Reading ‐ Can We Feed the World…?

List Three Food Problems need solving at the same time:

1. End hunger

2. Double food production by 2050

3. Reduce Agriculture’s damage to the environment

Reading ‐ Can We Feed the World…?

List Five Solutions suggested:

1. Stop expanding agriculture’s footprint

2. Close the world’s yield gaps

3. Use resources much more efficiently

4. Shift diets away from meat

5. Reduce food waste

What are some Crop Efficiency Indicators?

Keystone Centre for Science & Public Policy

• Defining and measuring the sustainability of food and fibre

production

• Developing outcome based metrics

• Measuring the environmental and socioeconomic impacts of

agriculture

• Providing tools to help growers analyse operations and food

companies explain how natural resources are being managed

What is Sustainable Agriculture?

An integrated system of plant & animal production practises having a

site‐specific application that will, over the long term

What are some ways we can make agriculture more sustainable?

• satisfy human food and fibre needs

• enhance environmental quality and the natural resource base upon

which the agricultural economy depends

• make the most efficient use of non‐renewable and on‐farm

resources

• integrate, where appropriate, natural biological cycles and controls

• sustain the economic viability of farm operations

• enhance the quality of life for farmers and society as a whole.

What are the 6 Challenges and Threats to Sustainable Agriculture

and Food Production

1. Demographic Change

2. Water Scarcity

3. Land Degradation

4. Climate Change

5. Energy Insecurity

6. Loss of Ecosystem Services

Suggestion: Integrate with the issues and solutions presentedin Wk 2 Reading “Can We Feed the World and Sustain thePlanet?”

Demographic Changes

•FOOD NEEDS

• pop’n reached 7 bill in 2011; should stabilize at ca. 10 bill by

2200

• >> 50% increase in food needs

• urbanization, income growth

• more diversified diets

• more PROTEIN ‐ fish, meat

• high value crops

• higher per capita caloric intake

INCREASED LIVESTOCK PRODUCTION

Grain Production and Demographic Changes

- 73% of grain grown in Canada is used for livestock feed

-66% of deforestation in Central and South America are used to create pasture land. 

40% of wheat grown in the UK is used to feed livestock

Food Insecurity

2010 – 925 mill people food insecure

• Per capita calorie consumption

• Recommended

2500 kcal]

• South Asia 2400 kcal> Below nutritional

recommendations

• Sub‐Saharan Africa 2200 kcal> Below nutritional

recommendations

• North America >3500 kcal>Above nutritional

recommendations

• World Average 2800 kcal> Above nutritional

recommendations

• Peak pop’ns in many food‐insecure countries will be more

than twice current pop’ns

• CHALLENGES – of meeting food needs of increasingly

affluent pop’ns

2. Water Scarcity

• Threatens sustainable agriculture where:

• increasing food demands as a result of pop’n growth

• rapid increase in demand for fresh fruits, vegetables, other

“water‐intensive” prod’n systems

• 1 kg rice -->3,000 L water

• 1 kg beef (grain fed) -->15,000 L water

• Increasing competition between agricultural & nonagricultural

uses of water

• direct consumption, hydro‐electric power, industrial uses

• Closing of river basins – demand exceeds supply

Water Uses – Food Production

• Rain‐fed + irrigation:

• 2010 7,130 km3 per year

• 2050 ca. 13,000 km3 per year

• in US 16% of cropland is irrigated ‐ high value crops that

account for 50% of total US crop sales

• Annual freshwater withdrawals

• consumptive water use

• 3,800 km3 per year ‐ 70% used for agriculture

•Up to 5,000 L to produce 1 person day of food

• MUST find ways to produce food with < water

Water‐Stress Threshold

•Water stress – disruptive water shortages are

frequent

• Per capita water availability < 1,700 m3 per year =

experiencing water stress

• 1995 – 2.3 bill (41%) people

• 2025 – 3.5 bill (48%) people

• <1,000 m3 per year = severe leading to problems with

food prod’n & economic development

• 1995 – 1.7 bill of the 2.3 bill above (74%)

• 2025 ‐ 2.4 bill of the 3.5 bill above (68.5%)

True of False

Water scarcity is a global issue?

False: Water scarcity is a often a regional rather than a global

issue

• Regions unequally affected

• SE Australia, N&W China, central India, central and

western Asia, northern and southern Africa, Sahelian

zone of W Africa, NE Brazil, N Mexico, SW US

3. Land Degradation

• Loss in intrinsic quality that leads to a decline in the

capacity of the land to satisfy particular uses

• Includes:

• wind and water erosion

• loss of organic matter and soil nutrients

• soil salinization

• acidification

• compaction and crusting

• reduced biological activity of soils

Land Availability

• Appears adequate globally to meet increased food

demands

•World surface area

• Food & fibre prod’n ca. 11% used 38% (degraded)

• Grazing ca. 24% 21%

• Forests ca. 31% 18%

• Land degradation is difficult to measure

• Measures above – GLASOD – Global Assessment of

Human Induced Soil Degradation study (1992) –

somewhat contentious

Effects on Productivity

• Reduces current and undermines future productivity

• Apparent decline in productivity of 12% of all land,

1983‐2000 (based on satellite imagery)

• Effects may be masked by extra use of inputs or

alteration of land use

• one reason why degradation is hard to assess

• Threshold effects – little loss of productivity on thick,

fertile soils initially despite soil erosion, then rapid

decline as critical thickness is reached

• i.e. fertile soil layer very thin

Spatial Variability in Degradation

• Sloping, marginal land = increased erosion

• Foothills of Himalayas; slopes of Andes; southern China;

SE,central and W Asia; semiarid lands of the Sahel

• These areas experience reduced use when agric

productivity increased in more favored prod’n areas

• Favored agric lands (esp. developed countries) –

excessive inputs, tillage, unsuitable rotations,

inappropriate water mgmt

• Heavily relied upon for global food security

4. Climate Change

• Agroecosystems impacts

•May trigger severe water shortages

• Higher temperatures and changes in hydrological

regimes

• shorter growing seasons

• increased frequency of extreme & destructive weather

events

• shifts in incidence of plant pests – insects, diseases and

weeds

Spatial Variability in Effects

Temperate climates

• Mostly benefit from moderate climate change

• Esp. high rainfall areas where moderate CO2 increases

may stimulate plant growth

• However, above 3‐40C increase global mean temp (GMT),

will largely result in widespread adverse impacts

Spatial Variability in Effects

Equatorial climates

• Low latitude areas, start with slightly warmer temps

• Rapidly shifts to higher than optimal temps for sensitive

crops

• Even moderate warming of 1‐20C, will decrease yields of

crops near their heat tolerance (e.g., maize)

• >30C increase, widespread, severe yield losses

• 20‐40% yield reduction in sub‐Saharan Africa, Central America,

tropical Africa

World Agricultural Emissions

• 24% GHG from agriculture

• nearly 50% as a result of land conversion i.e., loss of carbon

sinks

• Nitrous oxide emissions expected to inc. 60% by 2030

• Mitigation – reduced tilling, inc. incorporation of organic

materials, avoid overuse of N‐based fertilizers

• Mitigation of GHG

• improve manure mgmt – capturing methane for energy

• improve land mgmt

• restoration of degraded land

• increase tree/shrub cover on pasture

• reduce meat consumption

5. Energy Insecurity

• Effects of High Energy Costs

• Increased manufacturing and operating costs

• fertilizer, farm machinery, pumping water, transporting

inputs and produce

• Resulting in:

• decreased use of inputs and irrigation

• lower yields

• higher food prices

Intensification of agriculture needed to supply future

food demands quickly becomes untenable!

Spatial Variability in Effects

• Developed Countries

• Energy intensive agriculture

• 1 ton maize – USA 160 L oil vs. 4.8 L in Mexico

• 2005, energy costs = 16% of agricultural production costs

• Developing Countries

• Food security is esp. dependent on favored production

regions – reliant on fertilizer use

• Increased food prod’n also fertilizer reliant

• fertilizer costs closely linked to cost & availability of

oil/energy

Biofuels

Wood, charcoal, ethanol, biodiesel, biogas

Biofuels – List the balance of costs & benefits

•A use for crop residues

• BENEFIT = economic benefit to farmers in developing

countries

• HINDRANCE = to conservation agriculture & soil health

• Use of marginal lands

• BENEFIT = otherwise unsuitable for prod’n food crops

• HINDRANCE = may have unknown impacts on dryland

ecosystems; prod’n of oil‐bearing biofuel crops may not

be profitable on lands with poor soil moisture

Biofuels – balance of costs & benefits

• Cereals for ethanol (biofuels)

• higher prices for maize and other cereals

• higher food costs to consumers

• Increased reliance on bioenergy

• intensified competition for water, soil nutrients, and

land

• increased water use in agriculture

• by 2050 water use for biofuels will equal current use for all

of agriculture

• Nutrient depletion will require fertilizer inputs over time

6. Loss of Ecosystem Services

ECOSYSTEM

• A dynamic complex of plant, animal and micro‐organism

communities (biotic) and the non‐living (abiotic) environment

interacting as a functioning unit

ECOSYSTEM SERVICES

• the benefits people obtain from ecosystems

• Food, water, disease mgmt, climate regulation, spiritual

fulfillment, aesthetic enjoyment

• Humans are fundamentally dependent on the flow of

ecosystem services.

Millenium Ecosystem Assessment

• Human have made unprecedented changes to

ecosystems in recent decades to meet growing demands

for food, fresh water and energy

• Ecosystem services that have been enhanced in last 50yrs

• Increases in crop, livestock and aquaculture production

• Increases in carbon sequestration (global climate regulation)

• But on the negative side have weakened nature’s ability

to deliver other key services

• purification of air and water

• protection from disasters

• provision of medicines (natural)

• Outstanding ecosystem service problems:

• dire state of world fish stocks;

• intense vulnerability of the 2 bill people living in dry

regions to the loss of ecosystem services – including

water supply; and

• the growing threat to ecosystems from climate change

and nutrient pollution

• both affect agriculture

Millenium Ecosystem Assessment

(other concerns) 

• More land converted to agric since 1945 than in 18th and

19th centuries combined

• More than half of all synthetic nitrogen fertilizers used

1985 to 2005; first introduced in 1913

• Substantial and irreversible loss in biodiversity

• 10‐30% of mammal, bird and amphibian species currently

threatened by extinction