Porous Organic Polymers in Catalysis: Opportunities and Challenges
September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic...
-
Upload
miles-carte -
Category
Documents
-
view
238 -
download
0
Transcript of September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic...
![Page 1: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/1.jpg)
Agricultural Soils
September 9, 2013
![Page 2: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/2.jpg)
What is Soil?
» Soil – What is it?˃ Unconsolidated porous media
˃ Compromised of inorganic (clay minerals and oxides) and organic components (organic matter)
˃ Has distinct physical, chemical, and biological properties
» Soil is dynamic – modified over time by physical, chemical, and biological agents
![Page 3: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/3.jpg)
Midwest Agricultural Soils
» Typically fertile, but poorly drained» Drainage is often facilitated by networks of
artificial, subsurface drains to enhance productivity ˃ about 1 m below the soil surface ˃ can rapidly move excessive water (and
soluble contaminants) to surface waterways
![Page 4: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/4.jpg)
Sediment Movement
» Benefits of soil movement ˃ Nourishes floodplains˃ Creates deltas and islands˃ Replenishes wetlands
» Problems with soil movement˃ Loss of excessive amounts of fertile soil ˃ Decreases the depth of streams, rivers, lakes and
reservoirs+ This can increase water temperature, effecting
aquatic species ˃ Requires increased water purification
![Page 5: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/5.jpg)
Erosion
» Erosion: the wearing away of the land surface by rain or irrigation water, wind, ice or other agents that abrade, detach and remove soil from one point on the earth's surface and deposit it elsewhere
» The cost of water and wind erosion in the U.S. is estimated in billions of dollars each year˃ reduced productivity
˃ soil pollution of water and air
» Soil erosion is a global problem
![Page 6: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/6.jpg)
Organic Matter» Organic matter (OM) improves soil productivity
through physical, chemical, and biological actions» Organic matter is a small fraction (2% to 4%) of
soil -- mainly present on the soil surface» Erosion gradually depletes organic matter which
decreases soil productivity
![Page 7: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/7.jpg)
Effects of a Loss of Organic Matter» Soils tend to lose their physical structure hard,
compacted and cloddy» Soil aeration (water-holding capacity and
permeability) decreases˃ Less oxygen available for plant roots to grow ˃ Less water available for healthy plant growth ˃ Less water can soak into low permeability soils so run-off
increases
» Beneficial organisms are decreased » Suppress disease and break down organic residues˃ Do not function well at low soil oxygen and water levels˃ Reduces soil nutrient storage and supply ability
![Page 8: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/8.jpg)
Impacts of Erosion on Air Quality
» Soil particles blown by the wind into the air have a major impact on human and animal health
» Particles suspended in air by wind are easily inhaled and accumulate in lung tissues causing major respiratory problems
» Concentrated levels of wind blown particles can also reduce visibility and increase the risk of automobile accidents
![Page 9: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/9.jpg)
Factors Contributing to Soil Erosion» List all the factors that you can think of that
contribute to: Soil Erosion by Water Soil Erosion by Wind
![Page 10: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/10.jpg)
Factors Contributing to Soil ErosionWater erosion Wind Erosion
Climate
Soil properties (aggregation/soil moisture)
Soil cover
Land management
Topography Soil surface roughness
Unsheltered distance
Wind velocity and turbulence
![Page 11: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/11.jpg)
The Dust Bowl
» A period of severe dust storms » Caused major ecological and agricultural
damage » Affected American and Canadian prairie lands » 1930 to 1936 (in some areas until 1940)
![Page 12: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/12.jpg)
The Dust Bowl» Causes
˃ Severe drought˃ Decades of extensive farming without conservation to
prevent erosion˃ Deep plowing of the virgin topsoil of the Great Plains
+ displaced the natural grasses that normally kept the soil in place and trapped moisture even during periods of drought and high winds
» During the drought of the 1930s, soil dried, turned to dust, and blew away eastward and southward in large dark clouds
![Page 13: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/13.jpg)
The Dust Bowl
» At times the clouds blackened the sky reaching all the way to East Coast cities such as New York and Washington, D.C.
» Much of the soil ended up deposited in the Atlantic Ocean
» These immense dust storms—given names such as "Black Blizzards" and "Black Rollers"—often reduced visibility to a few feet
» The Dust Bowl affected 100,000,000 acres, centered on the panhandles of Texas and Oklahoma, and adjacent parts of New Mexico, Colorado, and Kansas
![Page 14: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/14.jpg)
Reducing Soil Loss
» What are we currently doing to reduce soil loss?» Have we had any dust storms recently?
![Page 15: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/15.jpg)
Wisconsin Dust Storm
» A massive dust storm that swept through central Wisconsin in late May, 2012
» Causes:˃ Partially the result of an increase in exposed
cropland in the region due to increased cultivation of the central sands region
+ The number of acres of cultivated cropland increased by almost 42 percent from 2005 to 2011
![Page 16: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/16.jpg)
2012 Drought
» The severe drought that hit the Farm Belt did not create another Dust Bowl or widespread crop failure
» Expected average national yields in 2012 would have been records in 1991
» Soil conservation mostly controlled erosion, despite record heat and lack of rain in June and July
» Other reasons for reduced erosion˃ Improved seed quality˃ Improved planting practices ˃ Improved farming technology
![Page 17: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/17.jpg)
Crop Residue
![Page 18: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/18.jpg)
![Page 19: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/19.jpg)
Tillage & Erosion » A tillage system that buries residue and
pulverizes soil leads to high erosion risk» A tillage system that preserves surface residue
and minimizes soil disturbance reduces erosion
![Page 20: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/20.jpg)
Tillage Practices» Conventional tillage creates soil disturbance and mixing » Conservation tillage reduces soil disturbance to a
minimum and keeps more residue from the previous crop at the soil surface
![Page 21: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/21.jpg)
Conservation Practices
» Contour planting» Strip cropping» Contour strip cropping» Grassed waterways
![Page 22: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/22.jpg)
Contour Planting
![Page 23: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/23.jpg)
Strip Cropping
![Page 24: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/24.jpg)
Contour Strip Cropping
![Page 25: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/25.jpg)
Grassed Waterways
![Page 26: September 9, 2013. » Soil – What is it? ˃Unconsolidated porous media ˃Compromised of inorganic (clay minerals and oxides) and organic components (organic.](https://reader033.fdocuments.in/reader033/viewer/2022061609/56649cbf5503460f949853d4/html5/thumbnails/26.jpg)
Reading Assignment
» New Conservation Program Protest Most Highly Erodible Croplands
» Gullies in Long-term No-till Fields can be Troublesome
» The Fate of Our Nation's Soil Resource
» Linked on Assignment webpage» “Due” Wednesday, Sept. 11