Presentation by: Alex Hezik

 Parent material (rock or sediments deposited by wind, water, or ice) is weathered to form soil  Soil separates are classified below the size of small stones; include  gravel/cobble/boulder (particles larger than 2.0 mm)  sand (made up of particles from 2.0 to mm)  silt (made up of particles from to mm)  clay (made up of particles finer than mm)  Soil texture refers to relative proportions of each type of particle in a given soil  Soil that consists of 40% sand, 40% silt, and 20% clay is called loam

Soil TextureWater Infiltration Water- Holding Capacity Nutrient- Holding Capacity AerationWorkability sandgoodpoor good siltmedium claypoorgood poor loammedium

Soil Horizons O horizon: humus (surface litter, decomposing plant matter) A horizon: topsoil (mixed humus and leached mineral soil) E horizon: zone of leaching (less humus, minerals resistant to leaching) B horizon: subsoil (accumulation of leached minerals like iron oxides) C horizon: weathered parent material (partly broken-down minerals)

 Erosion is the process of soil and humus particles being picked up and carried away by water or wind  Water erosion is broken up into three distinct phenomena: 1. splash erosion (compaction of soil that results when rainfall hits bare soil) 2. sheet erosion (loss of a layer of soil from land surface due to impact of rain and runoff from rainstorm) 3. gully erosion (produced by running water and resulting in formation of gullies)

 When wind removes fine particles from desert soil, a thin surface layer of stones and gravel is left behind, which is a called a desert pavement  Desert pavement protects underlying soil against further erosion  Rainfall-clogged soil that is dried becomes colonized by cryptogams (algae, lichens, and mosses), forming a cryptogamic crust that inhibits water infiltration and seed generation

 Practices that expose soil to erosion and lead to soil degradation include:  overcultivation  overgrazing  deforestation  Sediments that result from soil erosion can clog up streams and rivers, causing sedimentation  Can also build up in groundwater reservoirs, depleting groundwater resources

Laws involving soils include…  Sustainable Agriculture Research and Education (SARE) program: provides funding for investigating ways to accomplish goals of sustainable agriculture  Federal Agricultural Improvement and Reform Act (FAIR): reduced and eliminated subsidies and controls over many farm commodities; ended in failure, resulting in the maintenance of subsidies and controls FAIR initially targeted

 Farm Security and Rural Investment Act of 2002: successor to FAIR that continued to maintain subsidies to farmers  Food, Conservation, and Energy Act of 2008: maintains existing high levels of support and subsidies to farms  Wildlife Habitat Incentives Program (WHIP) and Environmental Quality Incentives Program (EQIP): encourages conservation-minded landowners to set aside portions of their land or address pollution problems