An Introduction to the Concepts of Sustainable Agriculture

IPM 401/601October 5, 2004

Geoff Zehnder, Coordinator

IPM and Sustainable Agriculture Programs

B28 Long Hall

zehnder@clemson.edu

www.clemson.edu/scg/sust

www.clemson.edu/scg/ipm

Farming in the U.S.The Last 50 years

• New technologies• Mechanization• Increased use of farm

chemicals• Specialization and

govt. policies that favor max. production

Fewer farmers with reduced labor demands produce the majority of food and fiber

Are “Mega-farms” Sustainable?

• Since WWII, US agriculture science and policy have favored large-scale, centralized farming

• The sustainability of this system is now being questioned

Benefits and Costs of Large, Corporate Farms

• Benefits– Increased production, cheap food prices– Many risks in farming reduced

• Costs– Topsoil depletion and loss of biodiversity– Groundwater contamination– Falling crop prices and increased prod. costs – Decline of family farms and rural communities

Growing Movement for a More Sustainable Agriculture

• Create direct connections between farmers and consumers

• Create regional food self-sufficiency • Reduce economic concentration in production,

processing and marketing• Encourage resource conservation

More small to medium size diversified farms growing food for local and regional consumption

Industrial vs. Biological Models of Agriculture

Industrial Model Biological Model

Farm as factory

Energy intensive

Farm as ecosystem

Information intensive

Linear process Cyclical process

Enterprise separation Enterprise integration

Single enterprise Many enterprises

Monoculture Diversity of plants/animals

Low value products Higher value products

Single use equipment Multiple use equipment

Passive marketing Active marketing

So What is Sustainable Agriculture?

• It means growing crops and livestock in ways that meet the following objectives simultaneously:– Economic profit– Social benefits to the farm family and

community– Environmental conservation

Transition is a long-term goal; normally requires a series of small steps. Requires all participants in the systems (farmers, retailers, consumers, policymakers, etc)

Environmental Sustainability

• Farming to mimic natural eco-systems

• Farm as a nature-based system, not a factory

• Natural cycles: waste becomes input

Managing Natural Processes on the Farm

• Energy flow; capturing solar energy– Maximize leaf area for photosynthesis; efficient cycling of stored

solar energy through food chain

• Water cycles; preventing runoff, erosion– Organic matter; increase soil water holding capacity

• Mineral cycles– Conservation of nutrients from soil-crops-animals-soil

• Ecosystem dynamics – Effective ecosystem: high level of plant/animal diversity

If managed properly will conserve resources and reduce costs

Economic Sustainability(If I grow it will they buy it?)

• Selecting profitable enterprises– Diversification spreads

risk, maximizes profit – Specialty crops,

organic, value added

• Comprehensive financial planning

• Market research and plan

Social SustainabilityDecisions on-farm effect community

• Find ways to connect with community

• Buying supplies locally• Marketing locally• Respect for neighbors,

farm workers• Farmland conservation

and preservation

Applying the Principles of Sustainable Agriculture

Some Examples of Sustainable Agriculture

Practices

Keep Soil Covered Year-roundCover Crops between Market Crops

• Plant material – moderates temperature – increases water

penetration and storage– enhances soil aeration– maintains soil structure,

prevents erosion by softening the impact of falling raindrops

Minimize Tillage

• Moldboard plowing– Brings subsoil to

surface– Buries crop residue

too deeply– Soil compaction– Soil exposed to

erosion

Crop RotationMarket and Cover Crops

• Long-term crop rotation plan– Diversity in the field

and at the market– Break pest cycles,

weed management– Improve soil quality,

add nutrients

Thomas Jefferson crop rotation plan forMonticello

Cover Crops and Green Manures

• Green manure crops– Soil incorporation of a

field or forage crop while green

– Add organic matter– Fix nitrogen– Suppress weeds,

pests– “Catch” crops

Mustard green manure crop between wheat and potatoes; Idaho

Fertilizer, Manure & Compost

• Some conventional fertilizers can reduce soil quality (e.g., anhydrous ammonia and potassium chloride)– Reduce populations of soil microbes necessary for

good soil structure

Other Forms of FertilizersImprove Soil Quality

• Manure: Composted and aged manure preferred (usually ideal C/N ratio)

• Other environmentally friendly fertilizers available (soybean meal, bone meal, feather meal, etc)

Pest ManagementMoving Along the IPM Continuum

• Pesticide Management Phase– Sampling, economic thresholds, spraying when

needed• Cultural Management Phase

– Knowledge of pest life cycles used to implement cultural practices like delayed planting and harvest, crop rotations, etc.

• Bio-intensive IPM Phase– Knowledge of pest and beneficial life cycles used to

implement cultural practices and to design favorable habitats for natural enemies. Broad-spectrum pesticides avoided

Weed Management

• Long-term plan based on a knowledge of weed ecology – Crop rotations to

suppress, smother weeds

– Allelopathic cover crops– Timed cultivation to

reduce weed stands and prevent seed set

– Mulch in high value crops

Insect Management

• Prevention and avoidance– Diversified habitat

reduces pests, enhances natural enemies

– Farmscaping– “Soft” insecticides if

necessary

Bio-Intensive IPM

http://www.attra.org/attra-pub/ipm.html

Disease Management

• Mixed cropping• Plant, row spacing• Vigorous plants more

resistant to disease– Healthy, microbially-

active soil suppresses root diseases

– Compost: disease-suppressive soil

– Compost extract

Happy Cow DairyA Successful Transition

• Losing money with conventional dairy management

• Transitioned to a rotational grazing system (12 Aprils)

• Added creamery• Now more profitable,

environmentally sound

Tom Trantham, Dairy Farmer

Pelzer, SC

Trantham Dairy Conventional Practices (Pre-1990)

• Confinement dairy operation– Herd kept in barn or

feedlot– Feed, hormone inputs

to maximize milk production (65% of income)

– High production, but not enough to cover costs

Trantham DairyRotational (paddock) Grazing System

• 70 acres for grazing• 75 small paddocks• Cows graze 24 hours

then moved• Moveable electric tape

fencing• Paddocks regenerate• Supplemental feed based

on available forage, # cows and weight, milk production goals

Trantham DairyForage Varieties

• 12 Aprils Concept• Plant a succession of

different forages throughout the year

• Varieties based on performance, longevity, preference, nutritional value

• Objective: Cows able to graze almost 12 months/year

Trantham DairySpecialized Equipment

• No-till seeder– Drills seed into existing

crop residue – Can plant seed for

second crop while first crop is being grazed

Trantham DairyWaste, Irrigation, Fertility Management

• Manure scraped into picket-dam • Waste water goes into lagoon• Solids spread onto paddocks with spreader• Waste water used to irrigate, fertilize paddocks

Benefits for Trantham Dairy

• 42% input cost reduction (62 cents/cow/day)

• Healthier cows, lower vet bills

• Improved soil quality, reduced use of pesticides, fertilizers

• Value-added benefits (better tasting milk, health benefits, creamery, farm market)

Questions?