1. What is an agroecosystem?
• Biophysical and socioeconomic
components
• Boundaries and hierarchies
• Structure and function
• History and legacy

2. Agroecosystem checklist (1)
(Brookfield et al., 2002)
• Management: field types and edges;
site and field surface preparation; soil
and water conservation; soil fertility
maintenance; planting materials;
cropping patterns and rotations; weeds
and weeding, pests and diseases; crop
harvesting, processing, and storage;
livestock; woodlots; fallow areas; wild
areas

3. Agroecosystem checklist (2)
(Brookfield et al., 2002)
• Biophysical structure and processes:
physical features at landscape and field
levels; soil characteristics; soil erosion,
degradation, and enhancement;
microclimates

4. Agroecosystem checklist (3)
(Brookfield et al., 2002)
• Organization: land tenure; farmer
gender; land ownership history; crop
and tree ownership; land-use history;
land-use intentions; types of livestock;
off-farm employment; food security;
water supplies; fuel supplies; labor
supplies; transportation networks;
marketing; decision-making processes

5. How do trees and other
perennials fit into
agroecosystems?

6. Agroecosystems are often
studied as part of an effort
to change them

7. The Evolution of Farming
Systems Research (Hart, 2000)
• Scale of target systems: from crop
populations to whole farms to communities
and watersheds
• System performance criteria: from production
to stability to sustainability
• Targeted beneficiaries: from ‘small farmers’ to
men and women to future generations
• Relationships: recognition of hierarchies

8. Sustainability in the Context of
Farming Systems Research
(Hart, 2000)
• A group of production technologies (e.g.
cover crops)
• Maintenance of the natural resource base
upon which production depends
• A measure of intergenerational equity

9. Participatory Rural Appraisal
• ‘Empowering rather than extractive’
• Outsiders as facilitators rather than
investigators
• Information owned, analyzed, and used by
local people rather than outsiders
• Often conducted by NGOs rather than
universities and government agencies

10. Prototyping Integrated and Ecological
Arable Farming Systems
(Vereijken, 1997)
• Establish a hierarchy of objectives
• Transform objectives into quantifiable
performance parameters
• Design and test prototypes that link
socioeconomic and biophysical objectives
with multi-faceted farming methods
• Place prototypes on pilot farms
• Refine and adapt prototypes
• Disseminate prototypes to other farms

11. Components of a farm’s ‘identity card’
(Vereijken, 1997)
• Abiotic environmental characteristics (soil,
water, and air quality)
• Non-agricultural species diversity (ecological
infrastructure)
• Food supply (quality and quantity)
• Health and safety (including pesticide
impacts)
• Income and profit (farm and regional levels)

12. Farming methods for I/EAFS
• Multifunctional crop rotation
• Nutrient balance
• Ecological infrastructure: restoration
and maintenance of landscape
elements
• Farm structural optimization (land,
labor, capital goods, technologies)

13. Principles of Agroeocosystem
Analysis (Conway, 1986)
• It isn’t necessary to know everything about an agroecosystem in
order to produce a realistic and useful analysis (‘optimal
ignorance’).
• Understanding the behavior and important properties of an
agroecosystem requires knowledge of only a few key functional
relationships.
• Producing significant improvements in the performance of an
agroecosystem requires changes in only a few key management
decisions.
• Identification and understanding of these key relationships and
decisions requires a limited number of key questions are defined
and answered.

14. Tractors and water buffaloes
in Sri Lanka
(Senanayake, 1984; Conway, 1986)
• Land area for rice vs. land for wallows and
non-crop vegetation
• Protein sources: buffalo milk, fish
• Refugia for fish, snakes, lizards
• Bund-boring crabs
• Rats
• Mosquitoes and malaria

15. Agroecosystem Analysis: Tools
(Conway, 1986)
• Diagrammatic history of the site, including major events
• Maps and transects showing important features, including topography,
soils, land use, problems, opportunities
• Seasonal calendars for climate, crop sequences, livestock, non-farm
activities, labor requirements, capital requirements, income, monthly
prices
• Long-term graphs showing prices, yields, acreages, population trends
(births, deaths, emigration, immigration)
• Bar diagrams showing sources of farm income, expenses on different
types of production inputs, etc.
• Flow diagrams showing production and marketing chains, flows of
income
• Decision trees depicting choice points, key factors
• Venn diagrams depicting overlapping institutions affecting decision-
making

22. A tentative plan (I)
1. Develop awareness of ecological,
agronomic, and socio-economic
components
2. Identify information needs and form
information gathering groups
3. Identify tools for organizing and presenting
information
4. Meet with farmers at ISU and/or on farm
5. Assemble information, by groups

23. A tentative plan (II)
6. Present information to classmates at debriefing
following farm visits
7. ‘Triangulate’ to determine accuracy of information
8. Assemble conceptual models of farms as natural
resource/human activity systems: system
boundaries, components, interactions, feedbacks,
control points
9. Identify key questions, hypotheses, and possible
changes
10. Assess impacts of proposed changes: ecological,
agronomic, socioeconomic

24. Some focal areas
• Natural resources: soils, water sources and drainage, water
quality, non-cultivated species, agricultural and non-agricultural
land use
• Crop and livestock systems: species, synergies and conflicts,
economics, nutrient dynamics, pest management systems,
calendars, buildings and machinery, product identity, target
markets
• Family: structure, gender issues, needs, goals, constraints,
decision processes, values, off-farm jobs, land tenure, credit
and debt, assets
• Local community: neighbors, medical and educational services,
social network, labor sources
• Private and producer organizations: inputs, marketing channels,
consultants, financing, information
• Government: subsidies, quality assurance, regulations,
information
• Local and regional history and future trajectories

25. Tasks
• Identify information gathering groups
• Specify preferences for groups
• Develop questions and framework for
interviews and on-farm surveys