Soil Science Written By Jim Melby Revised By Sam Behrends Winneconne High School Horticulture

The Basics Media-a substance in which you can grow plants Can be soil or a soil substitute Hold moisture Supports the plant Provides nutrients

The Basics Soil: Earthen-based media Sand Silt Clay Organic matter Living organisms Pore spaces (water and ‘air’)

The Basics Soil is classified according to the % of sand, silt, and clay it contains WI State Soil-Antigo Silt Loam

The Basics Particle Size: Sand is the largest Silt is in the middle Clay is the smallest

Pictures

Soil Composition Soils ‘vary’ greatly in general composition due to two main factors Rocks breaking down over thousands of years Materials that have been relocated by water

Organic Matter Top Soil Subsoil Bedrock Soil Profile Organic Matter Top Soil Subsoil Bedrock

Organic Matter Organic Matter is the top layer of most soil profiles Not always present Typically living materials such as sod, weeds, or even moss

Top Soil Contains some organic matter Typically the depth to which you would plow or till Typically the ‘highest quality’ for growing

Subsoil Reached by the deep rooting plants Roots will penetrate deep into subsoil due to the fact that some oxygen does exist A mixture of bedrock and top soil

Bedrock Mostly solid material Hard clay and rocks Little to no root penetration

Ideal Soil 50 percent solid material 50 percent pore space Will be full of valuable minerals Some OM will be present 50 percent pore space Small holes fill with oxygen and water

Eight Physical Properties of Soil 1-Texture How it feels….sandy, silty, or clayey 2-Structure Granular, Platy, blocky, prismatic, columar

Eight Physical Properties of Soil 3-Soil Density Measurement of the physical ‘looseness’ or ‘compaction’ of soil 4-Soil Consistency How well soil sticks together or resists fragmentation

Eight Physical Properties of Soil 5-Pore Space Open volume for air and water 6-Soil Color Can be an estimate of moisture, organic matter (OM), salt, boundaries

Eight Physical Properties of Soil 7-Soil Temperature Regulates germination and root growth 8-Water Content Possibly the most important factor as it relates to all other properties of soil

Properties Influence… Water Intake Water Storage Ease of Tilling or Plowing Amount of Aeration Amount of Fertilization

Chemical Properties Chemical properties of soil are what the soil is made up of. Certain chemical properties make soils better or worse for growing certain plants.