Presentation is loading. Please wait.

Presentation is loading. Please wait.

3-1 ATB What is desertification? Today: –Discuss the presentations you will create over the next three days.

Similar presentations


Presentation on theme: "3-1 ATB What is desertification? Today: –Discuss the presentations you will create over the next three days."— Presentation transcript:

1 3-1 ATB What is desertification? Today: –Discuss the presentations you will create over the next three days.

2 Soil Peds How sand, silt and clay are arranged Forms soil structure

3 3-2 ATB What is weathering? Today: –Research! –Is your worksheet done for the class??? (I need them tomorrow, at the latest)

4 3-3 ATB What was the dust bowl? Today: –Last day of research

5 3-4 ATB Is your presentation finished? Today: –Finish presentations –Give me your worksheet / note outline

6 3-7 – 2 hr delay --- No ATB

7 3-8 ATB What is IPM? Today: –Start presenting –I’ll need your rubric for grading your presentation

8 3-9 ATB What are the positive benefits of no-till farming? What could be a negative? Today: –Continue the presentations

9 3-10 ATB Where do some carnivores begin eating large prey animals? Today: –Continue with presentations

10 3-14 ATB Which is the worst type of erosion? Splash, Rill or Sheet erosion? Today: –Finish soil conserv and degradation –Start Tarek / Elliot presentation –Planet Earth…

11 3-15 ATB What is the most effective irrigation method? Today: –Continue with presentations

12 3-16 ATB What is salinization? How does it occur? Today: –Sir-Oly and J. Mutch present

13 3-17 ATB What was one benefit and one problem with the green revolution? Today: –Continue with presentations Quiz Monday on the first 3 presentations

14 3-18 ATB How long ago do we believe agriculture began? Today: –Get Soil Samples –Lab Quiz Monday –Ch 9 Quiz Monday (Tarek & Elliot – presentation posted?)

15 Soil Lab –HOMEWORK: –Soil Samples Find an area at your house that indicative of normal soil (IE, do not dig the soil out of a compost heap) Dig at least 6 inches down (no more then 10 inches) Get a a sandwich bag full of soil (write you name on the bag) –Read background on Soil Formation & Properties Quiz on the reading Monday (so yes, two quizzes on Monday)

16 3-22 ATB What was the green revolution? Today: –Ch 9 quiz –Lab background quiz –Tomorrow – start soil lab

17 3-24 ATB - none Soil Lab Today: –Get out your lab procedure –Get a piece of paper to make observations 5 observations from mechanical weathering 2 observations from the chemical weathering Make the applicable observations for the Soil Texture and Soil Consistence activities –Do not spray each other with the spray bottles –Make sure everything is cleaned up before you leave

18 3-25 ATB What is shaking the rock samples supposed to be simulating? Today: –Finish the mechanical weathering section of the lab –Set up the chemical weathering portion of the lab

19 3-28 ATB What is a monoculture? Today: –Finish the chemical weather part of the lab

20 3-29 ATB What were the three things that make up soil? Today: –Testing soil types

21 3-30 ATB What are some examples of problems caused by overgrazing? Today: –Finish the last two presentations –Thursday – Finish soil lab

22 3-31 What is aquaculture? What is one pro and one con? Today: –Lab: Finish “Determining Soil Consistence” Set up the “Soil Organization”, but do not add the food coloring –Test – next week

23 4-1 ATB Before agriculture, what was our primary means of obtaining food? Today: –Test / study guide -- Wednesday –Finish your lab from yesterday. –Read the Article, “Fighting Over Food” Create 5 questions that can be answered from the article Create 2 “thinking” questions dealing with the article. (due before you leave) –People on Ffaablaah trip: Get a review sheet – due when you get back. Finish your lab questions – skip pages 15 & 16.

24 4-6 ATB Even if no one cared about the dolphins being killed, what is dangerous about this? Today: –Finish “The Cove” –Paragraph or two on your feelings / questions about the movie. (Ie: Is this okay? What about the mercury? Etc) –Work on your review sheet – Test Friday

25 4-7 ATB What is bioaccumulation? Today: –Labs due, article Q’s due, “The Cove” paragraph due –Review – any questions about the test? –Test / Study Guide - Tomorrow –Discuss GM foods in the “Viewpoints” packet

26 4-7 Assignment Pg 259 –#2 –#8 Pg 291 –#1 –#8

27 Article, “Fighting Over Food” –Create 6 questions that can be answered from the article –Answer: Pg 24-25 in Viewpoints packet – Read –Which article do you find yourself siding with? Explain

28 Worksheet example Page # you’re presenting Term: Extra Info:

29 http://wps.aw.com/wps/media/access/Pearso n_Default/4893/5010916/login.html?name=lo uie_hak&errmsg=Invalid+login+name%2Fpas sword+combination+OR+you+don%27t+have +a+subscription+to+this+site.&abbrev=8574http://wps.aw.com/wps/media/access/Pearso n_Default/4893/5010916/login.html?name=lo uie_hak&errmsg=Invalid+login+name%2Fpas sword+combination+OR+you+don%27t+have +a+subscription+to+this+site.&abbrev=8574 LOGIN: APperiod2 PASSWORD: Hakim12345

30 Questions… Get a slice of paper and answer the following… What is no till farming? What are soil horizons? List them What is desertification? What is weathering? Name two factors that lead to the Dust Bowl. What is IPM?

31

32 This lecture will help you understand: The relationship between soils and agriculture Major agricultural developments The fundamentals of soil science Causes and consequences of soil erosion and degradation Principles of soil conservation

33 No-till agriculture in Southern Brazil Southern Brazil’s climate and soils make for bountiful harvests Repeated planting has diminished the productivity of the soil Leaving crop residues on their fields after harvesting and planting “cover crops” reduced erosion, increased yields and cut costs These no-till techniques have benefited everyone

34 Soil: the foundation for agriculture Land devoted to agriculture covers 38% of Earth’s land surface Agriculture = practice of raising crops and livestock for human use and consumption Cropland = land used to raise plants for human use Rangeland or pasture = land used for grazing livestock Soil = a complex plant-supporting system consisting of disintegrated rock, organic matter, water, gases, nutrients, and microorganism –It is a renewable resource

35 Population and consumption degrades soil Feeding the world’s rising human population requires changing our diet or increasing agricultural production Land suitable for farming is running out We must find ways to improve the efficiency of food production Mismanaged agriculture turns grasslands into deserts; removes forests; diminishes biodiversity; and pollutes soil, air, and water –Fertile soil is blown and washed away

36 Millions of acres of cropland are lost each year We lose 5-7 million ha (12-17 million acres) of productive cropland annually

37 Soil degradation has many causes Soil degradation results from deforestation, agriculture and overgrazing Over the past 50 years, soil degradation has reduced global grain production by 13%

38 Agriculture arose 10,000 years ago Agriculture was invented independently by different cultures The earliest plant and animal domestication is from the “Fertile Crescent” of the Middle East –Wheat, barley, rye, peas, lentils, onions, goats, sheep

39 Traditional agriculture Traditional agriculture = biologically powered agriculture, using human and animal muscle power –Subsistence agriculture = families produce only enough food for themselves –Intensive agriculture = produces excess food to sell –Uses animals, irrigation and fertilizer, but not fossil fuels

40

41 Industrialized agriculture is a recent phenomenon Industrialized agriculture = using large- scale mechanization and fossil fuels to boost yields –Also uses pesticides, irrigation and fertilizers –Monocultures = uniform planting of a single crop Green revolution = the use of new technology, crop varieties and farming practices introduced to developing countries –Increased yields –Created new problems and worsened old ones

42 Soil as a system Soil consists of mineral matter, organic matter, air, and water –Dead and living microorganisms, and decaying material –Bacteria, algae, earthworms, insects, mammals, amphibians, and reptiles Since soil is composed of living and non-living matter, it is considered an ecosystem

43 Soil formation is slow and complex Parent material = the base geologic material of soil –Lava, volcanic ash, rock, dunes –Bedrock = the continuous mass of solid rock comprising the Earth’s crust Weathering = the physical, chemical, or biological processes that break down rocks to form soil –Physical (mechanical) = wind and rain, no chemical changes in the parent material –Chemical = substances chemically interact with parent material –Biological = organisms break down parent material

44 Weathering produces soil

45 Other processes affect soil formation Erosion = the dislodging and movement of soil by wind or water –Occurs when vegetation is absent Biological activity includes deposition, decomposition, and accumulation of organic matter –Humus = a dark, spongy, crumbly mass of material formed by partial decomposition

46 A soil profile consists of horizons Horizon = each layer of soil Soil profile = the cross- section of soil as a whole Up to six major horizons may occur in a soil profile –Topsoil = inorganic and organic material most nutritive for plants –Leaching = dissolved particles move down through horizons

47 Soils are characterized in many ways Soils are classified based on color, texture, structure, and pH Soil color = indicates its composition and fertility –Black or dark brown = rich in organic matter –Pale gray or white = indicates leaching Soil texture = determined by the size of particles –From smallest to largest = clay, silt, sand –Loam = soil with an even mixture of the three –Influences how easy it is to cultivate and let air and water travel through the soil

48 Soil texture classification Silty soils with medium-size pores, or loamy soils with mixtures of pore sizes are best for plant growth and crop agriculture

49 Soil structure and pH Soil structure = a measure of soil’s “clumpiness” –Large clumps can discourage plant roots –Repeated tilling compacts soil, decreasing its water-absorbing capabilities –Plowpan = a hard layer resulting from repeated plowing that resists water infiltration and root penetration Soil pH = influences a soil’s ability to support plant growth –Soils that are too acidic or basic can kill plants

50 Cation exchange is vital for plant growth Cation exchange = process that allows plants to gain nutrients –Negatively charged soils hold cations (positively charged ions) of calcium, magnesium, and potassium Cation exchange capacity = a soil’s ability to hold cations, preventing them from leaching, thereby increasing their availability to plants A useful measure of soil fertility Greatest in fine soils

51 Regional differences in soils affect agriculture Rainforests have high primary productivity, but the nutrients are in plants, not the soil –Rain leaches minerals and nutrients deeper into the soil, reducing their accessibility to roots –Swidden agriculture = cultivation of a plot for a few years and then letting it regrow into forest Temperate grasslands have lower rainfall and less nutrient leaching

52 Erosion degrades ecosystems and agriculture Deposition = the arrival of eroded material at its new location Flowing water deposits sediment in river valleys and deltas –Floodplains are excellent for farming But, erosion is a problem because it occurs faster than new soil is formed Erosion increases through: excessive tilling, overgrazing, and clearing forests

53 Soil erodes by several methods Plants protect soils form erosion –Removing plants accelerates erosion Rill erosion moves the most topsoil, followed by sheet and splash forms of erosion Water erosion occurs most easily on steep slopes Erosion in the U.S. declined between 1982 and 2001 –Soil conservation measures Despite conservation measures, the U.S. still loses 6 tons of soil for every ton of grain harvested

54 Various types of soil erosion Splash Sheet Rill Gully

55 Soil erosion is a global problem Humans are the primary cause of erosion –It is occurring at unnaturally high rates In Africa, erosion over the next 40 years could reduce crop yields by half –Coupled with rapid population growth, some observers describe the future of agriculture as a crisis situation


Download ppt "3-1 ATB What is desertification? Today: –Discuss the presentations you will create over the next three days."

Similar presentations


Ads by Google