Soil Testing and Analysis Nutrient Management Basics

1. Soil Testing and AnalysisNutrient Management Basics Sustainable Small Acreage Farming and Ranching Slides adapted from the Living on the Land curriculum, University of Nevada-Reno, Sue Donaldson, et al. 2001

2. How do I know what to add to my soil???

3. Test your soil! UNCE, Rno, NV

4. What Information Does a Soil Test Provide? • Soil textural analysis • pH and salts • Soil nutrient content • Fertilization recommendations

5. A Fertile Soil Has: • The right kinds and amount of nutrients to grow pasture or crops • Low salinity and sodium • Close to a neutral pH (about 7) • Plenty of organic matter USDA NRCS Photo Gallery

6. How Often Should I Take a Soil Sample? • Prior to seeding a crop in new ground • At least every three years for established perennial crops • Frequently enough to make good decisions on fertilization • When it is cost effective

7. How to take a sample First select the site. Your soil sample should represent only one soil type or soil condition. OSU Extension Service

8. How to take a sample Each sample should consist of sub-samples taken from about 15 locations within the same soil type or sampling area. OSU Extension Service

9. How to take a sample Use the “slice” method for a representative sample. UNCE, Reno, NV

10. Soil test results • What do my soil test results mean? • What nutrients do plants need? • How can I supply those nutrients?

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

12. 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

13. 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

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

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

16. 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

17. 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

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

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

20. 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

21. 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

22. Nutrient Management • Meet crop nutrient needs • Maintain soil quality • Conserve resources • Protect water quality -- reduce leaching and runoff risk

23. Major Nutrients Nitrogen Phosphorus Potassium Calcium Magnesium Sulfur Micronutrients Boron Iron Manganese Zinc Copper Chloride Molybdenum Plant Nutrients

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

25. More macronutrients • Ca = calcium • Mg = magnesium • S = sulfur

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

27. 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?

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

29. Organic Materials • Little or no processing • Low nutrient content • Slow release of nutrients • Plant, animal, or mineral sources

30. Nutrient uptake • The forms of nutrients taken up by plants are the same for all types of fertilizer -- manufactured or organic.

31. Organic materials:Fertilizers vs. Soil amendments • Fertilizer1.High nutrient content and availability. 2. Main benefit is nutrients. 3. Relatively small amounts applied. • Soil amendment1.Low nutrient content and availability. 2. Main benefit is organic matter. 3. Large amounts applied.

32. 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

33. 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

34. 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

35. 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

36. 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

37. What we’ve learned: • Use soil test results to guide you in amending your soil • Nutrient management is more than just adding fertilizers to meet plant needs • Chemical fertilizers and natural or organic soil amendments both have advantages and disadvantages and must be managed based on each farms particular cropping system.