Land Classification and Use

1. Land Classification and Use Chapter 8

2. Land is more than soil • Natural and artificial characteristics of an area to be used for agricultural or other purposes • Includes renewable and nonrenewable resources plus improvements

3. Land • The surface of the earth not covered with water • Maybe temporarily or permenently covered with water • A pond for aquaculture is considered land

4. Cropland • Used for growing crops • Crops grown typically improve the tilth of the land

5. Major Characteristics of Cropland • Soil - Large impact on productivity. Soil texture, nutrients and internal structure • Climate - average of water conditions over a long time • Topography - form or outline of the surface of the earth • Water supply - amount of water available for crops

6. Subsurface conditions - Soil textures, hardpans • Pollution - can prevent plant growth

7. Alternative Uses • Best land use is determined by how the land will give the most benefits to people. • Which use will give the highest returns • What will happen if productive cropland is used for other purposes?

8. Land Capability • Suitability of land for agricultural uses. • Usage should not cause damage to the land although nutients maybe removed

9. Arable land • Land that can be used for row crops • Can be tilled • Alternatives include pasture and forest crops

10. Land Improvement • Four common practices to improve arable land • Irrigation • Erosion Control • Drainage • Forming (land forming)- surface is smoothed or reshaped.

11. Soil Tilth • Physical condition of the soil that makes it easy or difficult to work • Poor tilth has hard clod • Maybe very wet or very dry

12. Capability Factors • Characteristics of land that determine its best use • Surface texture • proportion of sand, silt, clay down to about 7 inches • three major classifications • sandy • loamy • clayey

13. Internal drainage • Permeability- movement of water and air through soil • Directly related to nutrient content • Classified as very slow, slow, moderate and rapid • water quickly soaks into sandy soil with high permeability • soils with clay have slow permeability

14. Soil Depth • Thickness of the soil layers • Requirement depends upon type of crop to be produced • Four soil depths are used • very shallow - less than 10 inches • shallow - 10 to 20 inches • moderately deep - 20 to 36 inches • deep - over 36 inches • Shallow soils are often the result of erosion

15. Erosion • Loss of topsoil by wind or other forces • Four categories • very severe erosion- 75% or more and large gullies are present • severe erosion - 75% of soil has eroded but no large gullies present • moderate erosion- 25 to 75% of soil has eroded with small gullies present • none to slight erosion - less than 25% of soil has eroded and no gullies are present

16. Slope • The rise and fall of the elevation of the land • Measured in percents • Important in determining the best use of the land

17. Surface Runoff • Water from rain, snow, or other precipitation that does not soak into the ground • Can be reduced by conservation practices • chopping stalks • terraces • ground cover

18. Land Capability Classes • Assigning a number to land • Eight classes used • I to VIII with I being the best arability • Class I to IV can be cultivated • V to VIII tend to have high slope or low and wet

19. Classes • Class I - Very good land • Very few limitations • deep soil and nearly level • can be cropped every year as long as land is taken care of • Class II - Good land • has deep soil • may require moderate attention to conservation practices

20. Class III - moderately good land • crops must be more carefully selected • often gently sloping hills • terraces and stripcropping are more often used • Class IV - fairly good land • lowest class cultivated • on hills with more slope than class III • Class V - Unsuited for cultivation • can be used for pasture crops and cattle grazing, hay crops or tree farming • often used for wildlife or recreation areas

21. Class VI - Not suited for row crops • too much slope • usually damaged by erosion with gullies • can be used for trees, wildlife habitat, and recreation • Class VII - Highly unsuited for cultivation • has severe limitations • permanent pastures, forestry, wildlife • slope is usually over 12 percent • large rock surfaces and boulders may be found • very little soil present

22. Class VIII • Cannot be used for row crops or other crops • often lowland covered with water • soil maybe wet or high in clay • aquatic crops maybe grown there • used for waterfowl habitat