1. Objective 15.02 Discuss soil as related to the production of food and fiber.

2. The Importance of Soil Nonrenewable resource –Can not be renewed in one generation Five Duties of Soil –Anchorage –Water –Nutrients –Oxygen for roots –Regulates temperature for plant growth

3. Soil Profile Properties O horizon –Organic layer –Decayed plant and animal debris –Common in forests A horizon-topsoil –Surface layer of soil for judging purposes –Usually contains more organic matter and is somewhat darker in color

4. Soil Profile Properties B horizon-subsoil –Zone of accumulation –Subsurface layer of soil for judging purposes –Most subsoil has an increase in clay content C horizon-parent material (bedrock) –Limestone, sandstone, granite

5. Soil Texture Refers to the size of soil particles –Sand-largest soil particle in soil Sandy soils have problems holding enough water for good plant growth Individual particles can be seen with naked eye –Silt-Intermediate size soil particles but can’t be seen with the naked eye –Clay-smallest particle-clayey soils hold lots of water but maybe airtight, infertile for root growth, and associated with wet soils

7. Desert

8. Prairie

9. Temperate

11. Soil Structure Refers to the way soil particles cling together to form soil units or aggregates, while leaving poor space to store air, water, nutrients, and allow root penetration –Single: grain is associated with sandy soils –Granular: particles cling together to form rounded aggregates-very desirable for all soil uses –Blocky: particles cling together in angular aggregates- typical of soils with high clay content

12. Soil Classification Land capability maps are based on the physical, chemical, and topographical aspects of the land. Land Capability are designated by Roman numerals I – VIII

13. Soil Classification Class I & II: the best land for the most intensive cultivation of field crops with the fewest limitations can be planted year after year. Class VII: very steeply sloped, best used for planting trees Class VIII: best suited for wildlife and recreation.

14. Soil Conservation and Enhancement Two types of erosion –Sheet –Gully No till: cropping technique used to reduce soil erosion –Crops are planted directly in to the residue of a previous crop without plowing of disking –Very effective erosion control

15. Soil Conservation and Enhancement Conventional Tillage: uses tillage system that disturbs the soil surface by plowing, disking, and/or harrowing Conservation Tillage: intermediate tillage system between conventional and no-till Use fertilizer to add nutrients to the soil

16. Soil Conservation and Enhancement Use lime as an amendment to raise soil pH. –Increases availability of nutrients –Example: If soil pH is 5.5, lime may be added to raise soil pH to a more acceptable 7.0 level.