Provides a guideline for soil sampling and processing techniques. Get more: http://worldagroforestry.org/research/land-health/spectral-diagnostics-laboratory

1. Guideline for soil sampling &
Processing
Ermias Betemariam (e.betemariam@cgiar.org)
Keith Shepherd
13 April 2015
Kampala
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2. ContextOutline
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• Context
• Sampling
• Field work
• Lab work

3. Context
• Soil comes to the global agenda:
– Sustainable intensification took soil as a x-cutting
– Global Environmental Benefits - land degradation and soils are among
the priority global benefits (GEF/UNCCD)
• Increasing demand for soil data at fine spatial resolution
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High spatial variability of SOC can rise sevenfold when scaling up from point
sample to landscape scales, resulting in high uncertainties in calculations of
SOC stocks. This hinders the ability to accurately measure changes in stocks at
scales relevant to emissions trading schemes (Hobley and Willgoose, 2010)

4. • Land productivity is key to feed the world
• Land degradation remains a global challenge and reducing/reversing land
degradation is a development/research priority
• Soil comes to the global agenda: sustainable intensification
• Global Environmental Benefits - land degradation and soils are among the priority
global benefits (GEF/UNCCD)
Context
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5. Soil nutrient balance
• Inputs
– Litter, roots, branches
• Outputs
• Autotrophic respiration: roots
• Heterotrophic respiration: CO2
respiration of soil organisms that use
dead plant matter as a food source
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6. Guidelines
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7. Remote sensing for carbon
monitoring
Consistent field
protocol
Soil spectroscopy
Coupling with
remote sensingPrevalence, Risk factors, Digital
mapping
Sentinel sites
Randomized sampling schemes
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8. 7
No. District No of EAs No. of Farms No of soil samples
1 Serere 15 180 360
2 Sironko 15 180 360
3
Iganga and
Mayuge 45 540 1080
Total 75 900 1800
How many samples

9. Field navigation
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10. Plot layout
Plots are laid out with four subplots (Y- frame)
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11. Field work
Preparation for field work
• Proper preparation before going to the field
• Collate existing information (e.g. soil map)
• Train staff and pilot all procedures
• Prepare logistics in terms of transport, etc.
Collecting field samples
• Locate the predetermined sample location
• Take composite soil samples from 4 points using
auger
• Collect any associated data required (e.g. land
management)
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12. 1
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Field work- composite samples

13. Field work- Texture analysis

14. Soil sampling
Field soil data collection Soil sample to be send to the lab
for processing
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15. Sample processing
• Drying
• Crashing
• Sieving
– 50 gm for spectral analysis= all samples
– 750 gm soil for reference analysis = 10% of of the total samples
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16. Soil Infrared Spectroscopy
 Rapid
 Low cost
 Reproducible
 Predicts many soil functional properties
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17. 0
2000
4000
6000
10 50 100 150 200 250
Cost(USD)
Number of samples
NIR spectroscopy
Thermal oxidation
Sample preparation
Soil sampling
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6
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12
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Costpersample(USD)
NIR spectroscopy Thermal oxidation
Sample preparation Soil sampling
Cost –error analysis
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2000
4000
6000
8000
0 500 1000 1500
Cost(USD)
Number of samples
Thermal oxidation
NIR spectroscopy
Comparisons of costs of measuring SOC using a commercial lab and NIR
Cost
IR is cheaper (~ 56%) than dry combustion
method for large number of samples
Throughput
Combustion ~ 30-60 samples/day
NIR ~ 350 samples/day
MIR ~ 1000/day
Cost –error analysis
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18. Things to be careful [2]
Proper labeling
Avoid contamination
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Properly locate your plots/sites

19. Ermias Betemariam | Hands-on soil infrared spectroscopy training course | Nairobi | Nov. 12, 2013 | 1
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Preliminary results from Ethiopia

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Preliminary results from Ethiopia

21. • More research on cost-effective measurement tools
• Reduce uncertainties in measurements- error propagates
• Develop national capacities, networking and partnership
• Enable decision makers have clear understanding of soil status and trends
Finally…
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