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 yrs

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

 Agriculture in the 20th century has damaged more than 10 9 ha of land through erosion and soil loss

Soils  In US One third of topsoil lost, 80 x 10 6 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 10 9 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

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

Food Security, India  In 1950, 51x10 6 tons food grain  In 1995, 200x10 6 tons food grain  In 1995, 30x10 6 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!