Understanding our Garden’s Soil

1. Understanding our Garden’s Soil

2. What Does Soil Do? • Provides nutrients for the plants • NPK • Regulates water • Provides support for roots • Filters potential pollutants

3. SOIL COMPONENTS: Physical • Mineral Particles • Sand • Silt • Clay • Organic Matter • Air • Water

4. SOIL COMPONENTS: Living • Microorganisms • Worms • Fungi • Bacteria “It’s Alive!” In 1g of soil there are: • >100,000,00 bacterial cells • >11,000 species of bacteria • Fungi and larger organisms

8. COMPOSITION OF SOIL BY VOLUME

9. SOIL FORMATION:ClORPT • Climate • Organisms • Relief • Parent Material • Time

10. SOIL HORIZONS • O-Horizon • Recognizable, recent • Less recognizable • Humus • A-Horizon • Mineral layer • E-Horizon • Elluviation layer • B-Horizon • Zone of Accumulation • C-Horizon • Clumps • Bed Rock

11. Physical Properties of Soil • Color • Texture • Structure • Drainage • Depth

12. SOIL COLOR • Light brown Low in organic matter • Dark brown High in organic matter • Black Very high organic matter • Red Weathered/nutrient poor • Red-brown Good drainage • Yellow Moderate drainage • Grey Poor drainage • White, light grey Sandy

13. SOIL TEXTURE • Sand, Silt, Clay • Excludes organic matter Water holding capacity Irrigation frequency Nutrient holding capacity Fertilization frequency CLAY LOAM SAND high medium low low medium high high medium low low medium high

14. Structure, Drainage, and Depth • Structure is the shape soil takes based on its physical and chemical properties • Destroyed by over-tilling and traffic • Soil drainage is improved by adding organic matter • The deeper the soil, the greater the storage capacity for water and nutrients

15. SOIL pH • pH is a measure of the acidity or the basicity of the soil NEUTRAL BASIC ACID 0 2 4 6 8 10 12 14 PLANT GROWTH

16. Effects of pH on Nutrient Availability Reprinted from the Arizona Master Gardener Manual, Chapter 2, page 20.

17. IRON CHLOROSIS Iron deficiency appears on the youngest leaves of plants growing in alkaline soils.

18. SOIL AMENDMENTS • Complete fertilizers • NPK • Incomplete fertilizers • Missing at least one of the primary nutrients • Organic fertilizers • Remains or by-products of plants or animals • Release nutrients slowly • Blood and bone meal • Fish emulsion • Manure

19. MANURES % of N P K Chicken manure 4.4 2.1 2.6 Cow manure 1.9 0.7 2.0 Pig manure 2.1 0.8 1.2 Horse manure 1.4 0.4 1.0 Sheep manure 3.5 0.6 1.0

20. NITROGEN • Necessary for formation of chlorophyll, as well as building amino acids for proteins. • Nitrogen deficiency symptoms • Yellowing leaves beginning in oldest leaves • Leaf tips and margins yellow and dies • Plants are stunted.

21. PHOSPHORUS • Phosphorus is necessary for almost all aspects of plant growth and is essential for flower and fruit formation • Phosphorus deficiency symptoms • Dark green foliage • Purplish foliage on stems • Reduced growth • Delayed maturity or reduced flowering

22. POTASSIUM • Potassium is necessary for the formation of sugars, starches, carbohydrates, protein synthesis and cell division in roots and other parts of the plant. • Potassium deficiency symptoms • Leaf tips and margins burn • Affects oldest leaves first • Plants have weak stalks • Small fruit

23. Sources of NPK

24. IMPROVING SOIL:Cover Cropping • Mixing vegetable plants with other crops such as grasses and legumes. • Add nutrients and organic matter to the soil • Helps hold moisture • Improves soil texture • Prevents erosion

25. IMPROVING SOIL:Compost—Nature Recyles! • Transformation of raw organic materials into biologically stable substances suitable for plants • Improves soil structure, texture, and aeration. • Increases water-holding capacity • Increases nutrients

26. IMPROVING SOIL:Crop Rotation • Planting crops in a prescribed rotation • Builds soil nutrients • Crops help to fertilize each other • “Tricks” pests • Adds diversity

27. IMPROVING SOIL:Reduced Tillage