Recarbonising the soil: what is the value proposition for farmers

1. Recarbonising the soil: what is the
value proposition for farmers?
Presented at the
SACAU ANNUAL CONFERENCE:
Taking Stock of Southern Africa’s Climate Smart Agriculture
Agenda: What are the Prospects for the Future?
by
Saidi Mkomwa, Executive Secretary
African Conservation Tillage Network (ACT)
27th to 28th May 2019, AFECC Gloria, Maputo, Mozambique

2. Massive Opportunities for African
Farmers
o Africa’s population is urbanizing – food market
of 250 M by 2030
o Africa’s annual food import bill $35 billion;
$110 billion by 2025
o Africa has 60% of the global total uncultivated
crop land
o Africa is the youngest continent, 60% under 35
years old. 420 million youth aged 15-35; to
double by 2040. 72% have access to Digital
Tools (CTA).

3. There are Serious Threats to Agriculture
in Africa
1. The number of the hungry is on the increase; it is
decreasing elsewhere
2. Threatening climate change challenges
3. Farming related land resource degradation and loss
of biodiversity – acidification, erosion, pollinators.
4. Declining rural labour force, ageing farming
population and increasing feminization of agriculture
5. Inadequate capacity at all levels
6. Inadequate coordination, harmonization, and
benchmarking for THE Agric. transformation

4. Recarbonizing Soils and CSA
o Recarbonizing Soils: practical actions for carbon dioxide
removals, and sequestration of carbon in soils.
o 25% of the climate change problem (& solution) is due to
land use issues. However, it is only 1% of the climate
conversation.
o Farms, forests and landscapes are front lines in this urgent
effort to recarbonize and revitalize soils.
o Regeneration and enhancement of soil health with CA-
based carbon sequestration and SOM improvements (humus,
manure, cover crops, no-till, crop & livestock rotations).
o CSA is an approach that helps to guide actions needed to
i) sustainably increasing agric. productivity and incomes;
ii) adapting and building resilience to climate change; and
iii) reducing and/or removing greenhouse gas emission.

5. Source: Reicosky
Tillage enhances Carbon Dioxide (CO2) Emissions

6. Engine GHG Emissions

7. Climate change mitigation through Conservation
Agriculture
Source: González-Sánchez et al., 2017

8. opportunities for African farmers
First, start with mitigation and adaptability of farming to climate change with CA and
show it cannot be done with conventional tillage agriculture;
Then show the work done by ECAF-ACT on this topic for Africa and mention other
places to include evidence from global sources to strengthen the argument.
Then, include the following:
• Regeneration and enhancement of soil health with CA-based carbon sequestration
and SOM improvements;
• Field based productivity gains leading to increased crop and farm profit and
stability with CA
• Farm-based improvements in environmental services to the household and
livelihood with CA
• Farm-based increase in market value of the farm with CA
• Farm-based participation in schemes that pay for ecosystem services harnessed
with CA
• Landscape and watershed based ecosystem services based on CA.
For the third step, there is quite a bot of evidence from the work doe in Africa as listed
in the ECAF-ACT meta analysis. Also, our book on CA for Africa: Building resilient

9. Conservation Agriculture
Mechanical Tillage
Biological Tillage
Action of Soil Biota
Structure/Porosity
ConventionalAgriculture
High Soil
Organic
Matter
low soil
organic matter
Soil Organic Matter = Drought Resistance
2
CO

10. 0
5
10
15
20
25
30
35
0 1 2 3 4 5 6 7
AvailableWaterholdingCapacity(AWC)
(%byweight)
Organic Matter (OM) % by weight
Sand
Silt loam
Silty clay loam
Source: Berman Hudson, 1994. JSWC 49:189-194
SOM increases available water holding capacity!

11. How much water can your soil hold?
45 kg of dry soil:
o With 4 to 5 % OM can hold about 81 kg
of water
o With 1.5 to 2% OM it can only hold 18 kg
of water
Walters and Fenzais 1979

12. Situation in Malawi – Tilled & CA
Tilled CA
Source: C Thierfelder, CIMMYT

13. Gains in Rainfall Infiltration Rate with CA
Less flooding – improved water cycle
Landers 2007
tillage + cover, measured
no-till + cover, measured
tillage, no cover, measured
tillage + cover, calculated
no-till + cover, calculated
tillage, no cover, calculated
Time (min.)
AccumulatedInfiltrationrate[mm.h-1]

14. Infiltration curves measured by mini-rainfall simulator in
January 2008 (left) and 2009 (right), Henderson Station
Time (min)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70
Infiltration(mmh-1
)
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Conventional ploughing (CP)
Rip-line seeded (RI)
Direct seeding (DS)
Time (min)
0 5 10 15 20 25 30 35 40 45 50 55 60 65 70
Infiltration(mmh-1
)
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
Conventional ploughing (CP)
Rip-line seeded (RI)
Direct seeding (DS)
January 2008 January 2009
Source: C Thierfelder, CIMMYT

15. How CA makes farming smart
The “top-dry” field with dusty
road nearby before planting on
20th Feb 2019.
Madrugada, Nakuru, Kenya. No
rain since Dec 2018.
Photo taken 20th March 2019. 92%
emergence.

16. How CA makes farming smart .. .. ..
• CA stops runoff & erosion, enhances
infiltration and insitu water harvesting
• SOM increase 0.1-0.2% per year. More
available water in soils (1 % OM =150 m3/ha)
• Less water needs (-30-40%)
• Less fertilizer use (-50%), and less pesticides
(-20->50%).
• Less machinery, energy & labour cost (50-
70%)
• Recharge of aquifers, improved water
quality

17. The ACT-ECAF studies on CC Mitigation
and Adaptability with CA (2018)

18. CA for Climate Change Mitigation in Africa
González-Sánchez et al., 2018

19. Potential SOC fixed annually by CA
compared to systems based on
soil tillage in Africa
145 Mt C per year
= 533 Mt
of CO2 per
year
Almost 3 times
Europe’s
potential!
co2
González-Sánchez et al., 2018

20. No-Tillage Solution: What equipment for
minimum soil disturbance?
Oxen ripping
Oxen direct seeding
Highly mechanized
The hand hoe –
for basins making The Dibble stick

22. CA Solution: Permanent
soil cover, crop rotations
& associations
Maize > Tephrosia
relay after 8 months
Maize – Canavalia
Maize – Lablab
You can’t have soil biology
without plants as their host.

23. Pan-African Level:
Creation of Enabling
Environments: ICAAP
Africa, iSAMAPAfrica,
National Level:
Building Institutions:
Centres of Excellence;
CSO, Service Provider
Associations,
Grassroots Level:
Builddemanded
Capacity:e.g.
Entrepreneurship &
Business Development
Systemic
Regulato
: Policies, Plans,
ry Frameworks
ational:EstablishOrganiz
efficient
processe
structures,
s andprocedures
Individua
compete
l: Skills, knowledge,
ncies and attitudes.
ACT NETWORK
The Africa We Want: Agenda2063
Prosperous Africa based on Sustainable Development
Cross Cutting
Level:
ICT-based platforms&
Knowledge
Management
ge Management &Knowled
Information Sharing
3. Modernized
infrastructure,
decent housing,
healthy and well
nourishedcitizens
7. Africa’s natural
endowmentsare
healthy &
protected, with
climate resilient
economies and
communities
6.Blue
ocean
economy for
accelerated
economic
growth
4. Transformed
economies for shared
growth, decent jobs &
economic opportunities
for all
1. A highstandard
of living, quality
of life and well-
being
2. Well educated&
skilled citizens,
underpinned by
science, technology
and innovation
5. Modernagriculture
for increased
production,
productivity & value
addition contributesto
prosperity and food
security
Developing CA/CSA Capacity at all Levels

24. Recarbonising the Soil results to: Summary
1. Mitigation: removals of carbon dioxide, and
sequestration in soils. Farming becomes a sink for
carbon (rather than source)
2. Positive co-benefits; for soil fertility, productivity,
water and nutrient retention. Thus more resilient
agroecosystems to deal with climate variability.
3. Improved soil health and functions (as a result of
carbon sequestration and increase in SOM due to
CA). Productivity (yield); input factor productivity
(efficiency); yield stability, and reduced inputs.
Greater and stable crop and farm profit.

25. Recarbonising the Soil results …cont. …
4. SOM & biodiversity build up. Land easier to work with
and the increase of land's economic market value.
5. Decrease in erosion, land degradation and improved
water infiltration and drainage. Improved water
quality and quantity in wells, underground water
supplies, streams & rivers. Better human health; less
time to look for quality water.
6. Participate in schemes that pay farmers to sequester
carbon.
7. Participate in schemes that pay farmers to deliver
good quality water in greater quantity e.g. supply
clean water into reservoirs, hydroelectricity, for
industry and for environmental services

26. General Overview
1. CA and CSA work. However, capacity is needed (and also
Quality Assurance) to support its practice as a system
(including livestock).
2. Livestock productivity needs to be enhanced by
integration with crop production under CA. They are
complementary and not competing.
3. Irrigation is feasible, for some areas. But, at what cost?
Can we target the youths and resource poor in semi-
arids (with no water to drink?). Note: Most irrigation
schemes are “white elephants”.
4. CA works even in wetter areas to address weed
management, leaching/acidification, and soil erosion.

27. ACKNOWLEDGEMENT
 ACT appreciates the invitation to the workshop
and the collaboration with SACAU in the
promotion of Conservation Agriculture –based
Climate Smart Agriculture.
 The collaboration and financial support from the
Norwegian Agency for Development Cooperation
(NORAD) to ACT is sincerely appreciated

28. http://africamechanize.act-africa.org/
https://facasi.act-africa.org/