Managing Soil to Keep It Productive

1. Managing Soil to Keep It Productive Developed by: Hudson Minshew Oregon State University Extension Service Susan Donaldson University of Nevada Cooperative Extension NRCS, Bozeman, MT

2. Part One: Fertilizing • What do my soil test results mean? • What nutrients do plants need? • How can I supply those nutrients?

3. What kind of information does my soil test report provide? • Particle size analysis • Soil organic matter content • pH • Soluble salts • Nutrient content USDA NRCS

4. Particle size analysis • Provides the relative percentages of sand, silt, and clay • Allows determination of soil textural class • A loamy texture is generally best for most plants NRCS, Bozeman, MT

5. Soil organic matter (OM) • Living or dead plant and animal residue • Measured in percent • OM content is highly variable • Generally, 3% to 8% OM content is good for plants UNCE, Reno, NV

6. pH • Indicates relative acidity or alkalinity • pH 7 = neutral; less than 7 = acid; more than 7 = alkaline or basic Adapted from library.thinkquest.org

7. Soil pH and nutrients Adapted from www.soil.ncsu.edu Widest part of the bar indicates maximum availability

8. What makes soils acid? • Acid soils: pH is below 7 • Soils become acid because of heavy rainfall that weathers soils quickly • Basic cations such as calcium, magnesium, and potassium are leached from the soil profile • This natural weathering process makes soils acid

9. Raising the pH of acid soils • Add lime to raise the pH (making soil less acid) • Lime most often consists of calcium carbonate • Plant response will be relatively slow, taking weeks or months

10. What makes soils alkaline? • Alkaline soils: pH is above 7 • Soils that have not been greatly weathered or leached • Soils high in calcium • Reduces solubility of all micronutrients Adapted from library.thinkquest.org

11. Example of crop in alkaline soil ag.arizona.edu

12. Adapted from ag.arizona.edu

13. Soluble salts • A measure of inorganic chemicals that are more soluble than gypsum, such as sodium, calcium, magnesium, chloride, sulfate and bicarbonate. • Salty soils are a problem in arid regions or in poorly drained soils USDA NRCS

14. Classifying salt-affected soils • Electrical conductivity measurements (EC) • Exchangeable sodium percentage (ESP) • Salt affected soils are commonly classified for management purposes into three groups: saline, sodic, and saline-sodic based on EC and ESP

15. Managing salt-affected soils • Select plants that can tolerate salinity • Avoid excess or salty forms of fertilizers • Incorporate organic matter • If appropriate, add sulfur to lower the pH

16. Managing salt-affected soils • In soils with good drainage, periodically leach the salts below root zone with high quality irrigation water (avoid if high water table present) • Check with your local Cooperative Extension office for help

17. Plant nutrients • Substances necessary for plant growth • Some, such as hydrogen, oxygen and carbon, come from the air and water • Others, such as nitrogen and phosphorus, may need to be added • Excess or improper use of fertilizers may result in water pollution

18. Macronutrients • N = nitrogen • P = phosphorus • K = potassium

19. More macronutrients • H = hydrogen • O = oxygen • C = carbon • Ca = calcium • Mg = magnesium • S = sulfur

20. Fe = iron Mn = manganese Zn = zinc B = boron Mb = molybdenum Ni = nickel Cu = copper Co = cobalt Cl = chlorine Micronutrients

21. Six questions to ask yourself before you add fertilizer: • Which elements do I need? (N, P, K, S, Ca) • How much do I apply? • What type of material do I use? • Which application method is best? • When is the best time to apply it? • Will I get a return on my investment?

22. Types of fertilizers • Chemical fertilizers • Organic fertilizers (bone meal, compost, manure,etc.) www.farmphoto.com

23. What’s in the bag?

24. How much fertilizer do I need to apply? • Estimate the amount of fertilizer needed based on soil test results, crop needs and area to receive fertilizer • Most fertilizer recommendations are in pounds per 1000 square feet, or pounds per acre

25. Calculating fertilizer rates To convert a recommendation to pounds/acre of an actual fertilizer material, use the following formula: Pounds of nutrient recommended Percentage of nutrient in fertilizer material X 100

26. Calculating land area • Length * Width = Area • If area is odd shaped or oval, calculate using a regular shape that closely fits the shape of the land to be fertilized 200 ft 150 ft 150 ft 100 ft

27. Fertilizing with manures • Good source of nutrients and organic matter • Protects soil from raindrop impact and erosion • Local supply often available at no cost OSU Extension Service

28. Different sources of manure have different amounts of nutrients • Poultry manure is high in nitrogen • Beef and horse manure tends to be lower in nitrogen • Sheep manure is high in potassium (K) UNCE, Reno, NV

29. Cautions for fertilizing with manures • Watch out for weeds and pathogens • Know the manure nutrient content • Consider the salt content N- P- K OSU Extension Service

30. Cautions for fertilizing with manures • Incorporate or apply evenly to avoid smothering plants • Don’t apply on frozen slopes • Avoid leaching nutrients into waterways UNCE, Reno, NV

31. Visual symptoms of deficiencies: Nitrogen agri.atu.edu

32. Visual symptoms of deficiencies: Phosphorus agri.atu.edu

33. Visual symptoms of deficiencies: Potassium Corn Alfalfa agri.atu.edu

34. Visual symptoms of deficiencies: Calcium agri.atu.edu

35. Visual symptoms of deficiencies: Zinc agri.atu.edu

36. Visual symptoms of deficiencies: Manganese agri.atu.edu

37. What we’ve learned: • Use soil test results to guide you in amending your soil • Test results are only as good as the sample you collect • Fertilize to meet plant needs, and avoid costly overuse that may pollute water

38. Part II: Soil Surveys • How to use a soil survey • How to find a map unit • Map unit descriptions • Soil ratings and capabilities

39. Where do soil surveys come from, and where can I get one? USDA NRCS

40. Why should we use soil surveys? • Contain practical information for the landowner • Can prevent management mistake • Help determine the potential of your land

41. How do I use a soil survey? • Locate your property on the “Index to Map Sheets” page • Note the number of the map sheet • Find that sheet • Locate your property on the map sheet • Make a list of map unit symbols

42. Soil Map Units • A map unit describes a soil “type” in the soil survey • “Map unit descriptions” are found at the beginning of the survey • Soil map units are arranged alphabetically as well as numerically in the soil survey

43. Soil map unit example 630 Fleischmann gravelly clay loam Name given by soil scientists conducting survey Number designation Soil textural class is part of map unit name

44. What do you do with the number? • Determine capabilities and limitations • See “Summary of Tables” in the Soil Survey for additional data on a specific soil use • For our example soil, can we build a septic absorption field? • See Table 10: Lists a severe limitation due to cemented pan

45. Soil limitations NRCS, Bozeman, MT

46. Suitability ratings Temperature and precipitation Freeze dates and growing season Productivity Building site development Other information:

47. Other information: • Suitability for irrigation • Physical and chemical properties (%OM, pH, permeability, AWC) • Soil surveys can differ in what information they provide.

48. Restrictive features • Cemented pan • Droughty • Erodes easily • Flooding • Low strength • Restrictive layer • Shrink-swell potential UNCE, Reno, NV

49. Capability classes • Class I & II --good farmland with few to moderate limitations • Class III & IV—severe to very severe limitations for growing crops • Classes V & VI—limitations that are impractical to remove. • Classes VII & VIII—very severe, unsuited for cultivation.

50. Capability classes USDA NRCS