agroecology: principles and practices
DESCRIPTION
A presentation written by Miguel Altieri, Professor of Agroecology at the University of California, Berkeley in the Department of Environmental Science, Policy and Management, with the participation of Angela Hilmi. You can choose to download the short or the long version; both of them are in Power Point format and available in English, French, Spanish and Portuguese download at ag-transition.orgTRANSCRIPT
AGROECOLOGY
Principles and Practices
(Long version)
By Miguel Altieri
With the participation of Angela Hilmi Design Francesca Lucci
Inter-
dependency
Self-regu
lating
Self-renewing
Self-sufficien
cy
Efficien
cy
Diversity
Inter-
dependency
Self-regu
lating
Self-renewing
Self-sufficien
cy
Efficien
cy
Diversity
Modern Practices- Specialization/ centralization
- Interventionist paradigm
- High import/ high export
- Therapeutic approach
Inherent Strengths of System
Erodes inherent pillar strengths
System/Community
SOIL LOSSESErosion; Loss oforganic matter
and Carbon dioxide
AIR EMISSIONSMethane; Ammonia;
Notrous OxideCarbon Dioxide
WATERCONTAMINATION
Pesticides; Nittrates;
Phosphates, Bacteria
Dead ZonesBIODIVERSITY LOSSWildlife and habitat;
Hedgerow and woodland loss;
Bee colony decline;Vanishing Crops and
Breeds
DISAPPEARINGWETLANDS
Draining and Tilling;
Dewatered Rivers;Impact on Species
HUMAN HEALTHPesticides; Asthma;Bacteria and viral
diseases;Antibiotic resistance;Mad Cow and E.Coli;
Bbesity
Abovethe cost ofFood at theCheckoutCounter
Healthy ecosystems
Crop genetic and species diversity
Intensive agricutlure replaces ecological services
AGRICULTURE
Soils
Nutrient cycling
Water
Climate
Pest control
Pollination
Domestic animals
Commercial varieties in
monoculture
Fertilizers
Ground-water pumping
Pesticides
Honey bees
Mechanization
Feed lots
Farmscapes, recreation, biodiversity
Meat, grains, vegetables, fruits, seeds, fibers, fuels
Monoculture landscapes
EXTERNALITIES: eutrophication, pollution; salinization; soil erosion and compaction, greenhouse gas emissions, biodiversity loss, human health
issues
DFS: restoring ecological services in farms
PLOT FIELD LANDSCAPE
Crop Border/Buffer Strips
Crop Rotation/Cover Crop
RiparianCorridors
NatureReserves
NUTRIENTS WATER SOILS PESTCONTROL
POLLINATION
Polyculture;Plants and
Animals
InsectaryStrips
AGROECOLOGY
Ecology
Anthropology
Ethnoecology
Sociology
Basic agricultural sciences
Ecological economics
Biological Control
Traditional Farmers’
knowledge
Principles
Specific technological forms
Participatory research in farmers’
fields
AGROECOLOGY integrates natural and social processes joining political ecology,
ecological economics and ethnoecology among the hybrid disciplines;
uses a holistic approach therefore it has long been considered as a transdiscipline as it integrates the advances and methods of several other fields of knowledge around the concept of the agroecosystem viewed as a socio-ecological system;
is not neutral and is self-reflexive, giving rise to a critique of the conventional agricultural paradigm;
recognizes and values local wisdom and traditions, creating a dialogue with local actors via participatory research that leads to a constant creation of new knowledge;
adopts a long-term vision that sharply contrasts with the short-term and atomistic view of conventional agronomy; and
is a science that carries an ecological and social ethics with a research agenda of creating nature friendly and socially just production systems.
THE HIDDEN CONNECTIONS
Principles of Ecology NetworksAt all scales of nature, we find living systems nesting within other living systems – networks within networks. Their boundaries are not boundaries of separation but boundaries of identity. All living systems communicate with one another and share resources across their boundaries.
CyclesAll living organisms must feed on continual flows of matter and energy from their environment to stay alive, and all living organisms continually produce waste. However, and ecosystem generates no net waste, one species’ waste being another species’ food. Thus, matter cycles continually through the web of life.
Solar energySolar energy, transformed into chemical energy by the photosynthesis of green plants, drives the ecological cycles.
PartnershipThe exchange of energy and resources in an ecosystem are sustained by pervasive co-operation. Life did not take over the planet by combat but by co-operation, partnership, and networking.
DiversityEcosystems achieve stability and resilience through the richness and complexity of their ecological webs. The greater their diversity, the more resilient they will be.
Dynamic BalanceAn ecosystem is a flexible, ever-fluctuating network. Its flexibility is a consequence of multiple feedback loops that keep the system in a state of dynamic balance. No single variable is maximized; all variables fluctuate around their optimal values.
Agroecological principles underlying productivity, sustainability and resiliency of agroecosystems
Spatial and temporal genetic and species diversity at farm and landcape level
Crop and animal integration
Biologically active organic matter rich soils
Hi biomass recycling rates and tight nutrient cycles
Optimization of the use of space (agroecological redesign)
Agroecosystem Processes to Optimize
• Organic matter accumulation and nutrient cycling
• Soil biological activity
• Natural control mechanisms (disease suppression, biocontrol of insects, weed interference)
• Resource conservation and regeneration (soil, water, germplasm, etc)
• General enhancement of agrobiodiversity
Sustainable agricultural systems are conceptualized here as being low in material input (pesticides, inorganic fertilizer, etc.) and high in information input (applied ecological knowledge of the system). High chemical input practices conceal and depreciate the importance of ecological processes occurring in agricultural systems. However, as pesticides, fertilizer, etc. are reduced, greater knowledge of the interaction occurring in agroecosystems is required for success. Furthermore, this knowledge must be applied in a practical manner to maintain agroecosystem productivity.
Input susbstitution vs agroecological approach
• Symptoms
• limiting factors
• external inputs
• maximize yields
• monoculture
• ususally one product
• Root causes
• processes
• interactions/synergy
• stabilization
• diversification
• multiple functions and products
Agroecological
Principles
The pillars of agroecosystem health
“Below ground”
Agroecosystem Design
“Above ground” Habitat Management,
Plant Diversification and enhancement of
beneficial fauna
Habitat Management
Biota Activation and Diversification (Soil Organic Matter Nutrient
Management)
Crop Health
Agroecosystem Health
The ecological role of biodiversity in agroecosystem function and the provision of ecosystem services by diversified farming systems (Lopez-Ridaura et al. 2002)
Rotational-intercropping design to reduce soil-nitrate losses
Biodiversity corridor in Fetzer Vineyard
Crop production
Animal production
Integrated System
This model shows an integrated barn with spatial and temporal design of crops, pasture, serials and trees. The pasture constitutes the changing phase of the rotation as grazing animals deposit manure improving soil fertility for the annual crops that use the nutrients thus representing the extracting phase of the rotation
An integrative scheme of peasant knowledge of Nature
Indigenous Mexican maize varieties
Based on indigenous knowledge and rationale
Economically viable, accessible and based on local resources
Environmental sound, socially and cultural sensitive
Risk averse, adapted to heterogeneous circumstances
Enhance total farm productivity
Features of appropriate technologies for poor farmers
Agroecological strategies
Animalintegration
Green manures
Organicamendments
Rotations
Polycultures
Finca “Del Medio” – José A. Casimiro Sancti Spíritus
Area (ha)
Energy (GJ/ha/yr)
Protein (kg/ha/yr)
People fed by produced energy (Pers/ha/yr)
People fed by produced protein (Pers/ha/yr)
Energy efficiency
10
50.6
867
11
34
30
Characteristics of an integrated farm
Findings from a study of MASIPAG organic farmers in the Philippines
Food security is significantly higher for organic farmers.
Organic farmers have grow 50% more crops thus eating more diverse, nutritious and secure diet.
Organic farms exhibit better soil fertility, less soil erosion, increased tolerance of crops to pests and diseases and climate change
Health outcomes were also substantially better for the organic group.
Badgley et al. 2007 (University of Michigan)
Casi 300 estudios comparativos de agricultura orgánica/agroecológica y agricultura convencional
1: org.=conven. < l: conven. mayor que org. >1: org. mayor que conven.
Agroecology
is socially activating as its diffusion requires constant farmers participation;
is a culturally acceptable approach as it builds upon traditional knowledge and promotes a dialogue of wisdoms with more western scientific approaches;
promotes economically viable techniques by emphasizing use of indigenous knowledge, agrobiodiversity and local resources, avoiding dependence on external inputs;
is ecologically sound as it does not attempt to modify the ergy and efficiency of existing production systems, but rather tries to optimize their performance promoting diversity and synergies
The Campesino a Campesino Movement
• The Campesino a Campesino movement is an extensive grassroots movement in Central America and Mexico.
• It is a cultural phenomenon, a broad-based movement with campesinos as the main actors
• The Campesino a Campesino movement is an excellent example of how alternative technologies and practices can be disseminated bypassing "official channels".
• It is a bottom up, horizontal mechanism for knowledge sharing and technology transfer
Pilars of food sovereignty
Agroecological strategies
Social movements
State supportMarkets, Credit, extensions, Research etc
Land reformAccess to land,water, seeds
Protection against dumping
Agroecology, resilience and the three types of sovereignty to be reached in a rural community.
Hypothetical threshold values established for an agricultural community for each type of sovereignty
Agroecosystem Diversity
Low external inputs, high recylcling rates,
crop –livestock integration
High
Eficiency
High inputs, industrial monocultures
Low
Low external inputs, diversified with low levels of integration
Medium-Low
Specialized systems with low external inputs
Medium
Pro
du
cti
vit
y
Alta
Baj
a
Baja
Alta
The basic requirements of a Viable and durable agricultural system
capable of confronting the challenges of the 21st century while
carrying out its productive goals within certain threshold established
locally or regionally.
The basic requirements of a Viable and durable agricultural system …
Thank you for your attention!