ecological soil management: an introduction to …

E C O L OG I C A L S O I L MANAG EMEN T :A N I N T R ODU C T I O N T O S O I L S C I E N C E

WASH INGTON S T A T E UN I V E R S I T Y E X T EN S I ON V ER S I ON 2 0 2 0

1 . INTRODUCT ION TO SO I L SC I ENCE BAS ICS

• 1.1 What is soil?

DE S E R T

AGR I CU L TURA L FOR E S T

* U N L E S S O T H E RW I S E N O T E D , A L L P H O T O S A R E C O U R T E S Y O F P X H E R E . C OM


• 1.2 What is in a volume of soil? 49%

24%

23%

1% 3%

Minerals Water Air

Biological Organic matter


• 1.3 What is soil

function?“The excited skin of the earth”

PHO T O C O U R T E S Y : D O U G L A S C O L L I N S


• 1.4 Disciplines of Soil Science

P E D O L O G Y B I O L O G Y

P H Y S I C S F E R T I L I T Y

C H E M I S T R Y

2. SOIL FORMATION, PHYSICAL PROPERTIES, AND NATURAL HISTORY

P H O T O C O U R T E S Y : N A T H A N S T A C E Y

2 . SO I L FORMAT ION , PHYS ICAL PROPERT I ES , AND NATURAL H I STORY

• 2.1 Soil forming factors:

I L L U S T R A T I O N R E C R E A T E D F R OM : H T T P S : / / D A R T M O U T H I G E R T . W O R D P R E S S . C OM / 2 0 1 5 / 0 1 / 2 3 / A N ‐ A P A T I T E ‐ F O R ‐ K E N Y T E /

Wind Blown Loess


• 2.1 Soil forming factors: Parent Material

Volcanic Basalt BedrockGlacial

Wind Blown Loess

SB15SB16


• 2.1 Soil forming factors: Parent Material and …

Alluvial + volcanicVolcanic ash and pumice (white pebbles) from Mt St. Helens eruption deposited over alluvial stream sediment (layers) along the Green River, Gifford Pinchot National Forest

PHOTO COURTESY: NATIONAL ASSOCIATION OF CONSERVATION DISTRICTS (LYNN SUCKOW)

transport parent material.

Aeolian processesWind‐deposited loess in the Palouse, Eastern WA


• 2.1 Soil forming factors: Climate

West Side

East Side

PHOTO COURTESY: STEPHEN BRAMWELL


• 2.1 Soil forming factors: Relief (aka topography)

Bedrock mountains: steep, shallow soils

Glacial moraine: rolling terrain, layered, gravelly soils

Floodplain: flat, layered, fine‐textured soils

PHOTO COURTESY: DOUG COLLINS PHOTO COURTESY: CRAIG COGGER


• 2.1 Soil forming factors: Biological organisms

Organism

PHOTO COURTESY: DOUGLAS COLLINS


• 2.1 Soil forming factors: Time

Inceptisol UltisolPHOTO COURTESY: HTTP://GEO.MSU.EDU/EXTRA/SOILPROFILES/


• 2.1 Soil forming factors: Are humans the sixth factor?

See: Howard, J. 2017. Anthropogenic Soils. Springer International Publishing, Cham, Switzerland.

2 . S O I L F O RMA T I ON , P H Y S I C A L P RO P E R T I E S , AND NA TU R A L H I S T O R Y

• 2.2 Soil texture


• 2.2 Soil texture

0.05mm


2.2 Soil texture

ILLUSTRATION COURTESY: WEBSOILSURVEY.NRCS.USDA.ORG


2.2 Soil texturehttp://www.geologia‐croatica.hr/index.php/GC/article/view/GC.2015.09


2.2 Soil texture

Particle size distribution affects: Drainage Aeration Water retention Nutrient exchange

http://www.geologia‐croatica.hr/index.php/GC/article/view/GC.2015.09


• 2.3 Soil structure

ILLUSTRATION COURTESY: UNIVERSITY OF HAWAII MANOA


• 2.3 Soil aggregation


• 2.3 Soil aggregation

PHOTO COURTESY: JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE, VOLUME: 181, ISSUE: 1, PAGES: 104‐136, FIRST PUBLISHED: 11 AUGUST 2017, DOI: (10.1002/JPLN.201600451)


• 2.3 Soil structure


• 2.4 Soil horizons

Soils are stratified vertically by horizons.

Soils in the same series have similar characteristics.

ILLUSTRATION COURTESY: NRCS.USDA.GOV


• 2.4 Soil horizons

O horizon ‐Mostly organic matter such as decomposing leaves. The O horizon is thin in some soils, thick in others, and not present at all in others.

A ‐(topsoil) Mostly minerals from parent material with organic matter incorporated. A good material for plants and other organisms to live.

B ‐ (subsoil) Rich in minerals that leached (moved down) from the A or E horizons and accumulated here.

C ‐ (parent material) The deposit at Earth’s surface from which the soil developed.

ILLUSTRATION COURTESY: NRCS.USDA.GOV


• 2.5 Typical WA soils

Everett(glacial outwash)

Bow(ash & lake sediment)

ILLUSTRATION COURTESY: SOIL WEB, UNIVERSITY OF CALIFORNIA, DAVISPHOTOS COURTESY: WASHINGTON STATE SOIL ATLAS


• 2.5 Soil survey

https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm

Click to add texthttps://casoilresource.lawr.ucdavis.edu/gmap/

3. SOIL FUNCTION

PHOTO COURTESY: NATHAN STACEY

3 . SO I L FUNCT ION

• 3.1 Definitions of soil function

What does soil do for us?


PHOTO COURTESY: NATHAN STACEY

3.1 Definitions of soil function …



What is degraded soil?

Photo by: Gene Williams, Snohomish County Surface Water Management



Soil can degrade the surrounding environment


• 3.2 Inherent & Dynamic properties

Shrink‐swell clays

Depth to bedrock


• 3.2 Inherent & Dynamicproperties

water air

organicmatter

biology chemistry


• 3.3 Soil biological communities

SE20SE21



Organism Number per gram (dry weight basis)

Bacteria 100 million to 1 billion

Actinomycetes 10 million to 100 million

Fungi 100,000 to 1 million

Algae 10,000 to 100,000

Protozoa 10,000 to 100,000

Nematodes 10 to 100

SB34SE17



Additional soil organism groupings and relative sizeEEco‐system engineers

ShreddersSecondary/higher

consumers

Primary consumers

Body Width (mm)20 2 0.1 0.003 0.001 0.00001

4 . SO I L F ERT I L I TY AND NUTR I ENTS


• 4.1 Soil nutrients and availability

Macronutrients MicronutrientsCarbon (C) 45.00% Chlorine (Cl) 0.01 %

Oxygen (O) 45.00% Iron (Fe) 0.01%

Hydrogen (H) 6.00% Manganese (Mn) 0.005%

Nitrogen (N) 1.50% Boron (B) 0.002%

Potassium (K) 1.00% Zinc (Zn) 0.002%

Calcium (Ca) 0.50% Copper (Cu) 0.0006%

Phosphorus (P) 0.20% Molybdenum (Mo) 0.00001%

Magnesium (Mg) 0.20% Nickel (Ni) 0.000001%

Sulphur (S) 0.20%

Percentages by plant dry weight


• 4.1 Soil nutrient and availability

Cations (+) Anions (‐)

AmmoniumNH4

+Potassium

K+PhosphorusH2PO 4

-

NitrateNO3

‐



ILLUSTRATION COURTESY: UNIVERSITY OF GEORGIA EXTENSION



pHMeasure of how acid or alkaline a substance is (related to H conc.)6.0 to 7.5 ideal for most crops. Blueberries 4.5 to 5.5



Rocks and minerals(parent material)

Organic Matter(litter, amendments, root exudates, protected, etc.)

Surface adsorbed(organo-mineral complexes)

Surface adsorbed(soluble organic molecules)

SO42-

K+

NO3-

Ca2+

NH4+

Mg2+Fe2-

PO4-

Nutrients in solution

BG15


• 4.1 Soil nutrient and availabilityChemical weathering

Very slowly available

Rocks and minerals(parent material)

Mineralse.g.: Hornblende ((Ca,Na)2(Mg,Fe,Al)5(Al,Si)8O22(OH)2)

Potassium Feldspar (KAlSi3O8)

Elements unavailable

Weatheringphysical and chemical Elements available

“nutrients”

K+Ca2+

Mg2+ Fe2-PO4-



Mineralizable

slowly available

ILLUSTRATION COURTESY: SOIL FERTILITY IN ORGANIC SYSTEMS: A GUIDE FOR GARDENERS AND SMALL ACREAGE FARMERS

Organic Matter(litter, amendments, root exudates, protected, etc.)

SO42-

K+

NO3-

Ca2+

NH4+

Mg2+Fe2-

PO4-




Nutrient pool

Quickly available

Surface adsorbed(organo-mineral complexes)

Surface adsorbed(soluble organic molecules)

SO42-

K+

NO3-

Ca2+

NH4+

Mg2+Fe2-

PO4-




Soil Type CEC meq/100g

Sands (light colored) 3 to 5

Sands (dark colored) 10 to 20

Loams 10 to 15

Silt Loams 15 to 25

Clay and clay loams 20 to 50

Organic soils 50 to 100

T Y P I C A L C E C V A L U E S F O R D I F F E R E N T S O I L T E X T U R E S

ecological soil management: an introduction to …

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