Soils 101- Physical properties

Soils 101- Physical properties It’s more than just “dirt”

Introduction – Why should I care?

Introduction – Why should I care? Different soil types have unique properties

Introduction – Why should I care? Different soil types have unique properties Those properties, along with environment, affect tree survival and growth

Introduction – Why should I care? Different soil types have unique properties Those properties, along with environment, affect tree survival and growth Planting the wrong tree for the site is a waste of time and $

Introduction – Why should I care? Different soil types have unique properties Those properties, along with environment, affect tree survival and growth Planting the wrong tree for the site is a waste of time and $ Soil physical properties – the first thing to know about a site

Photos courtesy of Dave Hopkins, NDSU Barnes soil Photos courtesy of Dave Hopkins, NDSU

Photos courtesy of Dave Hopkins, NDSU Barnes soil Bowdle soil Photos courtesy of Dave Hopkins, NDSU

Soil components

Soil components Solids and pores

Soil components Solids and pores Solids – Minerals + Organic matter

Soil components Solids and pores Solids – Minerals + Organic matter Pores – Water + Air

Soil components Solids and pores Solids – Minerals + Organic matter Pores – Water + Air Ideal soil – Even mix of solids and pores ...

Mineral 45% Organic 5% Brady, 1990

Soil components Solids and pores Note: Solids – Minerals + Organic matter Pores – Water + Air Ideal soil – Even mix of solids and pores ... Note: Minerals – Sand (largest), silt, clay (smallest)

Soil components Solids and pores Note: Solids – Minerals + Organic matter Pores – Water + Air Ideal soil – Even mix of solids and pores ... Note: Minerals – Sand (largest), silt, clay (smallest) Pores – Even mix of water and air

Soil components Solids and pores Note: Solids – Minerals + Organic matter Pores – Water + Air Ideal soil – Even mix of solids and pores ... Note: Minerals – Sand (largest), silt, clay (smallest) Pores – Even mix of water and air Organic matter is good stuff ...

Organic matter Holds onto water Great source of nutrients Binds soil particles together into larger aggregates

Texture

Texture Relative amount of sand, silt and clay only

Texture Relative amount of sand, silt and clay only Lots of one part – soil named by that part

Texture Relative amount of sand, silt and clay only Lots of one part – soil named by that part e.g., 20% sand, 20% silt, 60% clay – clay

Texture Relative amount of sand, silt and clay only Lots of one part – soil named by that part e.g., 20% sand, 20% silt, 60% clay – clay e.g., 12% sand, 82% silt, 6% clay – silt

Texture Relative amount of sand, silt and clay only Lots of one part – soil named by that part Mixtures are called loams

Texture Relative amount of sand, silt and clay only Lots of one part – soil named by that part Mixtures are called loams e.g., 40% sand, 40% silt, 20% clay – loam

Texture Relative amount of sand, silt and clay only Lots of one part – soil named by that part Mixtures are called loams e.g., 40% sand, 40% silt, 20% clay – loam e.g., 33% sand, 33% silt, 34% clay – clay loam

Texture triangle

Example: 20% sand 60% clay 20% silt

Example: 20% sand 60% clay 20% silt

Example: 20% sand 60% clay 20% silt

Example: 20% sand 60% clay 20% silt

Example: 20% sand 60% clay 20% silt Clay soil

Example: 62% sand 15% clay 23% silt ???? soil

Example: 62% sand 15% clay 23% silt sandy loam soil

Texture Relative amount of sand, silt and clay only WHY SHOULD I CARE?

Texture Relative amount of sand, silt and clay only WHY SHOULD I CARE? Different soil types have unique properties Those properties, along with environment, affect tree survival and growth Planting the wrong tree for the site is a waste of time and $

Pore Space

Pore Space Size matters

Pore Space Size matters – macropores and micropores

Pore Space Size Macropores – large, water drains easily

Macropores Brady, 1990

Pore Space Size Macropores – large, water drains easily Micropores – small, water held tightly

Macropores Micropores Brady, 1990

Pore Space Size Texture effects Macropores – large, water drains easily Micropores – small, water held tightly Texture effects

Pore Space Size Texture effects Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Sands – lots of macropores

Pore Space Size Texture effects Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Sands – lots of macropores Clays – lots of micropores

Pore Space Size Texture effects Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Sands – lots of macropores Loam – mixture of macro- and micropores Clays – lots of micropores

Effect on infiltration and water availability? Pore Space Size Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Sands – lots of macropores Loam – mixture of macro- and micropores Clays – lots of micropores Effect on infiltration and water availability?

McLaren & Cameron

Steady infiltration rate inches/hour Textural class Steady infiltration rate inches/hour Sands >0.8 Sandy loams 0.4-0.8 Loams, fine sandy loams 0.2-0.4 Clay loams, silty clay loams and clays 0.04-0.2 Sodic clay soils <0.04 Hillel, 1982 An Introduction to Soil Physics

Water drains out of macropores Brady, 1990 Water drains out of macropores

Water drains out of macropores Brady, 1990 Water drains out of macropores Water held tightly in micropores

Water drains out of macropores Brady, 1990 Water drains out of macropores Water held tightly in micropores

Water drains out of macropores Brady, 1990 Water drains out of macropores Effect of soil texture on available water? Water held tightly in micropores

Water drains out of macropores Brady, 1990 Water drains out of macropores Water held tightly in micropores

Pore Space Size Texture effects Where do roots grow? Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Where do roots grow?

Brady, 1990

Pore Space Size Texture effects Where do roots grow? Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Where do roots grow? “Bulk density” – an indicator of pore space

Bulk density = (Weight of soil particles) (Volume of soil (solids + pores))

Bulk density = (Weight of soil particles) High bulk density Low pore space Low bulk density High pore space Bulk density = (Weight of soil particles) (Volume of soil (solids + pores))

Pore Space Size Texture effects Where do roots grow? Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Where do roots grow? “Bulk density” – an indicator of pore space Compaction – Decreases pore space, esp. macropores Increases bulk density

Pore Space Size Macropores – large, water drains easily Micropores – small, water held tightly Continuity – Water drains better if soil texture is consistent and continuous

The sponge example The sponge example The sponge example

Pore Space Another way to look at it is Size Macropores – large, water drains easily Micropores – small, water held tightly Continuity – Water drains better if soil texture is consistent and continuous Another way to look at it is Water does not move well from one soil texture to another

Pore Space Another way to look at it is Size Macropores – large, water drains easily Micropores – small, water held tightly Continuity – Water drains better if soil texture is consistent and continuous Another way to look at it is Water does not move well from one soil texture to another Ever heard of the “teacup effect”?

Pore Space Size Texture effects Where do roots grow? Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Where do roots grow? “Bulk density” – an indicator of pore space WHY SHOULD I CARE?

Pore Space Size Texture effects Where do roots grow? Macropores – large, water drains easily Micropores – small, water held tightly Texture effects Where do roots grow? “Bulk density” – an indicator of pore space WHY SHOULD I CARE? Different soil types have unique properties Those properties, along with environment, affect tree survival and growth Planting the wrong tree for the site is a waste of time and $

Applications

Applications What trees can survive on sandy soils?

Drought-tolerant deciduous shrubs silver buffaloberry caragana common lilac silverberry

Drought-tolerant hardwood trees green ash Russian olive Siberian elm bur oak

Drought-tolerant conifers Rocky Mountain juniper ponderosa pine Eastern red-cedar

Applications What trees can survive on sandy soils? What species can survive on wet, poorly drained soils?

Native trees and shrubs commonly found in wet, poorly drained soils. American elm green ash boxelder American linden willows cottonwood ironwood (hophornbeam) chokecherry redosier dogwood juneberry False indigo

What species will NOT survive in wet, poorly drained soils? Colorado (blue) spruce common lilac ponderosa pine

Applications What trees can survive on sandy soils? What species can survive in wet, poorly drained soils? What happens to pore space when a soil gets compacted?

Brady, 1990

Applications What trees can survive on sandy soils? What species can survive on clay soils? What happens to pore space when a soil gets compacted? Bulk density increases (total pore space decreases) Greater percentage of micropores

Applications What trees can survive on sandy soils? What species can survive on clay soils? What happens to pore space when a soil gets compacted? Bulk density increases (total pore space decreases) Greater percentage of micropores Soil compaction  reduced tree health Might need to break up compacted soils

Colorado blue spruce in the yard at a rural farmstead Colorado blue spruce in the yard at a rural farmstead. And whatever is killing this tree is “moving down the row.”

Colorado blue spruce in the yard at a rural farmstead Colorado blue spruce in the yard at a rural farmstead. And whatever is killing this tree is “moving down the row.”

Colorado blue spruce in the yard at a rural farmstead Colorado blue spruce in the yard at a rural farmstead. And whatever is killing this tree is “moving down the row.”

Colorado blue spruce – the issue is soil fill from construction of the new home resulted in the roots of these trees being covered, thus killing the roots, and therefore the trees.

Applications What trees can survive on sandy soils? What species can survive on clay soils? What happens to pore space when a soil gets compacted? Bulk density increases (total pore space decreases) Greater percentage of micropores Soil compaction  reduced tree health Might need to break up compacted soils

Soils 101- Physical properties It’s more than just “dirt”  Questions?

Back to the canning jars ...

Sand Clay Silt

Back to the canning jars ... Measure height of each component Fill in calculations Determine soil texture

Component Height (inches) Component Percent Sand Clay Silt A B +C _____ D (A/D) x 100 ________% (B/D) x 100 (C/D) x 100 +______% 100%

Soil samples Sample Soil type WSG % clay A Williams/Bowbells loam 3 (1) 18-27 B Bowdle/Lehr loam 6G 10-27 C Bearpaw/Zeeland loam 4 D Parnell silty clay loam 2 27-40 E Zahl/Williams loam 10 (3) F Heimdal loam ? G Greenhouse loam N/A H Play sand I (G + H)

Before we even begin ...

Before we even begin ...

Before we even begin ... Place soil sample in jar

Before we even begin ... Place soil sample in jar Add 1 teaspoon of Calgon

Before we even begin ... Place soil sample in jar Add 1 teaspoon of Calgon Add water to within ~1/2” of top

Before we even begin ... Place soil sample in jar Add 1 teaspoon of Calgon Add water to within ~1/2” of top Fasten lid and band

Before we even begin ... Place soil sample in jar Add 1 teaspoon of Calgon Add water to within ~1/2” of top Fasten lid and band Shake for ~1/2 minute

Before we even begin ... Place soil sample in jar Add 1 teaspoon of Calgon Add water to within ~1/2” of top Fasten lid and band Shake for ~1/2 minute LET IT SIT ...

Soils 101- Physical properties Introduction Components Texture Pore space Applications