Soil Amendments & Nutrients

Depending on the particular needs of the soil in your area, here are some soil amendments and nutrients that can be used to improve your soil.


Decomposed leaves, grass clippings (without herbicides), plant-based kitchen scraps, and other organic materials. A well-balanced, slow-release, nutrient- and humus-rich amendment. Lightens heavy soils; enriches poor soil.


Use coarse sand in small amounts to improve drainage and loosen clay soil. Too much sand turns some soils into concrete. It contains no nutrients but lasts indefinitely.


Aged or rotted manure (from cows, sheep, horses, chickens, and others) boosts soil nitrogen. It loosens heavy soil and improves water retention in light soils. Fresh manure burns plants; compost it for a year before using.


Absorbs moisture; especially helpful in sandy soil. Loosens heavy or clay soils. If allowed to dry out, it can become hard, crusty, and difficult to remoisten. Peat or peat moss may be harvested from environmentally fragile peat bogs, a limited resource. Use sphagnum peat moss instead.


Made by heating mica until it bursts, this lightweight particulate holds moisture and loosens soil. Good in all soil types. Lasts indefinitely.


Powdered rock that contains potassium and other nutrients. Slows soil compaction and helps retain moisture.


Powdered mineral that loosens heavy and clay soil; improves drainage.

Basic Nutrients

The following organic materials, when added to soil, supply specific nutrients needed by plants.

Nitrogen (N) Sources for Leaf and Stem Growth

  • Alfalfa meal
  • Blood meal
  • Composted manure
  • Cottonseed meal
  • Feather meal
  • Fish meal or emulsion
  • Mushroom compost
  • Rice hulls

Phosphorus (P) Sources for Root Growth, Flower Color, and Disease Resistance

  • Bat guano
  • Bonemeal
  • Rock phosphate
  • Potassium (K) Sources for Fruit and Seed Production
  • Dolomite lime
  • Greensand
  • Kelp meal
  • Oyster-shell lime
  • Rock dust
  • Seaweed
  • Wood ashes

Soil Testing using the Soil Food Web method is available.  Contact us for more information.