MA Envirothon

SoilsGlenn Stanisewski, Soil Resource Specialist, USDA-NRCS

West Wareham, MA

Soil Formation

• Horizonation – the A, B, C’s of soils• A horizon = Topsoil• B horizon = Subsoil• C horizon = Substratum or Parent Material

Soil Horizons

Soil Properties

• Soil Texture• Soil Color• Rock Fragments – Gravel, Cobbles, Stones• Depth to Bedrock• Soil Structure• Depth to Water table

USDA-NRCS Davis, CA 5

Soil Texture• The % of sand, silt, &

clay in a soil sample• There are 12 USDA

Soil Texture Classes• Influences soil

erodibility.• Influences Water

Infiltration Rates.

Example of Soil Texture Chart

USDA-NRCS Davis, CA 7

Soil Structure• How Soil Particles

(sand, silt, clay) bind together to form larger units = PEDS

Granular

Blocky

Single-Grain

Soil Color

• A soil property that is used to indicate other soil chemical & physical properties

• Some of these are:– Water table depth– Organic matter content– Soil Mineralogy– Carbonate/Gypsum

content

What Colors Can Tell Us

• Grey Colors & Orange Colors– Can be indicators of Shallow water tables

• Black/Dark Brown Colors– Can indicate high organic matter contents

• Red Colors– Can indicate hematite iron mineralogy

• White Colors– Can indicate high carbonate/gypsum levels

Match the sample to the Chip

• Match a small, moist sample to the paint chips using the holes on the page.

• The arrow is pointing to the 10YR 4/4 chip = dark yellowish brown.

Soil Interpretations – What the Soil Properties Tell Us

• Drainage Class – Depth to water table• Hydric Soils – Wetland Areas• Flooding/Ponding Duration & Frequency• Depth to Bedrock – Building limitations

Drainage Class

• Very poorly drained – w.t. at surface• Poorly drained – w.t. at 1.0 ft from surface• Somewhat poorly drained – 1.0 – 1.5 ft.• Moderately well drained – 1.5 ft – 3.0 ft.• Well drained – w.t. > 5.0 ft.• Somewhat excessively drained – w.t. > 5.0• Excessively drained – w.t. > 5.0 ft.

Hydric Soil

•Poorly & Very Poorly Drained Soils.

•Found in Wetlands.

•Grey & Orange colors at 12” indicate seasonal high water table.

•Support wetland vegetation.

Black over gray;stay away. Drainage Classes often follow aLandform pattern.

Flooding

Ponding

Shallow to Bedrock

Soils and Geography

• Soils found in MA and HI are as different as the states of MA and HI

Crops

Cranberries Macadamia Nuts

Pop CultureCheers Hawaii 5-0

CoffeeDunkin Donuts Kona Coffee

MA & HI Soils are also differentMA – Paxton (Inceptisol) HI - Oxisol

Why Are They Different?

• Soils are a product of 5 Soil Forming Factors.

• Differences in these 5 factors results in different soils occurring in different places.

• Soils can differ from State to State, from Town to Town, or even from the Top of the Hill to the Bottom of the Hill.

5 Soil Forming Factors• Soil = fx (cl, org, pm,

topog., time)

– Soils are the result of climate, organisms, geologic parent material, relief, and time.

– Differences in any one or more of these factors results in different soils at different locations.

Topography - Soils & Landforms = A Pattern

A

B

CA B

C

B

A

Soil Parent Material• New England Soil Parent Materials

– Glacial till (ice deposited materials)• Lodgement (dense till, drumlin landform)• Ablation (loose till, rolling hills)

– Glacial Outwash (Meltwater sorted sands & gravels)

– Glacial Lake Bed (stratified silts & clays)– Eolian (Wind blown silts & fine sands)– Alluvium (Floodplain deposits)– Organic (Swamps, Salt Marshes)

Glaciers – Ice deposited materials

Dense Till = Drumlin Landform

Paxton Soil Type

• Dense Till Soil Type – MA State Soil.

• Dense till at 24 inches in profile.

• Soil consists of 3 basic layers: Topsoil, Subsoil, Substratum.

• Divided into A, B, and C horizons.

Ablation (Loose) Till

Moraines – Sandy Loose Till Landform

Canton Soil Profile

• Loose till soil type found in MA.

• Like Paxton soil contains A, B, and C horizons.

• Found on Rolling hills, & undulating landscapes.

GLACIOFLUVIAL - Outwash

Outwash Landform – Kame Terrace

Hinckley Soil Profile

• Consists of stratified layers of sand and gravel.

• Areas often mined for sand & gravel.

• Soils have low Available Water for plant growth.

Glacial Lake Bed Plains

Birdsall Soil Profile

• MA Glacial lake bed soil.

• Consists of stratified silts and clays.

• Iron deposits that indicate seasonal high water table.

• Very poorly drained soil found in wetland areas.

Eolian Landforms (Loess)

Haven Soil Profile

• Soil formed in Loess deposits over Sand & Gravel

• Well drained

• Silt loams = High Water Holding Capacity for plants.

• High AWC = Prime Farmland Soil

Floodplains – River Valleys

Hadley Soil Profile

• MA Floodplain alluvial soil.

• Buried Topsoil layers from flooding.

• Stratified silts and fine sands.

• High AWC = Prime Farmland Soil.

Wooded Swamps – Organic Soils

Freetown – MA Wooded Swamp Soil

• Consists of Muck = Highly decomposed plant material.

• Very Poorly Drained Wetland Soil.

• High amounts of organic C.

• Low Bulk Density (Very Light).

Salt Marsh – Organic Soils

Ipswich – MA Tidal Salt Marsh Soil • Consists of Peat – Partially decomposed salt grass.

• Very Poorly drained. Experiences daily tidal flooding.

• High in salinity.

• Soils often have a rotten egg smell (high in Sulfur).

Hands-on Exercises