Class Notes AFTER Exam 2 10 22 2014 Soil Considered geology but barely Subset of Regolith o Partially broken up rock o Able to support plant life o Needs to have all of the things plants need to grow Water nutrients organics etc Composition can be widely varied o Minerals 40 50 with rocks o Rocks o Air 25 ish with water o Water o Organics small amounts 1 3 Potentially Renewable processes to make o composting way to solve this How is soil made o Parent material rocks time soil Formation controlled by o 2 5 centimeters of topsoil takes a long time for natural o Climate need warm and wet o Vegetation secrete organic acids for use controls rock weathering and rock weathering controls rate o Parent material o Soil organisms microbes control what plants can use control chemical reactions o Topography o Time Parent Material o Quartzite thin soil o Shale thick soil Topography slope Time Process Regolith Easy to break up in weather wind rain etc o Bad to grow food on even a small slope o Top decaying vegetation O organic layer Living and recently deceased decomposing organisms Color rich brown black Causes plants to grow o A layer Bacteria plant roots Supports plant growth Tends to be darker in color mixing with sediment o B horizon Leaching Absolves acid from A layer Light in color not a lot of nutrients o C horizon Zone of deposition o Unaltered bedrock Parent material Examples of Soil Profits o Diagram in book o Desert Soil hot dry climate Mosaic of closely packed pebbles boulders weak humus material mixture dry brown to reddish brown with variable accumulations of clay calcium Grassland soil semiarid o Tropical rain forest soil humid tropical o Deciduous Forest Soil humid limd climate Forest littler leaf mold humus mineral mixture light grayish brown silt loam dark brown firm clay glacial deposits o Coniferous Forest Soil humid cold climate Acid litter and humus light colored and acidic humus and iron and aluminum compounds o Breaking up of organic material by a number of different Soil Food Webs organisms o All stay in the soil and die there add to organics o Tunnels bring air to soil zone Soil Nutrient Cycling o Diagram in book Soil Loss o Worldwide problem o Current estimate for every kg food eaten 6 kg soil lost o 7 each decade o Erosion Movement of soil Topsoil eroding faster than it forms in about 1 3 of the world s cropland 10 22 2014 Film 10 22 2014 Shorter lifespan than parents Because of what we eat Steve Macko University of Virginia Food eventually goes to hair Corn found in high fructose corn syrup Two men moved to Iowa Plant a single acre of corn o See what happens to it Idea place to grow corn iowa Raising crops without government payment losing money o 28 for telling the government they would be raising an acre of corn o the more you grow the more money you get Farm program 1973 o Drive plenty of food o New philosophy of expansion o Government pays farmer and little farmers get weeded out o Because of ammonia fertilizer can grow 4 times as much corn as grandparents generation o Today not uncommon for single farmer in Iowa to work 1 000 acres o Homesteads disappearing easier when you don t have to maneuver little houses 31 000 kernels to the acre only takes 18 minutes to plant no longer hands on experience o industrialized corn weeds are the biggest issue Commodity corn o Must be processed before we can eat it o Iowa farmer can no longer feed himself o Step 1 bring to town elevator Weigh wagon Dumped into elevator Acre of corn is impossible to track due to volume o Step 2 following corn into food system Game of probabilities 32 exported or turned into ethanol 490 pounds of the acre before sweeteners more than half the crop is fed to animals to become meat 60 of their food is corn the corn would kill the animals eventually corn has replaced grass as principle feed of cattle need cheap feed to do confinements cattle spend more of their lives in confinement gain weight faster if they can t move aren t meant to be on corn based diet for that long succumb to acidosis if untreated animal dies feed lots economic high yields of corn at high efficiency 10 29 Hamburger meat has become fat disguised as meat o Burgers made from corn fed beef cheap and easy to find Investment was made to develop corn sweetener industry o Introduction to corn syrup industry Don t allow cameras into the plants Factories lots of smoke coming out o Process soak corn in water and add sulfuric acid o Lots of technology that goes into sweetener o Blend the corn Corn is cheap Beneficial for people making processed foods to sweeten it with high fructose corn syrup Known to enhance flavors of spices America s consumption of table sugar has fallen Overall consumption of sweeteners has gone up 30 Nearly 70 chance corn ends up as syrup 1 in 8 new Yorkers has diabetes doesn t go away Total cost for acre of corn production 349 92 o Only get back 330 for big yield 200 bushels o Big loss o Farming used to be family operation and now it is commercial People used to spend much more of their incomes on food Earl But s farm program history o We spend less of our income on food than any generation in o Fewer of us needed to produce this food o Abundance brings too much o Industrialized agriculture brings larger operations all the time Part 2 Flood Creek o Waterways are contaminated because of the way herbicides are supposed to work o Chemicals sits on soil until rain absolves them Corn plants can process the chemicals Some that isn t consumed stays in the water Empties into the river Water is cloudy and born Make way into aquaphors 33 million americans exposed to atrozine o erosion can send carbon back to atmosphere and make the soil infertile o soil stores more carbon than the atmosphere danger to environment causes topsoil erosion o farmers rely on phosphate fertilizer and ammonia about 80 of cost of ammonia is in cost of producing natural gas 2000 cubic feet of natural gas burned o runoff from farm enters the Iowa river o Blue baby syndrome o Strips oxygen out of the blood when exposed to excess nitrate by consuming the water o Children in central Iowa subject to hospitalization or death Primary Concern Des Moines drinking water plant Gulf of Mexico Amount of nutrients has increased o Algae is growing more deficit of oxygen on the bottom o Fish can t live won t see crabs snails stingrays sharks etc Health risks Farmers and families exposed Due to pesticide usage cancer increases 10 22 2014 You can radically reduce