Land Classification and Use Chapter 8 Land is

Land Classification and Use Chapter 8

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

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

Cropland n Used for growing crops n Crops grown typically improve the tilth of the land

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

Subsurface conditions - Soil textures, hardpans n Pollution - can prevent plant growth n

Alternative Uses n n n 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?

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

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

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

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

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

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

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

Erosion Loss of topsoil by wind or other forces n Four categories n – 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

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

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

Land Capability Classes n n n 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

Classes n 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 n Class II - Good land – has deep soil – may require moderate attention to conservation practices

n Class III - moderately good land – crops must be more carefully selected – often gently sloping hills – terraces and stripcropping are more often used n Class IV - fairly good land – lowest class cultivated – on hills with more slope than class III n 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

n 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 n 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

Class VIII n n n 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