1. O K L A H O M A S T A T E U N I V E R S I T Y E VOLUTION OF N ITROGEN R EFERENCE S TRIPS

2. O K L A H O M A S T A T E U N I V E R S I T Y  1563 ◦ Huganote Bernard Palissy advocates the use of fertilizers in agriculture to stimulate plant growth  Did so after noticing that crops tended to have better production where manure had been applied

3. O K L A H O M A S T A T E U N I V E R S I T Y  1772 ◦ Daniel Rutherford discovers nitrogen  1790 ◦ French chemist Jean-Antoine-Claude Chaptal coins the name ‘nitrogen’ using a combination of Greek and French words meaning “to engender, bring forth”

4. O K L A H O M A S T A T E U N I V E R S I T Y  1827 ◦ Justus Liebig’s famous Mineral Theory.  The Mineral Theory states that plant growth is limited by the most limited available mineral in the soil. The application of this theory led to the development of mineral fertilizer.

5. O K L A H O M A S T A T E U N I V E R S I T Y  1913 ◦ The process that would become known as the Haber-Bosch process was developed by Fritz Haber and Carl Bosch.  The process was the first industrial chemical process to use high pressure for a chemical reaction.  This process is the most economical for the fixation of nitrogen and continues to this day  This process would help usher in the Green Revolution

6. O K L A H O M A S T A T E U N I V E R S I T Y  Since the introduction of synthetic fertilizers, inaccurate fertilizer rates (either too much or too little) have been applied. ◦ This is the result of failing to recognize temporal variability.

7. O K L A H O M A S T A T E U N I V E R S I T Y Ave Yld 42 bu/ac

8. O K L A H O M A S T A T E U N I V E R S I T Y N need determined by N-up 112 – N-up check * 50% efficiency

9. O K L A H O M A S T A T E U N I V E R S I T Y

10. NUE  Nitrogen Use Efficiency (NUE) in the world for cereal grain production ~ 33%  Crop production directly related to availability of N  Need methodologies that consider: ◦ Crop production practices  Every Farmer is different ◦ Aesthetic qualities  The crop has to look good ◦ Economical analysis  The bottom line is what counts ◦ Environmental stewardship  Pollution costs everyone

11. O K L A H O M A S T A T E U N I V E R S I T Y  Fueling a Tractor ◦ John Deere 7810  90 gal. Fuel Tank  ~ $315 30 gal 60 gal 90 gal

12. O K L A H O M A S T A T E U N I V E R S I T Y 30 gal 60 gal  Fueling a Tractor ◦ John Deere 7810  90 gal. Fuel Tank  ~ $315  Only Needed 45 gal Over-filled 45 gal (lost)  Cost ~ $315 Money lost ~ $157.5 90 gal

13. O K L A H O M A S T A T E U N I V E R S I T Y  Fueling a Tractor ◦ John Deere 7810  90 gal. Fuel Tank  ~ $315  Needed 0 gal Over-filled 90 gal (lost)  Cost ~ $315 Money lost ~ $315  The Fuel Gauge is our reference to how much fuel is in the tank. We can add accordingly. 30 gal 60 gal 90 gal

14. O K L A H O M A S T A T E U N I V E R S I T Y  Can there be such a thing? ◦ If so, how?  THE ANSWER…….. ◦ Nitrogen Reference Strips  N-Stamp, N-Rich Strip, N-Ramp

15. O K L A H O M A S T A T E U N I V E R S I T Y  An indicator that orients the producer to the nitrogen levels within the field to aid in making a better mid-season nitrogen rate recommendation. ◦ Superimposed on existing farmer pre-plant practices ◦ Provides a measure of how much additional N is needed, if any ◦ Minimizes risk

16. O K L A H O M A S T A T E U N I V E R S I T Y  Current practices for making mid-season fertilizer N recommendations in most crops are not consistent from one region to the next  1 N rate – In excess of what is required by the plant for the entire growing season. ◦ Answers the question – Do I need to apply any additional N fertilizer?  YES or NO ◦ With GreenSeeker sensor and SBNRC can obtain RI, predict yield potential, and determine optimum N rate for maximum yield

17. O K L A H O M A S T A T E U N I V E R S I T Y

19. N ITROGEN R AMP C ALIBRATION S TRIP – 2006 – 2009

20. O K L A H O M A S T A T E U N I V E R S I T Y

21. Ramp Calibration Strip Fertilization Strategy – 2006 – 2009  Concept of visually evaluating plots with incremental rates of pre-plant N ◦ Identify minimum N rate required for maximum production

22. O K L A H O M A S T A T E U N I V E R S I T Y March 2007, The Furrow, Larry Reichenberger

23. O K L A H O M A S T A T E U N I V E R S I T Y  Fueling a Tractor ◦ John Deere 7810  90 gal. Fuel Tank  ~ $315 30 gal 60 gal 90 gal  When Empty: 90 gal Over-filled 0 gal ( 0 gal lost)  Cost ~ $315 Money lost ~ $0  ONLY PUT IN WHAT IS NEEDED!

24. O K L A H O M A S T A T E U N I V E R S I T Y 30 gal 45 gal  Fueling a Tractor ◦ John Deere 7810  90 gal. Fuel Tank  ~ $315  When Half-Full: 45 gal Over-filled 0 gal ( 0 gal lost)  Cost ~ $157.5 Money lost ~ $0  ONLY PUT IN WHAT IS NEEDED!

25. O K L A H O M A S T A T E U N I V E R S I T Y  Fueling a Tractor ◦ John Deere 7810  90 gal. Fuel Tank  ~ $315  When Full: 0 gal Over-filled 0 gal (0 gal lost)  Cost ~ $0 Money lost ~ $0  ONLY PUT IN WHAT IS NEEDED!  The Fuel Gauge is our reference to how much fuel is in the tank. We can add accordingly. 0 gal

26. O K L A H O M A S T A T E U N I V E R S I T Y  N-REFERENCE STRIPS ◦ OUR GAUGE TO THE NITROGEN LEVEL IN THE FIELD ◦ OUR GAUGE TO IDENTIFY HOW MUCH ADDITIONAL NITROGEN, IF ANY, IS NEEDED BY THE CROP TO PRODUCE MAXIMUM YIELDS.

27. O K L A H O M A S T A T E U N I V E R S I T Y Mid-Season Evaluation of N Rich Strip (Ciudad Obregon, MX) Average Wheat Yields = 150 bu/ac (irrigated spring wheat) N-Rich Strip 300 lbs N ac -1 0 lbs N ac -1

28. O K L A H O M A S T A T E U N I V E R S I T Y SBNRC and the N-Rich Strip Using Sensor Data and the Nitrogen Fertilizer Optimization Algorithm, N-Rates are prescribed for each field and its condition/environment.

29. O K L A H O M A S T A T E U N I V E R S I T Y NDVI= NIR – Red NIR + Red NIR Red

30. O K L A H O M A S T A T E U N I V E R S I T Y Yield Prediction Model Response Index Nitrogen Removal What is needed for a The calculation looks like: N Rate = (Potential Yield of Farmer Practice * RI- YP FP)* N in Grain / NUE

31. O K L A H O M A S T A T E U N I V E R S I T Y N-Rich Strip Matt Steinert, Covington, OK (March 20, 2003) Planting date NDVI (sensing date) days from planting to sensing Predicted yield with no added N fertilization (YP 0 ) Predicted yield with N fertilization (YP N ) INSEY = (NDVI/days from planting to sensing where GDD>0) YPN = YP0 * RI Fertilizer N = (Grain N uptake at YPN – Grain N uptake at YP0)/0.7 RI Farmer Practice Response Index =0.75/0.57 = 1.31

32. O K L A H O M A S T A T E U N I V E R S I T Y SBNRC (YP0*RI =YPN) 100 Pre (100 lbs N/ac applied preplant) Yield Prediction

33. O K L A H O M A S T A T E U N I V E R S I T Y  Numerical, describe the crops BIOMASS.  DOES NOT really WORK WITH OUT A REFERENCE..........  Multiple options ◦ Companies ◦ Resolution

34. O K L A H O M A S T A T E U N I V E R S I T Y E XTENSION AND A NALYSIS OF THE R AMP C ALIBRATION S TRIP F ERTILIZATION S TRATEGY

35. O K L A H O M A S T A T E U N I V E R S I T Y P URPOSE OF S TUDY 2007 Intentions  Implement & Evaluate the RCS strategy in the following crops: ◦ Alfalfa ◦ Bermudagrass ◦ Corn ◦ Cotton ◦ Grain Sorghum  Extend the RCS strategy in the following crop: ◦ Wheat

36. O K L A H O M A S T A T E U N I V E R S I T Y M ATERIALS & M ETHODS  Grain Sorghum ◦ 4 replications of 5 treatments + 1 or 2 N-Ramp(s) ◦ Complete Randomized Block Design Grain Sorghum Trt. Pre-Plant N (kg ha -1 ) Mid-Season N (kg ha -1 ) 1.56 (50 lb N/Ac) 0 (0 lb N/Ac) 2.56 (50 lb N/Ac) 84 (75 lb N/Ac) 3.56 (50 lb N/Ac) 168 (150 lb N/Ac) 4.56 (50 lb N/Ac) RCS Visual 5.56 (50 lb N/Ac) RCS Sensor Experiment site – R.L. Westerman Irrigation Research Center located west of Stillwater, OK.

37. O K L A H O M A S T A T E U N I V E R S I T Y Grain Sorghum Application of N-Ramp Strategy R.L. Westerman Irrigation Research Center at Lake Carl Blackwell Plot size: 3 m x 6 m Alley: 1.5 m 4 replications Ramp: 4.25 m x 52 m Treatments (N applied mid-season) 1.0 kg N/ ha 2.84 kg N/ ha 3.168 kg N/ ha 4.RCS Visual 5.RCS Sensor N-RAMPN-RAMP 41352 45231 41352 24531 N E S W

38. O K L A H O M A S T A T E U N I V E R S I T Y G RAIN S ORGHUM – R ESULTS  Average Yields Grain Sorghum Trt.Pre-Plant N (kg ha -1 ) Mid-Season N (kg ha -1 ) Total N (kg ha -1 ) Yield (kg ha -1 ) Gross Return ($ ha -1 ) 1.56 (50 lb N/Ac) 0 (0 lb N/Ac) 56 (50) 2776 (2475) 292 ($118 / Ac) 2.56 (50 lb N/Ac) 84 (75 lb N/Ac) 140 (125) 5033 (4488) 490 ($198 / Ac) 3.56 (50 lb N/Ac) 168 (150 lb N/Ac) 224 (200) 6166 (5499) 547 ($222 / Ac) 4.56 (50 lb N/Ac) 73 (65 lb N/Ac) RCS Visual 129 (115) 4783 (4265) 470 ($190 / Ac) 5.56 (50 lb N/Ac) RCS Sensor 112 (100) 5370 (4789) 561 ($227 / Ac) Gross Return: N cost = $1.01 / kg, Sorghum = $0.125 / kg $0.46 / lb $0.057 / lb

39. O K L A H O M A S T A T E U N I V E R S I T Y  2003: OSU applied 62 NRS  2004: 300 NRS in Farmers Fields  2005: SBNRC released, 1000 NRS  2006: OSU applied 568 NRS 1,500 NRS by 1 cooperator alone estimated 230,000 acres under NRS  2007: 25 county educators reported having NRS  2009: Survey reported 4,000 NRS

40. O K L A H O M A S T A T E U N I V E R S I T Y W HEAT – E XTENSION OF N-RCS A PPROACH Recap  Fall 2006 ◦ N-Ramps placed in 586 farmer fields throughout Oklahoma covering a service area of 81,000 hectares (200,000 Acres)

41. O K L A H O M A S T A T E U N I V E R S I T Y  Fall 2007 ◦ N-Ramps or N-Rich Strips placed in 224 farmer fields throughout Oklahoma

42. O K L A H O M A S T A T E U N I V E R S I T Y  February/March 2007 ◦ County Extension Agents  Sensed N-Ramps  Provided top-dress N recommendations to producers  Collected data for submission to N-Ramp extension team

43. O K L A H O M A S T A T E U N I V E R S I T Y E XTENSION OF N-RCS A PPROACH IN W HEAT – R ESULTS  Average Typical Top-Dress N Rate ◦ 125 kg N / ha (110 lb N/Ac)  Average RCS N-Recommendation ◦ 60 kg N / ha (53 lb N/Ac)  Average Actual Top-Dress N Applied ◦ 90 kg N / ha (80 lb N/Ac)  50 % more than the RCS recommendation  73 % of typical top-dress N rate  Represents savings of $ 35.45 ha -1 ($13.80 Ac -1 )  Represents total savings of $ 2,760,000

44. O K L A H O M A S T A T E U N I V E R S I T Y 2009 Farmer PracticeSBNRC LocationNrateYieldProteinNrateYieldProtein Site 1 392311.91482612.08 Site 2 365313.51495413.68 Site 3 8439 33 Site 4 605211.69244410.66 Site 5 605914.4276114.54 Site 6 606611.69386210.83 Site 7 332910.15593710.20 Site 8 284210.26594811.12 Averages504511.95414611.87 2010 LocationNrateYieldProteinNrateYieldProtein Site 1 1606315.16236213.05 Site 2 603912.48494012.60 Site 3 604012.20724211.86 Site 4 509113.57349114.25 Site 5 406510.89486711.06 Site 6 504515.05124614.59 Averages705713.22405812.90 Total595012.54405112.35

45. O K L A H O M A S T A T E U N I V E R S I T Y C ONCLUSIONS  Current practices for making mid-season fertilizer N recommendations in most crops are not consistent from one region to the next  The N-Ramp Approach: ◦ Using automated gradients of pre-plant N fertilizer to determine mid-season N rates based on plant response ◦ Applied methodology integrating farmer input and insight in the decision making process ◦ Provides visual mid-season alternative approach for N fertilization