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

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

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”

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.

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

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.

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

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

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

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

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  ~ $ gal 60 gal 90 gal

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 ~ $ gal

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

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

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

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

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

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

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

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

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

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  ~ $ 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!

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!

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

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.

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

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.

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

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

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

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

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

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

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

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.

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 kg N/ ha 4.RCS Visual 5.RCS Sensor N-RAMPN-RAMP N E S W

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

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

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)

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

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

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 $ ha -1 ($13.80 Ac -1 )  Represents total savings of $ 2,760,000

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 Site Site Site Site Site Site Site Averages LocationNrateYieldProteinNrateYieldProtein Site Site Site Site Site Site Averages Total

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