Agricultural Land and Water Text extracted from The World Food Problem Leathers & Foster, 2004 ttp://www.amazon.com/World-Food-Problem-Toward-Undernutrition/dp/1588266389

Agricultural Land Use Source: NASA http://lcluc.umd.edu/images/Science_Themes/Foley1-large.jpg

Land Availability Ag land has increased slowly Most increases in pasture land Grazing cattle, Brazil http://www.ypte.org.uk/docs/factsheets/env_facts/env_images/brazil_cattle.jpg

Land with Crop Potential 2.57 billion hectares of land with crop potential Excluding china Only using < 1 billion Problems with most unused potential land Hilly Poor soil Poor drainage Could increase ag land 30% China http://www.agapetea.com/store/images/common/about_blacktea3.jpg

Potential arable land

Agricultural Intensity HANPP: Human Appropriation of Net Primary Production http://www.eoearth.org/upload/thumb/4/45/HANPP_Figure_3.jpg/625px-HANPP_Figure_3.jpg

Land lost to Ag production Urban expansion Small effect worldwide Global warming may flood coastal areas Soil degradation 1/3 cropland worldwide abandoned due to erosion http://upload.wikimedia.org/wikipedia/commons/thumb/7/7b/Erosion.jpg/397px-Erosion.jpg

Irrigation World Water Use: Agriculture 69% Domestic 8% Industry 23% Irrigated crops provide 40% of food worldwide Yields with irrigation increase 2-3X

Irrigated land http://upload.wikimedia.org/wikipedia/commons/4/4a/Irrigated_land_world_map.png

Water withdrawals for irrigation http://news.bbc.co.uk/nol/shared/spl/hi/pop_ups/04/sci_nat_feeding_the_world/img/3.jpg

Sandra Postel “Water use tripled between 1950 and 1990 as world population soared by some 2.7 billion… Worldwide demand for water cannot triple again without causing severe shortages for crop irrigation, industrial use, basic household needs and critical life-supporting ecosystems” http://www.hipco-ne.com/images/gated.gif http://www.globalwaterpolicy.org/images/sandrapostel1_19.jpg

Conserving Ag water Water harvesting Drip irrigation Collecting and saving runoff Drip irrigation Drought tolerant varieties Drip irrigation http://static.howstuffworks.com/gif/irrigation-drip.jpg

Colorado River River is drained dry Heavy irrigation use before it reaches the ocean Heavy irrigation use Colorado Arizona California Mexico City water supply Las Vegas Phoenix Tucson California irrigation from the Colorado River http://aquafornia.com/wordpress/wp-content/uploads/2008/02/irrigation-_2-by-bor-pfs.jpg

Irrigation in China Yellow river used for irrigation River ran dry in 1972 For 15 days Since 1986 runs dry every year In 1997, dry for 227 days Yellow River

India River Interlink Plan $200 billion plan to bring water to south India Will link 36 rivers with canals Completed in 2016 Potential benefits Reduce flooding Hydroelectric power Irrigation http://www.ben-center.org/riverMaps/RiverLinkingMainMap.jpg

Vandana Shiva Industrial ag requires 5x water of indigenous ag                                       Vandana Shiva Industrial ag requires 5x water of indigenous ag wheat and rice Pumping groundwater not the solution Aquifers depleted Big dams not the solution benefit cities, investors Ecologically destructive Displaces poor farmers Many small dams better Small dam, India http://farm4.static.flickr.com/3018/2397775485_c4fce43d8d_m.jpg http://www.netradiomeeting.it/public/foto/SHIVA_VANDANA.jpg

Aswan Dam, Egypt Benefits Problems Controls flooding of Nile River Hydroelectric power Problems Fertile silt not deposited Farmers must use fertilizer Schistosomiasis increase Nile delta receding Increased salinity http://www.2travel2egypt.com/sightseeing/images/aswandam.jpg