1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry
description
Transcript of 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry
![Page 1: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/1.jpg)
1. Soil pH and SMP Buffer pH methodologies
a. Time for SMP buffer to set in soil-water slurry
b. Conditions on LabFit for soil pH and Sikora buffer pH
2. Laboratory survey on pH and lime recommendations
prepared for SERA-6 conferenceJune 4-5, 2007
F.J. SikoraUniversity of Kentucky
Soil pH and buffer pH methodology:water and SMP/Sikora buffer reaction time
with soil and a laboratory survey
![Page 2: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/2.jpg)
Variations in methods for determining 1:1 soil:water pH
Reference pub
Quantity of soil
Stirring (or mixing) time after adding
water
Standing time before determining
pH
Stirring during/before pH measurement
SPAC, Inc. 4.25 cm3, 5 g, or 10 cm3
Stir for 5 sec 10 min stir during pH measurement
Southern 10 cm3 Mix for 5 sec 30 min stir soil suspension by swirling the cup slightly just
prior to reading pH
Northeastern Scoop 5 cm3 or weigh 5 g
Stir vigorously for 15 sec
30 min place electrodes in the slurry, swirl carefully and
read pH immediately
North Central
4.25 cm3
(5 g scoop)Stir
vigorously for 5 sec
10 min place electrodes in the slurry, swirl carefully and
read pH immediately
Western 5 0.1 g Stir thoroughly for 5 sec
15 min place electrodes in the slurry, swirl carefully and
read pH immediately
![Page 3: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/3.jpg)
Variations in SMP methods for determining buffer pH
Reference pub
Quantity of soilVolume of buffer added to soil pH
slurry and shaking time
Oscillations/minStanding time
before determining
pH
SPAC, Inc. 4.25 cm3 or 5 g 10 mL buffer, shake for 10 min
(or 15 min)
>180 30 min (or 15 min)
Southern
Northeastern Scoop 5 cm3 or weigh 5 g
10 mL buffer, shake for 10 min
(or 15 min)
250 30 min (or 15 min)
North Central 4.25 cm3
(5 g scoop)10 mL buffer, shake
for 10 min (or 15 min)
250 30 min (or 15 min)
Western 5 0.1 g 10 mL buffer, stir every 5 minutes for
20 min
20 min
![Page 4: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/4.jpg)
Mclean, Eckert, Reddy, and Trierweiler. 1978. An improved SMP soil lime requirement method incorporating double-buffer and quick-test features. SSSAJ 42:311-316.
excerpt from
1975 North Central publicationon soil test methods.
![Page 5: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/5.jpg)
Table in the current North Central region publication on soil test methods.
SMP Buffer pH
![Page 6: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/6.jpg)
Lexington Quality Control Sample 4108
6.3
6.4
6.5
6.6
6.7
6.8
6.9
7.0
0 50 100 150 200 250 300 350 400 450 500 550
Days after Jan 1, 2005
Bu
ffer
pH
- 2 s
- 3 s
+ 3 s
+ 2 s
SMP buffer
mean
Sikora buffer
![Page 7: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/7.jpg)
LEXINGTON LAB
![Page 8: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/8.jpg)
PRINCETON LAB
![Page 9: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/9.jpg)
![Page 10: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/10.jpg)
buf
buf
![Page 11: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/11.jpg)
![Page 12: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/12.jpg)
![Page 13: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/13.jpg)
stirring time for buffer in soil
time buffer set in soil prior to measurement
LabFit method with Sikora buffer
0.33 min.±0.11
37 min.±4
1.5 hrsfor 3 trays(n=120)
Method for adding water to soil
Each sample stirred with stir rod and let set for 30 min.
![Page 14: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/14.jpg)
y = 0.9613x + 0.1576
R2 = 0.9763
4
5
6
7
8
9
10
4 5 6 7 8 9 10
water pH, old way
water
pH,
new
inst
r
5,10
y = 1.0486x - 0.4033
R2 = 0.9607
5
5.5
6
6.5
7
7.5
8
5 5.5 6 6.5 7 7.5 8
SMP buffer pH, old way
KY b
uffer
pH,
new
inst
r
5,10
Sik
ora
Buf
fer
pH,
LabF
it in
stru
men
t
Soi
l pH
, La
bFit
inst
rum
ent
Soil pH, NAPT median SMP Buffer pH, NAPT median
Soil pH Buffer pH
1:1 line
regression line
![Page 15: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/15.jpg)
y = 0.8927x + 0.6065
R2 = 0.9647
4
5
6
7
8
9
10
4 5 6 7 8 9 10
water pH, old way
water
pH,
new
instr
5,10 tray swilred
y = 0.9613x + 0.1576
R2 = 0.9763
4
5
6
7
8
9
10
4 5 6 7 8 9 10
water pH, old way
water
pH,
new
inst
r
5,10
Soi
l pH
, La
bFit
inst
rum
ent
Soi
l pH
, La
bFit
inst
rum
ent
Soil pH, NAPT median Soil pH, NAPT median
Each sample stirred with stir rod for 5 sec and let set for 30 min.
Tray swirled for 5 sec. and let set for 30 min.
1:1 line
regression line
Soil pH
![Page 16: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/16.jpg)
A Mid-Atlantic Soil Testing and Plant Analysis Work Group survey on methods for
soil pH, buffer pH and lime recommendations
Objectives are to assess:
1. variation in lab methods being used.
2. effect of method variation on intra- and interlaboratory error.
3. variation in how lime recommendations are made.
& SERA6
![Page 17: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/17.jpg)
0
0.05
0.1
0.15
0.2
0.25
9811
3
9812
3
9910
9
9911
9
_001
09
_001
19
_011
09
_011
19
2002
109
2002
119
2003
109
2003
119
2004
109
2004
119
2005
009
2005
019
2006
009
2006
019
Soil pH MAD values in the NAPT program
![Page 18: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/18.jpg)
SMP Buffer pH MAD values in the NAPT program
0
0.05
0.1
0.15
0.2
0.25
9811
3
9812
3
9910
9
9911
9
_001
09
_001
19
_011
09
_011
19
2002
109
2002
119
2003
109
2003
119
2004
109
2004
119
2005
009
2005
019
2006
009
2006
019
![Page 19: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/19.jpg)
extra slides
![Page 20: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/20.jpg)
y = -0.837 x + 7.00
r 2 = 0.658
y = -0.803x + 6.347
R2 = 0.691
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
5 5.5 6 6.5 7 7.5 8
SMP buffer pH
Co
eff
icie
nt
of
Va
ria
tio
n (
%)
![Page 21: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/21.jpg)
y = -0.1749x + 2.6093
R2 = 0.1805
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4 5 6 7 8 9 10
water pH
Co
eff
icie
nt
of
Va
ria
tio
n (
%)
![Page 22: 1. Soil pH and SMP Buffer pH methodologies Time for SMP buffer to set in soil-water slurry](https://reader033.fdocuments.net/reader033/viewer/2022061610/56814577550346895db248ad/html5/thumbnails/22.jpg)
Variations in methods for Mehlich III extractable nutrients
Reference pub
Quantity of soil Volume of Mehlich III Mixing time and method
SPAC, Inc. 5 cm3 50 mL 5 min on reciprocating shaker
Southern 2.5 cm3 25 mL 5 min on reciprocating shaker
Northeastern Scoop 2.5 cm3
or 2.5 g(references orig. method on 10:1
ratio based on vol.)
25 mL 5 min on reciprocating shaker
at 200 epm
North Central
1.7 cm3
(2 g scoop)20 mL 5 min on shaker at
200 or more epm between 24 to 27oC
Western 2 0.05 g 20 mL 5 min on reciprocating shaker