Chapter 11 Producing Enough Food for the World

Relationship between World Food Supply and Environment Food production depends on the environment Agriculture changes the environment significantly Modern food problems result of the great increase in human population and its influence on the environment

How We Starve Undernourishment –Lack of sufficient calories in available food Malnourishment –Lack of specific chemical component of food Most important cause of starvation worldwide –Inadequate distribution of food sources Climate variability –Sub-average years can cause famine

Food Aid Programs Where one nation provides food to another or give or lends money to purchase food –Can lower food prices –Can reduce local food production –Can undercut the local farmers

Crops Rangeland: Provides food for grazing and browsing animals without plowing and planting Pasture: Plowed, planted and harvested to provide forage for animals Forage crops: Food for domestic animals Mixture of crops: Include root, stem, and fruit crops Allow secondary succession to occur Milpa agriculture; swidden agiculature, fang agriculture

Agriculture in Less-Developed Countries Significantly effected by: –Social disruptions –Droughts –Loss of organic matter –Accumulation of chemical compounds –Insect infestations

Aquaculture –The farming of food in aquatic habitats –Aquaculture, in combination with fishing, provides the majority of the world’s food supply Mariculture –The farming of ocean fish

Six Ways Agroecosystems Differ from Natural Ecosystems 1.Try to stop ecological succession and keep the agroecosystem in an early successional state 2.Monoculture: Large areas planted with a single species 1.Decreases organic matter in the soil 2.Simplifies ecosystem so vulnerable to disease outbreaks 3.Crops are planted in neat rows 4.Farming greatly simplifies biological diversity 5.Plowing is unlike any natural soil disturbance 6.Genetic modification of crops

Limiting Factors Limiting Factor: The single requirement for growth available in the least supply in comparison to the need of an organism –Liebig’s “Law of the Minimum” 2 Types of Life-Important Chemicals 1. Macronutrients 2. Micronutrients Synergistic Effects: a change in availability of one resource affects the response of an organism to some other resource

Demand Based Agriculture Based on highly mechanized technology High demand for resources, including land, water and fuel –Irrigation Drop irrigation Night-time irrigation Surge flow

Resource-Based Agriculture Based on biotechnology and conservation of land, water and energy –Grown without artificial chemicals –No genetic engineering –Ecological control methods employed –Crop rotation

Population growth and agriculture Past practice for an increase in food production has depended on: –Expanded irrigation –Growing use of fertilizer If the world’s population doubles in the future, either: –Agriculture acreage must double OR must increase the yield per acre

Increasing the Yield per Acre 1. The Green Revolution -Programs that have led to the development of new strains of crops with higher yields, better resistance to disease or better ability to grow under poor conditions 2. Improved Irrigation - Hydroponics

Organic Farming 3 Qualities 1.It is more like natural ecosystems than monocultures 2.It minimizes negative environmental impacts 3.The food that results from it does not contain artificial compounds

An Organic Farm Offshoot of resource- based agriculture No artificial chemicals No genetic engineering Ecological control methods employed

Agricultural Production in U.S. Regions differ for crop production Factors that influence: –Tradition –Access to technology and supplies –Local politics

Watershed Development Factors that limit land available for agriculture: –Slope –Elevation –Floodplain and river- delta development

Land use and crop production Converting rangeland to cropland can increase environmental damage –Not all land suitable for agriculture –Some is better suited for grazaing Land uses: –Tundra; silviculture; orchards; domestic animals; annual crops; aquaculture Wisest approach to sustainable agriculture –Use best agriculture land for crops, poorer lands for pasture and rangelands

Genetically Modified Food Genetically Modified Crops (GMC) are modified by genetic engineers to produce higher crop yields and increase resistance to drought, cold, heat, toxins, plant pests and disease.