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1
ATLANTIC SOIL AND WATER CONSERVATION CHALLENGES
Environmental Farm Planning WorshopCrystal Palace Convention Centre, Moncton, NB
March 30, 2001
Gordon Fairchild, Ph.D., P.Ag., Soils Specialist, ECSWCCand
Jean-Louis Daigle, P.Eng., P.Ag., Director, ECSWCC
Agriculture in Atlantic Canada• climate:
• humid & temperate (high rainfall)
• much is on hilly, rolling land,
• much is on soils naturally susceptible to erosion :
• from morainal deposits
• soils strongly leached, acidic (Podzols)
• soil loamy or sandy in texture
• dense subsoils that impede drainage
2
The climate, soils naturally susceptible to erosion, intensive agriculture in some areas, and economic constraints have led to several soil & water conservation challenges for Atlantic Canada
Atlantic Soil and Water Conservation Challenges
•• soil erosionsoil erosion & & soil degradationsoil degradation
•• NPS pollution NPS pollution --fertilizerfertilizer, pesticide & , pesticide & manuremanure useuse
•• water quality water quality & protection of & protection of water water suppliessupplies
•• water water for irrigationfor irrigation
•• habitat & habitat & biodiversitybiodiversity
•• climate climate changechange
The climate, soils naturally susceptible to erosion, intensive agriculture in some areas, and economic constraints have led to several soil & water conservation challenges for Atlantic Canada
Atlantic Soil and Water Conservation Challenges
3
M any Atlantic soils show serious soil erosion and degradation
Excessive Soil Erosion by WaterExcess Runoff Soil Compaction Loss of Organic Matter
Loss of Crop ProductivityLoss of Available Soil-Water
Estimated annual on-farm costs at 40 million dollarsin Atlantic Canada by AAFC in 1985
Sol Erosion & Degradation (Soil Quality)
It is estimated that 60-70% PEI & NB potato land experiences excessive soil loss as a result of farming undulated slopes
4
AAFC. (1995) The Health of Our Soils
Causes and effects of soil degradation
AAFC. (1995) The Health of Our Soils
Soil Erosion and Degradation
5
Soil Management & ConservationSheet & rill soil erosion are being addressed by:1. Better Crop Rotation 2. Strip cropping3. Winter cover crops4. Conservation tillage5. Green manures 6. Residue management 7. Mulching
1,2 3
4 3 & 5
766
8. Cross-slope & contour cropping9. Diversion terraces & grassed waterways10. Sub-surface drainage, subsoiling & 4x4 tractors 11. Straw cover, mulches
8,98
9 10 11
rill & gully soil erosion (steeper fields) by:
6
Some progress, with over 20,000 acres in each of NB & PEI protected with appropriate combinations of:
• diversion terraces
• grassed waterways
• strip cropping
• residue management
• mulching
• crop rotation
• cover crops
• etc
Soil Erosion and Degradation
Do Soil and Water Conservation Systems work ?
Site 22
Site 20
AAFC Study - Effectiveness of Terracing SystemsNW NB on NSCP SQEP Benchmark sites 20/22
Cross-slope cultivation, diversion terraces, grassed waterways
Up & down - slope cultivation, no terraces
7
Site 22
0 25 50 75
100 125 150 175 200 225
mm
Crg(90) Pa(91) Pa(92) C(93) Pa(94) Moy (90-94)
Terrasse Sens de la pente
Runoff (mm)
0 2 4 6 8
10 12 14 16 18 20 22 24
t/ha
Crg(90) Pa(91) Pa(92) C(93) Pa(94)Moy (90-94)
Terrasse Sens de la pente
Soil loss (t/ha)
terraced terracedUp & down slope Up & down slope
AAFC Study - Effectiveness of Terracing SystemsNW NB on NSCP SQEP Benchmark sites 20/22
Soil and Water Conservation Systems
Runoff & soil loss were greatly reduced on site with soil and water conservation system. Terraces and grassed waterways very effective.
Soil and Water Conservation SystemsChallenges to the Adoption of Conservation Practices:
• Market Pressures & Land Value• Land Availability and Land Tenure• Farming Efficiency & Land Lost• Economics of Soil Conservation ??
Before 1974
8
More concern recently for Water Quality & Farm Runoff Issues
Concern for cattle access to streams as a cause of streambankerosion, sediment in streams, soil compaction and coliform
contamination of water & streambank fencing
9
Events such as the Walkerton tragedy have served to served to heighten awareness of Water Quality & the protection of Water Supplies
Walkerton E.coli 0157:H7 OutbreakTragedy & Reality
• agricultural runoff was a source of contamination of the well water in the Walkerton tragedy, even if it was not the only cause.
• Agriculture is going to be under increasing public scrutiny and pressure for water quality reasons.
10
Heightened public interest in Watercourse Protection & Riparian Management
Ex: NB Watershed & Wellhead Protection for Drinking Water Supplies
aimed mostly at NPS - fertilizer, pesticides & bacteria
11
Agriculture
and
Agri-Food
Canada.
(2000)
What is agriculture’s role in water quality ?
Point-source pollution:• industrial plant, smoke stack, etc.
• Easier to identify and control
Non Point-source pollution (NPS):• all of the field or diffuse runoff pollution sources in a watershed, eg: farms, forestry, roads, etc.
• Diffuse source is harder to identify and control
Agriculture is Non Point-source pollution (NPS):
12
Surface Water Quality Key issues of surface water contamination in agricultural regions in Canada are:
• sediment
• nutrients
• pesticides
• bacteria
sediment entering surface water
• Sediment enters streams from soil erosion
• sediment can fill in streams and ditches
• sedimentation can reduce or elimination aquatic habitat
• sediment carries with it bound to the sediment:
• nutrients ( N & P) - eutrophication
• organic matter - soil degradation
• pesticides
• bacteria
13
Nutrients, bacteria and pesticides enter surface waters chiefly from:
Nitrogen (N): in runoff from fertilizer and manure
Phosphorus (P): mostly as P attached to sediments; some as soluble-P. (soils with high soil test P a problem)
Bacteria: in runoff from manure(tile drains, septic systems, sewage sludge)
Pesticides: in runoff from fields (spills, filling sprayers, spray drift, etc.)
Sediment in farm runoff after very heavy showers (NW NB)
Black Brook 6,000 t / yr ?
14
N and P in surface waters
eutrophication - the excess phosphorus (P) in runoff from fertilizer and manure causes a growth of algae in the water.
This algal bloom consumes oxygen in the water, killing fish or reducing aquatic habitat
Nutrients: N and P in surface waters
• eutrophication - nitrogen (N) can sometimes bethe cause eutrophication in estuarine waters. The anoxic conditions may affect aquaculture (shellfisheries) or reduce aquatic habitat
• High NH4+ can also affect fish in streams
15
Nutrients: N and P in surface waters
• NB AAFC Black Brook Watershed study, 1992-1994:
concentrations of nutrients in surface water• Nitrate-N ranged 2 to 9 mg/litre (1 mg/litre background)
• Phosphate generally < 100 mg/litre (AB, QC guidelines lower)
• PEI (G. Somers, PEIDFE)
surface water nitrate concentrations have risen, but may have stabilized ?
Pesticides in surface waters
concentrations rarely exceed drinking water guidelines, but sometimes aquatic guidelines
16
Bacteria in surface waters
Bacteria can be and are sometimes found in surface waters, particularly near manured fields
Ground Water Quality Key issues of groundwater contamination in agricultural regions in Canada are:
• nitrates (methhemoglobinemia, cancer)
• pesticides
• bacteria
17
Agro-chemical entry into groundwater
AAFC. 1995.
The Health of Our Soils
Agro-chemical entry into groundwater
Pesticide movement into groundwater is related to:
• solubility, ….the more soluble a pesticide, the more likely it is to leach into groundwater.
• stability (or persistence)….the longer the pesticide remains, the more likely it is to leach into groundwater.
Our newer generation of pesticides today are less soluble, lower dose, less persistent and less likely to leach into groundwater today than 20-30 years ago.
18
Bacteria entry into Ground Water
Usually related to:
• poor well construction (too shallow, poor cap, poor grout, shallow grout, poor initial disinfection)
• wells location too close to manure storage , manure runoff, manure application, or septic systems
• preferential transport through tile drains
• abandoned wells
•etc
Ground Water Quality Nitrate concentrations in groundwater can
be elevated in some intensively agricultural
areas
• some potato production areas• NW NB, Grand Falls, Drummond,
Saint-André
• some BC interior valleys• Abbotford-Sumas aquifer BC
19
Ground Water Quality NB, NS, PEI studies….
Pesticides can be found in groundwater,
but are usually well below drinking water
quality guidelines
Ground Water Quality
** Bacteria can be found in groundwater
AB 1995 14 %
QC 1990 26
NB 1985 21
Man 1993 37
PEI 1991 12
NS 1989 9
** indicates « presence » of total coliform, not E. coli 0157:H7
20
• Sharing water resources:who gets the top priority?
• Low Flow Maintenance
S oi l an d W ater C on ser vation C h a lle n ge s & Issu es
water quantity issues (both surface & ground water):
• for irrigation
• for habitat & biodiversity
Soil & Water Conservation may now also have to account for Climate Change considerations ?
21
Possible Atlantic Climate Change Considerations
• slightly increased annual precipitation ? (or decreased ?)
• increasing climate variability, eg: droughts, floods, temperature ?
• increased frequency of intense rainfalls ?
• warmer winters, earlier & larger runoff ?• growing season and temperature ?
• increase (?)
• decrease (?)
Increased climate variability in the intensityof storm events increased runoff & erosion ?
Drummond NB farm -40 mm intense rainfallevent during 15 min
22
•• soil erosionsoil erosion & & soil degradationsoil degradation
•• NPS pollution NPS pollution --fertilizerfertilizer, pesticide & , pesticide & manuremanure useuse
•• water quality water quality & protection of & protection of water water suppliessupplies
•• water water for irrigationfor irrigation
•• habitat & habitat & biodiversitybiodiversity
•• climate climate changechange
The climate, soils naturally susceptible to erosion, intensive agriculture in some areas, and economic constraints have led to several soil & water conservation challenges for Atlantic Canada
Atlantic Soil and Water Conservation Challenges
Tools For Change & Adaptation
• Environmental Farm Plan
• Agri-Conservation Clubs
• BMP Development • Codes of Practice
• Precision Agriculture & Env. Geomatics
• Program Incentives or Tax Benefits
• Economic benefits of S &W Conservation
Self assessment
EFP workbook
23
EFP Tools must be an integrated approach
BMPs
Air Quality
Water Quality
Soil Health
The Win-Win Approach
Tools For Change & Adaptation
• Environmental Farm Plan (EFP) Self assessment
EFP workbook
Environmental Farm Planning WorkshopCrystal Palace Convention Centre,
Moncton, NBMarch 29-31, 2001