Embed Size (px)
Citation preview
The
role of conservation agriculture in the management of hilly
watershedsÁdám Kertész
Head of Department
Department for Physical Geography Geographical Research Institute,
Hungarian Academy of Sciences
H-1112 Budapest, Budaörsi út 45.
Contents• Introduction
• Conservation
Agriculture in Europe
• Arguments against Conservation
Agriculture
• Benefits for the soil
• Environmental benefits
• The SOWAP project
• Conclusions
Introduction•
Conventional agriculture is based on tillage and it is highly mechanized
•
Cultivation is performed by inverting the soil using the plough or similar tools
•
Conventional agriculture causes severe land degradation problems including soil erosion and pollution as well as other environmental damages like biodiversity and wildlife reduction, low energy efficiency and a contribution to global warming (Boatman et al. 1999)
•
Conservation Tillage (CT) is understood as tillage
practices specifically intended to reduce
soil
disturbance
during seedbed preparation. The objective being to
improve soil structure
and stability. Conservation tillage
encompasses a range of tillage practices up to and including „Zero (no) Tillage”
What is "Conservation Agriculture"
"A holistic approach to crop production, which encompasses conservation tillage (CT), and also seeks to preserve biodiversity in terms of both flora and fauna. Activities such as Integrated Crop
(ICM), Integrated
Weed
(IWM), and Integrated Pest
(IPM) Management form part of Conservation Agriculture
(CA)”
To us Conservation tillage is not just zero-tillage
The concept of
""As little as possible, as much as is As little as possible, as much as is necessarynecessary""
is a guiding principle for both SOWAP and
ProTerra
•
Sustainable Land Management (SLM). This is one step beyond „Conservation Agriculture”
and
includes other „non-crop”
activities used to promote biodiversity (landscape) historic character in the wider „farmed”
landscape. CA is
practised on 45 million ha worldwide.
Conservation agriculture in Europe•
Slower development than in N and S America, S Africa,
Australia,
because:
• Production costs are less important then elsewhere
• Technology and technology transfer problems
• Lack of institutional support
•
Soil degradation is only recently considered to be a major problem
•
In Europe water erosion endangers 12% of the total land
area and wind erosion 4%, 16% of the
cultivated land is prone to different kinds of soil degradation
Table 1 Estimation of surface under Conservation Agriculture and Direct Drilling in different European
Countries (data obtained from ECAF National Associations)
Surface under Conservation Agriculture
% Agrarian Surface
Surface under No-Till
% Agrarian Surface
Belgium 140.000 10% Ireland 10.000 4% 100 0,3% Slovakia 140.000 10% 10.000 1% Switzerland 120.000 40% 9.000 3% France 3.000.000 17% 150.000 0,3% Germany 2.375.000 20% 354.150 3% Portugal 39.000 1,3% 25.000 0,8% Denmark 230.000 8% United Kingdom 1.440.000 30% 24.000 1% Spain 2.000.000 14% 300.000 2% Hungary 500.000 10% 8.000 0% Italy 560.000 6% 80.000 1% TOTAL 10.054.000 960.250
Arguments against CT• Without ploughing no good job
• Weed problems
• Straw and stubble have to be removed
• Increased risk of fusarium
• Not good for the soil
• Poor germination
• Machinery not available
Benefits for the soil
•
The main benefit of CT is that the soil will be
preserved more or
less in semi-natural conditions as soil
disturbance
by cultivation
is
minimized and physical
and chemical depletion are reduced.
•
Soil structure remains very good with drainage,
porosity, adsorption capacity and structural stability (Lavier
et al.
1997).
•
Compaction and loss of soil structure can be stopped
or reduced
by applying CT as well, since there is less traffic on
the field
and crop residues will not be buried in the soil.
•
OM
remains in the soil. Organic
matter influences soil structure,
soil stability, buffering capacity, water
retention, biological
activity and nutrient balance, all
of these determining erosion
risk as well (Holland 2004).
• Under conventional tillage 50% of soil C may be lost
• Under CT crop residues remain on the soil surface
• Not equally beneficial for every soil type
Environmental benefits• On-site and off-site effects, local, regional and global effects
• Global aspects –
reduced energy consumption and CO2
emission–
promotes carbon sequestration in the soil
–
reduced mechanical activity –
less SO2
emissions, reduced acidification
–
biodiversity: better nesting sites and food supplies–
reduced air pollution
• Nutrients under conventional agriculture → fertilizers → eutrophication
•
after
long-term
CT phosphate
can
accumulate → different fertilizer application techniques are needed
Table 2 Effect of tillage on soil erosion and diffuse pollution
(source: Jordan et al., 2000)
Comparison of herbicide and nutrient emissions from
1991 to
1993
on
a
silty clay loam soil.
Plots
12
m wide were
established and sown
with winter oats in
1991
followed by winter wheat and winter beans.
Measurements Plough Non-inversion tillage
Benefit compared to ploughing
Runoff (l ha-1) 213,328 110,275 48% reduction Sediment loss (kg ha-1) 2045 649 68% reduction Total P loss (kg P ha-1) 2.2 0.4 81% reduction Available P loss 3 X 10-2 8 X 10-3 73% reduction TON (mg N s-1) 1.28 0.08 94% reduction Soluble phosphate (μ g P s-1) 0.72 0.16 78% reduction Isoproturon 0.011 μ g s-1 Not detected 100% reduction
Environmental benefits 2
•
CT may reduce runoff 15-89% and the pollutants in runoff, it has a positive influence on leaching as well
•
there is an indirect positive affect on acquatic ecosystems
• soil biodiversity
• higher bird, small mammal and game population
Table 3 Machinery energy
per
tonne of crop produced under conventional and integrated
farming (source: Donaldson et al., 1996)
The SOWAP project•
a demonstration project started in 2003, supported by
the
EU LIFE Programme
• 3 years, 4 million €, co-funded by EU LIFE & Syngenta
•
SOWAP (SOil
and WAter
Protection)
aims to assess the
viability
of a more “conservation-oriented”
agriculture,
where fewer tillage practices replace the
numerous cultivations carried out under more
“conventional”
arable farming systems. The use of appropriate
chemicals is tested, and their potential for
off-site contamination assessed, to ensure that any
suggested approaches are
environmentally soundhttp://www.sowap.org
The main study topics of the project areSoil erosion
Erosion plots compare conventional, farmer and SOWAP conservation approaches
Measure sediment, pesticide and nutrient loss and water run-offAquatic ecology studies
A key environmental measureSoil disturbance produced by tillage creates high water run-off rates and silty water that drains into streams, ditches and ponds. This results in reduced water clarity, enhanced levels of nutrients, organics, pesticides and silty bottom sediments.
SOWAP will study the impact of “conservation” tillage on stream biodiversity (fish, invertebrates and plants), water chemistry and sediment loading.
Biodiversity –
Avian and Terrestrial Ecology
These vital biological indicators assess the impacts of differing land management practices on ecosystem sustainability
Counts of foraging farmland birds in winter and during the breeding season are undertaken
Of particular interest is the comparison of UK agriculture with the currently, lower intensity agriculture of Hungary
The abundance and availability of seed and invertebrate food resources are assessed
Earthworm numbers are an important indicator of “soil health” and so they are monitored
Biodiversity –
Soil Microbiology
The soil microbiology component of the project will complement the physical and chemical measurements
Microbiological surveys record indicator species and communities/populations
thereby indicating levels of bio-diversity in the soil
Details on microbial biomass, community structure and function add to the complex picture of biological activity in soil under different management regimes
Agronomy
Changes in the way crops respond to different soil management regimes are important to understand and disseminate
To facilitate this understanding, various assessments are made
crop coverdate of emergencedisease prevalenceweed incidence
This will guide farmers to an understanding of the benefits and pitfalls
EconomicsThe economic viability of the practices employed will bekey to their successful uptake by farmers
Project farmers are encouraged to keep farming calendars throughout the project duration, noting economic inputs
Costs of land preparationTreatment applicationCultivationsManagement practiceHarvesting costsMarketing costsTransportOther variable and fixed costsCrop yields and market pricesGross margins
SOWAP
–
where?UK, Belgium, Hungary and Czech Republic
(France to join)•
At least 1 demonstration site/country
and 2-4
treatments/site (2 replicates/treatment)•
Other co-operating farmers
(up to 15 per country)
undertake
field-scale comparisons to extend relevance and scope
Rainfall Simulation in
the UK
Run-off plots
Hungary
Run-off plots
UK
Rainfall Simulation in
France
SOWAP
–
in farmers fieldsDemonstration•
Strong emphasis on economic viability
and agronomy
•
Close collaboration with farmer•
Soil and agronomy database
•
Working with local Syngenta
companies
no-tillagenon-inversion
tillage
ploughing
Soil erosion• Belgium
•
Soil loss is significantly reduced by conservation tillage. Rainfall simulations*
at 20 fields show an average soil loss
reduction of 50% compared to traditional ploughing.
•
Rainfall simulations show that at 1/5 of the investigated fields, the runoff is higher at the conservation tilled part. At the other fields the runoff is lower. On average, runoff on conservation tilled fields is 60% of runoff on traditionally ploughed fields.
•
There
is a
large variability in runoff and soil loss between several fields.
This
is
currently
being
investigated,
as the causes
of this variability are not well understood.
*
Combined results of 3 projects: SOWAP, Testing of erosion control measures on arable land in the Loess Belt (Interreg), Sediment
transport from cultivated land to rivers: budget and evaluation of erosion control measures (Flemish government)
• Belgium
•
The average yields*
of sugar beet and maize on the traditionally ploughed part of the fields are approximately equal to the yields at the conservation tilled part.
• United Kingdom
*
Combined results of 3 projects: SOWAP, Testing of erosion control measures on arable land
in the Loess Belt (Interreg), Sediment transport from cultivated land to rivers: budget and
evaluation of erosion control measures (Flemish government)
Treatment Mean % of conventional for Rainfall Simulation + Erosion plot tank clearance
Runoff Sediment Conventional 100 100
SOWAP 78 87 Farmer
preference 88 102
SOWAP: Early results –
soil erosion Belgium
Daily rainfall
62.2
0
5
10
15
20
25
30
1/7
8/7
15/7
22/7
29/7
5/8
12/8
19/8
26/8
2/9
Rai
nfal
l (m
m)
Message:
-Up to 70%
reduction
in soil erosion
Non-inversion No-Tillage Plough
0
10
20
30
40
50
60
70
80
90
100
Eros
ion
of S
oil a
s %
of p
loug
h
Soil erosion
The SOWAP project
in
Hungary
Participants
•
Geographical Research Institute of the Hungarian Academy of Sciences
(GRI
HAS)
•
Syngenta
Hungary
•
Väderstad
Hungary
•
Farmers
•
Altogether
24 people
are involved in
the
project
July 2003
Selection of the study site
•
Main characteristics: - 1,5 ha
-
9-10% slope gradient -
2 x 2 plots
(24 x 50 m)
-
wheat –
sunflower –
maize crop rotation
Conventional
Conventional
Minim
um
Minim
um
Tanks
Collecting System
Meteorology Station
24 m
50 m10 m 10 m4 m
Sketch of St. George (Szentgyörgyvár)
Site
Boarding sheets
Slope: 9-10%
November 2003
Putting together the sediment
collectors
January 2004
Meteorological station and water
level sensors
Cultivation
Conventional
Minimum
Soil loss
172,6
453,8
0
50
100
150
200
250
300
350
400
450
500
Conventional Conservation
m3/
ha/y
ear
Mean runoff,
soil and nutrient loss values on conservation plots in percentage of those on conventional plots
2004-2006
Szentgyörgyvár
38,0
2,3 3,7
15,7
31,9
27,7
8,6 6,0
27,8
0
20
40
60
80
100
120
Runoff
Sedim
ent
dry
matter
Susp
ended
dry
matter
Tota
l dry
matter
TO
C N
Wate
rso
luble
P
Tota
l P K
%Runoff
96%
2,63x
62%
0,09
2,44
0
0,5
1
1,5
2
2,5
3
Conventional Conservation
t/ha/
year
Tolerable soil loss 2 t/ha/year
10
12
14
16
18
0-5
5-10
10-15
15-20
20-25
25-30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
80-85
85-90
90-95
95-100
Depth (cm)
Soil
moi
stur
e (%
)
Dióskál 2 (búza) C Dióskál 2 (búza) MDióskál 1 (kukorica) C Dióskál 1 (kukorica) M
2005 spring
2005 autumn
Gravimetric soil moisture measurements
2% more
soil moisture in the upper
15-20 cm
soil layer!
10
12
14
16
18
20
22
0-5
5-10
10-15
15-20
20-25
25-30
30-35
35-40
40-45
45-50
50-55
55-60
60-65
65-70
70-75
75-80
80-85
85-90
90-95
95-100
Depth (cm)
Soi
l moi
stur
e (%
)
Dióskál 2 (búza) C Dióskál 2 (búza) MDióskál 1 (kukorica) C Dióskál 1 (kukorica) M
Dióskál 2 (wheat) C
Dióskál
1 (maize) CDióskál
2 (wheat) M
Dióskál
1 (maize) M
Dióskál 2 (wheat) C
Dióskál
1 (maize) CDióskál 2 (wheat) M
Dióskál
1 (maize) M
Average nutrient concentration values in runoff and soil loss on
conservation plots given in percentage of conventional plots.
195.4
171.1 169.0153.3 152.6143.0
96.291.9
230.8
0
50
100
150
200
250
TOC N P K TOC N Vízold. P P K
Lefolyás Üledék
%
Higher concentration values of conservation plots refer to lower nutrient loss values
because of much lower runoff and soil loss on these plots.
Runoff Soil loss
Wat. Sol.P
Runoff,
soil and nutrient loss values under various crops (Szentgyörgyvár, 2004-2006)
Total runoff
0,001
0,01
0,1
1
10
100
Wheat 2004 Stubble field2004/2005
Sunflow er2005
Stubble field2005/2006
Maize 2006
mm
Összes talajveszteség Szentgyörgyváron, 2004-2006
0.001
0.01
0.1
1
10
Búza, 2004 Tarló,2004/2005
Napraforgó,2005
Tarló,2005/2006
Kukorica, 2006
Mg/
ha
Összes tápanyagveszteség a szentgyörgyvári kísérleti parcellákon, 2004-2006
0.001
0.01
0.1
1
10
100
N P K N P K N P K N P K N P K
Búza, 2004 Tarló,2004/2005
Napraforgó,2005
Tarló,2005/2006
Kukorica,2006*
kg/h
a
Total soil loss
Total nutrient loss
Wheat Stubble field Sunflower Stubble field Maize 2004 2004/2005 2005 2005/2006 2006
Wheat
2004Stubble
field
2004/2005
Sunflower
2005Maize
2006*
Stubble
field
2005/2006
Rill erosion at
DióskálMaize
2005
June
Wheat
2006
March
Maize
2007
May
141.7 – 5.4 t/ha
17.3 – 1.0 t/ha
9.6 – 0.2 t/ha
(4%)
(2%)
(6%)
Soil surface cover under different tillage
Hagyományos
Conventional
TalajkímélőConservation
Rainfall simulation experiments
-
Jos Meersmans’
simulator (K.U.Leuven)
-
Two times/year, 3 repetitions each
-
±
0,7m x 0,7m
≈
0,5 m²
0.00
2.00
4.006.00
8.00
10.00
12.0014.00
16.00
18.00
20.0022.00
24.00
26.00
búza tarlón napraf, vetésután
szántás/tarlóh. után
Kukorica,vetés után
tarlóhántásután
búza (márc.)
2004 2005 2005 2006 2006 2007
HagyományosTalajkímélő
mm/h
Runoff at rainfall simulation experiments
Wheat
Stubble
2004
Sunflower
after seeding
2005
Sunflower
after ploughing
/discing
2005
Maize after
seeding
2006
Maize after
discing
2006
Wheat
(March)
2007
Conventional
Conservation
0.00
2.00
4.006.00
8.00
10.00
12.0014.00
16.00
18.00
20.0022.00
24.00
26.00
búza tarlón napraf, vetésután
szántás/tarlóh. után
Kukorica,vetés után
tarlóhántásután
búza (márc.)
2004 2005 2005 2006 2006 2007
HagyományosTalajkímélő
mm/h
Conventional
Conservation
Wheat
Stubble
2004
Sunflower
after seeding
2005
Sunflower
after ploughing
/discing
2005
Maize after
seeding
2006
Maize after
discing
2006
Wheat
(March)
2007
0
50
100
150
200
250
tarlóh/ búzatarlón
napraf, vetésután
szántás/tarlóh. után
Kukorica,vetés után
tarlóhántásután
búza (márc.)
2004 2005 2005 2006 2006 2007
%Azonos esőterhelésre egalizáltbeszivárgás a hagyományosműv. %-ábanTalajveszteség a hagyományosműv. %-ában
Infiltration and
soil
loss
values
of
rainfall
simulation
experiments
given in percentage of conventional
tillage.
Runoff at rainfall simulation experiments
Wheat
Stubble
2004
Sunflower
after seeding
2005
Sunflower
after ploughing
/discing
2005
Maize after
seeding
2006
Maize after
discing
2006
Wheat
(March)
2007
Equalized infiltration in percentage of conventional tillage
Soil loss in percentage of conventional tillage
0
2
4
6
8
10
12
2004 D1 2005 D2 2006 D1 2007 D2 2004 D2 2005 D1 2006 D2 2007 D1
Winter-Wheat Maize
t/ha
Conventional Conservation Average of Zala County
4-5% smaller yield
of the conservation tillage
in
average
of
the
4 years. The profitability of the conservation
and conventional tillage was similar.
Yields
at
Dióskál
(2004-2007)
Costs
of cultivation at the conservation tillage in all cases are more favourable
(for both wheat and maize). This is mostly due to the smaller costs of mechanical operations, to the smaller amount of fuel consumed, which can reduce the costs with up to 10-15%. Considering the total costs of the cultivation, we achieved an average of 5% savings.
Distribution of costs at Dióskál (2004-2006)
Ecology study
2 sites were selected for the ecological survey besides the erosion site of Szentgyörgyvár
(St. George),
at Dióskál (1) and at Zalaszentmárton
(Dióskál 2)
24 plots were designed at the two sites, they were marked out in October 2003
Plots at Dióskál
Soil erosion plots Ecological survey sites
Birds ⎯ 1x a week
Insects March, May, July (3x a year)12 samples/ plot surrounding
March, May, July (3x a year)12 samples/strip
Earthworms October, March (2x a year)9 samples/plot surrounding
October, March (2x a year)9 samples/strip
Seeds October, March (2x a year)9 samples/plot surrounding
October, March (2x a year)9 samples/strip
Soil micro organisms October, March (2x a year)9 samples/plot surrounding
October, March (2x a year)3 samples/strip
Weeds ⎯ 1x a month
Gili
szta
szám
Dióskál 1
0,0
0,4
0,8
1,2
1,6
Hagyományos Kímélõ Dióskál 2
Hagyományos Kímélõ
The effect of tillage on earthworms
Gili
szta
szám
Dióskál 1
0,0
0,4
0,8
1,2
1,6
Hagyományos Kímélõ Dióskál 2
Hagyományos Kímélõ
Átlagos gilisztaszám Dióskál 1-en, 2004-2006
0
50
100
150
200
250
2004. ápr. 2004. okt. 2005.márc.
2005. okt. 2006. ápr. 2006. nov.
Mintavétel
Átl.
gil.s
zám
(db/
m2)
Hagyományos Kímélő
Átlagos gilisztatömeg Dióskál 1-en, 2004-2006
0.00
0.20
0.40
0.60
0.80
1.00
2004. ápr. 2004. okt. 2005.márc.
2005. okt. 2006. ápr. 2006.nov.
Mintavétel
Átl.
gil.t
öm. (
g/db
)
Hagyományos Kímélő
2004 2005
Average number of earthworms at Dióskál, 2004-2006 Average mass of earthworms at Dióskál, 2004-2006
No. o
f ear
thwo
rms/m
2
Mass
ofea
rthwo
rms/g
Sampling date Sampling date
No.
of e
arth
wor
ms
No.
of e
arth
wor
ms
Conventional Conservation Dióskál 1
Conventional Conservation Dióskál 1
Conventional Conservation Dióskál 2
Conventional Conservation Dióskál 2
Conventional Conservation
2004 2004 2005 2005 2006 2006
Apr Oct March Oct Apr Nov 2004 2004 2005 2005 2006 2006
Apr Oct March Oct Apr Nov
Conventional Conservation
The winter-wheat
/ maize crop rotation proved to be definitely favourable for the small songbirds,
as during winter-time, the amount of available food is larger here, increasing the survival prospects of the birds.
According to our observations, 2-3 times more birds occur on conservation tilled plots than on conventional tilled plots.
This is more striking, with a proportion 15-20 times larger, during winter-time, after ploughing of the conventional plots. Conservation
tilled
areas provide favourable conditions for sheltering and feeding of birds during
poor periods of time.
Results - Ecological study: Effects of tillage methods on birds
1
10
100
1000
10000
October 1
October 2
October 3
November
1Nove
mber 2
November
3Dece
mber 1
December
2Dece
mber 3
Janu
ary 1
Janu
ary 2
Janu
ary 3
February
1Februa
ry 2
February
3Februa
ry 4
March 1
March 2
March 3
March 4
Visits
Num
ber o
f bird
s
Total number of birds recorded at Dióskál between October 2004 and March 2005
Ploughing
Results - Ecological study: Effects of tillage methods on birds
Total number of birds recorded at Dióskál between April and September 2005
0
50
100
150
200
250
300
350
400
April 1
April 2
April 3
May 1
May 2
May 3
June 1
June 2
June 3
July
1
July
2
July
3Augu
st 1
August
2Septe
mber 1
Septembe
r 2Septe
mber 3
Visits
Num
ber o
f bird
s
76% of the observed birds are
protected, and 30% possess a European nature protection significance (Red-backed Shrike, Yellowhammer, Skylark etc.). Therefore, agricultural areas are important from the point of view of nature protection, as well.
As seeds are a basic food for 60% of the registered species, it is important that these areas are able to assure their provisions.
•
Conservation agriculture compared with conventional has significant advantages for the soil itself and for the environment.
•
In our experiment, under the given conditions (10% slope, cambisol), under wheat, maize and sunflower the effect of conservation agriculture on soil erosion and nutrient loss proved to be much better than in case of conventional tillage.
Conclusions
•
The amount of soil loss can be reduced below the value of tolerable soil loss. •
Conservation tillage is favourable from ecological
aspects, too, as shown on the examples of earthworm activity and birds.•
Conservation tillage provides also more favourable
soil moisture conditions.•
Our experiments show that even under the
circumstances of intensive agriculture soil and biodiversity conservation is possible by applying conservation tillage.
Conclusions
