Important Soil Characteristics for Restoration Planning and

Management

Physical Properties

• Texture

• Structure

• Porosity

• Bulk Density

• Temperature

• Aeration

Texture

• Sand– Largest particle size:

0.05 – 2.0 µm

• Silt– Middle particle size:

0.002 – 0.05 µm

• Clay– Smallest particle size:

< 0.002 µm

Texture

• Drives moisture holding capacity– Clay holds most water

– Sand holds least water

• Factor in ease of erosion– Sands are most easily

erodedhttp://www.dahlias.net/dahwebpg/Soil/Soil_07.htm

Structure

• How closely bound soil particles are– Aggregate

• Different shapes allow for different density of compaction– Ex. Platy structure

packs more particles than blocky

http://www.soils.agri.umn.edu/academics/classes/soil2125/doc/s3chap1.htm

Structure

• Soil structure is important for root penetration nutrient retention

• Influences erodibility

Profile

• How soil stratifies over time

• Different for different plant communities

• MULL– Forms under

hardwoods

• MOR– Forms under conifers

Bulk Density

• The mass of soil per unit volume– Kg/m3

• As compaction occurs bulk density increases– More soil in the same

area

• High bulk density makes rooting harder

Temperature

• Important for optimum root growth & aerobic/anaerobic processes

• A factor of moisture and aeration

• As temperature increases, so does respiration

Chemical Properties

• pH

• Fertility

• Soil Water

• Leaching/Weathering

• Soil Organic Matter

Porosity

• The total volume of space in a given volume of soil occupied by air or water

• Air space between soil particles = “pore space” http://www.mmm-tech.de/data/pix/bodenquer_en.jpg

Soil pH

• Log 1/[H+]• Plants grow best at

6.5-7.5 • To decrease pH:

– Lime

– Fish meal

– Wood ash

Fertility

• Fertility depends on nutrient status– Soils require specific ratios of nutrients – Key nutrients for fertility are N, P & K

• If soil is impaired by acid deposition:– Use soil amendments such as Ca or Mg which

can raise soil pH

Soil Water

• Water retained within soil pores

• Depends on soil:– Texture

– Porosity

– Bulk density

• Contains nutrients for plant intake

Leaching & Weathering

• How nutrients are added and removed from the soil over time

• Soil parent material inputs nutrients through weathering– When inputs decrease

= stress or pollution present

Soil Organic Matter

• Made up of decomposed organic material– Important for moisture

retention– Nutrients for plants

• C:N ratio– As C increases, N is

depleted by decomposers

Biological Properties

• Macroflora– Plant roots

• Microflora– Bacteria– Fungi

Macroflora

• Plant roots in soil– Coarse

– Fine

Microflora

• Bacteria:– Rhizobium

• Fix nitrogen

– Azotobacter• Members of the

rhizobium family

– Nitrosumonus

Microflora

• Fungi – Mycorrhizal Fungi!

• Ectomycorhizae• Endomycorrhizae

Ectomycorrhizae

• Provides pathogen resistance– Pinaceae

• Pine, Spruce, Firs

– Fagaceae • Beech, Oak

Endomycorrhizae• Does not provide pathogen

resistance• Vascular Arbuscular (VAM)

– Most in NE

• Aceraceae– Maple

• Betulaceae– Birch

• Juglandaceae– Walnut, hickory, butternut

• Salicaceae– Willow, poplar