Envirothon Soils K4: Soils, Land Use, and Society

Land Capability Classification (LCC) System

categorizes land into 8 classes for agricultural purposes based on suitability for sustained cultivation, risk of erosion/soil damage, and the most intensive long-term use for the land

Criteria:

• slope

• texture of soil

• depth of soil material

• drainage

LCC Class I

Land suitable for cultivation and other uses

Soils that have few limitations restricting their use. Lowest management risk. may be safely used for intensive production (continuous row crops, pasture, woodland, wildlife habitat)

• nearly level

• very low erosion hazard

• deep

• well-drained

• easily worked, hold water well, naturally fertile/responsive to fertilizer

LCC CLass II

Land suitable for cultivation and other uses

Soils that have some limitations, reducing the choice of plants or requiring moderate conservation practices(special tillage methods). conservation practices easy to apply. can be used for crops, pasture, woodland, wildlife habitat.

one or more limitations:

• gentle slopes

• slight wind/water erosion hazard

• moderate soil depths

• occasional damaging overflow

LCC Class III

Land suitable for cultivation and other uses

Soils that have moderate limitations that reduce the choice of plants or require special conservation practices, or both. conservation practices more difficult to apply/maintain. can be used for crops, pasture, range, woodland, wildlife habitat.

one or more limitations:

• moderate slopes

• moderate wind/water erosion hazard

• moderately shallow rooting depth

• wetness

• moderately low moisture holding capacity

LCC Class IV

Land suitable for cultivation and other uses

Soils that have severe limitations that restrict the choice of plants, require very careful management, or both. conservation practices more difficult to apply/maintain. can be used for crops, pasture, woodlands, wildlife habitat.

one or more limitations:

• steep slopes

• severe wind/water erosion hazard

• shallow rooting depth

• wetness

• low moisture holding capacity

LCC Class V

Land generally NOT suitable for cultivation (without major treatment). Suited for pasture, woodland, and wildlife.

Soils that have little or no erosion hazard, but have other limitations, impractice to remove, that limit their use largely to pasture, range, woodland, or wildlife food cover.

LCC Class VI

Land generally NOT suitable for cultivation (without major treatment). Suited for pasture, woodland, and wildlife.

Soils that have severe limitations that make them generally unsuited for cultivation and limit their use largely to pasture or range, woodland, or wildlife food and cover. can be used for crops with specific conservation and agronomic practices (drainage, stone removal). conservation practices needed for all land uses

one or more limitations:

• steep slopes

• severe wind/water erosion

• shallow rooting depths

• excessive wetness

• low moisture capacity

• stony

LCC Class VII

Land generally NOT suitable for cultivation (without major treatment). Suited for pasture, woodland, and wildlife.

Soils that have very severe limitations that make them unsuited to cultivation and that restricts their use largely to pasture, woodland, or wildlife. need to use carefully for pasture (impractical) and improve for woodland/wildlife habitat. needs careful conservation.

• stony/sandy on moderate slopes

• any soil on very steep slopes (>30%)

LCC Class VIII

Land generally NOT suitable for cultivation (without major treatment). Suited for pasture, woodland, and wildlife.

Soils and landforms that preclude their use for commercial plant production and restrict their use to recreation, wildlife, water supply, or aesthetic purposes. Highest management risk. can use for wildlife production. reserved for non-soil areas

one or more limitations that cannot be overcome

• erosion/erosion hazard

• stones

• very low moisture capacity

Identifying LCC

1. non-soil areas (river wash, quarries, dumps) —> VIII

if not:

2. Stony soils (>20% slope) —> VII
   Stony soils (0-20% slope) —> VI

if not:

3. water table within 36 in of surface —> use chart on front

if not:

4. dominant texture = sand/lomay sand
   0-6% slope —> IV
   6-12% slope —> VI
   >12% slope —> VII

if not:

5. all other soils —> use this chart (slope range —> soil texture —> soil depth)

Soil health

the continued capacity of a soil to function as a vital, living ecosystem that sustains plants, animals, and humans. —> views soil as a living ecosystem home to bacteria, fungi, and other organisms

ways soil ecosystems can be managed

• cycling nutrients

• absorbing/draining/retaining rainwater and snowmelt for dry periods

• filtering and buffering water to remove pollutants

  • providing habitat for soil biological population to flourish and diversify

four soil health principles

1. minimize disturbance (protect)

2. maximize soil cover (protect)

3. maximize biodiversity (feed soil organisms)

4. maximize presence of continuous living roots (feed soil organisms)

protecting soil habitat

minimize disturbance & maximize soil cover

maintain/increase stable soil aggregates and soil organic matter (SOM) —> protect surface of the soil (susceptible to wind/water degradation)

soil cover buffers against temperature fluctuations —> less stress to plants and organisms, reduces evaporation, increases infiltration

SOM stabilizes soil aggregates —> increased water infiltration, drainage, and storage; increased nutrient-holding capacity and release —> incresed habitat for organisms

feeding the soil organisms

maximize biodiversity & maximize presence of continuous living roots

more diversity of food + aboveground plants/animals —> more diversity of soil organisms —> breaks disease cycles, makes habitat for pollinators, stimulates plant growth

eliminate fallow + diverse crop rotation + cover crops + grasslands —> maximize presence of continuous living roots —> breaks disease/pest cycles + maintain/increase SOM content + enhance nutrient cycling

soil disturbances

physical: tillage, compaction

chemical: fertilizer, pesticide

biological: intro of invasive species, use of monocultures, over-grazing (compaction, reduction of perennial root systems)

soil cover

1. living plant canopy (growing crop, cover crop, grassland)

   1. mulch (dead plant material - crop residues, prunings, thatch - or amendment - compost, bark chips)

healthy soil functions

• effective nutrient cycling

• carbon + nutrient storage in organic matter

• good aeration for root growth

• improved farm/ranch resiliency/profitability

• improved yield stability

• runoff/erosion reduction

• improved water storage & plant available water (also protect WQ)

• drought/heavy rainfall/temperature extreme resilience

• disease/pest reduction

conservation crop rotation

grow diverse crops in a planned sequence to increase organic matter and biodiversity

increase nutrient cycling, manage pests, reduces erosion, holds soil moisture, adds microbe diversity

cover crop

grow unharvested crop as part of planned rotation for conservation benefits

increase organic matter, prevent erosion, conserve moisture, increase nutrient cycling, provide nitrogen for plants, suppress weeds, reduce compaction

no till

grow crops w/o disturbing soil with tillage

improve water holding capacity, increase organic matter, reduce erosion, reduce energy use, reduce compaction

mulch tillage

use tillage methods where soil surface is disturbed by maintains high levels of crop residue on surface

reduce wind/rain erosion, increase moisture, reduce energy use, increase organic matter

mulching

apply plant residues to soil surface to compensate for loss of residue from excessive tillage

reduce wind/rain erosion, moderate temperatures, increase organic matter, control weeds, conserve moisture, reduce dust

nutrient management

manage soil nutrients to meet crop needs while minimizing impact on environment/soil

increase plant nutrient uptake, improve physical/chemical/biological soil properties, budget/supplies/conserves nutrients for plant production, reduce odors/nitrogen emissions

pest management

follow an ecological approach to manage for pests that promotes healthy plant growth while increasing stress on pests and enhancing habitat for beneficial organisms

reduce pesticide water contamination, reduce chemical air contamination, decreases pesticide risk to pollinators/other beneficial organisms, increase organic matter

The Dust Bowl - 1930s

environmental disaster resulting from poor farming practices and policies on the Great Plains

plowing + removal of native grasses + overgrazing + drought —> wind erosion (huge sand/dust storms up to east coast)

fertile grassland —> desert