EVOLUTION OF NITROGEN REFERENCE STRIPS

HISTORY 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

HISTORY 1772 1790 Daniel Rutherford discovers nitrogen French chemist Jean-Antoine-Claude Chaptal coins the name ‘nitrogen’ using a combination of Greek and French words meaning “to engender, bring forth”

HISTORY 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.

HISTORY 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

FERTILIZER APPLICATIONS 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.

Crop production directly related to availability of N RESULT 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

EXAMPLE Fueling a Tractor 90 gal 30 gal 60 gal John Deere 7810 90 gal. Fuel Tank ~ $270 90 gal 30 gal 60 gal

EXAMPLE Only Needed 45 gal Fueling a Tractor 90 30 60 Over-filled 45 gal (lost) Cost ~ $270 Money lost ~ $135 Fueling a Tractor John Deere 7810 90 gal. Fuel Tank ~ $270 90 gal 30 gal 60 gal

EXAMPLE Needed 0 gal Fueling a Tractor Over-filled 90 gal (lost) Cost ~ $270 Money lost ~ $270 Fueling a Tractor John Deere 7810 90 gal. Fuel Tank ~ $270 60 gal 30 gal 90 gal The Fuel Gauge is our reference to how much fuel is in the tank. We can add accordingly.

GAUGE FOR NITROGEN IN OUR FIELDS? Can there be such a thing? If so, how? THE ANSWER…….. Nitrogen Reference Strips N-Stamp, N-Rich Strip, N-Ramp

NITROGEN REFERENCE STRIP 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

NITROGEN RICH STRIP – 2002 – Present 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

NITROGEN CALIBRATION STAMP – 2004-2005

NITROGEN RAMP CALIBRATION STRIP – 2006 – Present

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

March 2007, The Furrow, Larry Reichenberger

N-Reference Strip methodologies 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

The N-Reference Strip Approach: CONCLUSIONS Current practices for making mid-season fertilizer N recommendations in most crops are not consistent from one region to the next The N-Reference Strip Approach: Uses 1 rate or a gradient 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

EXAMPLE When Empty: 90 gal Fueling a Tractor Over-filled 0 gal ( 0 gal lost) Cost ~ $270 Money lost ~ $0 ONLY PUT IN WHAT IS NEEDED! Fueling a Tractor John Deere 7810 90 gal. Fuel Tank ~ $270 90 gal 30 gal 60 gal

EXAMPLE When Half-Full: 45 gal Fueling a Tractor Over-filled 0 gal ( 0 gal lost) Cost ~ $135 Money lost ~ $0 ONLY PUT IN WHAT IS NEEDED! Fueling a Tractor John Deere 7810 90 gal. Fuel Tank ~ $270 30 gal 45 gal

EXAMPLE When Full: 0 gal Fueling a Tractor ONLY PUT IN WHAT IS NEEDED! Over-filled 0 gal (0 gal lost) Cost ~ $0 Money lost ~ $0 ONLY PUT IN WHAT IS NEEDED! Fueling a Tractor John Deere 7810 90 gal. Fuel Tank ~ $270 0 gal The Fuel Gauge is our reference to how much fuel is in the tank. We can add accordingly.

LIKEWISE… 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.

EXTENSION AND ANALYSIS OF THE RAMP CALIBRATION STRIP FERTILIZATION STRATEGY

Crop production directly related to availability of N INTRODUCTION 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 Aesthetic qualities Economical analysis Environmental stewardship

Ramp Calibration Strip Fertilization Strategy Concept of visually evaluating plots with incremental rates of pre-plant N Identify minimum N rate required for maximum production

RAMP Calibration Strip 224 0 17 34 51 68 85 112 129 N Rate, kg/ha 224 34 17 224

March 2007, The Furrow, Larry Reichenberger

PURPOSE OF STUDY 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

MATERIALS & METHODS Alfalfa, Grain Sorghum Alfalfa Grain Sorghum Experiment site – R.L. Westerman Irrigation Research Center located west of Stillwater, OK. Alfalfa, Grain Sorghum 4 replications of 5 treatments + 1 or 2 N-Ramp(s) Complete Randomized Block Design Alfalfa Trt. N applied after each cutting (kg ha-1) 1. 0 (0 lb N/Ac) 2. 22.4 (20 lb N/Ac) 3. 44.8 (40 lb N/Ac) 4. RCS Visual 5. RCS Sensor 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. 84 (75 lb N/Ac) 3. 168 (150 lb N/Ac) 4. RCS Visual 5. RCS Sensor

(N applied mid-season) 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 Grain Sorghum Application of N-Ramp Strategy R.L. Westerman Irrigation Research Center at Lake Carl Blackwell 15.25 m 3 m 6 m 1.5 m 52 m 4.25 m Rep. 1 Rep. 2 Rep. 3 Rep. 4 6 7.5 13.5 15 21 22.5 28.5 3 9 12 29 m N - R A M P 4 1 3 5 2 N E S W 4 5 2 3 1 4 1 3 5 2 Plot size: 3 m x 6 m Alley: 1.5 m 4 replications Ramp: 4.25 m x 52 m 2 4 5 3 1

ALFALFA – RESULTS Alfalfa Inconclusive for 2007 Average Yields Limited number of cuttings Average Yields 1st Cutting 5607 kg ha-1 (5000 lb Ac-1) 2nd Cutting 3734 kg ha-1 (3330 lb Ac-1) Alfalfa Trt. N applied after each cutting (kg ha-1) 1. 2. 22.4 3. 44.8 4. 0 - RCS Visual 5. 0 - RCS Sensor

GRAIN SORGHUM – RESULTS Average Yields Grain Sorghum Trt. Pre-Plant N (kg ha-1) Mid-Season N (kg ha-1) Total N Yield 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. 168 (150 lb N/Ac) 224 (200) 6166 (5499) 547 ($222 / Ac) 4. 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

WHEAT – EXTENSION OF N-RCS APPROACH Recap Fall 2006 N-Ramps placed in 586 farmer fields throughout Oklahoma covering a service area of 81,000 hectares (200,000 Acres)

Garfield County Ramp Strips March 22, 2007

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

EXTENSION OF N-RCS APPROACH IN WHEAT – RESULTS 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

WHEAT – EXTENSION OF N-RCS APPROACH Fall 2007 N-Ramps or N-Rich Strips placed in 224 farmer fields throughout Oklahoma

CONCLUSIONS 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