This document discusses improving soil fertility and agricultural productivity in Sub-Saharan Africa, with lessons for research at IITA. It notes low agricultural productivity in SSA is due to low soil fertility, nutrient depletion, and low fertilizer use. Peri-urban agriculture contributes to inner-city food supplies and provides jobs and incomes while offering an opportunity to close rural-urban nutrient cycles. Research on nutrient recycling in peri-urban systems in West Africa showed adequate processing of excreta and organic wastes can reduce health risks while providing fertilizer equivalents. The document concludes soil fertility research at IITA could benefit from a paradigm shift toward nutrient cycle management, recycling and integrated practices, and involving more stakeholders.

1. Improving agricultural productivity in
the rural-urban interface: Lessons for
Soil fertility research at IITA
Olufunke Cofie (PhD)
Candidate for the position of Soil Fertility Specialist

2. Outline
• Soil fertility & agricultural productivity in SSA
• SSA Agriculture - the rural-urban interface
• Nutrient recycling in peri-urban agriculture
• Lessons for IITA Soils Research
• Conclusions

3. Low agricultural productivity in SSA
• Low inherent fertility
• Nutrient depletion
• Low per capital fertilizer use
• Low yield
Low
Investments
…a cycle
Low
Low yield
Income

4. The low performance of agriculture is the main
cause of its slow economic growth
It is the only region of the world where per capita
food production has been declining for the past
three decades

5. Cereal Yields in Developing Regions 1960-2005
4.0
3.5
East and Southeast Asia
3.0
Latin America South Asia
2.5
mt/ha
2.0
1.5
Sub-Saharan Africa
1.0
0.5
0.0
1960 1965 1970 1975 1980 1985 1990 1995 2000 2005
Source: FAOSTAT.

6. Nutrient Mining of Agricultural Land in Africa
(kg/ha/yr)
1995-97 2002-04
Source:
IFDC
- Africa loses $4billion/yr in soil nutrients

7. Fertilizer nutrient consumption per hectare of arable land in selected countries, 2002
(kg/ha)
Netherlands
Vietnam
Japan
UK
China
France
Brazil
USA
India
South Africa
Cuba
Benin
Malawi
Ethiopia
Mali
Burkina Faso
Nigeria
Tanzania
Mozambique
Guinea 60
Ghana 100 200 300 400 500
0
Uganda
Source: FAOSTAT, from Borlaug, 2004

8. Increasing food demand…
• Population growth
– Natural growth
– Rural urban migration

9. 450
400
350
Total
300
Population
250
Urbanization in West Africa
Urban
(in millions) Population
200
150
Rural
100 Population
50
0
1930 1940 1950 1960 1970 1980 1990 2000 2010 2020
Urban population is becoming as large as the rural.

10. Agriculture in the rural-urban interface
• contributes to inner-urban food supply,
• compensates for missing cool transport and
storage (required for perishable crops),
• provides jobs, income and livelihoods.
• provides opportunity for closing rural-urban
nutrient flows

11. Contribution of UPA to urban food supply
100
% contribution to specific food item
80
60
40
20
0
UA PUA RA UA PUA RA UA PUA RA
Accra Kumasi Ouagadougou
City and source of food
Pineapple Cabbage Lettuce Spring onion Garden egg Tomatoes

12. Urban centres are nutrient sink
• Provides opportunity for nutrient
recycling
• Closing the nutrient loop
• Enhance intensive agriculture in the
peri-urban

14. The fertilization equivalent of untreated organic solid waste
Nutrient Contribution in kg / cap
year
Nitrogen (as N) 0.55 – 1.1
Phosphorus (as P) 0.2 – 0.4
Potassium (as K) 0.55
Carbon (as C) 16 – 22

15. Resources in excreta
Nutrient in kg / cap year
Nutrient In urine In faeces Total Required for
(500 l/year) (50 l/year) 250 kg of cereals 1
Nitrogen (as N) 4.0 0.5 4.5 5.6
Phosphorus (as P) 0.4 0.2 0.6 0.7
Potassium (as K) 0.9 0.3 1.2 1.2
Carbon (as C) 2 2.9 8.8 11.7
1
= the yearly food equivalent required for one person
2
= indicative of the potential for soil conditioning, normally not designated a nu-
trient
Nutrient value of Excreta is high enough to produce
food BUT with health risks !!!

16. Recycling Process
Focus
– Mixing ratio
– Pathogen inactivation
– Nutrient quality

17. Adequate processing reduce health risk
Dynamics of Ascaris eggs viability reduction during co-composing of faecal
sludge and organic solids waste

18. COMLIZER development
- excreta based compost with minimum
fertilizer

19. Co-compost
Quality Concentration
parameter
(Unit)
N (g/kg) 11.9 2.3
P (g/kg) 16.2 4.8
K (g/kg) 17.0 4.7
Ca (g/kg) 35.1 8.7
Mg (g/kg) 7.9 2.0
Pb (mg/kg) 28 28
Cd (mg/kg) 0.4 0.1
•Free from toxic heavy metals

20. cumulative inflitration -Tuu tengli
10.07.2003
40
35
y = 8.3846Ln(x) - 7.1975
30
25
depth (cm)
20
15
y = 2.6036Ln(x) - 3.3556
10
5
0
0 20 40 60 80 100 120
time (minutes)
Faecal Sludge treatment control

21. Comparison of economic benefits between users’ and non-users’ of excreta
application on farmlands in Krobo District, Ghana
Variable Users Cost/ ha ($) Non-users Cost / ha ($)
Total revenue 918.56 606.54
Land Preparation 72.38 54.64
Hired labour 178.83 189.42
Seeds 10.32 7.71
Excreta / Fertilizer1 18.79 51.23
Chemicals 34.00 19.74
Total Variable Cost 314.32 322.74
Gross Margin 604.24 283.80
Fixed Cost 0.00 0.00
Depreciation 7.65 7.87
Family labour 112.21 80.37
Rent on land 70.90 48.22
Total Fixed cost 190.76 136.46
Net Income 413.47 147.35
1 Excreta apply to users whilst fertilizer apply to nonusers. The cost incurred on
excreta is for transporting the excreta to farm site.
Source: Cofie et al 2007

22. Communicating results
• Publications in several outlets
– Refereed journals
– International conferences
– Book chapters
– Newsletters

23. Capacity building
Co-supervision
• Eight M.Sc
• Two PhDs
Several interns

24. Working with Donors
• French Ministry of Foreign Affairs
• SDC
• DGIS
• IDRC
• EC

25. Partnerships
• ARI – EAWAG, NRI, IHE-UNESCO
• NARES – Ghana, Nigeria and Sierra Leone
• Policy makers
• Farmer organisations
• NGOs
• Private Sector

26. Networking
• International Network of Resource Centres
on urban agriculture and food security-
Regional Coordinator
• SWITCH consortium – Chair
• SWISS NCCR – Senior member

27. Lessons for IITA Soils Research
Paradigm Shift Required
• From management of part of soil resource base
- Nutrient Cycle Management.
• From single use of resources
- Recycling and Integrated organo-mineral cum
cultural management practices
• From disregard of soil resource base
- fertility-sensitive farming practices

28. Involving other stakeholders
• Involving the necessary people through multi-
stakeholder processes and platforms:
– Government Agency/Ministry
– Funding Agency
– Metropolitan Authorities
– NGO’s
– The private sector
– Media
– User Groups/associations
– Emerging initiatives – AGRA etc
• Coupled with social processes to move sustainable
resource management across the research-policy-
implementation interfaces

29. Conclusion
Given these experiences, it should possible to
transform the soil fertility research for
development in IITA.

30. Thanks for your attention

31. Associated constraints
• Lack of enabling policy environment
• Single approach – mono sectoral
• Too much focus on basic science – too
abstract for field application
• Relevant stakeholders are often left out