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Spinner Spreader Source: Fulton et al., 2003 and unpublished data Air-flow Applicator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

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.

Ammonia Volatilization Trap Data (avg. over two locations)

Additional Data 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

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)