Ms Marla Riekman, Manitoba Agriculture, Canada. Global Symposium on Soil Erosion (GSER19), 15 - 17 May 2019 at FAO HQ.

1. Assessing Soil Health
Following the Adoption of
Conservation Agriculture
in East Africa
Marla Riekman – Manitoba
Agriculture
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2. Conservation Agriculture (CA)
• Designed to improve food security on small-holder
farms
• Based on 3 principles:
• Minimal mechanical disturbance, reduced or zero tillage
• Maintaining permanent cover using cover
crops/mulches
• Using diverse crop rotations (FAO 2017)
• Advantages to CA include moisture conservation
and reduced soil erosion, through improved soil
structure and stability
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3. Scaling Up CA in East Africa Project
• Initiative of the Canadian Foodgrains Bank (CFGB),
with funding from Global Affairs Canada
• Purpose is to expand CA adoption in Ethiopia,
Kenya and Tanzania
• Measurement of soil health benefit is carried out
on the farm-level
• Observations are made on evidence of soil erosion,
either seen in person or through discussion with farmer
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4. Methodology
• Soil Health Assessment
• Uses simple tools such as a
pH meter, Munsell colour
chart, microbial respiration
• General observations on
soil texture (texturing by
feel method), water
movement, soil structure,
as well as soil erosion
• Observations are rated on a
scale of 1 to 5 to compare
soil change over time
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3 years
under CA
Non-CA

5. 3 years
under CA Non-CA

6. Methodology
• Soil Physical Characteristics help assess soil’s ability
to withstand erosion
• Soil Structure – assess for aggregate size and stability
• Soil Compaction – ease of digging, evidence of hard
pan/restrictive layers, clean away soil from roots to view
growth patterns
• Soil Crusting – evidence of soil sealing after heavy rains,
impact on seedling emergence
• Hoe Test - hoe 10 planting stations and rate based on
the ease of hoeing and how soil breaks up on impact
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7. Methodology example – Hoe Test
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8. Methodology example – Hoe Test
1. Soil is soft and easy to hoe, no chunks of soil are
observed, soil has good crumb structure
2. Soil is relatively easy to hoe, some chunks of soil may be
observed, chunks break up with ease
3. Soil is firm, able to hoe to proper depth, some chunks of
soil, chunks break up under moderate pressure
4. Soil is moderately hard, able to hoe to proper depth, soil
comes up as large chunks that are difficult to break up
5. Soil is hard, very difficult to hoe to proper depth
(evidence of hard pan/restrictive layer), soil comes up as
large chunks
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9. Preliminary Results – all fields
9
0
1
2
3
4
5
Hoe test soil structure soil compaction soil crusting
AssessmentScore
(Scaleof1to5)
Soil Structure Assessments, 2018
CA non CA
31 paired plots from Ethiopia, Kenya and Tanzania

10. Preliminary Results – by country
10
0
1
2
3
4
5
Hoe test soil structure soil compaction soil crusting
AssessmentScore
(Scaleof1to5)
Ethiopia, 2018 (5 pairs)
CA non CA

11. Preliminary Results – by country
11
0
1
2
3
4
5
Hoe test soil structure soil compaction soil crusting
AssessmentScore
(Scaleof1to5)
Kenya, 2018 (16 pairs)
CA non CA

12. Preliminary Results – by country
12
0
1
2
3
4
5
Hoe test soil structure soil compaction soil crusting
AssessmentScore
(Scaleof1to5)
Tanzania, 2018 (10 pairs)
CA non CA

13. Preliminary Results
• Soil physical characteristics are showing
improvement
• Ratings are closer to 1 for CA for all assessments
• Preliminary data shows only 2018 sampling of plots
3+ years in CA
• Greater number of fields assessed in Kenya and Tanzania
due to longer period of CA adoption
• 2019 sampling is currently underway, final sampling
will be conducted in 2020
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14. Summary
• Adoption of CA results in improvements in soil
aggregation and structure within just a few years
• Soil is getting darker in colour (data not shown)
indicating increased organic matter
• Use of mulch, reduced tillage and increased crop
cover help to protect soil from erosion, while also
building soil properties to better withstand erosive
impacts
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