Benefits of Genetically Modified Herbicide Tolerant Canola in Western Canada

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Oct 23, 2013 (4 years and 16 days ago)

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1


Benefits of Genetically Modified Herbicide Tolerant
Canola in Western Canada



Stuart J. Smyth
1
, Kenneth Belcher
1
, Michael Gusta
1
, Peter W. B.

Phillips
2
, and David

Castle
3


1

Department of Bioresource

Policy, Business and Economics, University of Saskatchewan

2

Johnson
-
Shoyama Graduate School of Public Policy, University of Saskatchewan

3
Innogen Centre
,
University of Edinburgh


Abstract


The commercial production of
genetically modified
herbicide tole
rant (
GM
HT) canola began
in Western Canada in 1997. With more than a decade of use, the actual farm
-
level
environmental impact of
GM
HT canola can be evaluated. This article reports on a spring
2007 survey of nearly 600 canola farmers in the three prairie p
rovinces of Western Canada.
Producers were asked about their crop production experiences for 2005 and 2006 and
expected crop planting for 2007.

The survey revealed that the new technology generated
between $1.063 billion and $1.192 billion net direct and i
ndirect benefits for producers
during
2005
-
7, partly attributed to lower input costs and partly attributed to better weed
control.

Prior to the introduction of GMHT

canola, weeds were controlled by herbicides and
tillage as the leading herbicides at that time required tillage to allow for soil incorporation of
the herbicide. Much of the tillage associated with
GMHT

canola production has been
eliminated as 64% of prod
ucers are now using zero or minimum tillage as their preferred
form of crop and soil management.
An estimated 1 million tonnes of carbon is either
sequestered or no longer released under land management facilitated by
GM
HT canola
production, as compared to

1995.

A reduction in the total number of chemical applications
over the three
-
year period was reported, resulting in a decrease of herbicide active ingredient
being applied to farmland in Western Canada of nearly 1.3 million kg annually.

When
comparing ca
nola production in 1995 and 2006, the environmental impact of herbicides
applied to canola decreased 53% and producer exposure to chemicals decreased 56%. The
cumulative environmental impact was reduced almost 50% with the use of GMHT canola.


Key words:


Biotechnology;
GMHT canola; economic impact; environmental impact;
weed management;
Canada


Corresponding Author:


Stuart Smyth, Research Scientist, College of Agriculture and Bioresources, University of
Saskatchewan, Agriculture Building, 51 Campus Drive
, Saskatoon, Canada S7N 5A8, email:
Stuart.Smyth@usask.ca; tel: 01
-
306
-
966
-
2929.





2


1.

Introduction



Innovation is pervasive in agriculture, but few single innovations have generated the
impacts or controversy of genetic modification. Advocates and
critics alike have argued and
debated the economic impacts from producer adoption of genetically modified (GM) crop
varieties, with a disturbing lack of empirical data. The paucity of direct producer data has had
a knock
-
on effect on diffusion of the techn
ology, as other nations have been unconvinced of
the costs and benefits of approving and adopting the technology to their markets.

Following the limited and controlled introduction of genetically modified herbicide
tolerant (GMHT) canola (
brassica napus
)
in 1995 and 1996, unrestricted commercial
production

began

in
1997.
Producers in Western Canada rapidly adopted the agricultural
innova
tion with the initial year adoption rate reaching 25%
,

it then rose to

84% by

2
002 and
98%

by
2007. There are currently t
h
ree HT systems available to produc
ers, two
developed
through genetic modification

and
o
ne through mutagenic breeding.

AgrEvo’s (now Bayer
CropScience)
Liberty Link


and
Monsanto’s
Roundup Ready
™ varieties

are commonly
referred to as
GMHT

varieties.
Pionee
r Hybrid’s

imidazolinone
-
tolerant
Clearfield®

system
was developed by mutagenesis
.
Varieties of herbicide tolerant (HT) canola have been created
using both genetic modification and mutagenesis.
1


Producers tend to be strongly focused on profit optimization
, adopting only those
technologies and products that improve their competitive position. The fact that virtually all
of the canola seeded for the 2007 crop year in Western Canada involved herbicide tolerance
suggests that there must be a substantial, susta
ined benefit from that innovation being realized
by farmers. While producers in Western Canada have identified personal and sectoral
benefits from the production of HT canola, this article identifies and quantifies a range of
benefits of HT canola that can

be seen to be of broad social, as well as individual, benefit.


For the
2005 and
2006 crop year
s, farmers reported that 48% of their acreage used
glyphosate
-
resistant

varieties, 37% used glufosinate
-
resistant

varieties and 10% used
imidazoline
-
resistant

v
arieties on average. These adoption rates are consistent with the
adoption rates provided by the canola industry, which identifies glyphosate
-
resistant

market
share at 44%, glufosinate
-
resistant

at 40% and imidazoline
-
resistant

at 11% (Chris Anderson,
pers
onal communication).

Thi
s article examines the
benefits of
GM
HT canola

adoption reported by Western
Canadian producers

in a survey undertaken in 2007
.

We specifically examine the economic
benefits, the environmental benefits and the changes in herbicide use. Section two reviews
the previous efforts to document the benefits of GMHT canola. Section three describes the
methodological framework for the surv
ey. Section 4 presents the results and analysis of the
survey. The article concludes with a discussion of the impacts from GMHT can
ola
.



2.

Background



Three g
enetically modified herbicide tolerant canola and mutagenesis canola
varieties

received federa
l regulatory approval in Canada in early 1995. The limited production acres
for GMHT canola in 1995 and 1996 were managed through an identity preserved production
system (IPPM) (Smyth and Phillips, 2001) as part of the seed multiplication process. The
IPPM

systems were discontinued in the winter of 1996
-
97 and unhindered producer adoption
began in spring 1997. The adoption rate of HT canol
a has been very rapid (Table 1).





1

Genetic modification of canola is done using the transfer of rDNA, while mutagenic varieties are developed by
chemical mutation.

3


Table 1: Adoption rate for HT canola varieties (million hectares)


Beginning in about 2000, a number of scholars and practitioners attempted to assess the
early
returns and prospects for future returns to producers. The bulk of the producer data that was
used for these studies was gathered between 1999 and 2002; one study gathered data as late
as 2004. The earlier data was gathered at the peak transition per
iod between conventional
canola and GMHT canola and the observances from these studies provide an excellent point
of reference for the results of our survey.


Phillips (2003) undertook a four year retrospective analysis of the economic impact of
the introd
uction of GMHT canola. Using 1995
-
2000 data, Phillips estimated the broad
economic impacts of GMHT canola on the global industry and economy, as well as the direct
and indirect effects on producers. Phillips identified the
net
effect of higher seed costs,
lower
herbicide costs, fewer herbicide applications, lower dockage and earlier seeding (adjusted for
the yield drag in early varieties and) was about $11.14
2
/acre by 2000. While this generated an
estimated $103 million gross producer gain in 2000, farmers
did not net the full amount as
lower prices due to increasing supply eliminated $32 million. Producers were estimated to net
$70 million in 2000.


The Canola Council of Canada (CCC, 2001) published a report based on data
collected in 1999 that quantified t
he agronomic and economic impacts associated with
GMHT canola. Adoption of GMHT canola by 2001 reached 80%, which allowed for in
-
field
comparisons of transgenic and conventional varieties. The study identified the key producer
impacts as: improved yield; s
lightly increased fertilizer usage; increased seed costs;
decreased tillage use; improved soil moisture conservation; decreased summer fallow;
improved rotation flexibility; lower dockage; and decreased herbicide inputs. Overall, the
study reported that di
rect producer benefits per acre of GMHT canola averaged $10.62 in
2000, yielding a net gain of about $66 million for producers.

Fulton and Keyowski (1999) noted that the adoption of an innovation depends upon
the perceived usefulness and ease of use to ado
pters; later adopters depend on the opinions
and experiences of early adopters. Mauro and McLachlan (2008) conducted a survey in 2003
to assess producer knowledge and perceptions of GM crops and the associated risks. A mixed
methodology approach was applie
d, with 15 producer interviews being used to develop a
questionnaire. Mauro and McLachlan found in their survey that 77% of GMHT canola
producers were satisfied with the results of GMHT canola. They found that the decision to
adopt and to continue to use w
as not solely an economic decision, as only 47% of producers
identified GMHT canola was more profitable than conventional varieties and only 21%
indicated that GMHT canola offered higher yields. Moreover, they found that producers
viewed the benefits of GM
HT to be decreasing, at least partly due to the 38% of producers
who had experienced GMHT volunteer canola on their land. About 80% of these producers
concluded the volunteers came mainly from their own production while 8% reported finding
volunteer canola

that they suspected originated elsewhere. The authors’ concluded that the



2

All monetary figures are expressed in Canadian dollars.

Year

1997

1998

1999

2000

2001

2002

2003

2004

2005

2006

2007

Total canola
ha

4.9

5.3

5.5

4.8

3.8

3.6

4.6

4.8

5.1

5.2

6.3

Roundup Ready

0.2

1.1

2.0

1.7

1.6

1.6

2.2

2.3

2.5

2.3

2.8

Liberty Link

0.4

0.7

1.0

0.7

0.6

0.6

1.0

1.5

1.7

2.1

2.5

Clearfield

0.7

0.9

1.0

1.2

0.8

0.6

1.1

0.9

0.7

0.6

0.7

Total HT

1.3

2.7

4.0

3.6

3.0

2.8

4.3

4.7

4.9

5.0

6.0

% HT

27
%

51%

7
3
%

75%

79%

78%

9
4
%

9
8
%

96%

96%

95%

Source: Canola Council of Canada
, 2008
.

4


earlier estimates of benefits of GMHT canola were suspect as they did not account for the
increasing cost of managing this volunteer canola for producers and their neighbors.


The C
CC (2005) released a second report that compiled the results from three
different weed surveys conducted between 2001 and 2003, as well as the results from a 2004
producer survey that examined the management of volunteer GMHT canola in subsequent
crops. Th
is report provided a comprehensive review of the impact of volunteer canola as a
weed and assessed the differences between the various GMHT canola systems. The study
discovered little difference between canola systems in regards to management of volunteer
canola in subsequent crops. Conventional canola producers were found to make slightly
fewer pre
-
seed passes to apply herbicides yet tilled more than GMHT systems.


Studies by Phillips (2003), the CCC (2005), Beckie
et al
.
,

(2006) and Kleter
et al
.
,

(2007)

found correlations between adoption of GMHT varieties and adoption of zero tillage
systems. The CCC (2005) also found 60% of GMHT adopters experienced a carry
-
over
benefit of improved weed control, which was judged to be equivalent to the cost of one
herb
icide application. Volunteer canola was found to be the fourth most common weed
targeted by herbicide; while it was not the sole target of herbicide applications, the estimated
cost of controlling for volunteer canola was determined to be around $2.00/acre
. Overall, the
study found the benefits of growing GMHT varieties to be greater than that of conventional
varieties.

Only one study of the impact of the new technology on the environmental effect of
Western Canadian agriculture exists. The Canola Council o
f Canada (2001) reports that the
average number of herbicide applications per acre for transgenic canola was just over two,
based on a sample of 321. In contrast, the average number of applications made by
conventional canola producers (sample size 315) wa
s 1.78. These results were based on
application data from the fall of 1999 and the spring of 2000. These results provide an
indication of the relative change of herbicide applications associated with the adoption of
transgenic crops.

No other studies exam
ine the impact of HT canola on chemical usage, but a number
of other studies
studied
chemical usage following introduction of other GM and HT crops.

A number of scholars estimate that GM crops have decreased the intensity and use of
chemicals. Brookes and

Barfoot (2005) estimate that from 1996 to 2004, the total global
volume of active ingredient applied to GM crops fell by six percent, a decline attributed to
the commercialization of GM crops. The authors additionally estimate a 14% reduction in the
‘envi
ronmental foot print’
3

made by crop agriculture, also attributed to the adoption of GM
crops. Young (2006) discusses the US introduction of glyphosate
-
resistant soybeans, cotton
and corn, focusing on the increased use of glyphosate in crops. He documents a

dramatic
increase in the use of glyphosate and is concerned about the impact this might have for weed
management strategies. Young does not discuss the difference in the environmental impact of
glyphosate being applied versus the herbicides that it displa
ced, somethin
g that has
occurred
with

canola
. Young’s concern is that between 1997 and 2002, the variety of herbicides
applied to glyphosate
-
resistant crops had decreased, thereby reducing the potential benefits of
applying glyphosate due to increased sele
ction pressure for glyphosate resistant weeds.
Young documents a decrease in the average number of herbicide active ingredients applied to
glyphosate
-
resistant

crops. For example, the average number of herbicide active ingredients
applied to soybeans decli
ned from 2.5 active ingredients in 1994 to 1.6 active ingredients in
2002 and in cotton the average number of herbicide active ingredients applied dropped from
3.1 active ingredients in 1997 to 2.1 active ingredients in 2001.




3

Brookes and Barfoot

use environmental footprint as an integrated indicator capturing the “environmental
impacts of individual pesticides at a single field value per hectare” (environmental impact quotient (EIQ/ha)
multiplied by the area planted to the subject type of product
ion.

5


Benbrook (2003, 2009) argues
that herbicide use increased between 1996 and 2003 by
50 million pounds and that by 2009 genetically engineered crops were responsible for an
increase of 383 million pounds of herbicide applied in the US. Benbrook draws upon United
States Department of Agr
iculture’s National Agricultural Statistics Service (NASS) for his
data, which does not differentiate between GM and non
-
GM crops and hence has to be
interpolated based on secondary estimates for GM and non
-
GM acres. USDA
-
NASS data is
available to 2005 and

Benbrook has extrapolated for subsequent years, which show the
largest increase in herbicide use. Benbrook’s increase in the rate of adoption is 5% annually,
which is ambitious. Adoption rates post 2005, have tapered off and to some extent, are close
to a
pproaching the upper limits of market share for this technology. Assuming a continual
rate of increased adoption of 5% does not reflect the realities of the market. In addition,
Benbrook assumed farmers used the recommended rate of application, which is no
t always an
accurate reflection of production decisions.
4

Depending on a variety of factors (e.g. moisture,
weed density and insect populations) producers will often apply chemical at a rate that is
below the recommended rate, particularly if there is no e
vidence of the target they want to
control. The final factor that discounts Benbrook’s assertions is that he does not take into
account the increase in the number of acres being planted to the commodities he examines.
For example, corn production in the US

increased by over 16 million acres between 2003 and
2008 (USDA
-
NASS, 2008).

While the change in herbicide use is important to the environmental impacts of HT
crops, it is only part of the debate as the change in tillage practices has increased carbon
seq
uestration. The Intergovernmental Panel on Climate Change (IPCC) (2007) estimates that
agriculture contributes 10
-
12% of anthropogenic greenhouse gas (GHG) emissions. The
World Bank (2010) estimates that 30% of world greenhouse gas emissions comes from
agr
iculture, deforestation, land
-
use change and forest degradation. Among all of the choices
we may make to reduce agricultural GHG emissions, crop choice and management are among
the most significant.

West and Post (2002) review the analysis of 67 long
-
term
agriculture experiments to
quantify the potential soil carbon sequestration rates. In the review of the 67 experiments,
they analyzed the results of 276 paired treatments and determined that changing tillage
practices from conventional tillage to zero till
age can sequester carbon at a rate of 57 grams
plus or minus 14 grams pe
r meter, per year
. In analyzing the annual rate of soil organic
carbon (SOC), they found that most SOC change happens within the first 10
-
15 years of
moving to zero
-
till. However, West

and Post note that while the sequestration rate will
decrease over time, it may continue for a longer period of time, possibly as long as 40
-
60
years.

Lal (2004) suggests that the carbon sink capacity of the world’s agricultural and
degraded soils is 50 t
o 66% of the world’s historic carbon loss of 42 to 78 gigatons of carbon.
Additionally, Lal
et al
., (2003) have argued that widespread adoption of conservation tillage
(including zero tillage) could sequester 24
-
40 metric tonnes (Mt) of carbon per year.
Ho
wever, Baker
et al
., (2007) suggest that carbon sequestration rates based on soil sampling
may have biased the rates due to sampling protocols. While not arguing against the increased
use of conservation tillage, the authors highlight that the soil samplin
g depth impacts the
carbon sequestration. They suggest that shallow sample depths of less than 30cm support



4

Leeson
et al
.
,

2004, identify that 75% of canola producers apply herbicide at a rate that is lower than the
recommended highest rate. The research found that 15% of producers in Saskatchewan sprayed at a rate that
was below the lowest recommended ra
te, while 12% did not spray at all. Slightly over 60% of producers
sprayed at a rate that ranged from the lowest to the mid
-
level of recommended rates, while less than 5% were
found to spray above the highest recommended rate.

6


carbon sequestration, while samples from depths greater than this do not support carbon
sequestration.

Comparing herbicides and their toxicity is n
ot a simple process. Each herbicide used
in agriculture has different environmental impacts and the application rate of each herbicide
varies, making direct comparisons between two or more herbicides very challenging. In an
attempt to establish the opportu
nity to undertake herbicide comparisons, Kovach
et al
.
,

(1992) developed the Environmental Impact Quotient (EIQ) which measures the relative
toxicity of chemicals. The EIQ is comprised of effects on three separate targets: the
ecological environment; farm
workers; and consumers. The EIQ is regularly updated to take
into account new toxicity impact studies and newly available herbicides, providing a
consistent tool for comparing different herbicides. Using these measures and applying them
to actual farm prac
t
ices, one can determine the

impact on the environment, farmers and
consumers.


The main limitation of using the EIQ model to assess changes in chemical
applications to large
-
scale crop production is that when it was developed in the early 1990s it
was des
igned to assist in exploring the environmental impacts of changes in agriculture
chemical use as part of integrated pest management system development in the fruit and
vegetable sector (Kovach
et al
.
,

1992). While we and others have used the EIQ to explore

the
environmental impact of different cropping systems, including conventional and
biotechnology
-
based agriculture, the EIQ was not specifically developed to evaluate large
area crops. The EIQ is better than assessments that only consider the active ingre
dient, but is
still a rough measure of impacts on the environment when applied to large
-
scale agriculture.


The EIQ utilizes a five point ordinal scale to indicate the relative toxicity of
chemicals, where one is equated to least toxic or least harmful and five is equated to the most
toxic or most harmful. The farm worker component is comprised of the effects on

the
applicator and the picker. This latter impact is more relevant to fruit and vegetable production
than it is to large
-
scale canola production in Western Canada, where harvesting is highly
mechanized. The consumer component is comprised of the direct co
nsumer effects from
consumption and the impact of residue in the groundwater. Given that consumers only rarely
directly consume unprocessed canola (most of the seed is crushed and refined into canola oil
and the meal is fed to animals), this aspect of the
EIQ in our study focuses predominantly on
groundwater effects. The ecological component is comprised of aquatic and terrestrial effects,
which includes assessments of chemicals on fish, birds, bees and beneficial arthropods.


Herbicides have a range of to
xicological impacts and exhibit both acute and chronic
toxicity. Acute toxicity measures the short
-
term poisoning potential of the organism. A value
of exposure is assigned when an amount of material is given all at once to a group of test
subjects that re
sults in half of the test population expiring

this is called the lethal dose 50, or
LD
50
. For chronic toxicity no numerical value is assigned; the chemical is annotated as
presenting ‘no effect’, ‘may affect’ and ‘does cause’.


Within the literature
(Table

2
) there is a consensus that the amount of active
ingredient per hectare has decreased, herbicides are applied at lower rates and that producer
exposure has been reduced. Total usage varies, depending on which crops are being planted.

For, example, while
the total area allocated to canola in Western Canada was virtually the
same in 1995 and 2006, there was significant volatility in production in response to the
expected relative price of canola and other crops. The data from 2008 shows an
unprecedented six
th consecutive year of increase in canola production, rising to 6.47 million
hectares. As the number of canola hectares increases over the reference level of
approximately 5.22 million hectares, the total volume of chemicals applied to canola crops
has cor
respondingly increased, but this has been offset somewhat with reduced chemical
usage at the per hectare scale.

7


The first
GMHT/non
-
GMHT

canola comparison done in Canada was based on data
from 1999
-
2000. The Canola Council of Canada (2001) commissioned a study to assess the
agronomic and economic impacts of transgenic canola. At that time, approximately three
-
quarters of
the canola was pro
duced using GMHT

varieties. Herbicide input costs were
examined, focusing on fields that had been left as summerfallow in 1999 (where some
farmers made chemical applications to the summerfallow field) and were then sown to canola
in 2000. The average per h
ectare cost over the tw
o
-
year period was C$33.79 for GMHT

canola and C$55.65 for non
-
GMHT

canola. The study estimates that the l
ower cost of
herbicide
-
use on GMHT

canola fields to be the equivalent of 6,000 fewer tonnes of herbicide
application by volume i
n 2000.


Table 2: Recent studies on herbicide
-
resistant

crops

Research study
a


Crop type and
country

Study
reference
period

Change in
herbicide
application

Environmental
impact

Canola Council of
Canada
,

2001

HR canola in
Canada

1999/2000

Aggregate 40%
decrease

na

Brimner
et al
.
,

2005*

Canola in Canada

1995
-
2000

20% decrease

37% decrease

Kleter
et al
.
,

2007*

Canola in the USA

2004 crop
year

30% decrease

42% decrease

Brookes &
Barfoot, 2010*

Canola in Canada
& USA

1996
-
2008

8% decrease

16% decrease

Leeson
et al
.
,

2006

Canola in Canada

1995
-
2003

12% decrease

22% decrease

a
The asterisk (*) indicates peer reviewed publication.



Brimner
et al
.
,

(2005) used Kovach’s method to examine the changes in herbicide
use
due to GMHT

canola adoption between 1995

and 2000. They found that herbicide use on
conventional canola had increased b
y 30%, while herbicide use on GMHT

canola had
decreased by 20%. In terms of the

Environmental Impact (EI) of GMHT

canola, a 37%
decrease was observed, while the EI of convention
al canola increased 56%. The authors
reported that they faced some challenges in determining her
bicide use. They assumed that
GMHT

canola was only sprayed with a corresponding herbicide and that no other herbicides
were tank mixed, thus potentially under
-
e
stimating the actual application rate. Conversely,
they may have over
-
estim
ated herbicide application to GMHT

canola if one of the relevant
herbicides was applied to conventional canola fields as a burn
-
off prior to seeding. While the
authors acknowledge t
he potential exists for either over
-

or under
-
estimation of herbicide
application, there is no
prima facie

evidence to indicate whether either is likely.

Thus, there is
no reason to reject these results; they will be used as the benchmark for comparison pu
rposes
in this study.


Beckie
et al
.
,

(2006)

examined the first decade of GMHT

crop use in Canada and
noted that,

prior to the introduction of GMHT

canola,

herbicide options for canola were
limited. The most common herbicide application method included soil incorporation, which
had a low efficacy rate and the residual activity of some herbicides resulted in crop rotation
restrictions in the subsequent year.
Leeson
et al
.
,

(2006) examined trends in herbicide use in
canola production through the use of a series of weed surveys. The authors compared the
results of weed surveys from the three Prairie provinces from 1995
-
97 against similar surveys
from 2001
-
03. Th
ey found a 12% reduction in herbicide use and an EI drop of 22% per
hectare.

8



A review study by Kleter
et al
.
,

(2007) compared conventional and transgenic canola
crops in the US

over four

years. The authors estimate that the application of
herb
icide activ
e
ingredient was 30% lower in GMHT

canola than in conventional canola crops. The total EI
per hectare was 42% lower, the ecological impact was 39% lower and the farmer impact was
54% lower.


Brookes and Barfoot

(2010) use the

EIQ methodology to
compare EIQ values for
biotech and conventional
crops, aggregating this data to

a national level. They provide

an
analysis of the changes in herbicide use between 1996 a
nd 2008. In their analysis of GMHT

canola in North Ame
rica, the

EI decreased by 24%. Th
e amount of active ingredient applied
to canol
a decreased by 13.7

million kg or 18%. The study assumed that the highest
application rate was used in all instances, which created the potential for an over
-
estimation
of active ingredient application, thus un
derestimating the decline in usage and the net overall
benefit.


3.

Methodology



The collection of data on agricultural practices in Canada often employs
a survey
instrument. This research i
s based on a four page, 80 question survey that was developed a
nd
distributed to agricultural producers. The
estimated time

to complet
e the survey was

30
-
45
minutes. The survey was comprised of six major areas of focus: weed control; volunteer
canola control; canola production history; specific weed control measures o
n canola fields
and subsequent crops; crop and liability insurance; and general demographics. Open, closed
and partially open questions were included in the survey. Space was provided to enable
producers to more fully explain changes within the production
system to facilitate a more
complete understanding of producer choices. Where a quantification of producer attitudes
was required, a simple three point scale was used, which allowed for positive, neutral and
negative responses. The University of Saskatchew
an’s Research Ethics Board approved the
survey design (BEH# 06
-
318).

Forty thousand surveys were distributed across the three Prairie Provinces in March
and April 2007. Distribution of the survey was through Canada Post’s un
-
addressed ad
-
mail
service provi
ding a cluster sampling method. This allowed for a selection of farms as defined
by Canada Post within the postal code system. Participant selection was based upon
geographic location in five targeted regions separated by provincial boundaries and based on

historic canola production levels. High production and low production regions in each of
Alberta and Saskatchewan and a high production area in Manitoba were surveyed. The target
population was producers having over 40 hectares of cropland. Surveys were r
andomly
distributed through the regions.

In total 685 surveys were received with 571 meeting the population criteria. Outliers
within the database were identified and removed utilizing the box plot method as developed
by Tukey (1977) and outlined by NIST/
SEMATECH (2006). Extreme outliers, or upper
outliers, were identified based on the amount of hectares treated by the herbicide. Table 3
outlines the distribution of usable responses across the three Prairie Provinces and between
areas of low and high canol
a production.
5


Canada is a large nation with numerous eco
-
regions, but most canola is grown in three
main regions. A small amount of canola is produced in the Boreal Shield West eco
-
region,
located in the very eastern part of Manitoba. While the number of

respondents relative to the
number of surveys distributed indicates a low response rate (1.71%) it is important to note



5

High and low production zon
es were based upon historical canola production data for the three prairie
provinces.

9


that the Canada Post’s un
-
addressed ad
-
mail service delivers surveys to all mail addresses
within the identified region. There is no wa
y to know how many households received surveys
that were not farmers or did not produce canola. Therefore, the actual response rate is
unknown and is most certainly greater than what can be calculated here. The important point
is that demographically, our
respondents are very representative of the national agriculture
census data.


Table 3
: Distribution of usable survey responses (N=571)


Low Production

High Production

Total

Alberta

14%

11%

25%

Manitoba

NA

16%

16%

Saskatchewan

32%

27%

59%

Total

46%

54%

100%



The demographics of the sample population are similar to the source population as
reported in the Statistics Canada 2006 Farm Census (Table 4) (Statistics Canada, 2006). The
average age of farmers is 52 in Saskatchewan and Alberta, and 51 in Manit
oba. Our survey
population has a substantially higher level of post
-
secondary education, where the census
data identifies the percentage of producers with a university degree in Manitoba at 8%,
Saskatchewan at 8% and Alberta at 9%.
6

Average farm size of th
e sample population was
greater than that of census data, where the average Alberta farm size was 427 hectares,
Saskatchewan 589 hectares and Manitoba 405 hectares.


Table 4
: Producer demographics



Alta
.

Sask
.

Man
.

Total/Ave
.

Number of respondents to
survey

144

3
35

92

571

Average age


Sample

45
-
54

45 to 54

45 to 54

45 to 54


Census

52

52

51

52

University degree

Sample

14%

21
%

7
%

14
%


Census

9%

8%

8%

8%

Average farm size

(ha)


Sample

669

705

549

6
70


Census

427

589

405

473

Average canola
area
(ha)

205

193

162

19
0

Average years growing

canola


19.3

20.6

20.8

20.3

First year with GMHT canola

1999

1999

1998

1999

Source: Survey and Statistics Canada 2006 Farm Census.



The survey respondents had relatively large operations (670 hectares), with,

on
average, over one
-
quarter of their operation dedicated to canola (Table 4). The average
respondent has farmed for 30 years and belongs to the 45 to 54 age group. These producers
reported growing canola for an average 20 years and adopting GMHT canola f
irst in 1999; on
average they reported that they removed conventional canola varieties from their crop
rotations by 2000.







6

The number of respondents with a university degree is substantially higher in Saskatchewan than is reflected in
the census data. A variety of factors contribute to this. The farm size is larger t
han average,

which tend
s

to be
correlated with higher levels

of education. Moreover, the affiliation of this research with the University of
Saskatchewan may have triggered a greater response from graduates than from others.

10


4.

Results and Analysis


4.1

Economic Benefits



The surv
ey asked questions on three

economic impacts from the adoption of GMHT
canola: cost of weed control; control of volunteer canola; and second
-
year benefits and costs.
To determine if a change in weed control practices of Western Canadian producers has
occurred, the two methods of wee
d control

chemical herbicide use and tillage practices

have to be examined.


Producers were asked if they have changed their chemical herbicide use over the past
10 years and 68% of respondents reported that a change had occurred. Of those reporting a
cha
nge, 94% found weed control effectiveness to have improv
ed or remained the same (Table
5
). More than 60% of respondents reported that previously difficult
-
to
-
control weeds

such
as wild mustard, stinkweed and cleavers

can now be more easily controlled. More

than one
-
third of producers reported that control over difficult weeds in canola fields is unchanged
from the situation that existed prior to the commercialization of GMHT canola. Just more
than 5% of respondents reported weed control has become less effe
ctive. While the majority
of those reporting a change in weed control after adopting GMHT varieties attributed the
changes to the new technology, about 36% of the changes in weed control were not related to
adoption

other agronomic circumstances (both posi
tive and negative) were at work.


Table 5
: Attribution of change in weed control after adopting GMHT canola

Weed Control

Change due to
a
doption
(n = 242)

Change not due to
adoption
(n = 145)

Total reporting
change
(n = 387)

Weed control less effective

5.4%

7.6%

7%

Weed control unchanged

34.3%

42.1%

36.2%

Weed control improved

60.3%

50.3%

56.8%



Land management practices in Western Canada changed substantia
lly following the
adoption of GMHT

canola varieties. When asked about weed management practices, the
survey respondents reported that many of them have adopted minimum
7

or

zero tillage
practices, with 66
% of respondents indicating that they use o
ne of these two systems (Table
6
). Producers

utilizing glyphosate
-
resistant systems were slightly more likely to conduct
tillage operations than other systems. When asked about weed control measures conducted on
their 2006 canola crop, 28% of producers reported they used both herbicides and tillage,

with
just 7% reporting only tillage. Use of tillage has markedly decreased since 2000, when 89%
conducted tillage operations as a form of weed control (Canola Council of Canada

2001). The
adoption rate for GMHT

canola at this time was 76%. The movement to

minimum or zero
tillage operations across Western Canada began to increase i
n the early to mid
-
1990s, just
prior to the commercializati
on of GMHT canola.


As indicated in Table 6, nearly two
-
thirds of producers utilize either zero
-
tillage or
minimum
-
tillage as their preferred form of land management. Harrowing is classified as a
method of minimum tillage. Despite the increasingly wide
-
spread adoption of mini
mum or
zero
-
tillage practices across Western Canada, one of the barriers to adoption of these reduced
tillage management practices has been fewer options for effective weed control. Therefore,
the effective weed control provided by the GMHT technology has
contributed to the



7

For the purposes of this survey, harrowing is defined as minimum tillage or min
-
till. Zer
o tillage is the use of
direct seeding methods. Conventional tillage is the continued use of cultivation as the preferred method of weed
control.

11


increased utilization of minimum or zero tillage operations. It is possible to state with
statistical confidence that there is a correlation between the adoption of GMHT canola and
the increased movement to conservation tillage (Ammann,
2005; Brookes and Barfoot, 2005;
Dill et al., 2008; Fawcett and Towery, 2002; Fernandez
-
Cornejo et al., 2010).


Table 6
: Tillage operations and
GM
HT canola systems (2006)

Tillage method

Clearfield

Liberty Link

Roundup Ready

Average/Total

Zero
-
till

60.0%

53.3%

50.3%

54.5%

Harrow

12.5%

11.9%

9.8%

11.4%

Cultivation

22.5%

20.0%

24.2%

22.2%

Cultivation
&

n
arrow

5.0%

14.8%

15.7%

11.8%

Margin of error

15.5%

8.4%

7.9%

5.4%

#

of respondents

40

135

153

328


Land management practices added some
incremental
costs. In 2006, 23
% of farmers
preformed harrow operations at least once, conducting an average of 1.2 passes on 88% of
their canola crop. The CCC (2001) estimated that harrowing cost $3.50 per acre. Assuming
the costs have not changed, the harrow operatio
ns on GMHT canola fields would be about
$3.72
8

for each harrowed acre; scaled up to the entire canola production area, this would add
$0.92 to the cost of the average acre seeded to canola.
9

Continuing cultivation similarly adds
cost
s. The survey revealed
that 34
% of farmers preformed cultivation operations on their
canola fields, conducting an average of 1.51 passes on 88% of their canola crop. Using the
CCC (2001) estimates of $6.00 per cultivated acre, the cost of these sustained operations
would add $7.
98
10

for each cultivated acre; scaled up to the entire canola acreage, the average
cost is $2.86 per acre of canola seeded.


Comparing the CCC (2001) survey of farmer practices in 1999 with our survey of
farm practic
es in 2006,

the total number of tillage operations for transgenic canola dropped
from 2.73 passes
to 0.74 passes per acre (Table 7
). Assuming the cost of tillage operations
have remained constant since 1999 (i.e. $6.00 per acre for cultivation and $3.50 for
harrowing
), the expected cost of all tillage conducted on canola acres would have been
reduced by $10.25 per acre or by 73%. Scaled up for the size of the canola crop in 2006, this
saving would translate into $153.8 million (assuming tillage on conventional canola
has
remained the same).


Tillage is used for both seeding and for weed control. When asked explicitly about
weed control measures conducted on the 2006 canola crop, 77% of producers reported they
only used herbicides while 28% of producers reported they co
mbined the use of herbicides
and tillage and 7% reported they only used tillage for weed control. Use of tillage has
markedly decreased since 2000, when 89% of producers reported conducting tillage
operations as a form of weed control (CCC, 2000). Perhaps
most importantly, weed control
had long been one of the main limiting factors in more producers moving both to lower
-
tillage agriculture and to greater cultivation of canola. The commercialization of GMHT
canola and the superior weed control it offers has
contributed to the increased utilization of
minimum or zero tillage operations. The costs of the various weed control systems are
identified in Table 8.





8

The cost of $3.72 is determined as follows: $3.50 harrowing cost x 1.2 passes x 88% of canola acres.

9

While

not all canola acres are harrowed or tilled any more, to be able to make a comparis on w
ith the CCC

s tudy, we have applied the cos t to all acres. Thus, allowing us to determine what changes have occurred.

10

The cos t of $7.98 is determined as follows: $6.00

tillage cos t x 1.51 pas s es x 88% of canola acres.

12


Table 7
: Comparison of harrowing and tillage costs: 1999 to 2006


1999 Data

2006 Data

Transgenic

Conventional

All Farmers

Cultivation Operations

n=321

n=316

N=340


Average number of operations

1.79

2.63

0.48


Average cost per acre cultivated*

$10.74

$15.78

$2.86

Harrowing Operations



Average number of operations

0.94

0.84

0.26


Average cost per acre**

$3.29

2.94

0.92

Overall



Average number of operations

2.73

3.47

0.74


Average cost for all tillage operations

$14.03

$18.72

$3.78


Percent Transgenic

67%

95%


Overall cost per acre

$15.58

$4.59


Total acres

13.7 million
acres

13.0 million acres


Overall expenditure

$213.5 million

$59.7 million

* assuming $3.50/acre; ** assuming $6/acre

Source: CCC (2001) for 1999 data. Margin of error on 2006 data is: cultivation 9% and
harrowing 11% at the 95% confidence level.



Table 8

shows that the cost of tillage has declined however, when a comparison of
financial costs is undertaken, tillage remains cheaper than herbicide weed control options.
The reported cost for tillage corresponds to the per
-
pass custom tillage rate in S
askatchewan
(Saskatchewan Ministry of Agriculture, 2008). Custom tillage rates vary depending on the
size of equipment and hours of annual use. The range of tillage costs in Saskatchewan for
2008
-
09 was $5.33
-
$7.79.

While the reported cost of tillage in Ta
ble 8

is $8.07 (marginally
above the provincial range), this cost is for one pass of tillage equipment and in an average
summerfallow year, a field would be tilled 4
-
6 times. Finally, tillage is typically done by the
individual producer who will not have a
dded in a cost for their time to till a field. The reality
is that when environmental aspects like moisture conservation and soil erosion are factored
in, the cost of tillage increases even further. Table
8

confirms that the producer costs drop the
year fo
llowing production of GMHT canola as respondents identify a reduction in herbicide
cost for weed control of 52.7%.


Table 8
: Cost of weed control ($C)


Weed control
method

Cost of weed control

on canola/acre

Cost of weed control on
subsequent crop/acre

2

year total
cost
($/acre)

Sample size

Average
cost

Sample size

Average
cost

Herbicide only

77

$19.61

77

$9.28

$28.89

Tillage only

15

$8.07

23

$10.58

$18.68

Herbicide and tillage

105

$13.74

31

$12.54

$26.28



Canola production has increased and
producers are growing canola more frequently in
their crop rotations. A concern with this increase in frequency of canola

and associated
herbicides in the rotation is the potential for the development of herbicide resistance in weed
populations. The survey

asked producers about their experiences in the management of
herbicide resistance in weeds. Management of herbicide resistance in weeds was found to
have improved by 28% of producers, 47% reported it was unchanged and 24% reported
13


herbicide resistance i
n
weeds was on the rise. Table 9

identifies present survey findings on
the issue of weed populations developing herbicide resistance from GMHT platforms.
Producers using Clearfield and Liberty Link™ canola were more likely to report a rise in
herbicide resis
tance in weed populations; 81% of producers using Roundup Ready™
identified that herbicide resistance was the same or weed control had become easier.


Table 9
: Management of herbicide resistance in weed populations

(2006)


Clearfield

Liberty Link

Roundup
Ready

Total


(n=46)

(n=165)

(n=209)

(n=432)

Harder

28.3%

27.3%

18.7%

23.4%

The Same

41.3%

35.2%

50.7%

43.8%

Easier

30.4%

37.6%

30.6%

32.9%

Maximum Margin of Error at
95% Confidence Interval

14.4%

7.6%

6.8%

4.7%



Producers were specifically asked
about weed control measures taken on their 2006
canola crops. The responses to this question closely reflected the responses to the question on
the management of herbicide resistance in weeds, with 17% reporting that no measures had
been used to control we
eds in their canola fields, 47% reported only using herbicides, 7%
reported only using tillage and 27% reported the use of tillage and herbicide. No significant
difference was found between the three HT systems. Producers utilizing tillage and herbicide
we
re found to be more likely (53%) to make only one herbicide application than those only
utilizing herbicide to control weeds (39%).


One concern with the increased use of GM agricultural crops, and of GMHT canola in
particular, is that volunteer GMHT canol
a could become a major in
-
crop weed because those
varieties are difficult to control with common broad spectrum herbicides. Mayer and Furtan
(1999) speculated that heavy use of a technology such as GMHT canola could be expected to
increase the weedy potent
ial of volunteer canola in the future. Given that producers have
demonstrably planted canola with increasing frequency, it would be logical to assume that the
challenges of controlling volunteer canola could be increasing. To test this concern, a section
o
f the survey asked producers about the effect of volunteer canola on producer operations and
decision
-
making processes.


When asked an open ended question about the top five weeds targeted by weed
control measures, 92% of producers did not mention voluntee
r canola; the 8% of producers
who did mention volunteer canola
on average
listed it as their fourth or fifth most
problematic weed. When asked specifically about controlling volunteer canola, 35%
responded that it required effort to control. One might conc
lude from this that volunteer
canola is viewed mostly as a nuisance and not a major economic drain on their operations,
which coincides with the Canola Council of Canada 2005 study. These results also support
the conclusion by Beckie
et al
.
,

(2006) that th
ere has been no marked change in volunteer
canola as a ‘weed’ as a result of the transition to GMHT systems.


Advances in control of volunteer canola appear to be keeping pace with the increase
in canola acreage. When asked whether they are targeting volun
teer canola, 62% of producers
identified that they no more focused on volunteer canola than they were ten years ago. About
74% of respondents reported that they are able control volunteer canola more easily or about
the same as ten years ago. The 26% that
find volunteer canola control to be more difficult
than ten years ago also reported that they are spending more on controlling volunteer canola.

Only 9% of producers reported that the loss in yields due to volunteer canola have worsened
over the last decad
e.

14



The cost of controlling volunteer canola remained constant for 73% of producers over
the past decade. Twenty
-
seven percent of producers reported increased costs, up an average
of $4.23/acre. A comparison of responses between ease of control and change

in targeting
revealed that 77% of those who found volunteer canola more difficult to control were
spending more for targeting control measures.


When asked specifically about fields in 2006 that were seeded to canola in 2005, 36%
reported that they did no
t conduct any weed control measures specifically for volunteer
canola. The rest made some investments: 46% sprayed herbicides; 8% conducted tillage
operations; and 11% conducted both tillage operations and sprayed herbicide. A range of
herbicides were used

58% used a single herbicide application, 29% made two applications
and 13% reported three or more applications. While the average reported cost of these weed
control operations was $12.70/acre, many respondents noted that these weed control
measures were
not specifically undertaken to control volunteer canola.


Improvements in weed control from GMHT canola can have a spill
-
over effect on the
same field from one year to the next. Producers were asked if they experienced any spill
-
over
benefits in terms of f
ewer weeds or easier weed control on fields that had been previously
seeded to GMHT canola. Fifty four percent reported a second
-
year benefit from the
technology, and 63% of those reporting assigned an economic value to this benefit worth an
average of $15
.05/acre. Table 10

illustrates the range of benefits that accrue across the Prairie
region divided into benefits to producers with lower than average (low) and greater than
average (high) levels of GMHT production. The Alberta low and high, the Saskatchewa
n low
and high and Manitoba correspond to the previously identified levels of production. The
benefits reported by Alberta low and high producers are significantly higher than for the other
regions. In Saskatchewan, it is the area identified as low, in ter
ms of canola production, that
realizes the highest level of benefits. This area
,

along the western and southern
borders

of the
province, had little canola production prior to the commercialization of GMHT canola. Spill
-
over benefits in Manitoba are lower t
han the other regions on average, but not significantly.
These results would tend to suggest that the spill
-
over benefits increase somewhat in the more
western regions of the Canadian prairies.


Table 10
: Second year spill
-
over benefits per acre across
Western Canada ($C)


Alberta

Sask.

Man.

Average



Low

high

Low

high

Number of producers

34

25

62

66

22


Average

$17.86

$18.93

$14.50

$13.92

$13.05

$15.05

Lower value

$15.91

$16.40

$13.29

$12.87

$11.65

$14.40

Upper value

$19.81

$21.46

$15.71

$14.97

$14.44

$15.69

At the 95% confidence interval margin of error is 8.4% for average and 14.8% or greater for
rest.



While over half (54%) of the producers reported spill
-
over benefits between cropping
years, the survey data also revealed a distribution of

average spill
-
over benefits

according to
the size of the benefit (Figure 1). Whil
e the most frequently reported
benefits (32%) were in
the $10
-
15 per acre range, one fifth of producers identified spill
-
over benefits that were in
excess of $25/acre. Over 7
5% of the producers reporting spill
-
overs estimated the benefit to
be greater than $10/acre.





15


Figure 1: Estimated spill
-
over benefits per acre




Previous surveys (Phillips 2003 and CCC 2001) put the producer benefit of GMHT
canola at $60
-
70 million in 2000. Neither study, however, attempted to calculate the impact
of any spill
-
overs or any increased costs from controlling volunteer canola. With the

estimates from this survey, we can now modify those earlier estimates based on more detailed
information.


The total producer benefit of GMHT canola can be represented as the direct economic
impact of the technology, spill
-
over benefits and the value of
reduced tillage, net of the
increased cost for controlling volunteer canola. Phillips (2003) did not include reduced tillage
as part of his calculations for direct benefits, hence their inclusion. This survey did not
directly estimate the primary economic
benefit of the technology to producer, but the data
does verify that the benefits likely fall in the range of $10.62 and $11.14 per acre, as
calculated by Phillips and the CCC (2001). Using the $11.14/acre benefit as a baseline, we
can then consider the po
tential importance of the spillovers and volunteer control costs.


The direct benefit ($11.14/acre) is applied to the total acres cultivated in 2005, 2006,
and 2007. Next, the low and high estimates
11

of the spillover benefits were applied to actual
acres
cultivated. The value of reduced tillage, $153.8M can be added to each of the years.
Finally, the additional cost of volunteer canola control cost
12

($1.12/acre) was deducted from
the total. Using the actual canola acreage for 2005
-
7, we estimate that the t
otal economic
benefit from GMHT canola ranged from $343 million to $422

million per year (Table 11
).
Over the three year period, the average benefit was in the range of $354 million to $397
million per year.


In relative terms, the cost of volunteer canol
a control has a marginal impact on the
technology. The reduction in total benefits is reduced by 4% on average per year. Much more



11

The range of low/high spillover

estimates were calculated from the

54% of producers
that
realized some
bene
fits

with 33% assigning a value of $15.05/acre, creating a range of spill
-
over benefits when dis
counting for
proportions of $4.97/acre to $8.19/acre
.

12

T
he cos t of controlling volunteer canola was reported by 26.6% of
producers to average $4.23/acre.
Allocating this cos t

acros s
all cultivated acres res ults in an

average

per acre cos t of $1.12

for the

entire prairie
region.

5.1%

19.0%

32.1%

10.9%

13.9%

19.0%

0.0%

5.0%

10.0%

15.0%

20.0%

25.0%

30.0%

35.0%

Under $5

$5 to 10

$10 to 15

$15 to 20

$20 to 25

$25+

Spill
-
over Benefit

Percent of Population experiencing Spill
-
over

Benefit

16


important, however, is the spill
-
over benefits, which account for 19% to 28% of the total net
benefits of the new technology.



Table 11
: Economic benefit of GMHT canola (2005
-
07)


Year

Acres


Direct

Spill
-
over

Reduced
tillage

Cost of
volunteer
control

Total Benefits


Low

High

Low

High

2005

12.6M

$141M

$63M

$103M

$153M

$14M

$343M

$383M

2006

12.8M

$143M

$64M

$105M

$153M

$14M

$346M

$387M

2007

14.8M

$165M

$73M

$121M

$153M

$17M

$374M

$422M

Average

13.4M

$150M

$67M

$110M

$153M

$15M

$354M

$397M



4.2

Environmental Benefits



Producers were asked how their herbicide application practices had changed
following the adoption of
GM
HT canola and they indicated that they were making an average
of one less application per year. These findings correspond to the broad observations over
a
range of crops and landscapes
(
Gianessi,
et al
.

2002
;

Bro
okes and Barfoot 2005). Table 12

reports the volume of
active
herbicide ingredient applied in 1995
;

the 3.36 million kg serves
as a benchmark for following comparisons. The percentage of hectares t
hat had herbicide
applied in 1995 is greater than the actual number of hectares that were sown to canola due to
the tank
-
mixing of herbicides. There were 5.19 million hectares of canola production in 1995.



Table 12
: Volume of herbicide applied in 1995

Herbicides

Percentage of
total hectares

Number of
hectares

Grams
/ha active
ingredient

A
ctive ingredient
applied (kg)

Ethalfluralin

32

1,660,830

1100

1,826,913

Trifluralin

31

1,608,929

800

1,287,143

Clopyralid

15

830,415

151

125,393

Sethoxydim

15

778,514

144

112,106

Ethametsulfuron

15

778,514

15

11,678

Total

109%

5,657,720

NA

3,363,233

Source: Brimner
et al
., 2005 and Smyth

et al
., In Press
.




The volume of active ingredient applied to canola following the commercialization of
GMHT canola has
declined (Table 13). Smyth

et al
. (unpublished data) provide the number
of hectares that had herbicides applied to them and the application rates. This table reveals
that only 70% of canola hectares received herbicide applications.
13

Cultivation as a form o
f
weed control will account for some of the variance in herbicide application.









13

As noted by Leeson
et al
., (2004), in 2003 12% of canola producers did not spray. This figure ranges as high
as 17% for barley growers in that year. Some producers only use tillage as their means to control weeds.

17


Table 13: Volume of herbicide applied in 2006

Herbicides

Percentage of
total hectares

Number of
hectares

Grams
/ha of
active ingredient

A
ctive ingredient
applied (kg)

Glyphosate

48

2,505,814

697

1,746,552

Glufosinate

12

626,453

477

298,818

Imazmox

4

208,818

15

3,132

Imazethapyr

4

208,818

15

3,132

2,4
-
D

2

104,409

414

43,225

Total

70%

3,654,312

NA

2,091,727

Source: Smyth et al., In Press.



While applying herbicide
to 70% of canola production might seem low, it is not
outside of what is normal in crop production. It is not uncommon for producers that use
tillage as part of their land management practices to get excellent weed control at the time of
seeding. In years
with excellent soil moisture and abundant heat, canola germination is rapid,
creating a canopy on the field that dramatically limits the number of weeds that emerge
following seeding. Therefore, in some years, producers do not need to apply a post
-
emergenc
e herbicide application to control weeds. In the spring of 2006, moisture conditions
were listed as excellent for most of the prairies and the temperature was above average
(Canadian Wheat Board, 2006).

Since Table 12 over
-
reports and Table 13

under
-
report
s the actual hectar
es of canola
production, Table 14

contrasts the actual hectares of canola production with the amount of
active
ingredient. Table 14

provides a contrast using the same application percentages for the
production between 2005 and 2007. Tabl
e 1 provides the canola hectares for the production
years of 2005, 2006 and 2007. While an application percentage of 70% in 2006 might be
lower than average, even if this increased by an addition 10% or 20% for 2007, the amount of
active ingredient being a
pplied would still be lower than the amount applied in 1995. The
amount of land in canola production has increased by 21% between 1995 and 2007, yet even
if the percentage of land that herbicides are applied to rises to 90%, the amount of active
ingredient

that is applied is still lower than w
hat was applied in 1995. Table 14

demonstrates
that while the production of canola has risen following the introduction of
GM
HT canola, the
amount of herbicide active ingredient is lower than what was applied previousl
y.


Table 14
: Comparison of canola hectares and active ingredient application


1995

2005

2006

2007

Hectares of canola
production

5,190,093

5,099,039

5,220,445

6,272,627

Amount of herbicide
active ingredient (kg)

3,363,233

2,046,142

2,091,727

2,517,081



One of the significant environmental impacts revealed through the survey was the
correlation between the adoption of
GM
HT canola and the increase in producer use of
minimum
-
tillage or zero
-
tillage practices. Use of tillage has markedly decreased from 199
9
when 89% of western Canadian canola was produced under management that used tillage
operations as the leading form of weed control (CCC, 2001). The survey revealed that in
2006, 65% of the canola grown on the Prairies is managed using zero tillage or

min
imum
tillage method (Table 6
). While in the last two decades changes in such factors as farm size
and farm equipment have contributed to a general movement across the prairies away from
the conventional practice of summerfallow, it is evident from this sur
vey that producers that
have made this transition to reduced tillage have found a benefit in using
GM
HT canola.
18


Young (2006) states that the introduction of glyphosate
-
resistant soybean and cotton is likely
a contributing factor in recent increases in no
-
t
illage production of these crops in the US. The
reason is that producers are getting very high levels of weed control in fields seeded with
GM
HT
crops
, to the level that there is no longer a need to pre
-
work fields before seeding in
the following crop year
. Traditionally, producers have tilled their fields prior to seeding as a
form of early weed control. The use of
GM
HT canola would appear to have eliminated this
practice as producers now apply herbicides to ‘burn
-
off’ weeds prior to seeding.

Producers rep
ort that they are able to gain superior levels of weed control by utilizing
GM
HT canola in their cropping rotations, which allows them to direct seed the second year
crop into the canola stubble. The survey revealed two major productivity benefits to be
ga
ined from this practice. First, maintaining stubble on the soil increases snow capture and
thereby increases spring soil moisture levels while greater levels of soil organic material
contributes to moisture conservation in the soil, enabling canola seed to

germinate in a soil
bed that has a higher level of moisture than conventionally
-
tilled fields. This is extremely
important in arid areas of the Prairies. Eighty
-
three percent of respondents indicated that they
have greater soil moisture with this land man
agement method. Second, the reduction in
intensive tillage of land and the move to minimum and zero
-
tillage allows producers to seed
GM
HT canola with a minimum of soil disturbance, thereby reducing the soil’s exposure to
wind. When asked about experiences with soil erosion following the adoption of
GM
HT
canola, 86% of producers in our survey reported that they have reduced soil erosion. S
oil
erosion is problematic for many areas of Western Canada, especially in the lighter soil zones
that typically receive less precipitation. When asked about the land that they routinely seed
canola into, 41% of producers indicated that they are seeding
GM
HT canola into land that
they identified as
erodible
. Producers further identified that soil humus is improving on their
erodible

land. Controlling weeds on
erodible

land previously meant that producers had to
utilize some form of tillage weed control. Pro
ducers can use zero
-
till equipment to seed
canola and use the same equipment the following year to seed a cereal or pulse crop. One
-
third of respondents indicated that they now have improved soil structure following the
adoption of minimum or zero tillage.

An additional environmental benefit facilitated by the adoption of

GM
HT canola and
the move to minimum and zero
-
tillage is greater carbon sequestration. The transition to these
methods of land management results in increased stocks of carbon (carbon sinks
) maintained
in soils being used to produce annual crops (West and Post, 2002). The reduced soil
disturbance associated with reduced tillage decreases the rate of decomposition of crop
residues and thereby maintains more of that carbon in and on the soil r
ather than releasing the
carbon into the atmosphere and contributing to atmospheric greenhouse gas stocks (Lal,
2005). Furthermore, the practice of continuous cropping, as compared to management
systems that include regular fallow periods, may increase the

amount of carbon that is
sequestered by annual cropping.

Using the response rate to this survey as a reflection of the percentage of producers in
each eco
-
region, it is possible to use the percentage of producers that are using reduced tillage
practices t
o determine the number of tonnes of carbon that are sequestered annually, relative
to land that is managed using conventional tillage. The economic value of that sequestration
can then be calculated. Results of

the survey, reported in Table 15
, suggest tha
t reduced
tillage related to canola cultivation in Western Canada sequesters just over 35,000 tonnes of
carbon annually. When this volume is valued using a carbon price of $5.00/t of carbon
($1.36/t of CO
2

equivalent), the financial benefit is $175,000. Wh
ile the price of carbon is
highly volatile (with values ranging from highs of $27.00/t to lows of $0/t) as markets for
carbon exchange are in the very early stages and subject to shocks, the authors believe that
19


$5.00/t of carbon is a conservative value wi
th long
-
term price predictions from the Chicago
Climate Exchange and the European Climate Exchange being significantly higher.


Table 15
: Value and amount of carbon sequestered using minimum tillage ($C)

Eco
-
region

Min
-
till
hectares

Carbon sequestration

co
-
efficient
(tonnes/h
a
/year)

Carbon
Sequestered
(tonnes/yr)

Value Carbon
Sequestered
($/yr)

Boreal Shield West

3,557

.04

142

$710

Boreal Plains

112,757

.04

4,510

$22,550

Subhumid Prairies

289,927

.07

20,295

$101,475

Semiarid Prairies

252,385

.04

10,095

$50,475

Total

658,626

na

35,042

$175,210

Source: Co
efficients come from McConkey
et al
., 2007.



The

number of producers that are presently utilizing zero
-
tillage practices is
considerably greater than in 1999, and therefore the volume and value of the
carbon being
sequ
estered is also larger (Table 16
). Over 3.3 million hectares were produced using zero
tillage in 2006, which annually sequesters 436,000 tonnes of carbon, relative to
conventionally tilled land. Again assuming a market value of carbon $5.0
0/tonne, the annual
value of this is approximately $2.18 million. When the value of carbon sequestered by
minimum and zero
-
tillage practices are combined, the annual value of increased carbon
sequestration, compared to conventional tillage management, is $
2.35 million, while the
volume of carbon being sequestered increases by approximately 470,000 tonnes per year.


Table 16
: Value and amount of carbon sequestered using zero tillage ($C)

Eco
-
region

Zero
-
till
hectares

Carbon
sequestration

co
-
efficient (t/h/y
r
)

Carbon
s
equestered
(tonnes/yr)

Value of carbon
s
equestered
($/yr)

Boreal Shield West

18,223

.16

2,916

$14,580

Boreal Plains

577,744

.14

80,884

$404,420

Subhumid Prairies

1,485,531

.15

222,830

$1,114,150

Semiarid Prairies

1,293,175

.10

129,318

$646,590

Total

3,374,673

na

435,948

$2,179,740

Source: Co
efficients come from McConkey
et al
., 2007.



A further environmental impact that can be linked to the adoption of
GM
HT canola is
the value of carbon no longer released due to the conventional
tillage of fields planted to
canola. Routine cultivation of land releases carbon into the atmosphere each time the land is
tilled. Since these fields are now being managed using reduced tillage, or zero
-
tillage, the soil
carbon stock is no longer decreased

through emissions when the field is seeded, or released at
a lower level, with reduced tillage
. Table 17

provides a value for this soil carbon that will not
be released due to the change in tillage management
. The combined value of Tables 15
-
17

is
C$4,960
,100, while the total volume of carbon sequestered and not released is 992,020
tonnes.



20


Table 1
7
: Value and amount of carbon no longer released through tillage ($C)

Eco
-
region

Zero
&

min
-

tillage
ha

Carbon
sequestration

co
-
efficient (t/h/y
r)

Carbon
seque
stered
tonnes/
yr
)

Value of
carbon
s
equestered

Boreal Shield West

21,780

.16

3,485

$17,425

Boreal Plains

690,501

.14

96,670

$483,350

Subhumid Prairies

1,775,459

.15

266,319

$1,331,595

Semiarid Prairies

1,545,560

.10

154,556

$772,780

Total

4,033,300

N
a

521,030

$2,605,150

Source: Coefficients come from McConkey
et al
., 2007.



Without a benchmark, it is difficult to appreciate the relative value of the carbon
seque
stration illustrated in Tables 15 and 16
. Because the number of hectares of land under
zero and minimum tillage has increase substantially over the past decade, it is misleading to
compare the above figures to data from a decade ago. To provide a comparable benchmark
that is meaningful, we have
determined the volume and value of carbon sequestration as if
GM
HT canola had not been commercialized. It is assumed that the rate of tillage would not
have changed. Canola Council of Canada data suggests only 11% of producers practiced zero
or minimum til
lage in 1999. While the CCC data does not differentiate between zero and
minimum tillage, the data calculated in Table
18

assumes either all producers using
conservation tillage used minimum tillage (MT) or all used zero till (ZT). The volume of
carbon seq
uestered ranges from 36,711 to 89,134 and the value of this ranges from $183,555
to $445,670.


Table 18
: Value and amount of carbon sequestered using pre
-
GM land management

Eco
-
region

MT or ZT
acres

Mt co
-
eff

ZT
co
-
eff

MT t/ac

ZT t/ac

$MT

$ZT

Boreal Shi
eld
West

3,726

.04

.16

149

596

$745

$2,980

Boreal Plains

118,126

.04

.14

4,725

16,538

$23,625

$82,690

Subhumid
Prairies

303,733

.07

.15

21,261

45,560

$106,305

$227,800

Semiarid
Prairies

264,404

.04

.10

10,576

26,440

$52,880

$132,200

Total

689,989

na

na

36,711

89,134

$183,555

$445,670

Source: Coefficients come from McConkey
et al
., 2007.



When the ranges from Ta
ble 18

are compared with

the combined values of Tables 15
and 16
, it becomes possible to comprehend the environmental impact of
GM
HT canola.
Compared to the scenario without
GM
HT canola, producers are presently sequestering
between 381,000 and 434,000 additional tonnes of carbon annually. The additional value of
this carbon sequestration ranges between $1.91M and $2.17M.


4.3

Changes in Herbicide
-
use



With weed management practices, it is important to investigate how they are related
to the use of herbicides as a form of weed control. To be able to make a statistically valid
comparison between herbicide application prio
r to th
e commercialization of GMHT

canola
and the situation a decade later, we have taken the application area data from Brimner
et al
.
21


(2005) and the EIQ co
-
efficient values from Kovach
et al
. (2009)
to provide
a representative
perspective based on 1995 canola p
roduction.
14

Table 19

shows the estimated total EIQ, the three EIQ subcomponent values

and the
grams of active ingredient per quantity applied, assuming the lowest application rate was
used. The area of herbicide application exceeds 100% due to tank mixing.

The five most
common herbicides used with the production of canola in 1995 are included
; they represented
nearly all the herbicides applied to canola
during this period
.


Table 19:

Top five prominent her
bicides used in canola in 1995

Herbicide

EIQ
f
a

EIQ
c
b

EIQ
e
c

EIQ
d

Grams of
a.i.
e

ha
-
1

Area
applied

Ethalfluralin

15.0

6.0

49.0

23.3

1100

32%

Trifluralin

9.0

5.5

42.0

18.8

800

31%

Clopyralid

8.0

8.0

38.4

18.1

151.2

16%

Sethoxydim

7.1

4.6

51.0

20.9

144

15%

Ethametsulfuron

8.0

6.0

45.6

19.9

15

15%

a Farmer; b Consumer; c Ecology; d Aggregate; a.i. Active Ingredient

Source: Brimner
et al
., 2005 and Kovach
et al
., 2009.



The subcomponent values of the EIQ, the application rate and the application area
provide the EI to farm workers, consumers and th
e ecology

on a per hectare basis (Table 20
).
The EI ha
-
1
, which is the sum of the three subcomponents divided by three, allows for direct
toxicological comparison between different active ingredients. These results indicate that
ecological impacts accounts

for about 72% of the cumulative impact of the top five
herbicides applied to canola in 1995. The farm worker impact contributed only 19% of the
total and, as expected, the consumer impact contributed only about 9%.


The top two herbicides applied to canola in 1995 have significant ecological impacts,
given that these two herbicides were applied to 63% of total canola acres. One of the
ecological challenges of farmers using trifluralin and ethalfluralin was that it had

to be soil
incorporated to provide the most effective weed control. As a result of herbicide residues in
the soil, options for subsequent crops were restricted.


Table 20: Environmental impacts in 1995

Herbicide

EI
f
a

ha
-
1

EI
c
b

ha
-
1

EI
e
c

ha
-
1

EI
d

ha
-
1

%
of total

Ethalfluralin

16,500

6,600

53,900

25,630

55

Trifluralin

7,200

4,400

33,600

15,040

32

Clopyralid

1,210

1,210

5,806

2,737

6

Sethoxydim

3,010

662

7,344

3,672

6

Ethametsulfuron

120

90

684

299

1

Cumulative impact

26,052

12,962

101,334

47,378


Percent of total

19

9

72


100%

a Farmer; b Consumer; c Ecology; d Aggregate; a.i. Active Ingredient



Comparable data for the top five canola herbicide
s in 2006 is provided in Table 21
.
15

The overall EIQ values for the five chemicals in 2006 are somewhat lower than for the top



14

We use the 200
9 EIQ co
efficients as they are the most accurate and up
-
to
-
date data. The coefficients have
been revised periodically since 1992 as more information regarding chemical application becomes
available. By
using the 2009 co
efficients we are able to make the mo
st accurate comparison possible between herbicide
applications in 1995 and 2006.

22


five chemicals used in 1995. Respondents reported that they applied glyphosate and
glufosinate at the rate of 0.70 kg ha
-
1
, which is marginally above the recommended

rate for
glyphosate (where the upper margin for the recommended rate is 0.69 kg ha
-
1
) and marginally
below the recommended rate for glufosinate where the lower margin is 0.20 kg ha
-
1
. A
mixture of imazamox and imazethapyr was applied at the recommended ra
te (42 g ha
-
1
).
Insufficient data was available for
the
2,4
-
D application rate and was assumed to be the
highest recommended rate. Application rates for chemicals can vary from the recommended
rates depending on the price of herbicides relative to the dens
ity of weeds per m², the type of
weeds being treated and the interaction between herbicides in a tank mix and its impact on
the weed population.


Table 21:

Top five canola herbicides

used in 2006

Herbicides

EIQ
f
a

EIQ
c
b

EIQ
e
c

EIQ
d

Grams of a.i.
e

ha
-
1

Area
Applied

Glyphosate

8.0

5.0

33.0

15.3

697

48%

Glufosinate

12.0

8.0

40.6

20.2

477

12%

Imazamox

8.0

8.0

42.6

19.5

14.7

4%

Imazethapyr

15.6

10.6

32.4

19.6

14.7

4%

2,4
-
D

24.0

7.0

31.0

20.7

414

2%

a Farmer; b Consumer; c Ecology; d Aggregate; a.i. Active
Ingredient

Source: Kovach
et al
., 2009.



The amount of active ingredient per hectare dropped substantially between 1995 and
2006. Producers in 2006 applied herbicides that are considerably more benign than those
applied in 1995. The lower amount of
herbicide active ingredient applied translat
es into lower
EI values (Table 22
).


When asked about herbicide applications, 27% of respondents reported no herbicide
use, which is higher than the 22% of farmers who reported using cultiva
tion methods (Table
6
). There are a number of possible reasons for this discrepancy. Eight percent of farmers
reported they did not need to spray widely; rather they had adequate weed control from
the
previous year’s cultivation or they may have only spot
-
sprayed limited parts

of a canola field
for weed control purposes. Glyphosate can also be used as a burn
-
off chemical prior to
seeding, which may account for some of the

variance between Tables 6 and 22.


Table 22: Environmental impacts in 2006

Herbicide

EI
f
a

ha
-
1

EI
c
b

ha
-
1

EI
e
c

ha
-
1

EI
d

ha
-
1

% total

Glyphosate

5,573

3,483

22,988

10,658

36

Glufosinate

5,724

3,816

19,366

9,635

32

Imazamox

118

118

626

287

.01

Imazethapyr

229

156

476

288

.01

2,4
-
D

9,959

2,905

12,864

8,590

29

Cumulative impact

21,603

10,477

56,320

29,458


Percent of total

24

12

64


100

a Farmer; b Consumer; c Ecology; d Aggregate; a.i. Active Ingredient







15

In the review process for this article it was brought to the authors
'

attention that the EIQ value for glyphosate
listed in Kovach
et al
.

2009 was erroneous. The value liste
d online for glyphosate by Kovach
et al
.
,

is 25.3. The
authors contacted Dr. Kovach by email to confirm the error and to inquire as to the correct value. In an email
dated Dec. 12, 2009, Dr. Kovach acknowledges the error and justifies the use of 15.3 as th
e EIQ value for
glyphosate.

23



The 2006 subcomponent values of the EIQ, the application rate and the application
area provide the EI to farm workers, consumers and the ecology

on a per hectare basis (Table
22
). These results indicate that ecological impacts accounts for about 64% of the cumulative
impact of the top five herbicides applied to canola in 2006. The farm worker impact
contributed only 24% of the total and, as expect
ed, the consumer impact contributed only
12%.

The top two herbicides applied to canola in 2006 were applied to 86% of total canola
acres. As expected, the EI to farm workers was lower, due to changes in the suite of
chemicals in use. In addition, improved

safe chemical handling awareness and education
programs have further reduced farmer exposure to herbicides.

Comparing the 2006 impacts (post
-
adoption) with the 1995 impacts (pre
-
adoption), it
becomes evident that there are sub
stantial environmental benefi
ts

associated with changes in
herbicide use patterns fr
om the widespread adoption of GMHT canola (Table 23
).
16

The
cumulative environmental impact effect from herbicides dropped by 53% between the two
periods. When the subcomponent values of the environment
al impact are compared, there is a
reduction of over 40% in each of the subcomponents. The farm worker and ecology
subcomponents decline by 56% and 54%, respectively, while the consumer subcomponent
declines by 42%. Given that the total canola acreage in 1
995 and 2006 was virtually identical,
the reduction in the environmental impact is almost entirely attributable to the adoption of
GMHT

canola. The total volume of herbicide active ingredient applied to canola fields
dropped by 1.3 million kilograms, repre
senting a 38% reduction in quantity between the two
years.


Table 23:

Differences between top five
canola herbicides 1995 and 2006

Comparison

1995

2006

% change

EI
a

ha
-
1


13,898

6,467

-
53%

EI
f
b

ha
-
1

8,176

3,575

-
56%

EI
c
c

ha
-
1


3,783

2,199

-
42%

EI
e
d

ha
-
1

29,798

13,659

-
54%

Grams of a.i.
e

ha
-
1

648

401

-
38%

Total a.i. (Millions kg)

3.4 million kg

2.1 million kg

-
1.3 million kg

a Farmer; b Consumer; c Ecology; d Aggregate; a.i. Active Ingredient



The lower usage of herbicides for canola production is
an important component in
affecting the environmental impact of crop production in Western Canada.

While total canola
acreage held constant in the two reference years in this study, the recent trend has been for
production to rise. Canola data from 2008 sh
ows an unprecedented sixth consecutive year of
increase in canola acreage, rising to over 6 million hectares (up from the reference rate of 5
million hectares). All other things holding constant, this rise in canola cultivation would have
raised herbicide
use by a
bout 60%. But the adoption of GMHT

canola and corresponding
reduction in application rates of active ingredient, more than offset this increase in
production.







16

The EI and the EI subcomponent values are d
erived from the data in Tables 19
-
22
. The EI and subcomponent
values for 1995 are de
rived from the values in Table 20

multiplied b
y the area percentage in Table 19
.
Conversely, the EI

an
d subcomponent values in Table 22

are multiplied by
the area percentage in Table 21
.

24


5.

Conclusions



This study agrees with previous
findings that the adoption of GMHT

canola and a
new suite of herbicides has benefited farmers, the environment

and consumers. The
correlation

of zero and min
-
till
land management practices and GMHT

canola have resulted
in a cropping system that delivers substantial safety improvements to f
armers, citizens,
consumers and the environment.

The attempt to quantify the reported spill
-
over benefits produced one of the most
surprising results. Our survey found that where they are observed, the spill
-
over benefits are
actually greater than the dire
ct benefits. The average estimate of spill
-
over benefits was $15
per acre

compared to the direct benefits of about $11 per acre (as
identified by Phillips 2003

and CCC 2001
). While some producers did not report any multi
-
year benefits, the impact of
those
that did contributed between 19% and 28% of the net benefits to producers in the three
years under review.

This under
-
reported and generally under
-
valued multi
-
year benefit may help to
explain the reality that GMHT canola was almost fully adopted within s
ix years. Neither the
comparative cost of the conventional and GMHT systems nor the estimated direct economic
impact of the technology upon adoption could fully explain the unparalleled adoption of this
new technology. Producers had to be realizing some su
bstantial economic benefits that those
earlier studies were not fully accounting for. This study confirms that substantial economic
benefits are recognized at the producer level. In farming, like any other business, operators
use technologies that consiste
ntly deliver high returns. The sustained rates of adoption and
expansion of the canola acreage in Western Canada are strongly correlated to the economic
benefits identified by this survey.

Environmental impacts have been, and are being, widely observed by
prairie canola
producers. Control of weeds was one of the barriers in a substantial movement to zero
-
tillage,
but the commercialization and adoption of GMHT canola has introduce a new weed control
option that has facilitated this change. Producers are now
able to direct
-
seed GMHT canola,
use the respective herbicide and gain a clear advantage in weed control. Producers that have
not or cannot adopt GMHT canola are forced to rely on tillage as their leading method of
weed control and thus foregoing the soil
conservation benefits of this new technology.

The value of carbon sequestration is substantial, especially when contrasted against
the period before GMHT canola was introduced. Had GMHT canola not been developed and
commercialized in Canada, the difference

in terms of carbon sequestering between canola
farming practices prior to GMHT canola and now is estimated to be nearly one million tonnes
of carbon annually. In this way GMHT has contributed to the sequestration of carbon, and if
farms in Canada were pla
ced on a total energy budget including greenhouse gas emissions,
farmers using GMHT canola would be better off than those using conventional varieties.

The adoption of GMHT

canola has substantially affected the environmental impact of
herbicide use in West
ern Canadian agriculture. Farmers have rap
idly and aggressively
adopted GMHT

canola as a tool to increase the flexibility of weed control. This has
contributed to a corresponding shift in the types of herbicides applied to canola, with farmers
moving away
from soil
-
incorporated pre
-
emergent herbicides (such as trifluralin and
ethafluralin) to foliar applied post
-
emergent herbicides (such as glyphosate and glufosinate).
The shift in herbicides has enabled farmers to adopt a more sophisticated approach to wee
d
control, with producers applying herbicide when and where it is needed and at an appropriate
rate for the control of observed weed populations.

It remains the case that citizens and consumers are likely to be unmoved by reports of
producer benefits. In C
anada, approximately two percent of the population
engages in
25


farming
, leaving the vast majority of people in urban and semi
-
urban contexts and unaware of
primary agricultural production. With increasing awareness of the environmental impact of
agriculture
,
an
impact that knows no boundaries, the indirect benefits of GMHT canola
production cited here may lead to more widespread
understanding and appreciation for
crop
biotechnology in Canada and elsewhere.



Acknowledgements


The authors’ research
is
support
ed
both by
VALGEN (Value Addition through Genomics and
GE3LS), a project sponsored by the Government of Canada through Genome Canada and
Genome Prairie
, and the
Network of Centres of Excellence for Advanced Foods and
Materials (AFMNet).


The work reported
in this paper has been published as follows:


Gusta, M, S. Smyth, K Belcher, P. Phillips, and D. Castle. 2011. Economic Benefits of
Genetically Modified Herbicide Tolerant Canola for Producers. AgBioForum

14(1):
1
-
13.

Smyth, S. M Gusta, K Belcher, P Philli
ps and D Castle. 2011. Changes in Herbicide Use
Following the Adoption of HT Canola in
Western Canada. Weed Technology In
Press. Accessed at
http://www.wssajournals.org/doi/abs/10.1614/WT
-
D
-
10
-
00164.1
.

Smyth, S., M. Gusta, K. Belcher, P. Phillips and D. Ca
stle. 2011. Environmental Impacts
from Herbicide Tolerant Canola Production in Weste
rn Canada. Agricultural Systems
104: 403
-
410.



References


Ammann, K. 2005. Effects of biotechnology on biodiversity: Herbicide
-
tolerant and insect
-
resistant GM crops.
TRENDS in Biotechnology

23: 8: 388
-
394.

Baker, J. M., T. E. Ochsner, R. T. Venterea and T. J. Griffis. 2007. Tillage and soil carbon
sequestration

What do we really know?
Agriculture, Ecosystems and Environment

118: 1
-
5.

Beckie, H. J., K. N. Harker, L. M.

Hall, S. I. Warwick, A. Légère, P. H. Sikkema, G. W.
Clayton, A. G. Thomas, J. Y. Leeson, G. Séguin
-
Swartz and M.
-
J. Simard. 2006. A
decade of herbicide
-
resistant crops in Canada.
Canadian Journal of Plant Science

86:
4: 1243
-
1264.

Benbrook, C. M. 2009.
I
mpacts of Genetically Engineered Crops on Pesticide use in the
United States: The First Thirteen Years
. Available online at:
http://www.organic
-
center.org/reportfiles/13Years20091126_FullReport.pdf
.

Benbrook, C. M. 2003. Impacts of Genetically Engineered C
rops on Pesticide Use in the
United States: The First Eight Years.
BioTech InfoNet

No. 6. Available online at:
www.biotech
-
info.net/technicalpaper6.html
.

Brimner, T., G. Gallivan, and G. Step
henson. 2005. Influence of herbicide
-
resistant canola on
the environmental impact of weed management.
Pest Management Science

61: 47
-
52.

Brookes, G. and P. Barfoot. 2010. Global impact of biotech crops: Environmental effects,
1996
-
2008. AgBioForum 13: 1: 7
6
-
94.

26


Brookes, G. and P. Barfoot. 2005. GM Crops: The global socio
-
economic and environmental
impact


the first nine years 1996
-
2004.
AgBioForum

8: 2/3: 187
-
196.

Canadian Wheat Board. 2006.
The 2006 Western Canadian growing season in review
.
Available on
line at:
http://www.cwb.ca/public/en/farmers/grain/crop/popups/110106.jsp.

Canola Council of Canada. 2008
. Provincial acreage and yields. Available online at:
http://www.canolacouncil.org/acreageyields.aspx
.

Canola Council of Canada. 2005. Herbicide Tolera
nt Volunteer Canola Management in
Subsequent Crops. Available online at: http://www.canola
-
council.org/gmo_herb.aspx.

Canola Council of Canada. 2001. An Agronomic and Economic Assessment of Transgenic
Canola. Available online at: http://www.canola
-
council.
org/gmo_toc.aspx.

Canola Council of Canada. 2000. Final Report on the Pest Management Study Conducted on
Behalf of the Canola Council of Canada. Available online at:
http://www.canolacouncil.org/contents10.aspx.

Dill, G. M., C. A. CaJacob and S. R. Padgett
e. 2008. Glyphosate
-
resistant crops: Adoption,
use and future considerations.
Pest Management Science

64: 326
-
331.

Fawcett, R. and D. Towery. 2002.
Conservation Tillage and Plant Biotechnology: How new
technologies can improve the environment by reducing t
he need to plow
.
Conservation Technology Information Center: West Lafayette, IN. Available online
at:
http://croplife.intraspin.com/Biotech/papers/35%20Fawcett.pdf
.

Fernandez
-
Cornejo, J., C. Hallahan, R. Nehring, S. Weschsler and A. Grube. 2010.
Conservation Tillage, Pesticide Use, and Biotech Crops in the U.S.A. Selected paper
presented at the American Agricultural and Applied Economics Conference, July 25
-
27, 2010, Denver, CO
. Available online at:
http://ageconsearch.umn.edu/bitstream/60941/2/

Fernandez
-
Cornejo%20
-
%20AAEA%202010%20SP.pdf
.

Fulton, M. and L. Keyowski. 1999. The Producer Benefits of Herbicide
-
Resistant Canola.
AgBioForum

2: 2: 85
-
93.

Gianessi, L. P., C. S. Silver
s, S. Sankula and J. E. Carpenter. 2002.
Plant Biotechnology:
Current and Potential Impact for Improving pest Management in U.S. Agriculture
.
Available online at:
www.ncfap.org
.

Intergovernmental Panel on Climate Change
. 2007.
Climate Change 2007: Synthesis Report
.
Available online at: http://www.ipcc.ch/pdf/assessment
-
report/ar4/syr/ar4_syr.pdf.

Kleter, G. A.,

R. Bhula, K. Bodnaruk, E. Carazo, A. S. Felsot, C. A. Harris, A. Katayama, H.
A. Kuiper, K. D. Racke, B. Rubin,

Y. Shevah, G. R. Stephenson, K. Tanaka, J.
Unsworth, R. D. Wauchope

and S.
-
S. Wong. 2007. Altered pesticide use on transgenic
crops and the associated general impact from an environmental perspective.
Pest
Management Science
63: 11: 1107
-
1115.

Kovach, J.,

C. Petzoldt, J. Degnil, and J. Tette. 2009. A method to measure the environmental
impact of pesticides, Table 2, List of Pesticides.

http://www.nysipm.cornell.edu/

publications/EIQ/files/EIQ_values_09.pdf.

Ko
vach, J., C. Petzoldt, J. Degnil, and J. Tette. 1992. A method to measure the environmental
impact of pesticides. New York’s Food and Life Sci. Bulletin 139.

Lal, R. 2005. Enhancing crop yields in the developing countries through restoration of the
soil or
ganic carbon pool in a
gricultural

lands.

Land Degradation and Development

17: 2
: 197

209.

Lal, R. 2004. Soil carbon sequestration impacts on global climate change and food security.
Science

304: 5677: 1623
-
1627.

27


Lal, R. R. F. Follett and J.M. Kimble. 2003
. Achieving soil carbon sequestration in the
United States: A challenge to the policy makers.
Soil Science

168: 12: 827
-
845.

Leeson, J.Y., A. G. Thomas, H. J. Beckie, C. A. Brenzil
, L. M. Hall, T. Andrews, K. R.
Brown, and R. C. Van Acker. 2006. Herbicide
-
Use Trends in Prairie Canola
Production Systems.
2006 Soils and Crops Workshop [CD
-
ROM], Extension
Division, University of Saskatchewan, Saskatoon, SK, Canada, March 2

3, 2006, pp.

7.

Leeson, J. Y., A. G. Thomas, C. A. Brenzil, and H. J. Beckie. 2004. Do Saskatchewan
producers reduce in
-
crop application rates? Proc. Canadian Weed Sci. Soc. Meeting.
November 28


December 1, Winnipeg, Manitoba.

Mauro, I. J. and S. M. McLachlan.
2008.
Farmer knowledge and risk analysis: Post release
evaluation of herbicide
-
tolerant canola in Western Canada.
Risk Analysis

28: 2: 463
-
476.

Mayer, H. and W. H. Furtan. 1999. Economics of transgenic herbicide
-
tolerant canola: The
case of western Canada.
Food
Policy

24: 4: 431
-
442.

McConkey, B., D. Angers, M. Bentham, M. Boehm, T. Brierley, D. Cerkowniak,

C. Liang, P. Collas, H. de Gooijer, R. Desjardins, S. Gameda, B. Grant, T. Huffman,
J. Hutchinson, L. Hill, P. Krug, T. Martin, G. Patterson, P. Rochette, W.
Smith, B.
VandenBygaart, X. Vergé and D. Worth. 2007. Canadian Agricultural Greenhouse
Gas Monitoring Accounting and Reporting System: Methodology and greenhouse gas
estimates for agricultural land in the LULUCF sector for NIR 2006. Agriculture and
Agri
-
Fo
od Canada, Ottawa, ON.

NIST/SEMATECH. e
-
Handbook of Statistical

Methods. 2006. Online Article:
http://www.itl.nist.gov/div898/handbook/.

Phillips, P. W. B. 2003. The economic impact of herbicide tolerant canola in Canada. In N.
Kalaitzandonakes (ed.)
The E
conomic and Environmental Impacts of Agbiotech: A
Global Perspective
. New York: Klewer Academic Publishers. 119
-
140.

Saskatchewan Ministry of Agriculture. 2008.
Farm Machinery Custom and Rental Rate
Guide: 2008
-
09
. Available online at:
http://www.agriculture.gov.sk.ca/Default.aspx?DN

=f4b84942
-
e058
-
4b5f
-
92eb
-
b4f5435bc9d6.

Statistics Canada. 2006.
2006 Census of Agriculture
. Ottawa: Queen’s Printer.

Smyth, S. J., M. Gusta, K. Belcher, P. W. B.
Phillips and D. Castle. (In Press) Changes in
herbicide use following the adoption of herbicide tolerant canola in Western Canada.


Smyth, S. and P. W. B. Phillips. 2001. Competitors Co
-
operating: Establishing a Supply
Chain to Manage Genetically Modified
Canola.
International Food and Agribusiness
Management Review

4: 51
-
66.

Tukey, J. 1977. Exploratory Data Analysis. Addison
-
Wesley, Reading, MA.

United States Department of Agriculture, National Agricultural Statistics Services. 2008.
USDA expects corn acre
s to drop in 2008
. Available online at:
http://www.nass.usda.gov/Newsroom/2008/03_31_2008.asp.

West, T. O. and W. M. Post. 2002. Soil organic carbon sequestration rates by tillage and crop
rotation: A global data analysis.
Soil Science Society of America
Journal

66: 1930
-
1946.

World Bank. 2010.
World Development Report 2010: Development and Climate Change
.
Available online at:
http://siteresources.worldbank.org/INTWDR2010/Resources

/
52
87678
-
1226014527953/WDR10
-
Full
-
Text.pdf
.

Young, B.G. 2006. Changes in herbicide use patterns and

production practices resulting
from
glyphosate
-
resistant crops.
Weed Technology

20: 301
-
307.