Feeding the world

Is there enough to nourish everyone?

Overview

World food production is adequate in quantity and quality (nutritional value) to feed the current human population.

Modern food problem is largely due to• Distribution Issues• Poverty in large part of the world

Some farmland is lost for food production• Suburban development (e.g., CT where

farming has been decreasing for years)

Overview

Increases in food production have been accomplished:• Increasing area in production• Increasing production per unit area

Soils

Definition:• Rock modified by biological, chemical and

physical processes such that the material will support rooted plants

How long does it take to make soils? 1mm per 10 - 40yrs

Soils

To grow crops we need soils. What is soil? ~Weathered rock?• Chemical elements, including organics,

required for plant growth• Air and water pass freely through the soil• Should retain water well• Fine clays help retain moisture, chemicals• Sands and coarse particles help with drainage

Soils

Soils are damaged due to:• Removal of natural ground cover

Farming, Deforestation, Overgrazing

• Erosion: wind and water• Acidification, excess leaching• Pollution

Soils

Soils

Soils

Agriculture in the 20th century has damaged more than 109 ha of land through erosion and soil loss

Soils

In US• One third of topsoil lost, 80 x 106 ha of land

ruined or marginalized for agriculture

• Rates of soil erosion are controversial but it seems that since the 1930’s rates have decreased from 17 to 13 tonnes/ha/yr

Soils

• Rivers carry 4 x 109 tons/yr of sediment, 75% from agricultural lands; sedimentation rates in coastal waters have increased by factors of 2-5 over the last 150 years (e.g. LIS)

Excess sedimentation wordwide is a problem

In US $500 million/yr dredging expenses

Soils & Agriculture

Advances have been made in tilling practices

• Contour Plowing: plow perpendicular to the slope. Tests show reduction in erosion from 14.4 tons/ acre to 0.1 ton / acre

• No-Till agriculture: currently ca. 100 million acres in US

• Terracing

‘No Till’ Agriculture reduces nutrient losses

Soil Erosion

Terraces

used in traditional cultures

Reduce erosion Maintain fertility

Bali rice paddies

Percentage of Land in Agriculture

9% Africa, 11% N. America, 11% Asia, 20% Europe, 11% World

Land & Agriculture

Land & Agriculture

Land & Agriculture

World Grain Production has leveled off

Per person production declining?

Land & Agriculture

World Grain Production has leveled due to:

in production from former USSR?

• limits fertilizer effects?

• erosion, salinization, lack of irrigation water?

World Food Supply Shrinking?

Year # Days in supply of grain

1987 104

1995 62

1996 49

Food Security, India

In 1950, 51x106 tons food grain In 1995, 200x106 tons food grain In 1995, 30x106 tons food grain in surplus In 1995, 40% of population (>350 million people)

were starving

People are too poor to buy the available food!

Food Security

Problem: distribution • Solution: increase local production

Problem: poverty – people too poor to buy available food• Solution: employment, social welfare

Food Security: Can we meet the future demands?

By 2025, we will have to triple irrigated lands• Volume of water will equal the Nile or 10 Colorado

Rivers

Water diversion will have competition from providing local drinking water and for local crops

In 2025, use of runoff to increase from 54% to 70%• Destruction of rivers, fisheries and aquatic species

Genetically Modified (GM) Crops

Placement of foreign genes into crops (or other organism)

Enhance production and growth under usually deleterious climates or conditions

Disease and insect resistance

Genetically Modified (GM) Crops

Panacea or Plague?????• NAS panel (2002) says no strong evidence of

environmental damage• Evidence for gene spreading (e.g., GM genes in taco

products)• Evidence for allergic responses in humans

Growth genes in cereal – shrimp – human allergy and immune response

Who owns the resources?????

Food production depends on soil, water and energy

supplies - all are stressed!