2007 NCERA-180 Annual Meeting

Veris NIR Spectrophotometer

www.veristech.com

Acquisition/Sampling Procedure

1) Map field NIRS at 10 cm level with Veris NIRS shank unit (15 m transects typical).

2) PC compression and remove outliers.

3) Fuzzy clustering into 15 clusters (use 3 PC’s).

4) Select 1 sample location per cluster (software).

5) Software guidance to sample locations.

• Lab-analyze soil carbon and bulk density (and other properties of interest).

• Calibrate NIRS data with lab analyses and validate. (Client responsible)

Calibration Procedure

IOWASet of 9 Iowa Fields (R^2 for leave 1 out cross-

validation)

00.10.20.30.40.50.60.70.80.9

property

coef

f. o

f d

eter

min

atio

n

(R^

2)

GEORGIA

KANSAS4 Kansas Fields: Avg R^2 without and with EC

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

carbon pH BpH-pH lime P K N

avg

R^

2

w/o EC

with EC

MONTANA

Lab results-Amino N

ILLINOIS: NIRS—Amino N

Goal: carbon inventory to 60 cm depth1. Map NIRS at 10 cm level with Veris NIRS shank unit.2. Use shank NIR (PCA, fuzzy c-means clustering) to identify 15

sample points for NIRS probe and soil cores.3. Collect NIRS data to 60 cm and 3” diameter soil cores (large

diameter to minimize probe effect on bulk density).4. Segment cores into 10 cm segments.5. Use probe NIRS (PCA, fuzzy c-means clustering) to identify

15 10 cm segments for lab analysis (each 10 cm level represented with at least two lab analyses).

6. Analyze soil carbon and bulk density in lab7. Calibrate NIRS data with lab analyses and cross-validate.

Carbon Sequestration Validation Problem: Soil carbon levels and rates of carbon change vary in the X, Y and –Z directions. This variability occurs at close spatial ranges within a field, and often exceeds the amount of newly sequestered carbon.

Grand Ave carbon inventory project—materials and methods

Acknowledgement

Funding for NIRS research provided by the Small Business Innovation Research programs

of the U.S. Departments of Agriculture and Energy