Agriculture Sustainability and Plant Physiology

Lecture Outline

• Sustainability defined• Issues related to food production

– Current situation of production and consumption– Public knowledge of agriculture

• Sustainability benefits• Challenges in food production sustainability• Linking knowledge of plant physiology in

sustainability discussions

Sustainable Agriculture is Basis of Farming

• Sustainable agriculture must:

– Preserve the capacity of the land to meet the needs of humans and other species (Ecology).

– Preserve farming as an economically viable occupation and a rewarding lifestyle (Economy).

– Preserve the integrity of rural communities (Society).

Patterns of Agriculture Production in US

• Consolidation of farms• Farm income• Farm workers• Land area farmed• Where food comes from• Consumption patterns• Types of consumption• Health related to food• Cost• Modern agriculture production trends• What needs to be done for sustainability?

Consolidation of U.S. Agriculture Production

• Farmers ~ 2% of population, average age ↑

• 8% of farms account for 68% of production

• 3 out of 4 farm household earn majority of income from off-farm employment

• In 2000, 19¢ of each $ spent on food returned to farmer

• 2008 – 53% of farm workers were illegal

• 2008 – 434 million A, 1997 – 454 million A

Consolidation in U.S. Food System

• 80% of beef packing market controlled by 4 firms

• 80% of soybean processing controlled by 4 firms

• Top 5 food retailers sell 42% of America’s food (in 1997 it was 27%)

U.S. Food Consumption – 2700 calories/day in 2000, a 24.5% ↑ since 1970

Food 1970 2005

lbs/person % ↑

Grains 137 192 47

Fruits & Veg 556 687 19

Milk & Milk Prod 564 601 6

Meat, eggs, nuts 225 242 7

Sugar &

Sweeteners 115 142 19

USDA Recommendations

• Grains – at least ½ whole grains

• Vegetables – eat dark green, orange and leafy types

• Fruits – choose a variety of fruits, < juice

• Milk – choose fat-free and low-fat

• Meat – choose lean meats and low-fat

• Sugars – avoid corn sweeteners

U.S. Population and Health

• 2/3 of Americans are overweight or obese (body mass index of 25 or >)

Compared to 47% in 1970• Obesity rate has doubled since 1970

from 15% to 30% for adult population• 400,000 premature deaths related to

poor diets and effects on heart, cancer and stoke health problems

• Will diets change and how?

U.S. Food Price Trends

• 2008 – greatest increase in prices in 17 years ~ 4.5% ↑

• 2007 – 4% ↑ compared with 2.5% over last 15 years

• U.S. disposable income spent on food was 7.2% in 2006, 225 in Poland, 44% in Egypt

• % of Hunger in U.S. is low• Recent food riots in world over food

shortages

Modern Agriculture• Feeds 6 billion people• By 2050 world population will be ~ 9 billion• Grain yields will need to double

– > inputs of fertilizer, water, pesticides, new cultivars

• Challenges– increasing development throughout world– reducing hunger– improving nutrition– sparing natural ecosystems from conversion to

agriculture

Global Grain Production

Have we maximized yields?

Benefits of Agriculture

• Benefits to humanity have been immense• Agriculturalists are principle managers of

useful global lands– They shape the future face of the earth -

hopefully in a positive manner– We must increase yields– Can not compromise environmental integrity or

public health– How? Yield doubling and society demands

AgricultureUnder Attack?

• Agriculture is probably one of the most disruptive human endeavor in changing ecosystems – Add and use high amounts of nutrients

especially - N and P– Nutrients additions will have to increase if

we are to achieve greater yields– Costs of agriculture have usually not been

measured, at least until recently

Ecosystem Services

• Natural and managed ecosystems provide:– food– fiber– fuel– materials for shelter– recreation– forests and watersheds – climate– atmosphere– nutrient cycling

Agriculture if Done Wrong can:

• Cause:– Pesticide contamination– Nutrient runoff– Species composition changes– Clear cutting– Pollution– Soil degradation– > use of non-renewable energy resources– Loss of useful farm land – Farming being done on marginal land

Benefits of Sustainability

• Sustainable Agriculture practices– must meet current and future societal

needs for• Food and fiber• Ecosystem services• Healthy lives

– must do this by• Maximizing the net benefits to society when all

costs of agriculture practices are considered

World Population Now and in the Future and Food Supplies

• 2000 – 6.1 Billion• 2050 – 9.2 Billion• 99% of growth will be in less developed

countries• Food Supplies are strained in 2008• Is current farming sustainable?• Reasons yes or no?• Solutions - hope or none?

Organic Agriculture• Organic production should fit into and benefit from nature’s system

• Goals – producing high quality safe food in a manner that tends to preserve the integrity and stability of the biotic community and builds or at least sustains the inherent productive capacity of the soil and biological resources used in the production process

Why Organic Farming?

• Environmental concerns

• Health concerns

• Economic concerns

• Ethics

Principles and Practices in Organic Production

• Biodiversity• Diversification and integration• Sustainability• Natural plant nutrition• Natural pest management• Integrity

Food Production and Environmental Costs

• Increasing Yields• Increasing Nutrient use efficiency• Increasing water use efficiency• Maintaining and restoring soil fertility• Disease and pest control• Sustainable livestock production• Balance in ecosystem• Law of return

Food Production and Environmental Costs

• Increasing Yields – hope or despair?

Nutrient Use Patterns

Increasing Nutrient Utilization

Importance of Nutrients

• High yields dependant on addition of fertilizers

• Between 1960 and 1995 global use of N increased 7 fold and P use increased 3.5 fold

• Their use will increase 3.5 fold by 2050 unless we increase efficiency

• Only 30-35% and 45% of applied N and P taken up by plant – rest goes where ?

Increasing Water Use Efficiency

• 40% of crop production comes from 16% of land that is irrigated

• Irrigation is a great contributor to increased yields

• Problems with dependence on water– Availability– Competition– Abuse of ground water use– Drought

Soils and Nutrients• Soil is the most important resource in

agriculture

• Quality soil is essential for increasing yields

• Some say: farmers only need the soil to hold the plant up – we provide everything else necessary to productivity

• Since 1945 – 17% of vegetated land has undergone human induced degradation

Soil EcologySoil Ecology dictates ecosystem processes:

1. Cycling of nutrients-decomposition

-mineralization

-energy turnover

2. Biodiversity – plants, animals, microbes

The diversity and abundance of life in soil exceeds that of any other ecosystem.

Organic Agriculture “Alternative strategies for managing plant growth.”

• Soil health (Quality) = Plant health

• Strongly related to soil biology• Soil “Organism” - the Living Soil

– Eats– Breathes– Circulates fluids and nutrients– Reproduces itself

Ecological Perspective: “Alternative strategies for managing plant growth.”

Biological

Chemical

Physical

Weathering

N-fixation

Mycorrhizae

Soil mixing

Aggregation

Mineralization

HumusFormation Aeration

Ecological Perspective:

• Sustainable Agriculture demands a holistic perspective:

• Don’t treat the symptoms, manage the cause!

Soil Farmers

Water

Crops

Wildlife

Livestock

Bad Soil Practices

• Too much tillage • Poor fertilizer and water inputs• Limited crop rotations • Decreased fallow periods• No cover or catch crops, legumes, manures,

composts• Result

– Decreased yields– Loss of productive soils

Pest Management

• Important input for increased yields and quality

• All effective pest management tools select for their own extinction

• Must use integrated approaches and a variety of tools

Pesticide Use

Importance of Plant Physiology Knowledge

• Developing a sustainable and productive agriculture– Next 50 years are critical– Expanding human population– Expanding environmental impacts– Agriculture practices will shape the earth + or -

• How to address this?– What have you learned in Hort 301 that can be

applied to the agriculture challenges posed ?

Methods to Achieving Sustainability

• Agronomic practices – The farmer– Technology – for instance?

• Changing the plant paradigm – The scientist– Improving plants – how?

• Society– Awareness and contributions

Challenges to Making Agriculture Sustainable

• Ways to improve sustainability and meet food needs of world– Nutrients – availability and utilization – Water – availability and utilization– Soil fertility – ways to maintain and

improve– Pest management – reduction in effects– Germplasm – how to improve?– Ecosystem services – how to sustain?

Summary

• Sustainability • Challenges facing Agriculture• Address these challenges• Achieving a sustainable agriculture and

world• What plant physiology knowledge will

help you to contribute to solutions– EITHER AS A PRODUCER OR AS A

SCIENTIST OR AS A CITIZEN?