Annual Nutrient Removal by the Primary Hay Crops in the South Adapted from Southern Forages, 2007 and Myer et al, 2010.

Spinner Spreader Air-flow Applicator

Spinner Spreader Source: Fulton et al., 2003; 2005

Air-flow Applicator Application Rate (lbs/acre) Desired Levels 400 lbs/A 100 lbs/A 200 lbs/A 300 lbs/A

Spinner Spreader Source: Fulton et al., 2003 and unpublished data Air-flow Applicator

Low to High High to Low Source: Fulton et al., 2003

Fertilization Trick Account for N Loss from Urea-based Products

N Fertilizer Application Urea urease + H 2 0

Urea urease Ammonia + H 2 0 Ammonium +

Urea urease Ammonia + H 2 0 Ammonium + AN Nitrate -

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* 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.

Alternative N Sources Take-home message: If you have to use a urea-based product, be careful about cutting your rate back too much. -They are relatively less effective at low rates.

Fertilization Strategies New N Fertilizer Products

Introduction 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

Ammonia Volatilization Trap Data (avg. over two locations)

Bermudagrass Hay Yield (Calhoun)

Results: Yield Data : Forage Yield of ‘Russell’ Bermudagrass Equal Splits † SourceEatontonCalhounEatontonCalhoun (lbs of DM/acre) ATU ‡ ESN NSN Urea Urea AN Check LSD † Equal split applications of N that occurred during the season. Total N applied = 300 lbs N/acre. ‡ Items that are in bold font are not significantly different from the highest value in the column.

Bermudagrass Hay Yield 2010 (Equal splits, 4 applications, 300 lbs N/ac total)

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.

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

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

K is the Key to a Good Stand

Low Soil pH

Aluminum Toxicity – Low Soil pH Alfalfa control treated

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

Tissue Sampling and Troubleshooting

Tissue Sampling 6 in.

Troubleshooting

Which is the better hay?

Chlorophyll and Nutrient Mg N H C O

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 1-2 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 1-2 lbs/acre of the nutrient  Works for many micro-nutrients (small quantities needed)  Not feasible for macro-nutrients without multiple applications. (large quantities needed)