Economic
evaluation
of
tillage
management
practices
at
the
watershed
scale
in
southern
Manitoba
Mohammad
Khakbazan
a,
*
,
Cliff
Hamilton
b
a
Agriculture
and
Agri-Food
Canada,
Box
1000a,
R.R.
#3,
Brandon,
MB,
R7A
5Y3,
Canada
b
Deerwood
Soil
and
Water
Management
Association,
Box
393,
Notre
Dame
de
Lourdes,
MB,
R0G
1M0,
Canada
1.
Introduction
The
South
Tobacco
Creek
(STC)
watershed,
located
in
south
central
Manitoba
(Fig.
1),
covers
an
area
of
almost
7700
ha,
71%
of
which
is
under
annual
and
perennial
management.
Climate
data
for
the
watershed
collected
at
two
Environment
Canada
weather
stations
since
1965,
indicates
an
average
annual
growing
season
(May
1
to
September
30)
precipitation
of
340
Æ
91
mm,
average
annual
precipitation
of
544
Æ
90
mm
and
growing
degree
days
for
the
growing
season
of
1806
Æ
105
(1995–2009).
Information
on
farming
practices
on
this
land
has
been
collected
since
1991
with
all
producers
cooperating
in
the
study
through
the
local
watershed
group.
The
5400
ha
under
cultivation
is
represented
by
more
than
350
fields
in
this
data
set
providing
data
on
land
management,
cultivation,
crop
yield,
nutrient
application
and
a
number
of
other
useful
agronomic
quantities.
Canola
was
the
most
common
crop
type
in
the
area
representing
approximately
27%
(approx.
1500
ha)
of
the
total
cultivated
land
area
in
the
watershed
per
year
as
part
of
a
two
year
crop
rotation
with
a
cereal
such
as
wheat
or
barley.
Conventional
tillage
(CT),
representing
73%
of
cultivated
land,
was
the
dominant
tillage
practice
in
the
watershed;
about
27%
of
the
land
was
managed
Soil
&
Tillage
Research
118
(2012)
40–51
A
R
T
I
C
L
E
I
N
F
O
Article
history:
Received
12
August
2011
Received
in
revised
form
7
October
2011
Accepted
20
October
2011
Available
online
16
November
2011
Keywords:
Zero
tillage
(ZT)
Minimum
tillage
(MT)
Conventional
tillage
(CT)
Crop
rotation
Economics
Watershed
A
B
S
T
R
A
C
T
The
costs,
risk,
and
additional
management
associated
with
the
conversion
of
agricultural
land
from
conventional
tillage
to
conservation
tillage
play
a
significant
role
in
the
producers’
likelihood
of
adoption
of
such
practices.
A
local
watershed
organization
in
the
South
Tobacco
Creek
(STC)
watershed
in
southern
Manitoba
has
been
collecting
land
management
data
for
almost
20
years.
As
part
of
the
national
Watershed
Evaluation
of
Beneficial
Management
Practices
(WEBs),
a
tillage
index
and
model
were
developed
based
on
field
tillage
operations
and
production
costs,
and
net
incomes.
The
index
and
model
quantified
economic
impacts
of
land
management
practices
for
three
crop
rotations
under
three
tillage
systems
at
the
watershed
scale.
Based
on
a
tillage
index
to
define
tillage
levels
for
zero,
minimum,
and
conventional
tillage,
a
tillage
cost
function
related
tillage
cost
to
tillage
passes
and
crop
residue
management.
Net
income
of
crops
and
typical
rotations
under
three
tillage
systems
has
been
estimated.
For
canola,
the
greatest
net
income
was
generated
in
the
conventional
tillage
(CT)
system,
which
is
attributed
to
the
yield
response
to
the
tilled
seedbed.
As
tillage
frequency
decreased,
net
income
for
canola
declined.
In
contrast,
the
income
response
for
cereals,
such
as
wheat,
was
highest
under
minimum
tillage
(MT)
due
to
reduced
fuel
and
depreciation
costs
relative
to
conventional
tillage.
However
net
income
for
cereals
managed
with
zero
tillage
(ZT)
was
significantly
reduced
due
to
increased
equipment
costs.
Using
the
same
tillage
index,
the
model
has
produced
results
suggesting
that
for
a
wheat–canola
rotation
there
is
a
significant
difference
between
cropping
system
costs
in
areas
of
labour,
oil
and
fuel,
chemical
and
tillage
costs;
however,
there
is
no
significant
difference
between
the
three
tillage
levels
in
areas
of
total
costs
and
net
income.
Although
MT
overall
performed
better
compared
to
ZT
or
CT,
net
income
of
these
three
different
tillage
systems
was
offset
between
crops
of
the
wheat–canola
rotation
and
generally
no
statistically
significant
differences
were
observed.
These
results
explained
why
most
farmers
in
the
STC
watershed
prefer
conventional
or
minimum
tillage
to
zero
tillage-due
to
increased
machinery
investment
and
lower
net
returns
for
zero
tillage.
If
conservation
tillage
is
to
be
promoted
in
this
region
of
Manitoba,
additional
incentives
may
be
required
to
encourage
its
further
adoption.
However,
increased
net
income
for
conservation
tillage
of
cereals
provides
a
clear
incentive
to
adopt
this
practice.
Crown
Copyright
ß
2011
Published
by
Elsevier
B.V.
All
rights
reserved.
Abbreviations:
ZT,
zero
tillage;
MT,
minimum
tillage;
CT,
conventional
tillage;
STC,
South
Tobacco
Creek;
WEBs,
Watershed
Evaluation
of
Beneficial
Management
Practices;
OLF,
oil–lube–fuel;
BMP,
Beneficial
Management
Practice.
*
Corresponding
author.
Tel.:
+1
204
578
3555;
fax:
+1
204
728
3858.
E-mail
address:
mohammad.khakbazan@agr.gc.ca
(M.
Khakbazan).
Contents
lists
available
at
SciVerse
ScienceDirect
Soil
&
Tillage
Research
jou
r
nal
h
o
mep
age:
w
ww.els
evier
.co
m/lo
c
ate/s
till
0167-1987/$
–
see
front
matter
.
Crown
Copyright
ß
2011
Published
by
Elsevier
B.V.
All
rights
reserved.
doi:10.1016/j.still.2011.10.009