Soils

hand on garden soil; photo by Edwin Remsberg

CORE COMPETENCIES

At the end of this session you will be able to articulate and explain:

  • The composition of soil
  • The difference between soil texture and soil structure (effects of excessive tillage), the advantages and disadvantages of each soil texture (clay, silt, sand), the importance of organic matter in the soil.
  • Soil fertility and pH
  • The role and importance of soil pH
  • The pH scale (acidic to basic, logarithmic)
  • How pH adjustments are made in the soil
  • Cation Exchange Capacity (CEC) and its relation to fertility
  • Essential macronutrients  and micronutrients needed for plant growth
  • Soil testing and interpretation
  • Don’t Guess, Soil Test! – The importance of soil testing.
  • How to sample soil and complete the soil testing form properly
  • How to interpret a soil test and its recommendations
  • How to compare fertilizers
  • Types of fertilizers and their relative attributes (synthetic & organic)
  • How to interpret a fertilizer label
  • How to select the appropriate fertilizer for a specific use
  • How to select a substitute fertilizer, when the fertilizer recommended in your soil test results is not available at the store
  • How and when to apply fertilizers to minimize environmental impact
  • Cover cropping and organic soil amendments
  • Reasons to use cover crops
  • Appropriate cover crop for each reason
  • Cover crops and when they are planted in Maine
  • Organic amendments and how they affect soil

SELECTED READINGS AND CONTENT

Soil and Plant Nutrition: A Gardener’s Perspective, by Lois Berg Stack, Ornamental Horticulture Specialist, University of Maine Cooperative Extension

UMaine Extension Bulletins

UMaine Extension Videos

Additional UMaine Resources

MOFGA fact sheets — Look for:

  • Using Green Manures
  • Natural Sources of Plant Nutrients
  • An Organic Farmer’s Guide to the Interpretation of a Standard Soil Test from the University of Maine

Additional Resources


PRACTICAL SKILLS GAINED AND STRENGTHENED

  • How to sample soil and complete the soil testing form properly
  • How to interpret a soil test and its recommendations
  • How to interpret a fertilizer label
  • How to select the appropriate fertilizer for a specific use
  • How to select a substitute fertilizer
  • How and when to apply fertilizers to minimize environmental impact