AGRICULTURA SOSTENIBLE

•"This is a philosophy and set of goals, not a way to farm.” • "Sustainable agriculture is a new name for organic farming.” • "I'm already sustainable, or I would not be in business.” • "You're suggesting that what I've been doing is unsustainable!” • "If we can't define sustainable agriculture, can we research it?"

Principles of Agroecology & Sustainability

The goal of agroecology is to develop and manage sustainable

agroecosystems. •What is agroecology?

•What are agroecosystems?

• What is sustainability?

• What are the agroecological principles that guide development of sustainable agroecosystems?

• How do we measure sustainability in agroecosystems?

• What are the best agroecological indicators of sustainability?

Sustainable agr iculture: A whole­systems approach to food, feed, and fiber production that balances environmental soundness, social equity, and economic viability among all sectors of the public, including international and intergenerational peoples. Inherent in this definition is the idea that sustainability must be extended not only globally but indefinitely in time, and to all living organisms including humans.

Sustainable Agroecosystems: • Maintain their natural resource base.

• Rely on minimum artificial inputs from outside the farm system. • Manage pests and diseases through internal regulating mechanisms • Recover from the disturbances caused by cultivation and harvest

Principles of Agroecology and Sustainability An interface to agroecology in list form

I. Use Renewable Resources

II. Minimize Toxics

III. Conserve Resources

IV. Manage Ecological Relationships

V. Adjust to Local Environments

VI. Diversify

VII. Empower People

VIII.Manage Whole Systems

IX Maximize Long‐Term Benefits

X. Value Health

I. Use Renewable Resources

•Use renewable sources of energy instead of non‐renewable sources.

•Use biological nitrogen fixation.

•Use naturally‐occurring materials instead of synthetic, manufactured inputs.

•Use on‐farm resources as much as possible.

Recycle on‐farm nutrients.

II. Minimize Toxics

•Reduce or eliminate the use of materials that have the potential to harm the environment or the health of farmers, farm workers, or consumers.

•Use farming practices that reduce or eliminate environmental pollution with nitrates, toxic gases, or other materials generated by burning or overloading agroecosystems with nutrients.

III. Conserve Resources

Conserve Soil

Sustain soil nutrient and organic matter stocks.

Minimize erosion.

use perennials.

use no‐till or reduced tillage methods.

mulch.

Conserve Water

Dry farm.

Use efficient irrigation systems.

Conserve Energy

Use energy efficient technologies.

Conserve genetic resources

save seed.

maintain local landraces.

use heirloom varieties.

Conserve Capital

Keep bank debt to a minimum.

Reduce expenditures.

IV. Manage Ecological relationships

A. Reestablish ecological relationships that can occur naturally on the farm

instead of reducing and simplifying them.

B. Manage pests, diseases, and weeds instead of “controlling” them.

C. Use intercropping and cover cropping

D. Integrate Livestock

E. Enhance beneficial biota

1. In soils

mycorrhizae

Rhizobia

free‐living nitrogen fixers

2. Beneficial insects

Provide refugia for beneficials.

Enhance benefial populations by breed and release programs.

F. Recycle Nutrients

Shift from throughflow nutrient management to recycling of nutrients.

Return crop residues and manures to soils.

When outside inputs are necessary, sustain their benefits by recycling them.

G. Minimize Disturbance

Use reduced tillage or no‐till methods.

Use mulches.

Use perennials

V. Adjust to Local Envir onments A. Match cropping patterns to the productive potential and physical limitations of the farm landscape. Adapt Biota adapt plants and animals to the ecological conditions of the farm rather than modifying the farm to meet the needs of the crops and animals. VI. Diver sify

A.Landscapes Maintain undisturbed areas as buffer zones. Use contour and strip tillage. Maintain riparian buffer zones. Use rotational grazing.

B. Biota Intercrop. Rotate crops. Use polyculture. Integrate animals in system. Use multiple species of crops and

animals on farm. Use multiple varieties and landraces of

crops and animals on farm.

C. Economics

Avoid dependence on single crops/products.

Use alternative markets.

Organic markets.

Community Supported Agriculture (CSA).

"Pick your own" marketing.

Add value to agricultural products.

Process foods before selling them.

Find alternative incomes.

Agrotourism

Avoid dependence on external subsidies.

Use multiple crops to diversify seasonal timing of production over the year

VII. Empower People

Ensure that local people control their development process.

Use indigenous knowledge

Promote multi‐directional transfer of knowledge, as opposed to "top‐ down" knowledge transfer.

Teach experts and farmers to share knowledge, not "impose" it.

Engage in people‐centric development.

Increase farmer participation.

link farmers with consumers (CSA).

Strengthen communities.

Encourage local partnerships between people and development groups.Ensure intergenerational fairness.

Guarantee agricultural labor.

Ensure equitable labor relations for farm workers.

Teach principles of agroecology & sustainability.

VIII. Manage Whole Systems

Use planning processes that recognize the different scales of agroecosystems.

Landscapes

Households

Farms

Communities

Bioregions

Nations

Minimize impacts on neighboring ecosystems.

IX. Maximize Long‐Term Benefits

maximize intergenerational benefits, not just annual profits.

maximize livelihoods and quality of life in rural areas.

facilitate generational transfers.

Use long‐term strategies.

develop plans that can be adjusted and reevaluated through time.

Incorporate long‐term sustainability into overall agroecosystem design and management.

Build soil fertility over the long‐term.

build soil organic matter.

Add value to agricultural products.

X. Value Health

A. Human Health

B. Cultural Health

C. Environmental Health

Value most highly the overall health of agroecosystems rather than the outcome of a particular crop system or season.

Eliminate environmental pollution by Toxics and surplus nutrients.

D. Animal Health

E. Plant Health

Properties of Natural Ecosystems Compared with Sustainable and Conventional Agroecosystems

Natural Ecosystems

Sustainable Agroecosystems*

Conventional Agroecosystems*

Production (yield) low low/medium high Productivity (process) medium medium/high low/medium Diversity high medium low Resilience high medium low Output stability medium low/medium high Flexibility high medium low Human displacement of ecological processes

low medium high

Reliance on external human inputs

low medium high

Autonomy high high low Sustainability high high low *Properties given for these systems are most applicable to the farm scale and for the short­ to medium­term time frame. From: Gliessman, S.R. 1997. Agroecology: Ecological Processes in Sustainable Agriculture. Ann Arbor Press: Chelsea, MI

Traditional Agroecosystems:

Do not depend on purchased inputs.

Make use of locally available and renewable resources.

Emphasize nutrient recycling.

Are beneficial for both on‐ and off‐farm environments.

Are adapted to local conditions.

Take full advantage of microenvironments.

Maximize yield while sustaining productive capacity.

Maintain spatial and temporal diversity and continuity use production to meet

local needs first.

Rely on and conserve local genetic diversity.

Rely on and conserve indigenous knowledge and culture.

Sustainable farming meets environmental, economic, and social objectives simultaneously. Environmentally sound agriculture is nature­based rather than factory­based.

Economic sustainability depends on profitable enterprises, sound financial planning, proactive marketing, and risk management. Social sustainability results from making

decisions with the farm family's and the larger community's quality of life as a value and a goal. We will discuss the

principles of environmental, economic, and social sustainability.

Nutr ient Absorption Critics are often under the illusion that organic farmers believe

plants obtain all their nutrients from an organically managed soil in a chemically organic form. While a few organicists may believe that, the majority recognizes that

digestion processes in the soil release minerals in forms similar to those applied as commercial fertilizers. Unfor­

tunately, the notion that organic farmers are naïve and ignorant about basic agronomy is a red herring that has

often foiled intelligent discussion about the pros and cons of the system.

Among the facts that are often obscured is the reality that plants can and do absorb significant amounts of large

organic molecules from the soil; herbicide and systemic insecticides are among these. In healthy soils they also absorb vitamins, chelated minerals, hormones, and other

beneficial compounds (16).