New Technology and Strategies for Nitrogen Management

1. New Technology and Strategies for Nitrogen Management

2. Traditional N Recommendations • 2 lbs/bushel of wheat • 1.2 lbs/bushel of corn • 50 lbs/ton of bermudagrass • 60 lbs/ton of fescue, small grain pasture

3. Conventional Strategy is Easy and Profitable. Crop N requirement = 2 lb N/bu yield Average profit from N = $36/acre/yr

4. In season environmental conditions Within field variability Temporal and Spatial Variability

5. What Scale is Necessary for Precision Ag?

6. Temporal Variability • Historically, it was thought that if N was not applied annually crop production would eventually deplete the soil of its N reserve. $17/A Benefit from in-season yield estimate

7. Optimum N Rate(Grain N Uptake Max Yield – Grain N Uptake Check)/0.50 Long-Term Winter Wheat ExperimentLahoma, OK “After the FACT” N Rate required for “MAX Yields” Ranged from 0 to 140 lbs N/ac

8. GreenSeeker® Sensor Function Emits Red & InfraRed Wavelengths Outputs NDVI— indicates Biomass and Plant Vigor Day or Night Use No Effect from Clouds

9. Normalized Difference Vegetative Index - NDVI • Calculated from the red and near-infrared bands • Measures Biomass • Correlated with: • Plant biomass • Crop yield • Plant nitrogen • Plant chlorophyll • Water stress • Plant diseases • Insect damage

10. Can Yield Potential (similar to “yield goals”) be Predicted MID-SEASON? Sensor Reading

11. Winter Wheat, Enid, 2005

13. Handheld Unit – • Temporal Variability • In season environmental conditions

14. Sensor Based Nitrogen Recommendations • N Rates Vary from one year to the next, and field to field • When you fill up your gas tank, do you put in 20 gallons every time no matter what? • Sensors allow in season decisions for nitrogen rates

15. Progress timeline • 1991: Developed optical sensors and sprayer control systems to detect bindweed in fallow fields and to spot spray the weed • 1993: Sensor used to measure total N uptake in wheat and to variably apply N fertilizer. • 1994: Predicted forage biomass and total forage N uptake using NDVI (Feekes 5). • 1994: First application of N fertilizer based on sensor readings. N rate was reduced with no decrease in grain yield. • 1996: Worlds first optical sensing variable N rate applicator developed at OSU • 1997: OSU optical sensor simultaneously measures incident and reflected light at two wavelengths, (670 ±6 nm and 780 ±6 nm) and incident light is cosine corrected enabling the use of calibrated reflectance. • 1997: Variable rate technology used to sense and treat every 4 square • 1998: Yields increased by treating spatial variability and OSU’s In-Season-Estimated-Yield (INSEY) • 1998: INSEY refined to account for temporal variability • 1999: Found that adjacent 4 square foot areas will not always have the same yield potential • 1999: Entered into discussions with John Mayfield concerning the potential commercialization of a sensor-based N • 2000: N fertilizer rate needed to maximize yields varied widely over years and was unpredictable; developed RI • 2001: NDVI readings used for plant selection of triticales in Mexico. • 2001: NFOA algorithm field tested in 2001, demonstrating that grain yields could be increased at lower N rates when N fertilizers were applied to each 4 square feet (using INSEY and RI) • 2002: Ideal growth stage in corn identified for in-season N applications in corn via daily NDVI sampling in Mexico as V8. • 2003: CV from NDVI readings collected in corn and wheat were first used within NFOA’s developed at OSU. • 2003: When site CV’s were greater than 18, recovery of maximum yield from mid-season fertilizer N applications was not possible in wheat • 2004: Calibration stamp technology jointly developed and extended within the farming community • 2004: OSU-NFOA’s (wheat and corn) used in Argentina, and extended in China and India. • 2005: USAID Grant allowed GreenSeeker Sensors to be delivered in China, India, Turkey, Mexico, Argentina, Pakistan, Uzbekistan, and Australia. • 2006: Delivery of 586 RAMPS and 1500 N Rich Strips (using RCS and SBNRC approaches respectively) in farmer fields across Oklahoma resulted in an estimated service area exceeding 200,000 acres and increased farmer revenue exceeding $2,000,000.

16. Handheld Unit – • Temporal Variability • In season environmental conditions Handheld GreenSeeker™ units located in several NE District Extension Offices

19. 2005-2006 WheatGreenSeeker/N Rich Strip • 1 Farm – 43 wheat fields – 1665 Acres • Traditional Program – 100 pounds N/A • Handheld GreenSeeker ($3600) Saved 149,529 lbs of Urea, $14.59/A, $24,300

20. Regional GreenSeeker Grain Yields - 2005

21. Regional GreenSeeker Profits

22. 2006 NE GreenSeeker/Corn Trials 75 lbs N – Pre+GreenSeeker 175 272 346 367 290 0 N – Pre+GreenSeeker 209 280 333 348 293 Farmer Practice 203 259 265 289 254 Treatment Miami South Coffeyville Webbers Falls Ft. Gibson All Site Average Check 228 253 270 375 282 N-Rich 141 171 351 324 247 Gross Return ($/A)

23. 2006 NE GreenSeeker/Corn Trials 75 lbs N – Pre+GreenSeeker 87 123 155 167 133 0 N – Pre+GreenSeeker 89 120 140 150 125 Farmer Practice 92 122 144 153 128 Treatment Miami South Coffeyville Webbers Falls Ft. Gibson All Site Average Check 91 101 108 150 113 N-Rich 102 114 186 175 144 Grain Yield (Bu/A)

24. 2006 NE GreenSeeker/Corn Trials 75 lbs N – Pre+GreenSeeker 112 (37) 93 (17) 110 (35) 132 (57) 112 (37) 0 N – Pre+GreenSeeker 36 52 45 71 51 Farmer Practice 70 120 250 246 172 Treatment Miami South Coffeyville Webbers Falls Ft. Gibson All Site Average Check 0 0 0 0 0 N-Rich 300 300 300 300 300 Total N Applied (lbs N/A)

25. Calibration Stamp Visual Interpretation of “Stamps” provides mid-season fertilizer N recommendation

26. Nitrogen Stamp N Stamps applied – Nov. 16, 2004

27. Optical Sensor Alternative N Stamps 40 N 80 N 120 N N Stamp – Sperry, OK Jan 27, 2005 Wheat planted Sept. 30, 2004

28. GDD 74 NDVI N Rich .562 NDVI FP .364 Yield Potential 0 N – 42 bushels Yield Potential + N – 73 bushels N recommedation – 75 lbs./A Ottawa County February 15, 2005 120 lbs N 80 lbs N 40 lbs N

30. NDVI RI = 1.5 RI = 1.5 Distance 0 50 100 150 N Rate

31. NRamp Calibration Strip

35. Ramp Calibration Strip • Walk it off • Or use Hand-Held Sensor 0 N 195 N

36. RAMP Calibration Strips • Ramped calibration strip is superior than yield based N recommendation • It can be easily implemented, be used for other fertilizers and amendments

38. 200 N 0 N 325 N McIntosh County 2007 Visual Estimate from Ramp

39. 200 N 0 N 325 N Delaware County 2007 Visual Estimate from Ramp

40. We have the capability to fertilize individual plants

41. Soil Testing Still Needed • Every 3 years or less • Routine test for P,K, pH • To diagnose production problems