Soil Management for the Home Gardener Dr. Greg Schwab Extension Soil Management Specialist

1. Soil Management for the Home Gardener Dr. Greg Schwab Extension Soil Management Specialist Estill County Horticulture Seminar February 3, 2004

2. Idealized Kentucky Soil Pore Space 50% Soil Minerals (Silt loam) 47% Organic Matter 3%

3. Macropores • Include earthworm channels • Old root channels • Surface Cracks Controls soil permeability and aeration Beach sand is almost entirely macropores – infiltration is very high, but water holding capacity is very low

4. Micropores • Very fine pores • Similar to pores in a sponge or towel • Hold water against the force of gravity Much of the water held in micropores is available to plants, but some is held so tightly that plant roots cannot use it.

5. Idealized Kentucky Soil Macropores 25% Soil Minerals (Silt loam) 47% Miropores 25% Organic Matter 3%

6. Disturbed/Compacted KY Soil Air 5% Water 20% Soil Minerals (Silt loam) 72% Organic Matter 3%

7. Characteristics of soil with poor internal structure • Slow permeability • Very wet natured • Crust easily • Poor plant productivity Once lost, soil structure is very hard to rebuild – prevention is the key

8. Gray Soil = No Oxygen = No Root Growth

9. Optimum M.C.=14.3% for a silt loam Potential Compaction 8 10 12 14 16 18 20 22 Soil Moisture Content (%) Maintaining Soil Structure • Prevent soil compaction

10. Higher Yield Potential?

11. Maintaining Soil Structure • Use roto tiller sparingly

12. Compaction caused by tillage 4 – 8” 0.5 – 2” Inaccessible water and nutrients Slide by: R. Pearce

14. Use mulch to control weeds and conserve moisture

15. Incorporate Compost or Organic Material when Tilling • Don’t exceed 10% per year • ½ inch mixed into the surface 5 inches • Stabilized compost is much better • Fresh manure use very sparingly • Uncomposted leaves or straw tie up soil nitrogen • Wood ash is a good sources of nutrients, but doesn’t contain organic matter

16. Use Cover Crops • Turnips and mustard greens • Grow very good in the fall • Provide ground cover to prevent erosion • Have strong tap roots to break compaction and provide future root channels for better infiltration • Wheat • Roots provide organic matter • Improves soil structure • Reduces winter annual weed pressure

17. Soil Minerals Macropores 25% Soil Minerals (Silt loam) 47% Miropores 25% Organic Matter 3%

18. Soil Mineral Phase • Sand • Large soil particles – feel gritty and can be seen with the naked eye • Silt • Much smaller than sand – feel smooth about the size of flour particles • Clay • So small particles can only be seen under a microscope • Chemically active part of the soil Soil Texture

19. Ca++ Plant Root NH4+ H+ K+ - - - H+ - - - - - - Ca++ H+ - - Ca++ - - - - - K+ NH4+ K+ Mg++ Ca++ Ca++ Mg++ Ca++ K+ NH4+ H+ H+ Mg++ H+ H+ K+ Mg++ Mg++ Ca++ NH4+ Ca++ Cation Exchange Capacity Clay Clay K+ Clay Clay H+ Ca++ H+ K+ Soil Solution

20. azaleas Vegetables Soil pH is the most important soil test conducted

21. Estill County Soil Test Results Elemental Sulfur Reduces pH Lime Increases pH Gypsum Has No Effect

22. Soil Testing - Nitrogen • Nitrogen is the fertilizer needed most in KY soils • Very little soil nitrogen is in the plant available form so soil testing is not generally recommended • Soil testing can be used to diagnose excessive fertilizer applications • Plants take up inorganic (NO3 and NH4) nitrogen – Organic sources must be mineralized before they are plant available

23. Fertilizer Recommendations Soil Testing is the only way to know for sure how much phosphorus and potassium is needed. If soil test phosphorus is above 100 lbs/a PLEASE DON’T apply any more phosphorus

24. Fertilizer Recommendations Soil Testing is the only way to know for sure how much phosphorus and potassium is needed.

25. Fertilizer Analysis Analysis Nutrient Concentration 34-0-0 34% N – 0% P2O5 – 0% K2O 5-5-5 5% N – 5% P2O5 – 5% K2O Fertilizer recommendation is for 1 lb N per 1000 sq ft how much 34-0-0 or 5-5-5 is needed? 1 lb N/1000 sq ft 0.34 lb N/lb material 3 lbs 34-0-0 per 1000 sq ft

26. Nutrient Content of Manure

27. Other Essential Elements Sulfur, Calcium, Magnesium, Zinc, Iron, Copper, Manganese, Boron, Molybdenum, and Chlorine Are almost always adequate if soil pH is adjusted for the crop

28. Questions???