Erosion Control with Polyacrylamide for Highly Disturbed Upland Soils Nazifi Rabiou, Graduate Research Assistant Dr. Clark J. Gantzer, Advisor Soil & Atmospheric Sciences Soil & Atmospheric Sciences University of University of Missouri Missouri
Transcript
Slide 1
Erosion Control with Polyacrylamide for Highly Disturbed Upland
Soils Nazifi Rabiou, Graduate Research Assistant Dr. Clark J.
Gantzer, Advisor Soil & Atmospheric Sciences University of
Missouri
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Acknowledgments Advisor, Committee Members, and Cliff Mongler
Niger Government and the Fulbright Program Water Resource Research
grant support
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Outline of the Presentation Krilium water soluble polymers use
Why is Polyacrylamide being on focus as an alternative soil
conditioner and recent research on PAM The ongoing research on
guidelines development for use of PAM
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1948: Research started to find a synthetic soil conditioner
1951: Krilium
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Enhances Flocculation Compared effect of PAM on water
turbidity: aft PAM application and Control
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Why is Polyacrylamide of Interest? Results from research on PAM
show Effective erosion control Sustained water infiltration rates
Reduce soil surface sealing Reduced cost of erosion control
Potential use for prairie restoration and construction sites
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Upland Erosion Control: PAM Research at MU PAM application
methods were studied to determine and compare effectiveness of
application methods: Infiltration, runoff runoff and erosion data
on Mexico clay soil with PAM rate of ~10kg/ha resulted in: 62% of
runoff with PAM vs. 72% without PAM 46% of sediment reduction with
PAM compared to untreated Thompson et al. 2001. ASAE Annual
International Meeting
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Devaney et al. 2002. ASAE Annual International Meeting PAM
Research at MU Erosion from different PAM applications methods
after 1.25 hr of simulated rainfall at 6.4 cm/h.
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PAM Research at MU Devaney et al. 2002. ASAE Annual
International Meeting PAM Reduces Erosion Erosion from different
PAM applications methods after 1.25 hr of simulated rainfall at 6.4
cm/h.
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Devaney et al. 2002. ASAE Annual International Meeting PAM
Research at MU PAM treatments have mixed Infiltration effects
Runoff after 1.25 hr of simulated rainfall at 6.4 cm/h.
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Other Research on PAM Costal plain of Israel (Smith et al.
1990) National Soil Erosion lab (Flanagan et al., 2002)
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PAM Reduces Soil Erosion Smith et al. 1990. SSSAJ
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Polyacrylamide (PAM) PAM increases soil cohesion & enhances
the aggregates by binding particles together
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PAM & GypsControlPAM PAM - Soil Erosion
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PAM Increases Final Infiltration Rate Smith et al. 1990.
SSSAJ
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Raindrop & Soil Detachment after Ellison 1947
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PAM Reduces surface sealing
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Reduced Cost Application of PAM at 80 kg ha -1 costs ~$400 ha
-1 (Green and Stott, 2000) Application of traditional mulch is
~$1,600 and $400 (Less than the cost of mulch a traditional method
of erosion control (Chaudhary and Flanagan, 1998)
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PAM for Prairie Restoration Prairie restorations sites are
often subjected to frequent tilling a full year before planting to
reduce weed seed competition. This has a beneficial effect of
reducing weed competition BUT at a high cost because the soil is
left totally unprotected from erosion. Eroded sediments move to
stream causing degradation of aquatic habitats.
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PAM for Prairie Restoration PAM amendments are well suited to
reduce soil erodibility during this period of soil preparation
Springtime erosion for a prairie restoration site at the Prairie
Fork Conservation Area. Gantzer 2000.
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PAM can help prevent such PFCA gully erosion Gully created from
Dec. 2003- to Apr. 2004. Prairie Foundation Site in preparation for
prairie restoration. Gantzer, 2004
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PAM For Construction Sites Erosion Control Major problem
associated with erosion on a construction: Movement of soil off the
site and its consequent pollution of receiving rivers, streams and
lakes In Missouri 70 to 90 percent of the eroded soil (sediment)
that reaches any type of channel is transported to the states water
resource
(http://www.dnr.mo.gov/wpscd/wpcp/field-guide/fg02_erosion.pdf.)
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Construction Site Erosion -East Broadway, Columbia, MO Soil
Conservation Class 2003
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Construction Sites Disturbing thousands of hectares results in
severe erosion due to steep slopes, bare soil and compaction High
costs over short times PAM application reduced soil erosion by 83%
and decreased runoff by 16% ( Roa-Espinoza et al, 2000) PAM can
provide environmental benefits an also reduce management
costs.
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Reduction of Nutrient and Pesticides from Eroded Sediments in
Water Effluent containing excess nutrients promotes algal blooms in
surface waters. PAM has been shown in USDA-ARS work in Idaho, to be
capable of reducing nutrient loss from surface waters (Sojka &
Entry, 2001)
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PAM may be Effective on Steep Slopes Large scale land
excavation that leave great areas of soil, subsoil and tailing
materials exposed poses erosion and water contamination risks
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Ongoing MS Research Rationale - factors that affect PAMs
longevity in soil remain largely unanswered Rationale - factors
that affect PAMs longevity in soil remain largely unanswered
Objectives - to study different PAM application methods to learn
about the longevity of its effectiveness in reducing erodibility,
and maintaining infiltration Objectives - to study different PAM
application methods to learn about the longevity of its
effectiveness in reducing erodibility, and maintaining infiltration
Methods - to evaluate sieved repacked Mexico Ap soil in 0.3- by
0.3-m simulated rainfall box Methods - to evaluate sieved repacked
Mexico Ap soil in 0.3- by 0.3-m simulated rainfall box
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Rationale Construction sites soil are susceptible to erosion
before re-establishment of vegetation Repair of eroded slopes is
costly Sedimentation and water pollution result in environmental
and economic losses to the general public and the contractor
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Rainfall Simulation Miller, W.P. 1987. A solenoid-operated,
variable intensity rainfall simulator. Soil Sci. Soc. Am. J.
51:832-834.
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Rainfall Simulation Miller, W.P. 1987. A solenoid-operated,
variable intensity rainfall simulator. Soil Sci. Soc. Am. J.
51:832-834. A rainfall simulator is being used with this study.
Coefficients of uniformity for a 1 m 2 plot under a single nozzle
are 90 to 95. Kinetic energy of the rainfall, determined from drop
size distributions, is about 23 J m -1 mm -2, which is within the
range for natural rainfall.
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Rain Simulator Nozzle A Spraying Systems Fulljet 30 Wide Square
nozzle with a spray angle of 104 used A precision pressure
regulator provides 28 kPa water pressure to provide a water
discharge of 7 L min -1 to provide a rain rate of 70 mm h -1
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Rainfall Simulator gauges 49 small rainfall collectors 10cm by
10cm to evaluate the the rainfall variation with, time space and
pressure.
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Problems with Spatial Variability of Rainfall Intensity 3
nozzles 50WSQ type were evaluated Surface curve of the rain
intensity from 49 rain collectors
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Problems with Spatial Variability of Rainfall Intensity 3
nozzles 50WSQ type were evaluated Surface curve of the rain
intensity from 49 rain collectors
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Soil Bed Positioning The work is being conducted at the
Biological Engineering Hydraulic Lab The test bed is located 3m
directly below at wide angle nozzle The bed is set at a 5%
slope
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Soil Test Bed The test bed is 0.3 by 03 m The Bed has 15 2-mm
holes for drainage A screen is placed on the bed and then a 50-mm
layer of coarse sand is filled over which 10-mm deep layer of 10-mm
sieved Mexico soil is packed to 1.3 Mg m -3
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30 WSQ Nozzle Calibration New pressure regulator to set and
monitor the desired water supply
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Rain Intensity Variation with Time Rainfall intensity for 5 min
periods Statistical analysis shows rainfall intensity is highly
variable with time (P