1000.6
0.8
1
1.2
1.4
1.6
1.8
2
% sand
soil
dens
ity, g
/cm
3
M3 assumes 1.18 g / cm3
+ 40%
- 40%
0 10 20 30 40 50 60 70 80 90 10010
15
20
25
30
35
40
45
50
55
assume 3 mg/L in M3 extract
% sand
Meh
lich
3 P,
mg/
kg
1.7 cm3 scoop & 1.18 g / cm3
Hot-water and Mehlich-3 B
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Mehlich B, mg/kg
Hot w
ater
B, m
g/kg
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
0.2
0.4
0.6
0.8
1
1.2
1.4
1.6
Mehlich B, mg/kg
Hot w
ater
B, m
g/kg
2 g 20 mL
10 g 20 mL
Limit of quantification = 0.05 mg/L
0 0.2 0.4 0.6 0.8 1 1.2 1.4 1.60
10
20
30
40
50
60
70
80
90
Mehlich-3Hot water
B, mg/kg
%RM
AD (M
AD/M
ED x
100
)
Micropipette method for soil texture
0 10 20 30 40 50 600
10
20
30
40
50
60
f(x) = 0.730612996212147 x + 0.816281062041538R² = 0.785993754083984
Clay analysis
% Clay, NAPT median
% C
lay,
mic
ropi
pett
e m
etho
d
1:1 line