Chapter 19 Agricultural and Related Technology · Jethro Tull developed the first horse drawn seed...

Chapter 19Agricultural andRelatedTechnology

Did You Know?

� The following important events tookplace in the history of agriculture:� Jethro Tull developed the first

horse drawn seed drill in 1701.� The first steam-powered plow-

ing was done in 1830.� The first successful combine har-

vester was developed in 1836.� The first successful gasoline

tractor was developed in 1892.� The average American eats this

amount of the following foodseach year:� About 300 pounds of fruit.� About 420 pounds of vegetables.� About 200 pounds of meat,

poultry, and fish.� About 10 pounds of nuts.� About 200 pounds of flour and

cereal products.

ObjectivesThe information given in this chapterwill help you do the following:� Explain what agriculture is.� Name the two major types of

agriculture.� List the six major groups of crops

grown on farms.� Describe the seven main types of

machines used in growing andharvesting crops.

� Label the five main types of live-stock farms.

� Give examples of how technologyis used in aquaculture.

� Summarize how biotechnologycan be used in agriculture.

� Identify five methods of foodpreservation used today.

� Paraphrase the definition of artifi-cial ecosystem.

435

Key WordsThese words are used in this chapter. Do you knowwhat they mean?

agriculturaltechnology

agricultureanimal husbandryanimal scienceaquacultureartificial ecosystembalerbiotechnologycombinecropcultivatordiscdrip irrigationforestrygenetic engineering

gene splicinggrain drillharrowharvesthydroponicsirrigationpest controlpivot sprinklerplantplant scienceplowsprinklerswathertillagetractor

Early nomads are thought to havebecome the world’s first farmers. Theyplanted seeds of certain grasses forfood. These grasses produced a newcrop we now call grain. These peoplebuilt villages as they waited for theseeds to grow and ripen. All this tookplace about ten thousand years ago. Ithappened in several places, includingareas that are now Jordan, Iraq, andTurkey. The villagers tended the cropswith crude hoes and bone sickles (cut-ters). This was some of the first tech-nology people developed.

Today, modern farming uses bothscience and technology. Science isused in cross-pollinating crops andcrossbreeding livestock. These typesof science are called plant science and

animal science. Likewise, science isused to describe the seasons. Scientificknowledge of weather helps guideplanting and harvesting. Technology,however, has caused massive changesin farming. See Figure 19-1. New andmodern machines and equipmentallow fewer people to grow more food.Technological advances have helpedpeople preserve and store food for lateruse. These and other advancements arepart of agricultural technology.

What is agriculture? It is using sci-ence and technology in planting,growing, and harvesting crops andraising livestock. Agriculture includesusing materials, information, andmachines to produce the food and nat-ural fibers needed to maintain life.

436 Section 4 Technological Contexts

Figure 19-1. Technology has greatly changed farming. This pea combine harvests green peas.

Types of Agriculture

Agriculture takes place on thefarms and ranches of the world. SeeFigure 19-2. Agriculture is also prac-ticed on small plots of land calledgardens.

Agriculture has two main bran-ches. Crop production grows plants forvarious uses. It provides human food,animal feed, and natural fibers to meetdaily needs. Crop production producesingredients for medicines and indus-trial processes. It provides plants forlandscaping needs. Crop productionproduces trees for ornamental andwood product needs.

Animal husbandry involves breed-ing, feeding, and training animals.These animals are used for food andfiber for humans. In some cases, theyare used to do physical work. Manyanimals are raised for pleasure. Theyare used in hobbies, for riding, and in racing.

Agricultural Crops The crops raised today have

evolved from specific regions of theworld. Corn, beans, sweet potatoes,white potatoes, tomatoes, tobacco,peanuts, and sunflowers came fromNorth and South America. China and

Chapter 19 Agricultural and Related Technology 437

Figure 19-2. Crops and livestock are grown on farms and ranches. (U.S. Department ofAgriculture)

central Asia gave us peas, sugar cane,lettuce, onions, and soybeans. Sugarcane, rice, citrus fruits, and bananascame from Asia. The Middle East,southern Europe, and North Africagave us the common grains. Thisregion also was the home of sugar beets,alfalfa, and most grasses. Crops can bedivided into several major groups:� Grains. These are members of the

grass family grown for their edibleseeds. See Figure 19-3. This groupincludes wheat, rice, corn (maize),barley, oats, rye, and sorghum.Grains are the main food energysource for about 75 percent of theworld’s population. All the grainscan be used in processed humanfood. Also, they can be used to pro-duce oils, such as soybean, corn,and canola oils. Grains are widelyused for animal feed.

� Vegetables. Plants grown for theiredible leaves, stems, roots, andseeds are called vegetables. See

Figure 19-4. These plants provideimportant vitamins and mineralsfor the daily diet. Vegetables includeroot crops, such as beets, carrots,radishes, and potatoes. They also


Figure 19-3. Grains are a major food crop. (Deere and Company)

Figure 19-4. These watermelons are avegetable crop. (U.S. Department ofAgriculture)

include leaf crops, such as lettuce,spinach, and celery. Other vegetablesprovide food from their fruit andseeds. This group includes sweetcorn, peas, beans, melons, squash,and tomatoes. Vegetables such ascabbage, cauliflower, and broccoliare called cole plants. Vegetables arewidely grown on commercial farmscalled truck farms.

� Fruits. Other plants cultivated fortheir edible parts are called fruitsand berries. See Figure 19-5. Theyinclude apples, peaches, pears,plums, and cherries, which aregrown in temperate climates. Citrusfruits (oranges, lemons, limes,grapefruits, and tangerines), olives,and figs are grown in warmer

climates. Tropical fruits includebananas, dates, and pineapples.Smaller fruits and berries includegrapes, strawberries, blackberries,blueberries, raspberries, and cran-berries. Fruits are grown on farmscalled orchards or berry farms.

� Nuts. Plants grown for their hard-shelled seeds are called nuts. Theyinclude walnuts, pecans, almonds,filberts (hazelnuts), coconuts, andpeanuts. All, except peanuts, aregrown on trees in orchards.Peanuts grow underground onplants grown on farms.

� Forage crops. Plants grown for ani-mal food are classified as forageplants. These plants include the haycrops, such as alfalfa and clover.


Figure 19-5. These apples are almost ready to be harvested.

Also grasses used for pasture andhay are included in this group.

� Nonfood. Plants are grown foruses other than food. These plantsinclude tobacco, cotton, and rub-ber. They also include nurserystock grown for landscape use andChristmas trees.

Technology inAgriculture

Crops, like all living things, have alife cycle. They are born when seedsgerminate. Crops grow and reachmaturity. They can be harvested orallowed to die. Farming takes advan-tage of this cycle through fourprocesses. These include planting,growing, harvesting, and, in somecases, storing. See Figure 19-6. Theedible parts of many crops areprocessed into food. For example,wheat can be processed into flour.

Flour can be further processed, withother ingredients, into bread.

At one time, growing crops waslabor-intensive. It took many people to grow the food and fiber peopleneeded. Today, technological advance-ments allow a few people to grow foodfor many people in a relatively shortperiod of time. Farming has becomeequipment-intensive. New tools andmachinery have been designed tomake work easier and more produc-tive. Fewer people are involved withproducing food now, but more peopleare needed for processing, packaging,and distributing it.

Growing crops involves a numberof technological devices and systems.These specialized pieces of equipmentare used to improve the production of food, fiber, fuel, and other usefulproducts. These devices can be dividedinto the following classifications:� Power (pulling) equipment.� Tillage equipment.


Figure 19-6. These are the processes in growing crops.

Growing

Storing

HarvestingPlanting

� Planting equipment.� Pest control equipment.� Irrigation equipment.� Harvesting equipment.� Storage equipment.

Power, or Pulling,Equipment

People tamed and trained animalsto pull loads in the Stone Age. By3,500 B.C., oxen were used to plowfields. Until the twentieth century,animals provided the majority of thepulling power needed in farming. SeeFigure 19-7. During the 1900s, thetractor replaced animal power on mostfarms. In the early 1900s, the modern

all-purpose tractor was developed. By the 1950s, there were more than 3.5 million of these tractors in use.Today, the farm tractor can be foundin all parts of the world. These devicesprovide the power to pull all types offarm equipment. There are two basictypes of tractors: wheel tractors andtrack machines. See Figure 19-8. Bothof these types of machines have thefollowing features:� A power source (engine).� A way to transmit the power

(transmission and drive train) forpulling a load.

� A method of controlling speed anddirection.

� Traction devices (wheels or tracks).


Figure 19-7. Up until the mid-1900s, horses, mules, and oxen provided pulling power neededon farms. (U.S. Department of Agriculture)

� An operator’s area (seat, cab, andcontrols).

� A hitch onto which equipment canbe fastened.

Tillage EquipmentTillage equipment is designed to

break and pulverize the soil. It devel-ops a seedbed for the seeds and plants.The cornerstone of tillage is the mold-board plow. It can be traced back to treebranches and antlers used to prepare

the soil. In the 1800s, iron and steelplows were developed. They, like mod-ern plows, had a blade-shaped plow-share that cut, lifted, and turned overthe soil. See Figure 19-9.

Discs (or disc plows) are also usedto prepare the seedbed. Sometimesthese machines are used after theplow. At other times, the disc is usedinstead of a plow to start preparing afield for planting. A disc, like its nameimplies, is a series of curved discs ona shaft. See Figure 19-10. When themachine is pulled through the ground,it slices and crumbles the earth.

Generally, a harrow is used afterplowing and discing are completed. Aharrow is a frame with teeth. Theseteeth may be spikes or spring-shaped.The harrow is dragged over theground to give the soil tilth. Thismeans fine and crumbly soil.

Today, farmers are reducing theamount of tillage they do. This isespecially true on soil that can erodeeasily. This technique is called mini-mum tillage. It uses small amounts of


Figure 19-8. Wheel (left) and track (right) tractors are used on modern farms. Can you see themajor parts of the tractor described in the text? (Deere and Company)

Figure 19-9. A plow is used to cut, lift, andturn the soil. (Case IH)

work to prepare the soil. Often, a setof chisels on a frame is used to openthe soil. In some cases, no-tillage sys-tems are used. In these cases, crops areplanted without working the soil fromthe previous crop. Special plantersslice open the soil and plant the seeds.

Planting EquipmentOnce the soil is prepared, fertilizer

must be applied. Fertilizer is a liquid,powder, or pellets containing impor-tant chemicals. It primarily delivers

nitrogen, phosphorus, and potassiumto the soil. Other nutrients are also inmany fertilizers. Fertilizer can be ap-plied before, during, or after plantingseeds. It may be applied with specialequipment or along with a seedplanter. Often, dry fertilizer is scattered(broadcast) before planting. Liquid andgaseous (anhydrous ammonia) fertil-izer is applied by injecting it into thesoil. A machine with a series of knivesis pulled over the ground. The liquidor gaseous fertilizer is injected into thetrench the knives create.


Figure 19-10. A disc cuts and pulverizes the soil. Note the close-up of the discs on the right.(Deere and Company)

The seeds must be planted to startthe crop cycle. Over most of history,this was done by hand. In the early1700s, however, a new machine wasdeveloped. It was called the seed drillor grain drill. See Figure 19-11. As it ispulled along, it opens a shallow trench,

and then a seed is dropped. The trenchis closed, covering the seed.

Other planting machines have beendeveloped for potatoes and corn. SeeFigure 19-12. Specialized machines areused to plant vegetable plants, such astomatoes and cabbage.

Pest Control EquipmentIn nature, not all plants that sprout

live to maturity. Diseases and insectskill some of the plants. Neighboringplants crowd out others. Farm cropsface the same dangers. A number ofmachines have been developed tohelp control these pests.

Cultivators are used to removeweeds and open the soil for water.These machines are a series of hoe-shaped blades pulled through theground. See Figure 19-13. The bladesbreak the crust and allow rain and irri-gation water to enter the soil. They


Figure 19-11. This shows a grain drill in use.(Deere and Company)

Figure 19-12. This farmer is planting cornwith a six-row corn planter. Fertilizer isapplied from the front hoppers. Corn seed isin the back hoppers. (Deere and Company)

Figure 19-13. This farmer is cultivating a rowcrop (corn). Notice the tank on the front of thetractor. Fertilizer and an herbicide are beingapplied as the plants are being cultivated.(U.S. Department of Agriculture)

also cut off and pull out weeds. (Aweed is any out of place plant.)

Sprays can be applied to controlweeds and insects. Those controllingweeds are called herbicides. Insectsprays are called pesticides. Groundequipment or airplanes can applyboth of these materials. The equip-ment has a tank, a pump, and spraynozzles on a boom. See Figure 19-14.As the plane or ground applicatorcrosses the field, a mist of pest controlis applied.

Irrigation EquipmentIn parts of the world, rainfall is suf-

ficient to raise crops. Many places, how-ever, are too dry for successful farming.In some of these areas, irrigation isused. This is artificial watering to main-tain plant growth.

Irrigation systems can be tracedback to 2100 B.C. The Egyptians devel-oped systems using the water from the

Nile to irrigate crops. Their systems,like all irrigation systems, containedthese elements:� A reliable source of water.� Canals, ditches, or channels to

move the water.� A way to control and distribute the

water.The source of water is usually

a lake, a river, or an undergroundsource (an aquifer). A dam at its outletoften controls water in the lake. A dambacks up river water to form a reser-voir. See Figure 19-15. A well andpump obtain underground water. Aseries of canals and pipes moves thewater from the source to farm fields.One of three basic methods is used toapply the water to the land.

Flood irrigation is used on levelfields and where there is a lot of wateravailable. A sheet of water advancesfrom a ditch across the field. Lateralditches and pipes with holes along their


Figure 19-14. A field is being sprayed from the air with chemicals protecting it from weeds andinsects.

lengths supply the water to one side ofthe field. Gravity causes the water toflow across the field. Other ditches orpipes may carry off excess water. In rowcrops, furrows (small ditches) betweenrows of plants are used. They move the

water from one end of the field to theother. See Figure 19-16. Pipes or tubesare used to control the water enteringeach furrow.

Sprinkler irrigation is used to bet-ter control water. It also uses less water.These systems involve a water source,a pump, main (distribution) lines, lat-eral (sprinkler) lines, valves, and sprin-kler heads. The pump forces water intothe main distribution lines. The waterflows through them to pipes that havesprinkler heads attached at set inter-vals. Valves between the main and lat-eral lines can shut off or control thewater flow. The water in the laterallines enters the sprinkler heads, whichspray water onto the land.

Sprinkler systems may have anumber of straight sprinkler lines.Each line can apply water to a long,narrow band across the field. The


Figure 19-15. This reservoir behind GrandCoulee Dam provides water for powergeneration and irrigation.

Figure 19-16. These strawberry plants are being flood irrigated. (U.S. Department ofAgriculture)

water is allowed to run for a set time.This irrigates the bands on each sideof the sprinkler lines. Then these linesare moved by hand or rolled to thenext position. Here, they apply waterto the next bands.

A large number of straight linesmay be used to cover the entire field.When the lines are turned on, theentire field is irrigated at once. Thiseliminates the need to move individ-ual lines. These lines are called solid setsprinklers.

Other sprinkler systems are calledpivot sprinklers. See Figure 19-17.These systems use one long line. It isattached at one end to a water source.The line pivots around this point onlarge wheels electric motors power. Theline is constantly moving very slowly

in a circle. Sprinkler or mist heads applythe water as the line pivots.

Drip irrigation is the third type ofirrigation. The system uses main linesto bring water near the plants. Indi-vidual tubes or emitters bring waterfrom the main lines to each plant.This ensures each plant is properlywatered. It also reduces the amountof water lost to evaporation.

Harvesting EquipmentOnce a crop reaches maturity, it

must be harvested. Each type of crophas its own special harvesting equip-ment. Combines are used to harvestgrains. See Figure 19-18. A combine isa combination of two early farmmachines: the header (cuts heads fromthe grain) and thresher (removes grain


Figure 19-17. The pivot sprinkler system is irrigating crops. (U.S. Department of Agriculture)

from chaff). The combine cuts off thetops of the plants containing the grain.The heads and straw move into themachine. A cylinder causes the grain tobreak away from the heads. Blasts ofair and screens separate the grain fromstraw, chaff, and weed seeds. The grainis moved into storage hoppers on themachine. The unwanted materials areconveyed out the back of the machineand dropped onto the ground.

Other crops use different harvest-ing machines. A combine or a specialcorn-picking machine can harvestcorn. Mechanical pickers are used toharvest almost all cotton grown in theUnited States. Vegetables may be har-vested by special purpose machines orby hand. See Figure 19-19. Specialmachines dig and collect onions and


Figure 19-18. This combine is harvesting grain on a hillside. Notice that the header (cuttingarea) is at the same angle as the hillside. The machine itself, however, is kept level. This isnecessary to make the grain separation efficient. (Deere and Company)

Figure 19-19. This special purpose machineharvests green beans. It is unloading a batchinto a truck, which will move the beans to afreezing plant.

potatoes. See Figure 19-20. Fruits andgrapes are usually picked by hand andplaced in boxes. Special machinesmay, however, be used. They shake the

trees, causing the fruit to fall intoraised catching frames. Nuts are alsoharvested in this manner.

A series of machines harvests hay.A mover may cut the plants and letthem fall on the ground. After the hayhas dried for a day or more, a rake isused to gather it into windrows (bandsof hay). In other cases, a windrower, orswather, may be used. This machinecuts and windrows the hay in one passover the field. See Figure 19-21. Afterthe hay has dried, it is usually baled. Ahay baler picks up a windrow and con-veys it into a baling chamber. There, thehay is compressed into a cube. Wire ortwine is tied around the cube to main-tain its shape. The finished bale isejected out the back of the machine. SeeFigure 19-22. Special balers have beenproduced to make round bales.


Figure 19-20. This harvesting machine is picking up onions that were machine dug and placedon top of the ground to dry. Workers of this machine separate clods and rocks from the onions.

Figure 19-21. The swather is cutting andwindrowing hay. (Deere and Company)

Storage EquipmentMany crops are stored before they

are sent to processing plants. Grain isstored in silos or buildings at grain ele-vators. See Figure 19-23. Hay is storedin hay barns that are roofs attached tolong poles. These buildings generallydo not have enclosed sides or ends.Many vegetables and fruits are storedin climate-controlled (cold storage)buildings. The crops will be trans-ported to processing plants through-out the country and world, as demandrequires.

Raising Livestock Farmers and ranchers raise large

numbers of livestock. These includecattle, sheep, goats, horses, swine(pigs), and poultry (chickens andturkeys). These animals are primarily

raised to provide meat, milk, or mate-rials for clothing.

In historical time, many farmsraised a few of each of these animals.Today, most livestock are raised onsingle-purpose farms. These farmsinclude the following:� Cattle ranches. They raise beef

cattle for meat and hides.� Dairies. They raise dairy cattle pri-

marily for milk.� Swine farms. They raise hogs for

meats and hides.� Horse farms. They raise horses for

pleasure riding and racing.� Poultry farms. They raise turkeys

for meat and chickens for meat andeggs.A number of different technolo-

gies are involved in livestock raising.


Figure 19-22. This picture shows a bale ofhay leaving a baler. (Deere and Company)

Figure 19-23. These trucks are bringing grainto an elevator for storage.

Specialized equipment and practicesare used in the care of animals. Manylivestock operations require buildingsto house animals and process feed. SeeFigure 19-24. These buildings areerected using construction technology.Livestock production also includesmachines used to feed animals. Feed

processing mills are required. Theycontain machines that grind and mixfeed for the animals. Feed troughs orbunkers are required so the animals caneat grain and hay. See Figure 19-25.Water must be provided using manu-factured pumps and tanks. Finally,machines and equipment are used to


Figure 19-24. These chickens are contained in a large house on a poultry farm.

Figure 19-25. Look at the cattle feedlot. There is a feed mill in the background. Fences containthe animals within a set area. Feed bunkers can be seen in the foreground.

dispose of the animal waste (such asmanure). See Figure 19-26.

Special Types ofAgriculture

There are several unique types ofagriculture practiced in North Amer-ica. The three main types are hydro-ponics, aquaculture, and forestry:� Hydroponics. This consists of

growing plants in nutrient solu-tions without soil. Hydroponicsystems supply nutrients in liquidsolutions, while the plants grow ina porous material.

� Aquaculture. This is growing andharvesting fish, shellfish, andaquatic plants in controlled condi-tions. It uses ponds, instead of soil,to grow its crop. See Figure 19-27.

� Forestry. This includes growingtrees for commercial uses, such aslumber and timber products, paperand pulp, and chips and fibers.

Agriculture andBiotechnology

A specific technology that hasgreatly impacted agriculture isbiotechnology. The term, biotechnol-ogy, is fairly new. The practice, how-ever, can be traced into distant history.Evidence suggests the Babyloniansused biotechnology to brew beer asearly as 6000 B.C. The Egyptians usedbiotechnology to produce bread as farback as 4000 B.C. Both of these activi-ties are directly related to agriculture.

Modern biotechnology can betraced back to at least World War I. Sci-entists used an additive to change theoutput of a yeast fermentation process.The result was glycerol instead ofethanol. The glycerol was a basic inputto explosives manufacturing.

During World War II, the next stridein biotechnology took place. Thisinvolved the production of antibiotics(antibodies). These drugs are also theproducts of fermentation processes.

What is biotechnology? Specifi-cally, biotechnology deals with usingbiological agents and principles in


Figure 19-26. This hog farm contains pens inbuildings and a waste containment lagoon(upper left of photo).

Figure 19-27. These workers are usingequipment to harvest catfish at a fish farm.

processes to produce commercialgoods or services. The biologicalagents are generally microorganisms(very small living things), enzymes (aspecial group of proteins), or animaland plant cells. They are used as cata-lysts in the selected process. The wordcatalyst means they are used to causea reaction. The catalyst does not, how-ever, enter into the reaction itself.

Agricultural biotechnology is atype of biotechnology. It consists oftechniques used to create, improve, ormodify plants, animals, and microor-ganisms. This biotechnology can beused to improve many different activ-ities impacting agriculture.

Biotechnology technology can beused to combat diseases. This was thefirst major use of biotechnology. For

example, insulin used to treat diabet-ics can be produced less expensivelyusing biotechnology. Also, enzymesreducing blood clots can be producedusing biotechnology. Golden rice pro-viding infants in developing countrieswith beta-carotene to fight blindnessis a result of biotechnology. Biotech-nology can be used to promote humanhealth. The nutritional value of foodscan be improved using biotechnologi-cal techniques.

Another use of biotechnology is fighting animal diseases. See Figure 19-28. It was used in develop-ing a vaccine for shipping fever. Thisdisease is a major factor in feedlotdeaths. Biotechnology was also usedin producing a vaccine protecting wildanimals against rabies.


Figure 19-28. Biotechnology can be used to fight diseases in animals.

Biotechnology is a major factor inincreasing crop yields. It has helpedproduce more food on the same num-ber of acres. This factor has allowedfarmers to feed more people using thesame effort. For example, biotechnol-ogy was used to produce soybeansresistant to certain herbicides (weedsprays). Also, it was used to develop acotton plant resistant to major pests.

It can be used to supplement thecommon techniques of selectivebreeding and pollinating. This specificapplication is often called geneticengineering. It enables people to movegenes in ways they could not before.It allows people to develop plants andanimals with desirable traits.

Gene splicing is based on a majordiscovery called recombinant DNA.

The structure of DNA is a doublehelix (spiral) structure. It consists ofa jigsaw-like fit of biochemicals. Thetwo strands have biochemical bondsbetween them.

The DNA molecule may be consid-ered a set of plans for living organ-isms. It carries the genetic codedetermining the traits of living organ-isms. Scientists can use enzymes tocleanly cut the DNA chain at anypoint. The enzyme selected will deter-mine where the chain is cut. Then twodesirable parts can be spliced backtogether. This produces an organismwith a new set of traits. The process isoften called gene splicing.

This process allows scientists toengineer plants having specific charac-teristics. See Figure 19-29. For example,


Figure 19-29. Biotechnology can be used to develop crops yielding more food and resistingdiseases and pests.

resistance to specific diseases can beengineered into the plant. This couldreduce the need for pesticides to con-trol insect damage to crops.

This activity has received manyheadlines in newspapers and maga-zines. It is controversial. Some peoplethink it will make life better. Othersthink we should not change thegenetic structures of living things.

Food Production People must eat to live. We eat

many different kinds of food, pre-pared in a variety of ways. Few cropsproduced through agricultural tech-nology are sold in their natural states.

Most foods have been processed orpreserved in some way by the time weeat them. Food processing is one of themost important of all agriculturaltechnology processes.

Food production is primarily thejob of farmers. Many other people,however, handle the food the farmersproduce before it reaches the con-sumers. After being harvested, mostfood products go to processing plants.Then, the food products must betransported to consumers. The trans-portation chain they follow includestruck, airfreight, and train personnel;food brokers; distributors; foodwholesalers; and finally, food retail-ers, such as your local grocery store.See Figure 19-30.


Figure 19-30. Foods must go through a lengthy transportation chain before you can buy themin your grocery store.

Food ProcessingThe conversion of harvested crops

into food that is ready to eat is calledprocessing. This is not just a singleprocess, however; it includes many dif-ferent processes, which vary depend-ing on the food being processed. At theprocessing plants, skilled workers per-form many jobs, including sorting,washing, peeling, slicing, roasting,grinding, canning, flash freezing, box-ing, cooking, adding preservatives,and packaging.

Early humans ate their food exactlyas they found it. They ate fruits, nuts,leaves, and roots as they gathered them,and they even ate the fish and gamethey hunted without cooking it. Thesepeople began cooking with the discov-ery of fire about 1 million years ago.This is the first way food was processed.

Cooking makes food softer andeasier to digest. The heat kills bacteriathat might cause the food to rot ormake you sick. Most modern cookingappliances use heat from electricity orgas flames. Microwave ovens useradio waves to heat the food.

Some foods are sold ready to eat.Other foods come partly prepared.You must cook these types of foods,such as frozen pizzas, TV dinners, andcake mixes, before you eat them.

Grains are processed in mills. Theycan be ground, sifted, steamed, shred-ded, or toasted. Then they are madeinto products such as flour, bread, andcereal products. See Figure 19-31.Fruits and vegetables must be peeledbefore being processed, and some-times fruits are crushed to make juice.

Milk is processed into whole milk,skim milk, condensed milk, cheese,butter, and cottage cheese.

Some processed foods containadditives. These are chemicals thatimprove the food or keep it from spoil-ing. Preservatives, flavorings, and dyesare all additives.

Food PreservationMost food spoils after a while. Bac-

teria, mold, and insects feed on it.Because food is so important to sur-vival, food preservation is one of theoldest technologies used by humans.Some of these technologies have beenused for thousands of years. Over


Figure 19-31. Grains can be processed intomany popular food items, including bagels.

time, people began to understand whythese methods work. They learnedhow to create the conditions prevent-ing the growth of microorganisms thatspoil food. These are some of the tech-niques used today for preserving food:� Refrigeration and freezing.� Canning.� Dehydration.� Chemical preservation.� Irradiation.Other methods of food preservationinclude freeze-drying, pasteurization,fermentation, carbonation, smoking,and cheese making.

Refrigeration and FreezingRefrigeration and freezing are the

most popular forms of food preserva-tion used today. See Figure 19-32.Long ago, people used to bury food insnow or ice to keep it fresh. This isbecause cold temperatures cause bac-teria to stop growing. Refrigerationslows the growth of bacteria so foodstays fresh longer—usually a week ortwo—instead of spoiling in just a fewhours. Freezing stops bacterial growthall together. It keeps food fresher thanrefrigeration does. These methods areso popular because they have verylittle, if any, effect on the taste andtexture of most foods.


Figure 19-32. The most common form of food preservation is the household refrigerator.

Bacteria stop growing below 14°F,but they do not die. To destroy all bac-teria, food is steamed before freezing.In food preserved in this way, once thefood is thawed, bacteria can growagain.

Vegetables, fish, and poultry arefrozen by dipping the packaged foodsinto tanks of freezing salt water. Thesame process is used to freeze cannedjuices. A spray of liquid nitrogen with atemperature of –320°F freezes more ex-pensive foods, like shrimp. Meat isfrozen by traveling through a tunnel, asfans blow air at a temperature of –40°Fon it. This process is called blast freezing.

CanningCanning uses a cooking process to

preserve food in glass jars or metalcans. It uses heat to remove oxygenfrom the container, kill microorgan-isms in the food, and destroy enzymesthat could spoil the food. During thecanning process, the can or jar is filledwith food. The air is pumped out toform a vacuum, and the container issealed. The food is heated, then cooledto prevent the food from becomingovercooked. This heating inactivatesenzymes that could change the food’scolor, flavor, or texture. Canning isused to preserve many foods, includ-ing fruits, vegetables, jams and jellies,soups, and juices.

DehydrationDehydration is the process by

which foods are dried to preserve them.During this process, most water isremoved from the food. This increasesthe concentrations of salt and sugar,

and these high concentrations kill anybacteria. Dried foods kept in airtightcontainers can last a relatively longtime.

Early humans dried meat and fruitin the sunshine. Today, many foods,such as powdered milk, soup, potatoes,dried fruits and vegetables, beef jerky,pasta, instant rice, and orange juice, can be dehydrated. See Figure 19-33.You may eat them as they are sold, or you may need to add water. Dryingoften completely changes the taste andtexture of foods, but many new foodscreated by dehydration have proven tobe just as popular as the original forms.


Figure 19-33. We eat many foods, such asthese dried cherries, that have beenpreserved through dehydration. (CherryMarketing Institute)

Chemical PreservationPeople have used salt, sugar, and

vinegar to preserve foods, especiallymeat, for thousands of years. Whensalt or sugar is used, the process iscalled curing. The salt or sugar dis-solves in the water in the food andkills the bacteria. Today, this processis most often used to create foods suchas “country ham,” dried beef, cornedbeef, and pastrami. When vinegar isused, the process is called pickling.This process has been used to preservemeat, fruits, and vegetables, but todayit is used almost exclusively for mak-ing pickles, or pickled cucumbers. SeeFigure 19-34.

Today, new chemicals, such asnitrites, benzoates, and sulphites, areused as preservatives. They eitherinhibit the growth of bacteria or killthem. These chemicals can be foundon the ingredient lists of many differ-ent foods. For example, sulfur dioxidepreserves fruits used to make jam,fruit juice, and dried fruits. All of thesechemicals may be harmful if used inlarge amounts. The Food and DrugAdministration (FDA) limits theamounts of these chemicals allowedin foods.

IrradiationIrradiation is the process by which

X-ray radiation is used to kill bacteriain food. This process kills bacteriawithout significantly changing thefood. It can occur after foods have beenpackaged, which is a big advantage. Ifa food is sealed in plastic and then irra-diated, it becomes sterile and can bestored on a shelf without refrigeration

for a long time. The FDA has approvedthe irradiation of chicken and beef. Theuse of this technique could preventmany forms of food poisoning. Largeamounts of radiation must be used,however, and many people are notsure whether or not it is safe. Peoplegenerally do not like the term radiation,so this process is still not very commonin the United States.

Artificial Ecosystems

Artificial ecosystems are human-made complexes reproducing somefacets of the natural environment.They can be used to study agriculturalprocesses and systems as they would


Figure 19-34. One common form of chemicalpreservation turns cucumbers into pickles.


be useful to biological ecosystems.Some examples of artificial ecosys-tems are terrariums and the hydro-ponics stations discussed earlier. Theyfunction as part of a larger closed sys-tem supporting living organisms.

A terrarium is used to nurtureplant or animal life in an enclosed

environment. It acts as a completehabitat using all the systems of life,such as food, water, shelter, and space.Terrariums can be used for decorationand enjoyment, but they can also beused to study the ways in which theelements of an ecosystem depend onone another. See Figure 19-35. Some

1. Seeding trays are selected.

2. Planting mix (soil) isautomatically placed in the trays.

3. Seeds are automaticallyplaced in each cell of thetrays.

4. The soil and seeds aresprayed with water.

5. The moist trays are placedin controlled environmentsuntil seeds sprout.

6. The trays with new plantsare placed in greenhouses.

Technology Explained

landscape plants: Plants grown in a controlled environment.They provide flowers and vegetablesfor home gardeners and landscape contractors. Below is a picture story of how technology is usedto produce these plants.


7. The plants are transplantedinto trays with larger cellsor into plastic retail packs.

8. Throughout the growingprocess, the plants receiveautomatic watering.

9. Light and humidity are con-trolled to produce an idealgrowing environment.

10. The plants are put intogreenhouses when theyare ready for sale.

11. The finished plants areloaded onto carts and madeready for delivery to retailers.

12. The plants are transplantedinto home gardens.

greenhouses can be considered large-scale terrariums, and they can be usedto grow plants and animals in areasdiffering from their natural habitats.

A hydroponics station is used togrow plants without soil. Similar toterrariums, these stations are con-trolled environments supplying the

light, humidity, food, and water theplants need for growth. They are analternative to traditional agriculturefor farmers in areas with poor soil.Using hydroponics stations, farmerscan grow vegetables and other plantsin the middle of a desert or in an alleyin a crowded city.

Managing an artificial ecosystementails collecting facts to plan, orga-nize, and control processes, products,and systems. Operating such a systemnecessitates absolute control and cul-tivation. Temperature, nutrients, light,water, air, circulation, waste recycling,and monitoring of insects all requiremanagement in order for the systemto function well.

Quality Control inAgriculture andBiotechnology

Quality control is critical in agri-culture technology and biotechnology.The U.S. Food and Drug Administra-tion (FDA) regulates food to ensurepublic health. Agricultural processesmust adhere to FDA guidelines. Food

products must be FDA approvedbefore they can be sold.

There are many areas of qualitycontrol. In livestock farming, for ex-ample, the feed given to the animalsmust meet quality standards. The ani-mals must be carefully checked toensure that they have no harmful dis-eases. The preparation of meat for con-sumption must occur in a sanitaryenvironment. In crop raising, crops areinspected for diseases or other signs ofdistress. Fertilizers must be approvedfor use on crops. Fruits and vegetablesare inspected after they are harvested.

Food processing systems also havequality controls in place. Since these sys-tems prepare food for human consump-tion, a breakdown of the quality controlsystem could have health risks for theconsumer. Therefore, the systems mustbe carefully designed to ensure that thefood products do not become contami-nated or spoiled. Food product isinspected as part of the system. Allmaterials the food product contactsmust be kept clean and sanitary.

Summary Agriculture involves growing

plants and animals on farms andranches. It includes crop productionand animal husbandry. It involves theuse of many types of machines. It usespulling, tilling, planting, pest control,irrigation, harvesting, and storageequipment. It also uses structures andequipment to feed and care for cattle,hogs, horses, and poultry. A specialkind of agriculture is aquaculture. It


Figure 19-35. Artificial ecosystems, like this greenhouse, allow plants to grow incontrolled environments. (AgriculturalResearch Service, U.S. Department ofAgriculture)


involves raising fish and plants in con-trolled water environments.

Agriculture often employs biotech-nology. This type of technology appliesbiological organisms to productionprocesses. We use biotechnology toproduce new strains of plants anddrugs.

Technology is also used in food pro-duction. The food agriculture produces

must go through many processesbefore reaching consumers. Technol-ogy is used to make sure the food staysfresh.

Natural agricultural environmentscan be recreated artificially. They maybe used for enjoyment or for educa-tional purposes. Terrariums and hydro-ponics stations are the most commontypes of these artificial ecosystems.

Agricultural Managers

The Job: Agricultural man-agers manage the daily activi-ties of farms, ranches,

nurseries, and other agriculturalestablishments.Their activitiesdeal with running the farm,rather than performing actualproduction activities.They hireand supervise workers, whoperform the production tasks.Agricultural managers deter-mine what crops to plant, over-see production activities, hireworkers, assign duties to work-ers, and oversee maintenanceactivities.

Working Conditions:These managers spend timein the office and in the field,supervising workers. Work forlivestock farm managers iscontinuous throughout theyear. Crop farm managers usu-ally work long hours during the

planting and harvestingseasons. During the rest of theyear, they have a reduced workschedule as they plan for nextseason’s activities.

Education and Training:Growing up on a family farmwas once the major trainingprogram for farmers and farmmanagers. The increasinglycomplex scientific andbusiness aspects of farming,however, require advancededucation from community col-leges or universities. Manyyounger agricultural managershold a bachelor’s degree inbusiness, with a concentrationin agriculture. Additionally, theyoften need farm or ranch workexperience.

Career Highlight


Curricular Connections Social Studies

Science

Activities

1. Select a food you eat. Describe how its basic ingredient was planted,grown, and harvested.

2. Go to a local farm implement dealer or locate an appropriate site on the Internet. Gather information on how a specific piece of farm equipment operates.

3. Build a diorama (model) of a farm. Show the technology used on it.

Develop a timeline for the invention of agricultural equipment. Select one machine and write a report on its inventor, operation, and importance.

Mathematics

Measure the school plot and convert the measurement to hectares and acres.

Research how cross-pollination and crossbreeding are used toimprove animal and plant species.

Science

Mathematics

Research the units of measurement used for agricultural crops.Develop a poster or other display presenting and contrasting these units of measurement.

Research DNA and its application to gene engineering.


Test Your Knowledge Do not write in this book. Place your answers to this test on a separate sheet of paper.

1. What is agriculture, and why is it important?2. What are the two branches of agriculture?3. Members of the grass family that have edible seeds are called _____.4. Grass and hay crops grown for animal feed are called _____ crops.5. The four processes in growing crops using technology are _____, _____, _____,

and _____.6. Growing and harvesting fish in controlled conditions is called _____.7. Using biological agents to produce goods is called _____.8. Producing a new organism by cutting and joining genes is called _____.9. Label the following types of food preservation:

A. Used to preserve pasta, instant rice, beef jerky, and powdered soup. _____B. Can be used to preserve meat, but people are concerned about its

safeness. _____C. Used to make pickles and corned beef. _____D. The most common form of food preservation today. _____

10. Summarize the purpose of artificial ecosystems.

Technology Teachers

The Job: Technology teach-ers help students learn informa-tion and apply concepts aboutthe development, production,and use of technology. Theymust have the ability to select,organize, and deliver appropri-ate material to students.

Teachers must possess excel-lent communication skills andunderstand their subject areawell. They need to know how tohelp students solve problems,work in groups, and documentprogress and solutions.

Working Conditions:These teachers generally workin laboratory-type classroomsequipped with a variety of toolsand machines. They can expe-rience rewards from studentssuccessfully completing work,but they can also become frus-trated from having to deal withunmotivated or disrespectfulstudents. Most teachers workin individual classrooms, caus-ing them to be somewhat

isolated from their colleagues.Many teachers work more than40 hours a week.

Education and Training: Allpublic school teachers need tobe licensed by the state in whichthey teach.Technology teachersmust hold a bachelor’s degreefrom an approved teacher edu-cation program.They must havecompleted a set number ofclasses and completed a prac-tice teaching assignment. Inaddition, most states requireapplicants to pass a basic com-petency test before they receivea teaching license. Also, manystates require teachers to partic-ipate in continuing educationprograms.

Career Highlight

Chapter 19 Agricultural and Related Technology · Jethro Tull developed the first horse drawn seed...

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Transcript of Chapter 19 Agricultural and Related Technology · Jethro Tull developed the first horse drawn seed...