Soil Amendments Comprehensive List

Photo by Jorge Vivanco
LabColoradoStateUniversity_edu

 An improved way to look at soil! 

CrabappleLandscapExperts picture the soil food web as a living, breathing mass teeming with the roots of living plants, insects, worms, invertebrates, amoeba, bacteria and fungi (both beneficial and pathogenic). All of these living organisms need both moisture and oxygen to stay healthy, along with nutrients and the proper acid/base environment.

There are many options for soil improvement. The LandscapExperts view soil amendments as any material added to the native earth in order to improve its ability to grow plants and create outstanding landscapes. Physical properties such as soil structure, aeration, permeability and water infiltration and drainage, as well as fertility properties such as soil acidity or alkalinity, pH, cation exchange capacity and nutrient levels all play a role. 

Unlike mulch, amendments are thoroughly mixed into the soil. 

Crabapple LandscapEXPERTS divide the list of Soil Amendments into 6 categories: 

1. organic soil conditioners

2. inorganic soil additives

3. mineral nutrient sources

4.  biological inoculants and activators

5. plant stimulants, growth regulators, plant hormones 

6. wetting agents or surfactants (primarily for potting mixes) 

Following is a selected list of some of the materials that can be added to metro-Atlanta’s Georgia red clay.

         

      Organic soil conditioners

Crabapple's Green Recycling Program
turns landscape waste into rich compost.

Organic Compost

Aerated compost tea

Animal manure, aged and well-rotted

Manure tea

Bagged humus and compost

Mr Natural

Nature’s Helper

Mushroom compost

Worm compost

Worm tea 

Seaweed 

Humus

Ground pine bark

Coffee grounds

Blood meal

Bone meal
Alfalfa, Soybean or Cottonseed meal – adds nitrogen, lowers pH

Wood ashes  - quick source of potassium, raises pH

Grass clippings

Wood chips

Straw

Sawdust

Peat moss

Inorganic soil additives or “place holders”

Coarse river sand - NOT the fine builders or bricklayers sand bagged at the big box stores

Granite grit - byproduct of Georgia's granite industry

Pea gravel - inert

Perlite -  heat-expanded mica

Vermiculite - heat expanded mica that holds water and 

Shredded tire chunks

      Mineral nutrient sources

Adding lime to surface of lawn.

Lime - Dolomitic lime is magnesium calcium carbonate

Gypsum – calcium sulfate

Rock Phosphate or Triple superphosphate - slow release does not pollute riversheds

Greensand – iron potassium silicate aka glauconite

Sulfur - acidifies the soil 

Epsom salts – magnesium sulfate

Aluminum Sulfate - acidifies the soil, as for Japanese Iris or BLUE Hydrangeas 

  

Biological inoculants and activators

Beneficial bacteria, friendly fungi to inoculate roots and mycorrhizal associations

 benefiting plants through increased nutrient uptake 

Agverra SRT, Dr. Earth  Super Active Biological Inoculant, Soil Smart 

Plant stimulants, transplant solutions, growth regulators

Superthrive rooting hormone, vitamin and plant hormone (1 drop per gallon formula) 

Rootone rooting hormone

Wetting agents and surfactants

Terra-Sorb Hydro Gel - a "water grabber" commonly mixed into potting mixes to allow water absorption by hydrophobic (water-hating) peat moss 

The LandscapExperts select from among this lengthy list to provide your landscape soils with amendments  to bring them to optimum condition. 

Digging Deeper 

Very helpful University of Georgia PDF entitled Soil Inoculants http://www.caes.uga.edu/applications/publications/files/pdf/C%20990_1.PDF

This is the Mother of all Soil Additive Lists:  http://www.soils.wisc.edu/extension/pubs/2006noncon_with_ref.pdf