Agriculture

1. Agriculture Soils By: Fernanda Arroyo

2. Agriculture • Agriculture: is the practice of raising crops and livestock for human use and consumption Currently agriculture is covering 38% of the total earth’s land surface to both raise crops and feed livestock. Cropland: land used to raise plants Rangeland: land used for grazing livestock.

3. Soils • Soils: a complex system consisting of disintegrated rock, organic matter, water, gases, nutrients, and microorganisms. • Healthy soil is vital for agriculture. Productive soil is a renewable resource

4. What is Soil Composed of? • Soil is composed of 50% of mineral matter and up to 5% organic matter. The organic matter in soil includes living and dead microorganisms as well as decaying material derived from plants and animals.

5. Soil Formation • Parent Material: is the base geologic material in a particular location. It can be hardened lava or volcanic ash; rock or sediment deposited by glaciers; wind-blow dunes; sediments deposited in riverbeds, floodplains, lakes, and the ocean; or bedrock. Then parent material is broken down by weathering.

6. Soil Formation Cont. • Weathering: is the physical, chemical, and biological processes that convert large rock particles into smaller particles Once it has fine particles biological activity will do its job through deposition, decomposition and accumulation of organic matter.

7. Soil’s Layers • O Horizon: consist mostly of organic matter deposited by organisms. • A Horizon: it has some organic material mixed with mineral components. • E Horizon: it is where minerals and organic matter tend to leach out. • C Horizon: it has largely parent weathered parent material. • R Horizon: pure parent material.

8. What Affects Soil? • Amount of rain • Temperature • Population densities

9. Soil Degradation • Soil degradation: is a deterioration of soil quality and decline in soil productivity. It results from forest removal, cropland agriculture and overgrazing livestock.

10. Erosion • Erosion: is the removal of material from one place and its transport toward another by the action of wind or water. Erosion is a natural process that can help create the soil, however it is often a problem for ecosystems and agriculture because it generally occurs more quickly than soil is formed Erosion removes topsoil

11. Soil Erosion as a Global Problem • Human activities move over 10 times more soil than all other natural processes on the surface of the planet combined. More than 19 billion ha of the world’s croplands suffer from erosion and other forms of soil degradation resulting from human activities.

12. Desertification • Desertification: describes a form of land degradation in which more than 10 % of productivity is lost as a result of erosion, soil compaction, forest removal, overgrazing, drought, salinization, climate change, water depletion, and other factors. Desertification endangers the food supply of more than 1 billion people in over 100 countries.

13. The Dust Bowl • A drought made worse the ongoing human impacts, and the region’s strong winds began to erode million of tons of topsoil. • The most affected region in the Great Plains became known as the Dust Bowl which forced thousands of farmers off their lands. Area affected by the Dust Bowl

14. U.S. Congress passed the Soil Conservation Act of 1935. • They established the Soil Conservation Service (SCS). Currently named Natural Resources Conservation Service.

15. Soil Management • A number of farming techniques can reduce the impacts of conventional cultivation on soils and combat soil degradation.

16. Crop Rotation • Crop Rotation: is the practice of alternating the kind of crop grown in a particular field from one season or year to the next.

17. Contour Farming • Contour Farming: is the practice of plowing furrows sideways across a hillside, perpendicular to its slope, to help prevent the formation or rills and gullies.

18. Terracing • Terracing: is the cutting of level platforms, sometimes with raised edges, into steep hillsides to contain water from irrigation and precipitation. *Transforms slopes into series of steps like a staircase.

19. Intercropping • Intercropping: planting different types of crops in alternating bands or other spatially mixed arrangements.

20. Shelterbelts • Shelterbelts: a row of tress or other tall perennial plants that are planted along the edges of farm fields to break the wind and thereby minimize wind erosion.

21. No-till Farming • No-till Farming: it does not involve tilling (plowing, disking, harrowing, or chiseling) the soil. The most extreme form of conservation tillage.

22. Overgrazing • Overgrazing: the consumption by too many animals of plant cove, impeding plant re-growth and the replacement of biomass. It can cause damage to soils, natural communities and land’s productivity for further grazing.

23. Agricultural Subsidies • Many nations spend billions of dollars in government subsidies to support agriculture. **1/5 of the income of the average U.S. farmer comes from subsidies**

24. Soil Conservation • The Conservation Reserve Program was established in the 1985 farm bill. • It pays farmers to stop cultivating highly erodible cropland and instead place it in conservation reserves planted with grasses and trees • Besides reducing erosion the Conservation Reserve program generate income for farmers, improves water quality, and provides habitat for wildlife.

25. Soil Conservation Cont. • Internationally, the United Nations promotes soil conservation and sustainable agriculture through a variety of programs led by the Food and Agriculture Organization (FAO).