Targeting innovations to combat soil degradation and food insecurity in semi-arid Africa. Pablo Tittonell

ABACOAgro-ecology based aggradation-conservation agriculture

Targeting innovations to combat soil degradation and food insecurity in semi-arid Africa

Pablo Tittonell, Eric Scopel, Gerardo Halsema, Nadine Andrieu, Helena Posthumus, Paul Mapfumo, Rabah Lahmar, Marc Corbeels, Tom Apina, Jacqueline Rakotoarisoa, Florence

Mtambanengwe, Barry Pound, Regis Chikowo, Saidi Mkomwa

Problem statement Poor soil fertility and soil degradation limit food security

CA may be low-cost investment strategy to increase water productivity and

resilience to climate variability, and reverse soil degradation

But adoption by smallholders in sub-Saharan Africa seems to be hampered by:

Concerns on initial yield decreases

Lack of sufficient biomass for effective mulching

Increased labour requirements if no access to herbicides

Lack of access to and use of external inputs

CA has to be tailored to local agro-ecological and socio-economic conditions

Adoption of innovations is a non-linear process

Sharing knowledge and building capacity through innovation platforms may

enhance adaptation and adoption of CA by smallholders

ABACO projectObjective: reduce vulnerability of smallholder farmers to climatic variability by building capacity through innovation platforms to design, evaluate and implement targeted technological options for, and mechanisms to promote adoption of, conservation agriculture based on agro-ecological principles to combat land degradation and food insecurity in semi-arid sub-Saharan Africa.

Specific objectives:1. To target CA to smallholders’ conditions2. To involve farmers and researchers in co-

innovation platforms to facilitate adaptation/appropriation

3. To assess the social and economic viability and tradeoffs across scales and scenarios

4. To promote dissemination of CA alternatives and approaches

5. To reinforce existing knowledge networks on CA

ABACO projectProject leader: Saidi Mkomwa – ACT

Consortium: ACT, CIRAD, CIRDES, EMBRAPA, FOFIFA, SOFECSA, University of Greenwich (NRI), Wageningen University, Yellow Window

Timeframe: 2011 – 2014

Funded by EU

Semi-arid areas of East (Kenya, Tanzania), West (Burkina Faso, Mali) and Southern (Zimbabwe, Mozambique, Madagascar) Africa

Building on previous projects: KASSA, CA2Africa

Project sites

ACT

CIRDES

SOFECSA FOFIFA

A focus on dryland areas

(400 – 1200 mm)

Rabah Lahmar (2009)

Stepwise ‘aggradation’

Aggradation: slow process of soil formation (borrowed term from geography used for alluvial soils)

How fast does this happen?What is the importance to farmers’ livelihoods?What indicators can be used for monitoring?

Stepwise ‘aggradation’ABACO’s approach of aggradation/conservation agriculture consists of:

• Implementing measures traditionally promoted as soil and water conservation, water harvesting technologies or (indigenous) agroforestry, during an initial phase of soil restoration or ‘greening’.

• Only when a minimum efficiency of nutrient and water capture has been achieved to allow increasing primary productivity, the three principles of CA may become effective: zero tillage, permanent soil cover and crop rotation.

• Particularly in dry environments the response of soil productivity to soil restorative measures may exhibit a faceted pattern characterised by an initial response to increased water availability (i.e., the ‘greening’ effect) with a slight loss in water productivity, followed by a response to increased soil fertility once nutrients become available (resulting in greater water productivity).

ti

Plant biomass (kg ha-1)

Transpiration (mm)

Increased water availability

Incr

ease

d nu

trie

nt

avai

lab

ility

ti+1

ti+2

wi wi+1

bi

bi+1

bi+2

Stepwise ‘aggradation’Water productivity

Soil rehabilitation

The response of a degraded agro-ecosystem to rehabilitation measures may be fast or slow, and exhibit weak or strong hysteresis (i.e., h, h’ or h”). The periods t25%, t50% and t100% represent the delay necessary to achieve 25 to 100% of the original performance, efficiency or stock level. The rate of responsiveness depends on:• the indicator chosen to characterize the response (productivity, efficiencies, stocks), • on the type of measure(s) implemented to restore productivity, • on the biophysical properties of the agro-ecosystem, and • on the behaviour of external factors (e.g. rainfall).

Feasibility and tradeoffsharvest

Crop

leaching

fertilizer

cropuptake

gaseous losses

erosion

harvest

Pruningsmulch

competitive tree uptake

‘safety-net’ tree uptake

Tree

Crop

N2fixation

leaching

fertilizer

cropuptake

gaseous losses

erosion

NPKNPK

NPK

NPKNPK

NPK

NPKNPKNPKNPK

NPKNPK

Experimental field

On-farm

Landscape

Co-innovation platform

Research for development

Rural community

Promotion & extension Knowledge

networks

Field schools

Action research

Other stakeholders

Other stakeholders

Other stakeholders

Innovation platforms

Based on Learning Centres model, Zimbabwe

The 5 ABACO principles

1. Rehabilitation of degraded soils to restore biomass productivity, in order to secure the various functions of CA that depend on above and belowground plant biomass;

2. Increased water productivity and soil water buffering capacity to face increasing risks associated with climate change, creating more conducive conditions for farmers’ investments;

3. Intensifying agro-ecological functions to capitalise on natural interactions, increase resource use efficiency and reduce dependence on external inputs;

4. Embed these principles in sustainable innovation support systems that recognise the complexity and non-linearity of agricultural innovation processes;

5. Institutionalization of enabling policies and market conditions so as to facilitate uptake and promotion of CA among smallholder farmers.

ABACO activities

1. On-station and on-farm field experimentation

2. Gender-sensitive characterisation of conditions for implementing CA technologies and gender mainstreaming of all activities

3. Action research with rural communities

4. Participatory & model-based scenario analysis and tradeoffs evaluation

5. Training & capacity development

6. Dissemination

7. Policy analysis and recommendations

Existing CA knowledge

Site charac-terisation & diagnosis Field testing

& niche targeting

Supportive basic

research

Field demonstra-tion, farmer valuation & adaptation Feasibility

and tradeoffs evaluation

Dissemina-tion & out-

reach

Pro

jec

t p

rog

res

s

FP6 CA2Africa

Policy recommen-

dations

Analysis tool development

Field activities

Innovation platforms

FP7 KASSA

Best-bets

Material development

Policy analysis

The ABACO project

WP1. Diagnosis, design and testing

WP3. Feasibility and trade-offs evaluation

WP4. Dissemination, impact and networking

Soil rehabilitation and integrated fertility

management

Water productivity and climatic variability

I

II

Design and testing of water capture and climate coping alternatives based on CA

Evaluation of CA alternatives under climatic scenarios, risk and vulnerability

Documentation of 4W(*), adoption and adaptation strategies; Mechanisms of dissemination-learning

Documentation of 4W(*), adoption and adaptation strategies; Mechanisms of dissemination-learning

Themes

Work packages

WP2. Innovation support

Farmer testing & adaptation of soil rehabilitation & fertility management alternatives

Farmer testing & adaptation of water capture and climate coping alternatives

Livelihood, gender and policy evaluation

IV

Gender-sensitive socio-economic diagnosis of enabling environments & local perceptions

Evaluation of social & economic viability of CA; tradeoffs under policy and market scenarios

Analysis of adoption, adaptation and learning processes; Policy design & recommendations

Innovation systems support, organisational landscapes, capacity needs & development

(*) the 4W stand for “What Worked, Where and Why?”

Methods and tools Surveying & diagnosis, on-farm & on-station

experiments, measurements

Dynamic and bio-economic modeling at different scales,

participatory evaluation

Meta-analysis, stakeholder platforms, dissemination

events & material

Stakeholder analysis, farmer groups, action research &

training

Agroecological functions and environmental

servicesIII

Multi-criteria evaluation of CA functions & sustainability: tradeoffs from field to regional scale

Farmer testing & adaptation of biodiversity mediated functions, valuation of indicators

Assessment of externalities and service provision (e.g. carbon sequestration, biodiversity, water saving)

Design and testing of CA alternatives for soil rehabilitation and fertility management

Diagnosis & identification of biodiversity-mediated CA functions, definition of indicators

Evaluation of C and nutrient flows and tradeoffs for CA implementation from field to regional scale

Organisational matrix

Flows

WP3: Feasibility and trade-offs evaluation

WP4: Dissemination and impact assessment

WP1: Diagnosis, design and testing

WP1-W WP1-E WP1-S

Field testing & targeting

Supportive research

Dissemination & outreach

Network reinforcement

Scenario analysis

Model development

Diagnosis & characterisation

Innovation platforms

Participatory evaluation

Policy analysis &design

WP0: Coordination

Training of trainers

WP2: Innovation support

WP1-M

Concluding remarks

• ABACO is a concept relying on 5 principles, borrowing from ISFM, agroecology and innovation systems

• We cannot ‘conserve’ what has already been degraded – a stepwise ‘aggradation’ phase is needed

• The EU-funded ABACO project targets innovations to combat food insecurity in semiarid areas

• Four transversal themes organise the research questions

• Four work packages delineate the project activities

• We are not starting from zero…

For questions:On water productivity: [email protected] On soil fertility: [email protected] On diagnosis & design: [email protected] On feasibility & tradeoffs: [email protected] On agro-ecological functions: [email protected] innovation platforms, adoption & gender: [email protected] ABACO: [email protected]

A B A C O

THANK YOU!