Sensors and Fertility Management

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Sensors and Fertility Management

Randy TaylorExtension Engineer, Machinery Systems

Biosystems and Ag Engineering

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Reference Strips for Nitrogen Oklahoma State has recommended

nitrogen reference (rich) strips to assist in season nitrogen management for corn and wheat

Recently OSU has implemented Ramped Calibration Strips (RCS) to allow visual and sensor assessment of nitrogen management

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2006-07 Ramp Program

586 farmer’s fields have had Ramp Calibration Strips placed in them

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Documenting Impact Each RCS has an

associated contact person who will collect sensor data. complete the data

sheet.

Many were lost due to grazing, drought, or freeze.

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What is a RCS?

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Reading Ramp Strips

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Can the Sensor Perform?

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0 50 100 150 200 250

N Rate, lbs/ac

ND

VI

NDVISAS

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Recommendations

Statewide SBNRC 22

lbs/ac RCS 54

lbs/ac

Garfield County SBNRC 27

lbs/ac RCS 60

lbs/ac

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Statewide Data Summary 117 fields with sufficient data to draw

inferences Applied N was 73% of “typical”

topdress rates Applied N was 147% of RCS

recommendation Applied N was 290% of the SBNRC

recommendation

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RCS Applicators

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RCS Applicator Components

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We constructed a sprayer with sets of 4 StreamJet nozzles from TeeJet per location. Nozzles are spaced on 24 inch centers. The four nozzles are an 01, 02, 04, and 08. We are using a design pressure of 40 psi.

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Nozzle Control

RCS Starts

RCS Ends

GPM flow rates are for 28% fertilizer solution.

Each step lasts approximately 10 feet.

SJ3-01 SJ3-02 SJ3-04 SJ3-08 GPM lbsN/acON ON ON ON 1.33 200

ON ON ON 1.24 187ON ON ON 1.15 173

ON ON 1.06 160ON ON ON 0.97 147

ON ON 0.88 133ON ON 0.80 120

ON 0.71 107ON ON ON 0.62 93

ON ON 0.53 80ON ON 0.44 67

ON 0.35 53ON ON 0.27 40

ON 0.18 27ON 0.09 13

0.00 0ON ON ON ON 1.33 200

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Rendel Farms Applicator 7 tip sets on 20” center 4 solenoid control valves 50 gallon poly tank PTO-driven roller pump 1” supply line ½” spray line

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Johnson Farms Applicator

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Boom Width Ramps

0

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-40 -30 -20 -10 0 10 20 30 40

Nozzle Location, ft

Ap

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lbsN

/ac

3 nozzles together to make a 5 ft. section of one rate.

A challenge is the large rate steps at the higher end.

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EXTENSION AND ANALYSIS OF THE RAMP CALIBRATION STRIP

FERTILIZATION STRATEGY

D.E. Edmonds, D.B. Arnall, B. Chung, M.C. Daft, K. Girma, C.R. Dotson, B.B. England, S.L. Holtz, C.J. Mack, W.R.

Raun, J.B. Solie, R.K. Taylor, B.S. Tubaña, P.L. Turner, O.S. Walsh, D.L. Zavodny

ASA-CSSA-SSSA2007

New Orleans, LA

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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

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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

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Y 224 0 17 34 51 68 85 112 129 224 0 17 34 51 68 85 112 129 N Rate, kg/ha N Rate, kg/ha

224224

001717

3434

224224

RAMP Calibration StripRAMP Calibration Strip

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March 2007, The Furrow, Larry Reichenberger

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PURPOSE OF STUDY

Implement & Evaluate the RCS strategy in the following crops: Alfalfa Bermudagrass Corn Cotton Grain Sorghum

Extend the RCS strategy in the following crop: Wheat

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YMATERIALS & METHODS

Alfalfa, 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 0

2. 56 84

3. 56 168

4. 56 RCS Visual

5. 56 RCS Sensor

Experiment site – R.L. Westerman Irrigation Research Center located west of Stillwater, OK.

Alfalfa

Trt.N applied after each cutting (kg ha-1)

1. 0

2. 22.4

3. 44.8

4. RCS Visual

5. RCS Sensor

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YGrain SorghumApplication of N-Ramp StrategyR.L. Westerman Irrigation Research Center at Lake Carl Blackwell

Plot size: 3 m x 6 mAlley: 1.5 m4 replicationsRamp: 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

-

R

A

M

P

4 1 3 5 2

4 5 2 3 1

4 1 3 5 2

2 4 5 3 1

15.25 m3 m

6 m

1.5 m52 m

4.25 m

Rep. 1

Rep. 2

Rep. 3

Rep. 4

0

6

7.5

13.5

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21

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3691215

29 m

N

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Y ALFALFA – RESULTS

Inconclusive for 2007 Limited number of cuttings

Average Yields 1st Cutting

5607 kg ha-1

2nd Cutting 3734 kg ha-1

Alfalfa

Trt.N applied after each cutting (kg ha-1)

1. 0

2. 22.4

3. 44.8

4. 0 - RCS Visual

5. 0 - RCS Sensor

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Y GRAIN SORGHUM – RESULTS

Average Yields

Grain SorghumTrt. 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 0 56 2776 290

2. 56 84 140 5033 488

3. 56 168 224 6166 545

4. 56 73

RCS Visual

129 4783 468

5. 56 56

RCS Sensor

112 5370 558

Gross Return: N cost = $1.01 / kg, Sorghum = $0.125 / kg

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WHEAT – EXTENSION OF N-RCS APPROACH

Fall 2006 N-Ramps placed in 586 farmer fields throughout

Oklahoma covering a service area of 81,000 hectares

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Garfield County Ramp Strips

March 22, 2007

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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

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Y EXTENSION OF N-RCS APPROACH IN WHEAT – RESULTS

Average Typical Top-Dress N Rate125 kg N / ha

Average RCS N-Recommendation60 kg N / ha

Average Actual Top-Dress N Applied90 kg N / ha

50 % more than the RCS recommendation73 % of typical top-dress N rate

Represents savings of $ 4.38 ha-1

Represents total savings of $ 354,375

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Y 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

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YEXTENSION AND ANALYSIS OF THE RAMP CALIBRATION STRIP FERTILIZATION STRATEGY

QUESTIONS

DANIEL E. EDMONDS

www.nue.okstate.edu/