AGRICULTURE and HUMAN IMPACT on the BIOSPHERE Chapter 6

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WORLD POPULATION Current world population is over _____________ Image from: http://www.sleepbamboo.com/planet_people.jpg WORLD POPULATION World clock Current world population is over _____________ Estimates predict it will reach 9 billion by _______ 7 BILLION 2050 http://www.peopleandplanet.net/

Does this look familiar? What is the Earth’s carrying capacity? ?

SUSTAINABILITY How can we grow enough food for all the people on the planet without destroying the environment? http://www.enjoy.org/hstech/HungerSite02/america/FordSchwartz/ http://ejcw.org/wp-content/uploads/2015/08/640x360-ag-runoff.jpg

Importance of Agriculture By middle of 20th century, despite agricultural advances there were ________________in many parts of the world. Governments and scientists began a major effort to ___________ food production food shortages http://www.enjoy.org/hstech/HungerSite02/america/FordSchwartz/ increase

__________ REVOLUTION GREEN __________ REVOLUTION strains New plant ________ had higher yield & resisted pests 2. Modern farming__________ allowed planting larger areas 3. Chemical ___________ & ___________ boosted crop production and controlled pests techniques fertilizers pesticides http://interactive.usask.ca/ski/media/stills/agriculture/crops/t_plant-breeder.jpg http://www.wfbf.com/media_center/photo_gallery/Soybean%20combine.jpg

HOW DO WE GROW MORE FOOD? Large fields are planted with a single variety year after year = ____________ MONOCULTURE http://imagesource.allposters.com/images/NGSPOD04/107870.jpg

Allows farmers to grow large quantities of food BUT . . . MONOCULTURE Allows farmers to grow large quantities of food BUT . . . http://agronomyday.cropsci.illinois.edu/2003/csrec-welcome/aeriel-view.jpg

But . . . HAS HUGE IMPACT ON ECOSYSTEMS __________ increase yield BUT . . . RUNOFF can cause algal blooms and ____________ Fertilizers DEAD ZONES http://www.biology-blog.com/images/blogs/10-2007/fertilizer-15101.gif

But . . . HAS HUGE IMPACT ON ECOSYSTEMS ________ kill insects that damage crops BUT . . . they kill ________ insects too Pesticides beneficial Bees Hand pollination http://cms1.good.is/posts/full_1289265646pesticides.jpg http://www.fllt.org/content/uploads/2014/12/1-Honey-Bee-001.jpg

_____ was first modern insecticide Example: _____ was first modern insecticide It was cheap, stayed active for long time, and killed many different insects Used to control agriculture pests and disease carrying _______________ DDT MOSQUITOES http://www.michigan.gov/images/mosquito_65147_7.jpg

http://www. ci. cypress. ca http://www.ci.cypress.ca.us/public_works/stormwater_images/kids_watershed.jpg When DDT was sprayed, runoff carried it into rivers and streams in LOW concentrations. http://www.geocities.com/~greyhawk_1/sh_eagle-9.jpg DDT then passes into organisms through the ___________, is stored in _______, and doesn’t ___________. http://www.geocities.com/~greyhawk_1/sh_eagle-9.jpg food chains tissues degrade

→ → BIOLOGICAL MAGNIFICATION ______________________________ = the ____________ of a harmful substance ____________as it passes to organisms at _______________levels in food chain or web. concentration increases higher trophic Plants pick up DDT from water & store it Herbivores eat plants and store some DDT Carnivores eat herbivores and store more DDT → →

The wide spread use of DDT threatened many species… especially fish eating birds like osprey, brown pelican, and bald eagles. DDT causes birds to lay eggs with ___________ shells so eggs would break when sat on. American Bald Eagle was declared endangered in 1967. It has since been reclassified as _____________________ http://image10.webshots.com/11/3/94/67/2146394670011493049pwlCDV_ph.jpg fragile “threatened”

told of DDT’s harmful effects. http://www.kimball.k12.sd.us/Heroes%20Web%20Page/Pictures/Rachel%20Carson.jpg In 1962, American biologist _______________ published the book,_____________ which told of DDT’s harmful effects. The book led to a large public outcry and eventually resulted in DDT being _________ in the United States in the 1970’s The book was one of the important events in the birth of the _________________________. Rachel Carson Silent Spring banned environmental movement

But . . . HAS HUGE IMPACT ON ECOSYSTEMS Wearing away of topsoil = _________ is caused by plowing land and removing plant roots Soil erosion http://coweeta.ecology.uga.edu/coweeta_photographs/erosion.htm

But . . . HAS HUGE IMPACT ON ECOSYSTEMS http://i.telegraph.co.uk/multimedia/archive/02075/COW_2075448c.jpg ________ from feedlots and fields can contaminate surface and ground water ____________ happens to clear trees for beef farms Raising cows uses lots of ______ and releases ________ into the atmosphere increasing climate change. Runoff Deforestation water methane

Impact of Agriculture ______________ = changing of fertile land in dry climates into desert areas caused by farming, overgrazing, and drought Desertification http://4.bp.blogspot.com/-Pao2Oe2O_W0/U5F99ppqiII/AAAAAAAAAlY/rlbQFoR4b2c/s1600/invisible+fences+1.jpg

But . . . HAS HUGE IMPACT ON ECOSYSTEMS Many Midwest states rely on the _________ aquifer for their water needs. We are using water faster than the ______cycle can replace it. Evidence indicates this aquifer may _________ within 20-40 years. OGALLALA water run dry http://www.suu.edu/faculty/bowman/Econ1740/HeilbronerZinn/ogallala_aquifer_map_pic_2.gif

HOW DO WE HELP? technology Modern_________ is changing how farmers farm and lessening the impact on the environment. EX: __________ imaging _____ technology enable farmers to only apply chemicals where__________ Satellite GPS needed

HOW DO WE FIX IT? “No-till” ________ keeps plant residue in fields Reduces __________ and protects ecosystems from runoff soil erosion http://cbarc.aes.oregonstate.edu/images/no-till.jpg

HOW DO WE FIX IT? Planting legumes, alfalfa, grasses and other __________ keeps plants on soil between food crops - reduces __________ and protects ecosystems from runoff - reduces ______ - reduces need for fertilizer Cover crops soil erosion weeds

HOW DO WE FIX IT? Crop rotation ______________ alternates what is crops are planted each year. - helps control ________ without pesticides - alternating with __________ replenishes soil nutrients without fertilizer insects legumes

HOW DO WE FIX IT? Controlled grazing ________________ = managing graze periods and herd densities - improves nutrient cycling - retains water - ________ desertification prevents http://www.uaex.edu/farm-ranch/animals-forages/images/006.jpg

HOW DO WE FIX IT? Biological __________ pest control uses natural predators like insects or spiders to kill insects instead of chemical pesticides Biological http://static.dudeiwantthat.com/img/outdoors/garden/1500-live-ladybugs-11829.jpg

HOW DO WE FIX IT? Contour plowing _______________ = on hilly areas, plowing is done across the hill rather than straight up and down - prevents soil _______ from runoff Contour plowing erosion http://images.slideplayer.com/24/7068759/slides/slide_25.jpg

WHAT CAN YOU DO? - Eat _____ meat - Don’t ______ food ~ 1/3 of all food produced worldwide, ($1 trillion) gets lost or wasted ~ US avg: 20 lbs/person/month wasted LESS Per capita/year waste Food waste http://teacherweb.com/CA/NogalesHighSchool/mespinoza/fig50EnergyPyramid.jpg http://languagesoftheworld.info/wp-content/uploads/2014/10/Meat-consumption-World.jpg

WHAT CAN YOU DO? Be aware of ___________ water Water the is used to produce products that we don’t know or don’t think about INVISIBLE The PRODUCTION OF: 1 kg wheat costs 1,300 L water 1 kg rice costs 3,400 L water 1 kg eggs costs 3,300 L water 1 kg beef costs 15,000 L water 1 cotton shirt costs 2,500 L water 1000 g of blue jeans costs 10,850 liters water 1 ton passenger car costs 400,000 liters of water Building a house uses about 6 million liters of water Change the way you think Change the way you think about your laptop