Agriculture and Society: Part IIAgriculture and Society: Part II

PA E & E Standards 4.4PA E & E Standards 4.4

VIII. Farming MethodsVIII. Farming Methods

1. All agriculture ultimately depends on the 1. All agriculture ultimately depends on the soil. soil. What is What is soilsoil??

– SoilSoil is the upper layer of the land surface is the upper layer of the land surface that contains pieces of rock, water, air, that contains pieces of rock, water, air, organic matter, and living organisms.organic matter, and living organisms.

– Where does it come from?Where does it come from?

2.2. Soil comes from the Soil comes from the weathering of surface weathering of surface rocks.rocks.

– Wind, water, organisms Wind, water, organisms and temperature changes and temperature changes break down surface rock. break down surface rock.

– This process is very This process is very slow. Depending on the slow. Depending on the location, it may take location, it may take between 200 to 1,000 yrs between 200 to 1,000 yrs to make just one inch of to make just one inch of new soil. new soil.

– Would you consider Would you consider soil to be a renewable soil to be a renewable or nonrenewable or nonrenewable resource?resource?

3.3. Soil is made out of Soil is made out of several layers:several layers:

a.a. Surface LitterSurface Litter (“O” (“O” Horizon)– recently Horizon)– recently fallen leaves or sticks fallen leaves or sticks that are beginning to that are beginning to decompose.decompose.

b.b. Topsoil Topsoil (“A” (“A” HorizonHorizon) – partially ) – partially decomposed matter decomposed matter (humus), roots, living (humus), roots, living organisms, and some organisms, and some minerals.minerals.

Layers (cont)Layers (cont)

c.c. SubsoilSubsoil (“B” Horizon(“B” Horizon) ) – fine particles of – fine particles of materials leached from materials leached from above, some roots.above, some roots.

d.d. Parent MaterialParent Material (“C” (“C” HorizonHorizon) – weathered ) – weathered bedrock and some bedrock and some leached material from leached material from above.above.

e. e. BedrockBedrock – the – the underlying solid rock underlying solid rock material.material.

4.4. One of the major One of the major concerns in agriculture concerns in agriculture is is soil erosionsoil erosion..

– Some erosion Some erosion happens naturally happens naturally due to the influence due to the influence of wind and running of wind and running water but…water but…

– Human actions also Human actions also cause erosion.cause erosion.• Logging Logging • Livestock grazingLivestock grazing• FarmingFarming

5.5. Since soil is the farmer’s Since soil is the farmer’s most valuable resource, most valuable resource, farming methods have farming methods have developed to reduce soil developed to reduce soil loss.loss.a.a. The greatest cause of The greatest cause of

erosion in farming is erosion in farming is plowingplowing or or tillingtilling. . (breaking up the (breaking up the surface of the soil to surface of the soil to prepare for planting)prepare for planting)

b.b. Some farmers have Some farmers have changed to changed to conservation tillage conservation tillage methodsmethods..

c.c. In conservation tillage, the ground is disturbed as In conservation tillage, the ground is disturbed as little as possible during planting.little as possible during planting.

• One method just loosens the soil without One method just loosens the soil without turning it over.turning it over.

• No-till cultivationNo-till cultivation involves drilling holes into involves drilling holes into the topsoil without loosening or turning over the topsoil without loosening or turning over the soil.the soil.

• Another method uses the leftover stubble from Another method uses the leftover stubble from the previous crop as cover between the seeded the previous crop as cover between the seeded areas of the field.areas of the field.

d. Advantages and disadvantages of conservation d. Advantages and disadvantages of conservation tillage.tillage.

AdvantagesAdvantages• Prevents or reduce soil Prevents or reduce soil

erosion.erosion.• Remaining plant stubble Remaining plant stubble

breaks down to make breaks down to make humushumus. (. (HumusHumus is a is a mixture of decomposing mixture of decomposing organic matter in topsoil organic matter in topsoil that provides nutrients that provides nutrients and holds moisture.)and holds moisture.)

DisadvantagesDisadvantages• Greater use of Greater use of

pesticides to kill pesticides to kill weeds that may weeds that may compete with the crop.compete with the crop.

• Require different Require different machinery from machinery from typical farming.typical farming.

• Change from Change from traditional practices.traditional practices.

e.e. Erosion is sometimes Erosion is sometimes the result of the the result of the topography of the topography of the land.land.

• Ideal farmland is Ideal farmland is flat.flat.

• Real farmland can Real farmland can range from gently range from gently sloping to very sloping to very steep.steep.

• Runoff from Runoff from sloped or steep sloped or steep areas can result in areas can result in loss of valuable loss of valuable soil.soil.

f.f. Farmers reduce erosion on Farmers reduce erosion on sloping land by using sloping land by using conservation methods such conservation methods such as: contour farming, strip as: contour farming, strip cropping, and terracing.cropping, and terracing.

• Contour farmingContour farming is when is when the farming plow and the farming plow and plant their fields across plant their fields across the slope instead of with the slope instead of with the slope.the slope.• Reduces runoff of Reduces runoff of

water and reduces water and reduces erosion from 30 to erosion from 30 to 50%.50%.

• Strip croppingStrip cropping is a method is a method of alternating wide rows or of alternating wide rows or strips of a crop with grasses strips of a crop with grasses or legumes.or legumes.– The grasses or legumes The grasses or legumes

help hold the soil and help hold the soil and water while protecting the water while protecting the soil from wind erosion.soil from wind erosion.

– An added benefit of An added benefit of growing two or more growing two or more crops close to each other crops close to each other is a reduction in pests and is a reduction in pests and plant diseases.plant diseases.

• On very steep hills, On very steep hills, farmers use farmers use terracingterracing to to reduce soil erosion.reduce soil erosion.– In terracing, a series In terracing, a series

of broad, flat ridges of broad, flat ridges are built down the are built down the slope similar to stairs.slope similar to stairs.

– Each ridge holds the Each ridge holds the water and the soil. It water and the soil. It also provides a also provides a relatively flat surface relatively flat surface for planting.for planting.

6.6. Another important part of soil conservation is Another important part of soil conservation is maintaining and restoring the nutrients of the soil.maintaining and restoring the nutrients of the soil.

a.a. The use of fertilizers and crop rotation help restore The use of fertilizers and crop rotation help restore nutrients back to the land. nutrients back to the land.

– FertilizersFertilizers can either be natural organic or artificial. can either be natural organic or artificial.• OrganicOrganic examples include animal manure, green examples include animal manure, green

manure (plant material) or compost.manure (plant material) or compost.• ArtificialArtificial are typically chemical fertilizers made are typically chemical fertilizers made

up of nitrogen, phosphorus, and potassium.up of nitrogen, phosphorus, and potassium.

b. b. Crop rotationCrop rotation is the is the process of changing crops process of changing crops planted in the same field planted in the same field from year to year.from year to year.– Each crop adds or Each crop adds or

removes particular removes particular nutrients.nutrients.

– By varying the crops, By varying the crops, the farmer tries to the farmer tries to minimize nutrient loss.minimize nutrient loss.

– Legume crops are Legume crops are excellent for restoring excellent for restoring nitrogen to the soil.nitrogen to the soil.

7. We have discussed earlier how the green 7. We have discussed earlier how the green revolution has increased the crop yields around the revolution has increased the crop yields around the globe.globe.

a.a. However, at the same However, at the same time, the human time, the human population is continuing population is continuing to increase.to increase.

b.b. The current agriculture The current agriculture of the world produces of the world produces just enough food to meet just enough food to meet the minimal nutritional the minimal nutritional requirements of requirements of everyone on the planet.everyone on the planet.

c. c. Millions of people lack Millions of people lack access to the necessary access to the necessary food.food.

d.d. Many people in Many people in developing countries developing countries suffer from malnutrition suffer from malnutrition and undernutrition.and undernutrition.

• MalnutritionMalnutrition is when is when someone receives someone receives enough daily calories enough daily calories but is lacking essential but is lacking essential protein, vitamins, and protein, vitamins, and minerals in their diet.minerals in their diet.

Why are people still Why are people still lacking food?lacking food?

– UndernutritionUndernutrition is when is when someone does not meet their someone does not meet their daily caloric amount.daily caloric amount.

– Both conditions can lead to Both conditions can lead to lack of development, illness, lack of development, illness, and poverty.and poverty.

– The good news is that both The good news is that both conditions are reversible conditions are reversible with a proper diet.with a proper diet.

e. Many individuals in developed e. Many individuals in developed countries suffer from countries suffer from overnutritionovernutrition or eating more or eating more than their daily caloric amount.than their daily caloric amount.

f.f. So how are we going to So how are we going to meet the needs of a meet the needs of a continually growing continually growing world population?world population?

Consider the following:Consider the following:• Most of the land that Most of the land that

is suitable for is suitable for agriculture is already agriculture is already cultivated.cultivated.

• Most crop yields have leveled off or declined.

• Wetlands are being drained and forests are being cut down to make room for new farmland.

• Many crops are now being used as energy sources for heating and automobiles.

g.g. As a result for this need for food, agriculture has As a result for this need for food, agriculture has caused serious environmental problems.caused serious environmental problems.

• Wildlife habitat is destroyed.Wildlife habitat is destroyed.• Chemical pesticides and fertilizers pollute soil Chemical pesticides and fertilizers pollute soil

and water.and water.• Soil erosion and nutrient loss.Soil erosion and nutrient loss.• Heavy reliance on fossil fuels.Heavy reliance on fossil fuels.• Desertification – when land becomes desert-Desertification – when land becomes desert-

like due to nutrient loss.like due to nutrient loss.• Salinizaiton – when salts build up in the soils Salinizaiton – when salts build up in the soils

due to over-irrigation and become unusable.due to over-irrigation and become unusable.

IX. Food SafetyIX. Food Safety

1. There are always stories in the news about food safety recalls or food contamination.

• What are major sources of contamination?

• Bacteria• Viruses• Chemicals

2. Most food borne contamination results in diarrhea and vomiting. However, they can result in serious illnesses or even death.

3.3. So how do we protect our So how do we protect our food…food…

• There are steps we can There are steps we can take at hometake at home• Thoroughly cooking Thoroughly cooking

raw meats.raw meats.• Washing fruits and Washing fruits and

vegetables.vegetables.• Proper washing of Proper washing of

hands, utensils, hands, utensils, serving dishes, and serving dishes, and kitchen equipment.kitchen equipment.

But how do we know the food But how do we know the food we are buying is safe?we are buying is safe?

4.4. For the most part, food in For the most part, food in the U. S. is safe…largely the U. S. is safe…largely due to the regulations of due to the regulations of three agencies.three agencies.

• USDA (U.S. USDA (U.S. Department of Department of Agriculture)Agriculture)

• FDA (Food and Drug FDA (Food and Drug Administration)Administration)

• EPA (Environmental EPA (Environmental Protection Agency)Protection Agency)

5.5. The USDA ensures food The USDA ensures food safety by safety by

• Inspecting Inspecting slaughterhouses and slaughterhouses and processing plants.processing plants.

• Grading meat and Grading meat and dairy products to dairy products to indicate quality.indicate quality.

• Enforce regulations.Enforce regulations.• Conducting research.Conducting research.• Fostering soil Fostering soil

conservation.conservation.• Education.Education.

6.6. The FDA is concerned The FDA is concerned about:about:

• Truthfulness in food Truthfulness in food labels.labels.

• Safety of food Safety of food packaging.packaging.

• Maintenance of sanitary Maintenance of sanitary conditions in restaurants conditions in restaurants and public eating areas.and public eating areas.

• Safety of dairy products Safety of dairy products and shellfish.and shellfish.

• Label listing of nutrition Label listing of nutrition facts.facts.

7.7. The EPA regulates the use of pesticides on The EPA regulates the use of pesticides on foods.foods.

8.8. Even with all this protective measures, the CDC Even with all this protective measures, the CDC (Centers for Disease Control and Prevention) (Centers for Disease Control and Prevention) estimate 325,000 people go the hospital over estimate 325,000 people go the hospital over food illnesses each year. 76 million people food illnesses each year. 76 million people suffer from some form of mild food poisoning suffer from some form of mild food poisoning and about 5,000 people die each year due to and about 5,000 people die each year due to food illnesses.food illnesses.

X. Important Agricultural X. Important Agricultural Advances.Advances.

1.1. Farming has come a long way over the Farming has come a long way over the past 11,000 years. Farmers now use past 11,000 years. Farmers now use computers, satellite technology, and computers, satellite technology, and genetically modified foods and animals to genetically modified foods and animals to maintain food production.maintain food production.

2. Here are some the important agricultural 2. Here are some the important agricultural advances that made farming easier and more advances that made farming easier and more efficient:efficient:

• Cotton GinCotton Gin (1793) – (1793) – Eli WhitneyEli Whitney – made – made cotton easier to clean.cotton easier to clean.

• Cast-Iron PlowCast-Iron Plow (1797) (1797) - stronger than the - stronger than the wooden plow. Made wooden plow. Made tilling faster and tilling faster and better.better.

• ReaperReaper (1831) – (1831) – Cyrus McCormickCyrus McCormick – – cut the time and labor cut the time and labor to harvest wheat crops.to harvest wheat crops.

• Steel PlowSteel Plow (1837) – (1837) – John John DeereDeere – strong enough to – strong enough to plow the thick soils of the plow the thick soils of the Midwest.Midwest.

• Chemical FertilizersChemical Fertilizers (1849) – allowed farmers (1849) – allowed farmers to replace nutrients in to replace nutrients in depleted soil.depleted soil.

• Transcontinental Transcontinental RailroadRailroad (1869) – opened (1869) – opened up new areas for up new areas for agriculture and trade.agriculture and trade.

• Barbed WireBarbed Wire (1874) – (1874) – ability to fence off fields ability to fence off fields from roaming cattle.from roaming cattle.

• PasteurizationPasteurization (mid- (mid-1880s) - 1880s) - Louis PasteurLouis Pasteur – – killing bacteria and other killing bacteria and other harmful microbes in harmful microbes in dairy products and wines.dairy products and wines.

• TractorTractor (1926) - allowed (1926) - allowed farmers to work the land farmers to work the land faster, leading to increase faster, leading to increase in farm production.in farm production.

3.3. The latest advance in agriculture is The latest advance in agriculture is biotechnologybiotechnology. . BiotechnologyBiotechnology is the is the management or manipulation of living management or manipulation of living organisms for the benefit of people.organisms for the benefit of people.

• Most well-know form is Most well-know form is genetic engineeringgenetic engineering which alters the characteristics of plants and which alters the characteristics of plants and animals by transferring genes.animals by transferring genes.

• Scientists are especially interested in genes Scientists are especially interested in genes that code for desirable traits like: greater that code for desirable traits like: greater nutrients, drought tolerance, salt tolerance, nutrients, drought tolerance, salt tolerance, etc… etc…

Any Questions ?!?Any Questions ?!?

Let’s review….