Tuesday, May 8, 2012: 8:00 a.m.-9:20 a.m.
Terrace Room D-F (Hyatt Regency Orange County)Since 1950 the world’s population has increased from 2.5 to 6.5 billion. To accommodate the increase in food production, water withdrawals have tripled and irrigated acreage has doubled. Approximately 70% of annual freshwater withdrawals are now used in the agricultural sector. In the United States the use of groundwater for irrigation increased from 23% in 1950 to 42% in 2000. Anthropogenic chemicals are widely used in agriculture to increase crop yields and prevent crop damage by pests. Chemicals of concern in groundwater include fertilizers (primarily nitrate) and pesticides. In 2000, U.S. farmers used approximately 12 million tons of nitrogen and applied more than 1.2 billion pounds of pesticides (active ingredient). Protecting groundwaters from contamination by agricultural chemicals has proven to be very difficult. Sustainable management of groundwater will be significantly constrained in the future due to this increased demand and increasing competition between agriculture and energy needs.