Food Resources: A Challenge For Agriculture

Kwashiorkor is a virulent form of childhood malnutrition characterized by edema, irritability, anorexia, ulcerating dermatoses, and an enlarged liver with fatty infiltrates. The presence of edema caused by poor nutrition defines kwashiorkor.[1] The cause of kwashiorkor was thought to be due to insufficient protein consumption alone, however micronutrient and antioxidant deficiencies are now believed to play important roles.

Overview

• Food and Nutrition• World Food Problems• Principle Types of Agriculture• Challenges of Producing More Crops and

Livestock• Environmental Impact of Agriculture• Solutions to Agricultural Problems• Fisheries of the World

Human Foods

Food and Nutrition• Carbohydrates

– Sugars and starches metabolized by cellular respiration to produce energy (in the form of ATP)

• Proteins– Large, complex molecules composed of amino acids that perform critical roles in

body (hair nails and muscles are made of protein)– There are 20 different amino acids required for human nutrition.– The Human can synthesize 10-11 of these on it’s own – Humans lack the ability to synthesize the other aa’s called “essential amino acids”– They are Isoleucine, leucine, lysine, methionine, phenyalanine, threonine,

tryptophan, valine, histadine, and, in children arginine• Lipids

– Include fats and oils and are metabolized by cellular respiration to produce energy• Vitamins (help regulate metabolism)and Minerals (ingested in the form of salts dissolved in water)

World Food Problems

• Feeding growing population is difficult• Annual grain production (left) has increased since 1970• Grain per person has not (right)

The answer lies in controllinghuman population growth

World Food Problems• Famine– Failure of crops caused by drought, flood or

catastrophic event– Temporary but severe shortage of food (Africa, Asia,

and Latin America most at risk)– Worst = African Famine 1983-85 Etiopia hit hardest)

• Maintaining World Grain Carryover Stockpiles– Amounts of rice, wheat, corn and other grains

remaining from previous harvest– Provides measure of food security– Decreased each year since 1987

– UN feels carryover stock should not fall below 70 days

World Grain Carryover Stock

• Why the decline?– Rising temperatures– Falling water tables and

droughts– Ethanol production– More grain is going

towards feeding livestock as more people eat meat especially in China as their incomes rise ***see table 18-1 p.413

World Food Problems

• Poverty and Food– 1.3 billion people are so poor they cannot afford

proper nutrition– More common in• Rural than urban areas• Infants, children and the elderly

• Economics and Politics– Cost money to store, produce, transport and

distribute food– Getting food to those who need it is political (some

dishonest politicians sell food instead of giving it to the hungry)

Principle Types of Agriculture

Industrialized agriculture– Modern

agriculture methods that require large capital input, and less land and labor

Principle Types of Agriculture

• Subsistence Agriculture– Traditional agricultural methods, which are

dependent on labor and large amounts of land• Examples:– Shifting cultivation– Slash and burn agriculture– Nomadic herding– Intercropping– See mini-glossary pg.417

Challenges of Producing More Crop and Livestock

• Domestication and Genetic Diversity– Domestication of crops and livestock causes a loss

of genetic diversity• Farmer selects and propagates animals with desirable

agricultural characteristics

• Many high yielding Many high yielding crops are genetically crops are genetically uniformuniform

• High likelihood that High likelihood that bacteria, fungi, bacteria, fungi, viruses, etc. will viruses, etc. will attack and destroy attack and destroy entire cropentire crop

Dutch Belted Cow now very rare in Netherlands where it originated

• Increasing Crop Yield

Challenges of Producing More Crop and Livestock

• Food production Food production increased in increased in developed developed countries countries (wheat (left)(wheat (left)

• PesticidesPesticides• Selective Selective

breedingbreeding

Green Revolution

• The production of more food per acre of cropland by using modern cultivation methods, and the new high yielding varieties of crops

• Norman Borlaug 1940-1950’s credited with the start of G.R.

• Worked with wheat• Awarded Nobel Prize in 1970 for his work

Problems with the Green Revolution

• Critics argue that developing countries now rely on imported technologies

• High energy costs associated with the higher crop yields (requires fossil fuels)

• Environmental problems associated with inorganic fertilizers and pesticides

Case-In-Point Green Revolution

• High Yielding Rice Varieties

Traditional(a);High yield dwarf variety(b); very high yield, dwarf-thick stock variety(c)

• Increasing Livestock Yields– Hormone supplements• US and Canada do this• Europe does not citing human health concerns• Studies have shown that hormones could cause cancer

– Antibiotics• 40% of antibiotics produced in US are used in livestock

operations• Gain 4-5% more weight with antibiotics• Problems with increased bacteria resistance (MRSA)

Challenges of Producing More Crop and Livestock

Antibiotic Use and Resistance

Environmental Impacts of Agriculture

• High use of fossil fuels and pesticides– Air pollution

• Untreated animal wastes and agricultural chemicals– Water pollution– Harms fisheries

• Insects, weeds, and disease-causing organisms developing resistance to pesticides– Contaminate food supply

Colorado Potato Beetle has become resistant to most pesticides that are used

Environmental Impact of Agriculture

• Land degradation– Decreases future ability of land to support crops

or livestock• Habitat fragmentation– Breakup of large areas of habitat into small,

isolated patches• Cultivating marginal lands– Irrigating dry land– Cultivating land prone to erosion

Solutions to Agricultural Problems- Sustainable Agriculture

Sustainable Agriculture

• Examples:– Natural Predator-prey relationships instead of

pesticides (lady bug and aphids)– Crop selection (insect resistant varieties)– Crop rotation and conservation tillage– Supplying nitrogen with legumes– Organic agriculture

• Integrated Pest Management (IPM)– Limited use of pesticides with sustainable

agriculture practices

• Manipulation of genes by taking specific gene from a cell of one species and placing it into the cell of an unrelated species

Genetic Engineering

Issue with Genetically Modified Organisms (GMOs)

• Determined to be safe for human consumption

• Concerns about GMO seed or pollen spreading in wild

. Monarch Butterfly/Super Weeds• Backlash against GMOs• GMOs are not currently labeled– FDA finds it would be counterproductive and

expensive to label

Fisheries of the World- Problems

• Ocean Pollution - dumping ground– Oil– Heavy metals– Deliberate litter dumping– Stormwater runoff from cities and agricultural

areas• Aquaculture– Growing of aquatic organisms for human

consumption– Great potential to supply food

Fisheries of the World- Problems

• No nation lays claim to open ocean– Resource susceptible to

overuse and degradation• Overharvesting– Many species are at point of

severe depletion– Cod (right)– 62% of world’s fish stock

are in need of management action

MR PLATT, OVERHARVESTING COD IN ALASKA

Fisheries of the World- Problems

• Overharvesting (continued)– Sophisticated

fishing equipment– Bycatch killed off– Magnuson

Fisheries Conservation Act

Fisheries of the World- Problems• Aquaculture (continued)

– Locations of fisheries may hurt natural habitats (removing mangroves for shrimp)

– Produce waste that pollutes adjacent water (lots of fish waste in a relatively small area)

Aqualture used for shrimp is the single largest factor responsible for mangrove habitat loss