1. 2004 Big Rivers Annual CCA Meeting January 21, 2003 Greg Schwab, Ph.D., CPAg. Extension Soil Specialist UK Department of Agronomy Nutrient Management: Managing Soil pH and Liming

2. The effect of soil pH on the activity of soil micro- organisms, availability of plant nutrients, and occurrence of toxic elements Corn Alfalfa Alfalfa

3. Mn Toxicty Caused by low soil pH –not enough lime –too much N fertilzer Stunts growth May reduce yield 200 to 300 lbs./A Soil test and add lime as needed

4. Manganese Toxicity, Soybean Photo by: L. Murdock

5. Low Soil pH

6. Wheat yield as affected by soil pH NC State

7. Corn yield as affected by soil pH

8. Using Ag lime to correct soil pH Collect a representative soil sample and apply recommended rate. Why didn’t soil pH reach target level after testing and lime application?

9. Representative soil sample 330’ x x x x x x x x x x x

10. Determining the Quality of Agricultural Limestone Purity – The ability of lime to neutralize soil acidity relative to pure CaCO 3 CaCO 3 = 100% MgCO 3 = 120% Impurities – sand, iron, other minerals 0 %

11. Particle Size Determines Reactivity 1” Surface area = 6 sq. inches Surface area = 8 sq. inches 1” 0.5” Fineness of Grind

12. One cubic inch of limestone ground to pass a 100-mesh screen would have approximately 600,000 sq. inches of surface area. 0.25” Surface area = 20 sq. inches 0. 5” Particle Size Determines Reactivity

13. Solubility of limestone based on particle size Size of Particles Years after application OneFour Coarser than 8 Mesh 515 8 to 30 Mesh 2045 30 to 60 Mesh 50100 Finer than 60 Mesh 10100

14. Relative Neutralizing Value Calculation of both purity and fineness used to compare lime from different sources. CCE % between 10 and 50 % less than 50 100 2 + x RNV= Kentucky state law requires at least 80 % CCE 90% passing 10 mesh 35% through a 50 mesh RNV = 50% with the minimum state requirements

15. Comparing Lime Sources Some good quality lime don’t satisfy state lime laws because of fineness of grind – example: CCE = 90 % Smaller than 10 mesh = 92% Smaller than 50 mesh = 32% RNV= 56% UK Lime recommendations assume 67% RNV Other labs may vary ** FAILED

16. http://soils.rs.uky.edu/Lime%20Report%20Spring%202003.pdf Spring 2003 Ag Lime Test Results 60 51

17. Comparing Lime Price Source 1 – RNV = 85 %Price = $12/ton Source 2 – RNV = 65 %Price = $10/ton UK Recommendation 3 tons/acre What is cheapest for the farmer?? Source 1 (67/85) x 3 = 2.36 tons per acre = $28.32/acre Source 2 (67/65) x 3 = 3.09 tons per acre = $30.09/acre

18. Adjusting Application Rate Based on Depth of Incorporation UK Recommendation assume 6 2/3 inches of soil to be neutralized Depth 24682468 pH 5 6 7 Typical reduced tillage profile Depth 24682468 pH 5 6 7 Typical conventional tillage profile

19. Adjusting Application Rate Based on Depth of Incorporation UK Recommendation assume 6 2/3 inches of soil to be neutralized Tillage Depth Multiplying Factor 4 inches 0.60 8 inches 1.20 9 inches 1.35

20. Not adjusting for RNV and depth of lime incorporation is the main reasons why recommended lime rates do not achieve the desired change in soil pH.

21. Zinc Deficiency of Corn

22. Liming Materials Byproducts Suspension Lime 40 – 75 Burned Lime150 – 185 Hydrated Lime 125 – 145 Ground Oyster Shells90 – 95 Wood Ash30 – 70 Reclime ® 85 – 90

23. Byproducts

24. Pelletized Lime Manufactured by bonding together finely ground agricultural lime using lignosulfanates. How much can the rate be reduced if using pelletized lime? When calculations are made based on RNV, rates of pelletized lime should not be reduced. How much can the rate be reduced if using pelletized lime?

25. Pelletized Lime How fast will pelletized lime react? Pelletizing requires very fine material without any course material. One would assume that it reacts more quickly. Actual research result show that pelletized lime reacts slower than an equal RNV of aglime due to bonding agents an distribution across soil surface.

26. Conclusions Natural processes continuously reduce soil pH Soils should be sampled at least every three to four year to assess pH Relative neutralizing value of lime material should be used to adjust lab lime recommendation The quality of limestone varies across the state, the least expensive lime might not be the cheapest per ton.