1. Soil

2. What we will cover
Theory
 What is soil ?
 Understanding your soil
 Soil Food web
Practical - Observations
 Soil sampling and analysis

3. What is Soil
 A mixture of mineral matter, organic matter, water,
and air
 A thriving ecosystem
 Very variable from place to place and forever
undergoing change. The soil is dynamic.
 Under appreciated.

4. Mineral Inputs-Rocks
Rocks break down overtime and by doing so contribute
the mineral content to the soil .
 Physical weathering-
Frost shattering
Root growth

5. Mineral Inputs-Rocks
 Chemical weathering
Not only causes rocks to disintegrate, also changes the
chemical nature of the minerals
Water reactions
Root Secretions
Soil Organisms

6. Organic Inputs
 Primary Colonisers

7. Transformation – Minerals
 The disintegrated rock takes the form of three main observable particle
sizes
 SAND – SILT – CLAY

8. Transformation –Organic Matter
 In healthy soil organic material inputs decompose and transform into Humus
and minerals.
 Humus
Persists in the soil providing foods and protective substances for plants
Holds incredible volume of water
Creates good soil structure
Creates ideal environment for soil life

9. Texture
 Texture refers to the proportion of sand-silt and clay in the soil and can give
us a read on how our soil will interact with vegetation and soil life.
 Sand: Fast Drainage – easy to work – Low fertility – warms quickly
 Silt: Med fertility – easy to work – prone to crusting – poor structure – drains well
 Clay: High Fertility- hard to work- poor drainage- prone to compaction
 Loam: Equal proportions of sand-silt and clay. The ideal texture

10. Structure
 Structure refers to how the sand silt clay and SOM are bonded together into
aggregates. A diversity of aggregates provides a diversity of pore space
which is the ideal situation for plant growth and provides habitat for soil
organisms

11. Organic Matter - Soil Food Web

12. Organic Matter - Soil Life

13. Organic Matter – Benefits of Healthy Soil Food Web
 Increased Nutrient retention
 Improved crop quality
 Pest and disease suppression
 Improved soil structure
 Decomposition of Toxic chemicals
 A cleaner environment

14. Soil Profile
 Most of the fertility is present in the top 10cms (The Rhizosphere)
 Most of the soil life inhabits this horizon
 Most of the crop plants we grow feed from this horizon

15. Indicator Plants
 Cytisus scoparius - Broom : Infertile soil ,nitrogen deficient
 Achillea millefolium – Dry soil
 Rumex acetosella - Sorrel : Poor light dry, acid soil
 Stellaria media - Chickweed : Fertile soil
 Urtica dioecia - Stinging nettle : Fertile soil
 Sonchus sp – Sow thistle : Acid soil
 Caltha pulustris - Marsh Marigold : Poorly drained ,waterlogged soils
 Chenopodium album - Lambs Quarter : Previously cultivated soil

16. Other Soil Factors
 pH
 Nutrient Storage
 Water Relations

17. Essential points
 A diversity of soil life creates healthy soil
 We are aiming to grow soil and the soil will take care of the
plants
 Organic matter is the most important ingredient for the
functioning of healthy soil therefore healthy plants
 By adding organic matter we feed the soil and keep it in good
condition to take care of the plants
 Only when fresh organic matter has been mineralised by the
soil life is it available to plants.