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  1. 1. Soil
  2. 2. What we will coverTheory What is soil ? Understanding your soil Soil Food webPractical - Observations Soil sampling and analysis
  3. 3. What is Soil A mixture of mineral matter, organic matter, water,and air A thriving ecosystem Very variable from place to place and foreverundergoing change. The soil is dynamic. Under appreciated.
  4. 4. Mineral Inputs-RocksRocks break down overtime and by doing so contributethe mineral content to the soil . Physical weathering-Frost shatteringRoot growth
  5. 5. Mineral Inputs-Rocks Chemical weatheringNot only causes rocks to disintegrate, also changes thechemical nature of the mineralsWater reactionsRoot SecretionsSoil Organisms
  6. 6. Organic Inputs Primary Colonisers
  7. 7. Transformation – Minerals The disintegrated rock takes the form of three main observable particlesizes SAND – SILT – CLAY
  8. 8. Transformation –Organic Matter In healthy soil organic material inputs decompose and transform into Humusand minerals. HumusPersists in the soil providing foods and protective substances for plantsHolds incredible volume of waterCreates good soil structureCreates ideal environment for soil life
  9. 9. Texture Texture refers to the proportion of sand-silt and clay in the soil and can giveus 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. 10. Structure Structure refers to how the sand silt clay and SOM are bonded together intoaggregates. A diversity of aggregates provides a diversity of pore spacewhich is the ideal situation for plant growth and provides habitat for soilorganisms
  11. 11. Organic Matter - Soil Food Web
  12. 12. Organic Matter - Soil Life
  13. 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. 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. 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. 16. Other Soil Factors pH Nutrient Storage Water Relations
  17. 17. Essential points A diversity of soil life creates healthy soil We are aiming to grow soil and the soil will take care of theplants Organic matter is the most important ingredient for thefunctioning of healthy soil therefore healthy plants By adding organic matter we feed the soil and keep it in goodcondition to take care of the plants Only when fresh organic matter has been mineralised by thesoil life is it available to plants.