Precision Agriculture

Prescription Validation

Nicole Rabe (Land Resource Specialist)

Environmental Management Branch

OMAFRA

Feb 14, 2017.

Co-operator yield

data submitted

+

collect other base

data layers to fill gaps

Goals: wireless

data transfer &

analyze data layers

with transparent

mathematics for

teaching farmers

Rx maps:

implemented with

validation built in

& industry

support

Current Project:

This project was funded in part through Growing Forward 2, a federal-

provincial-territorial initiative.

The Agricultural Adaptation Council assists in the delivery of Growing

Forward 2 in Ontario.

Requirementsfor Sites:

• ~50 acres

• Corn, soy, wheat rotation

• good drainage

• average to medium base levels P & K

• Manure history is fine BUT during project would have to be monitored for impacts

• Farmer had to have VR equipment for at least 1 project operation (seed or fertilizer )

Goal: site-specific management of two most expensive inputs:1. Seed2. Fertilizer (nitrogen)

Total of 20-25 fields (constant), 3 year study (2015-2017)

Base Data Layers

4

Elevation: Topographic Wetness Potential7 Year - Yield Potential Index (YPI)

UAV Natural Colour

Image

July 2016Electrical Conductivity

Proxy for Soil Texture

Highest producing areas

Middle

Lowest producing areas

Baseline Soil Chemistry

Directed 1 ac grid

AGRONOMIC VALIDATION?Action of checking or proving the validity or accuracy of something. A technique required in controlled trials….

2016Strip Trial Examples

Variable Rate Nitrogen

VR Soybean Population

2016 “Learning Stamp” Example

7

Prescription Maps

Yield Potential Index

based so far…

As-Applied

Verification of Equipment

Cleaned Yield Data

Case Study 1: VR Population SoybeansPerth County: Learning Stamps 8yrs yield

8

Year Crop Mean

2007 Soybeans 45.76

2008 Wheat 97.11

2009 Corn 181.17

2010 Edible Beans

32.03

2011 Wheat 88.90

2012 Corn 191.21

2013 EdibleBeans

49.19

2014 Wheat 81.16

2015 Corn 196.51

Soybean Theory- low zones get high seeding rates

- high zones get low seeding rate (due to disease pressure)

• Each grid is planter width of 30ft• Stamps 90x90 ft• To see response we have extra

low (100k sds/ac) & extra high (200k sds/ac)

Yield Potential Index

1.99 2.634.07 4.67

13.36

0

5

10

15

May June July Aug Total

Precip Monthly(CoCoRahs CAN-ON-185)

Validation through the growing season…

Acknowledge UAV Partner:

Green NDVI

June 29th 2016

Soybean Population Count

July 6, 2016

Each point represents a transect for population counts

The value of sufficient replication in each management zone

HIGH Zone

– No statistical diff. for yield or economics from 100 to 200k sds/acre

– Supports theory that lower seeding rates is good assumption,

– Rx rate of 100k sds/ac was good

MEDIUM Zone

– No statistical diff. for yield or economics from 100 to 200k sds/acre

– Medium rate was fine at 150k sds/ac

LOW Zone

– No statistical difference for yield; tendency for lower yields with increasing seeding rates.

– Economics: $97/ac loss from 100 to 200 thousand seeds/ac

– Rx theory that higher rate in low yielding zone was incorrect

Overall YPI Zone Assessment:Soybeans in the higher yield mng’t zone actually did yield higher than the low (+6.6bu/ac) and medium (+4.7bu/ac) yield mng’t zones

[F-test significant at p= 0.04]

Zone& Rate

Avg yield (bu/ac)

Economics* ($/ac)

HIGH100 64.1 $ 809.67

125 63.3 $ 782.71

200 66.1 $ 779.19

LOW100 60.2 $ 755.83

175 58.6 $ 690.68

200 57.0 $ 655.55

MED100 58.4 $ 730.96

150 62.8 $ 762.02

200 62.6 $ 730.94 *Soybean Price: $13.50/bu / Seed Cost $0.57 per 1000 seeds. Return calculated as

(13.5*Yield)-(0.57*Target Seeding Rate in thousands)

Case Study 2: VR Population Soybeans

Municipality: City of Ottawa • Formerly 1-1 was pasture, lighter soils

• 305-2 & 305-3 cropped longest, tiled drained 7yrs ago, some compaction

• 305-7 Long term hay until 5yrs ago

Statistic (Yield bu/ac)

2011 Corn

2013Corn

2014Soybeans(Partial)

2015 Corn

(VR-N)

Min 102.11 60 25.07 90.21

Max 238.22 287 61.91 299.73

Mean 177.33 208 46.34 221.48

X-Factor 2.33 4.29 2.47 3.32

Peaks / Tops of knolls

Upper Slopes

Lower Slopes

Lowest areas /

Depressions

RTK-GPS Elevation

Survey 2015

Electrical

Conductivity

1m shallow

Dual EM

CEC Soil Test

2014 – 1ac grid

directed

2 rep’s in the low yield zone

3 rep’s in the medium

2 rep’s in the high zone

**lack of 3 rep’s in each zone

lowers confidence in statistics

Remember theory:

High corn yielding zones

get low soybean seeding

rates & vice versa

3 yr Corn YPI

2016 Prescription Map

2.4

0.9

3 2.6

4.1

13

0

2

4

6

8

10

12

14

April May June July August Total

VVF - Rainfall (Inches) 2016 Soybean

Yield Map

Zone Target Yield Return*

High 120 67.7 $ 839.86

High 155 65.6 $ 793.58

High 175 67.3 $ 801.53

Low 120 67.2 $ 838.41

Low 155 68.0 $ 824.34

Low 175 66.8 $ 802.40

Med 120 66.7 $ 815.49

Med 155 67.4 $ 829.73

Med 175 67.6 $ 808.14

*Soybean Price: $13.50/bu .Seed Cost $0.57 per 1000 seeds.

Return calculated as (13.5*Yield)-(0.57*Target Seeding Rate in thousands)

Overall YPI Zone Assessment: Soybean yield and

yield response to seeding rate were similar for all

zones of this field in 2016.

Seeding Rates:

• Seeding rates of 120, 155 and 175 thousand seeds/ac produced similar soybean

yields within each of the 3 management zones.

• no economic advantage associated with planting soybeans at a seeding rate that

exceeded 120,000 seeds/acre in 2016 in each of the 3 management zones.

2016 Results

AcknowledgementsIan McDonald (Crop Innovation Specialist)

Ben Rosser (Corn Specialist)

Ken Janovicek (UofG – Research Assistant)

Thank-you!

nicole.rabe@ontario.ca