2. Outline Drought update/outlook  Stand losses Soil management strategies Sounds too good to be true!  N fertilizer savings  Foliar fertilizers

3. Organic Matter How Soil Holds Nutrients Ca 2+ K+K+ Mg 2+ Al 3+ K+K+ Mg 2+ Soil Particle CEC = 10 Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ Ca 2+ K+K+ Mg 2+ K+K+ CEC = 200

4. Soil Acidity and CEC pH = 7.0 Soil BS = 100% Ca 2+ K+K+ Mg 2+ Ca 2+ K+K+ BS = ~ 50% pH = 6.0 H+H+ H+H+ K+K+ Ca 2+ Mg 2+ Soil H+H+ H+H+ H+H+ BS = 0% Al 3+ pH = 5.5 Al 3+ H+H+ Soil Strength of cations: Al 3+ > H + > Ca 2+ > Mg 2+ > K +

5. Ca 2+ K+K+ Mg 2+ H+H+ Al 3+ H+H+ CaCO 3 pH = 5.5 Soil Ca 2+ + CO 3 Soil + HCO 3 + Al(OH) 3 pH = 6.5

6. DO NOT cut back on lime! Get your priorities right! 1.Lime is still job #1. Get your priorities right! 1.Lime is still job #1.

8. How Soil pH Affects Availability of Plant Nutrients The difference of a soil pH of 5.6 vs. 6.2: Nutrient Amt. Used Annually Unit Price Dec. in Efficiency Value of Decrease (Lbs/acre)($/lb)($/acre) N200$0.7035% -$49 P2O5P2O5 50$0.5850% -$15 K2OK2O150$0.5510% -$8 Total -$72

9. Fertilization Strategies Hayfield 2 & 3 pH = 5.5 P = 15 K = 90 OM = 1.5% Hayfield 2 & 3 pH = 5.5 P = 15 K = 90 OM = 1.5% Hayfield 1 pH = 6.0 P = 25 K = 120 OM = 2.5% Hayfield 1 pH = 6.0 P = 25 K = 120 OM = 2.5% Pasture A pH = 6.2 P = 35 K = 180 OM = 3% Pasture A pH = 6.2 P = 35 K = 180 OM = 3%

10. Low Soil pH

11. H+H+ Al 3+ H+H+ Gypsum CaCO 3 pH = 5.5 Soil Ca 2+ + SO 4 Soil + AlSO 4 pH = 5.5 Ca 2+ + H+H+ H+H+ H+H+ H+H+ H+H+ Ca 2+ Mg 2+ Ca 2+

12. Aluminum Toxicity – Low Soil pH Alfalfa control treated

13. Effect of Gypsum (CaSO 4 ) on Root Growth - Alfalfa Source: Dr. M.E. Sumner

14. Hybrid Bermudagrass Yield Response to N Rate Hybrid Bermudagrass Yield Response to N Rate

15. Nitrogen Response: Rules of Thumb N Response Above Critical Level * Forage TypeEarly SeasonMid-SeasonLate-Season ------- lb of DM/lb of N added ------- Coastal bermuda30-4535-4520-35 Tifton 85 bermuda30-4045-5530-40 Annual ryegrass5-1210-2015-30 * N fertilization above an annual ~40, 50, or 25 lbs of N/acre for Coastal, Tifton 85, and ryegrass, respectively.

16. Cost Implications of Different Nitrogen Response Rates Cost of N, $/lb of N $0.50$0.60$0.75$1.00 Nitrogen ResponseN Cost of Additional Production lbs of DM/lb of N--------------------------- $/lb of DM --------------------------- 5$0.100$0.120$0.150$0.200 10$0.050$0.060$0.075$0.100 15$0.033$0.040$0.050$0.067 20$0.025$0.030$0.038$0.050 25$0.020$0.024$0.030$0.040 30$0.017$0.020$0.025$0.033 35$0.014$0.017$0.021$0.029 40$0.013$0.015$0.019$0.025 45$0.011$0.013$0.017$0.022 50$0.010$0.012$0.015$0.020 55$0.009$0.011$0.014$0.018

17. A Fertilization Trick Long-term, this can increase yields by 5-10% and increase NUE by 25-30%  Especially important under extremes  Leaching  Volatilization (in the case of urea-based products)  Late freeze  Drought Helps to prevent NITRATE TOXICITY! Split Your Nitrogen Applications!

18. N Application Strategies MAMJJASO Green-up Only (Common Strategy with Poultry Litter)

19. N Application Strategies MAMJJASO Green-up & After 2 nd Cut

20. N Application Strategies MAMJJASO Green-up & After Each Cut

21. Fertilization Trick Account for N Loss from Urea-based Products

22. The Effectiveness of Some Alternative N Sources at Low, Medium, and High Fertilization Rates on Hybrid Bermudagrasses (Relative to Ammonium Nitrate). Nitrogen SourceFertilization Rates < 200 lbs*250-350 lbs> 400 lbs Ammonium Nitrate 100% Amm. Sulfate 95-97%95-105%60-70% Anhyd. Ammonia 92-94%93-95%94-95% UAN Solution 80-85%85-92%92-95% Urea 79-82%82-92%88-93% * Actual lbs of N per acre per year. Source: Burton and Jackson, 1962; Silveria et al., 2007.

23. Use of Urea-Based Products Without AN, users of N face risky alternatives.  NH 3 volatilization loss Urease is abundant in thatch & organic layers  High N use in hay. Enhanced Efficiency N Fertilizer Products may reduce volatilization loss  Urease inhibition  Encapsulate & release Ammonium Nitrate Urea NBPT maleic-itaconic co-polymer Polymer Coating

24. Ammonia Volatilization Trap Data 2008-2009 (avg. over two locations)

25. Bermudagrass Hay Yield 2008-2009 (Calhoun)

26. Summary of EE N products Agrotain Treated Urea as compared to urea applied in the same way (averaged over 4 site-yrs): Reduced ammonia volatilization by over 63%. Produced 11% more forage yield. Recovered 19% more of the applied N. Did not substantially affect crude protein content. Did not substantially affect the risk of nitrate toxicity.

27. Another Fertilization Trick Apply P in late summer or fall.

28. Another Fertilization Trick Split Your Potassium Applications! 40-50% in the Spring 50-60% in mid – late season

29. Poor Stress Tolerance Leafspot Diseases The Stand is Gone! Not Competitive Grows Very Slow Poor Winterhardiness K is for Persistence

30. K is the Key to a Good Stand

31. Tissue Sampling and Troubleshooting

32. Tissue Sampling 6 in.

33. Troubleshooting

34. Which is the better hay?

35. Chlorophyll and Nutrient Mg N H C O

37. Over 50% of applied N is absorbed in < 5 hrs. But, this is at relatively low rates -Avg. over 4.5 and 11 lbs of N/acre in this study. -Stiegler et al., 2010. Crop Sci. 51:1253-1260. Foliar Fertilization for Forage Crops?

38. Even if 60% absorption, at rate of 11 lbs/acre, that’s only 6.7 lbs of N absorbed foliar. -Highest rate of absorption I could find in literature. At higher rates, foliar fertilizers often burn (salt or chemical injury) the plant tissue In a separate study (Totten et al., 2008. J. Plant Nutr. 31:972-982), no consistent difference in clipping yield of turf.

39. Calculations Using 42-0-0 Five 25-lb bags/100 gallons of spray = 10 A  125 lbs of product/10 A or 12.5 lbs of product/A  12.5 lbs x 42% N = 5.25 lbs of N/A 42% N x 25 lbs = 10.5 lbs of N $47/bag / 10.5 lbs of N = $4.48 per lb of N Ammon. Nitrate is currently ~$0.70 per lb of N Five 25-lb bags/100 gallons of spray = 10 A  125 lbs of product/10 A or 12.5 lbs of product/A  12.5 lbs x 42% N = 5.25 lbs of N/A 42% N x 25 lbs = 10.5 lbs of N $47/bag / 10.5 lbs of N = $4.48 per lb of N Ammon. Nitrate is currently ~$0.70 per lb of N

40. Calculations Using 42-0-0 Let’s assume 4 applications of 75 lbs of N/acre  Conventional: 4 x 75 lbs x $0.70/lb= $210  Plus: spreading costs  Grasshopper (their rate) : 4 x 5.25 lbs x $4.48/lb = $94  “ (rec. N rate) : 4 x 75 lbs x $4.48/lb = $1344  Plus: water and spreading costs 1-ton of bermudagrass, @ 1.6% N = 32 lbs of N Bottomline: their math doesn’t add up (5.25 < 32). Let’s assume 4 applications of 75 lbs of N/acre  Conventional: 4 x 75 lbs x $0.70/lb= $210  Plus: spreading costs  Grasshopper (their rate) : 4 x 5.25 lbs x $4.48/lb = $94  “ (rec. N rate) : 4 x 75 lbs x $4.48/lb = $1344  Plus: water and spreading costs 1-ton of bermudagrass, @ 1.6% N = 32 lbs of N Bottomline: their math doesn’t add up (5.25 < 32).

41. Their 42-0-0 is Straight Urea!

42. Foliar Fertilizer Applications Even if the product is 100% efficient (likely isn’t) The most a plant can take up across via the leaves is the equivalent of 10-12 lbs/acre of the nutrient  Works for many micro-nutrients (small quantities needed)  Not feasible for macro-nutrients without multiple applications. (large quantities needed) Even if the product is 100% efficient (likely isn’t) The most a plant can take up across via the leaves is the equivalent of 10-12 lbs/acre of the nutrient  Works for many micro-nutrients (small quantities needed)  Not feasible for macro-nutrients without multiple applications. (large quantities needed)

43. www.georgiaforages.com