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United States Department of Agriculture

Agricultural Research Service

PAM Slide Set - 1996
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This slide set represents a summary of the research of Bob Sojka & Rick Lentz on polyacrylamide (PAM) which was presented at the PAM conference on Managing Irrigation-Induced Erosion with PAM on May 6-8, 1996. Slide sets are no longer available. The following are thumbnails of all the slides in the set together with text from each slide. To view a larger picture of each slide, click on the thumbnail.

1 Title Slide USDA-ARS1. Fighting Irrigation-Induced Erosion with Polyacrylamide (PAM)

A Summary of Research Findings and Application Tips from

USDA Agricultural Research Service

Northwest Irrigation and Soils Research Laboratory Kimberly, Idaho

R.D. Lentz and R.E. Sojka


2. Extent of Irrigated Agriculture2. Extent of Irrigated Agriculture
  • Worldwide Cropped Acres: 3.0 - 3.5 billion
  • Irrigated Cropped Acres: 600 million (15 - 17%)
  • Total US Irrigated Crop Acres: 59.5 million (14.8%)
  • Surface flow: 32.5 million Sprinkler: 24.5 million Other: 2.5 million
  • 17 Western States total: 46.5 million

3. Importance of Irrigated Agriculture3. Importance of Irrigated Agriculture
  • Irrigation occurs on 1/6 of global & US cropped acres
    • 1/3 the annual global & US harvest
    • 1/2 the monetary value of crops harvested 125 million irrigated A. produce 1/3 the global food harvest
    • Irrigation frees 1.2 billion acres for nature (36 Iowas)
    • Greater food security, i.e. yield reliability
    • Common side-benefits: flood control, transport, recreation, hydropower

4. Importance of Irrigated Agriculture4. Importance of Irrigated Agriculture
  • Predominant Association with Aridity
    • Greater photosynthetic efficiency
    • Less: soil-incorporated herbicide, fungicide, pesticide, lime, potash
    • Displaces fewer species

5. arial photo of white soils5. Aerial photo of "white soils"
6. Aerial photo of Sediment in river6. Aerial photo of Sediment buildup in Snake River return flow
7. Table of % Maximum Yield in White Soils7. % Maximum Yield in White Soil Areas
  • Wheat 51
  • Sweet corn 52
  • Alfalfa 67
  • Dry beans 60
  • Barley 68
  • Sugarbeets 79

8. Figure of Furrow Erosion8. Furrow Erosion Diagram showing Detachment, Transport, and Deposition of Sediment
9. Erosion Control Practices9. Erosion Control Practice and Soil Loss Control (%)
  • PAM 90+
  • Conservation Tillage 90+
  • Furrow Mulch 90+
  • Pump-Back 90+
  • Sediment Basins 65-85
  • Filter Strips 40-60

10. Diagram of PAM molecule10. Diagram of PAM molecule
11. Anionic PAMs are Off the Shelf . . .11. Anionic PAMs are "Off the Shelf " Industrial Flocculants. Used Extensively for:
  • Potable Water Treatment
  • Dewatering of Sewage Sludges
  • Washing and Lye-Peeling of Fruits and Veg's
  • Clarification of Sugar Juice and Liquor
  • Adhesives and Paper in Contact with Food
  • Animal Feed Thickeners & Suspending Agents
  • Cosmetics
  • Paper Manufacturing
  • Various Mining and Drilling Applications

12. Photo of PAM in hands12. Photo of PAM crystals
13. PAM binding to the soil surface13. PAM Treated Furrow Irrigation. Diagram of PAM binding to soil surface.
14. What Does PAM Do?14. What Does PAM Do?
  • Strengthens soil cohesion
  • Preserves surface roughness
    • These reduce particle detachment
  • Flocculates suspended solids (coalesces or clumps together)
    • This reduces sediment transport
  • These processes preserve pore continuity
    • This maintains higher infiltration

15. Aggregate Stabilization Demo15. Photo showing effect of PAM on aggregate stabilization
16. PAM flocculation of suspended soil particles16. Photo showing PAM flocculation of suspended soil particles
17. Control Furrow17. Photo of control furrow showing cloudy water and erosion
18. PAM treated furrow18. Photo of PAM treated furrow showing clear water and no erosion
19. PAM vs Control runoff samples19. Photo of PAM vs Control runoff samples in Imhoff cones
20. Initial 10 ppm PAM treatment20. Initial 10 ppm PAM Treatment
  • Sediment Reduction
  • Range 80 - 99 %
  • Avg 94 %

21. Graph Sediment Loss vs PAM treatments21. Graph of Sediment Loss vs PAM Treatments
22. Graph of Soil Loss vs Time22. Graph of Soil Loss vs Time during an irrigation
23. PAMs Potency23. Graph showing PAMs potency on different slopes
24. PAM Effects on Infiltration24. PAM Effects on Infiltration
  • Soil dependent
  • Net increases
    • 15 % on silt loams
    • 50 % on clays
  • 25 % increase in lateral wetting on shallow furrows

25. Photo of Lateral Wetting25. Photo showing PAM effect on lateral wetting
26. Infiltration Increase graph26. Graph of Infiltration Increase with PAM at 5 and 10 ppm
27. Graph of mean runoff losses27. Graph showing mean runoff losses
28. In-stream PAM concentration28. Graph of in-stream PAM concentrations for a fresh furrow
29. PAM application safety29. PAM Application Safety (<10ppm)
  • EPA and FDA approved as food and water additives
  • No known toxicities in soil/water
  • Monomer content controlled
  • No accumulation in crops

30. Persistence in Soil30. Persistence in Soil
  • PAM N-groups quickly consumed by microorganisms
  • PAM carbon backbone more resistant, UV & mech. shear (degrades 10%/yr)
  • Monomer biodegrades rapidly in soil, <18 hour half-life in soil

31. Persistence in Irrigation Streams31. Persistence in Irrigation Streams
  • Dissolved PAM conc. decreases downstream from application point
  • Decreases less in later irrigations
  • Dissolved PAM conc. drops to zero 30 min after application ceases
  • Monomer degrades rapidly in water

32. NRCS PAM Interim Standard32. NRCS PAM Interim Standard
  • Labelled water soluble (not crosslinked) product only
    • High Mol Wt (15 Mg mol-1)
    • Moderate anionic (-) charge (18%)
    • < 0.05 % AMD
  • Treat disturbed furrow (10 ppm in adv.)
  • PAM must be in water before reaching frw
  • Considerations
    • Mix thoroughly
    • Mix-in slowly
    • Turbulence w/dry applicators
    • Maybe individual furrow treatment w/dry or emulsion PAM

33. PAM costs33. PAM Costs
  • $3.00 - 5.50 per lb
  • 1 lb/acre full rate
  • Full rate when soil is disturbed
  • 3 - 5 full rate applications/season??
Offset by:
  • Less furrow reshaping/cultivating
  • Less pond construction or cleaning
  • Less soil respreading
  • Possible yield/quality improvement

34. Granular PAM-Ditch Applicator Cost34. Granular PAM-Ditch Applicator Cost
  • gandy/auger head ditch applicators
    • $225-550 electric motor (battery)
    • $400-550 paddle wheel
    • $800+ electric & auto timing
  • some are easily portable

35. PAM Application Tips - Mixing35. PAM Application Tips - Mixing
  • sprinkle dry PAM into water slowly
  • mixing to separate wetted granules
  • warm water dissolves PAM faster
  • never dump large quantities into water
  • never add water to dry PAM

36. PAM Application Tips - Other36. PAM Application Tips - Other
  • most effective on well-structured soils
  • most effective on dry soils
  • water quality affects PAM efficacy
    • more effective as salts increase
    • less effective as sodium increases
  • Sprinklers? Pressurize line before PAM injection. Backflow protection a must.

37. PAM Furrow Application Tips37. PAM Furrow Application Tips
  • 10 ppm PAM in first water into furrow
  • boost initial inflow rate (e.g. double), go up 1 syphon size, then cut back
  • High-sediment inflows?
    • increase syphon size or head
    • orient slide gates downward
    • settling basin before applic. point

38. Other PAM Research Thrusts38. Other PAM Research Thrusts
  • Furrow PAM application methods
    • Granular patch - Emulsion - Drip line
  • Sprinkler Irrigation
    • Injection technology / rates / benefits
  • Anti crusting properties
    • Application methods / rates / benefits
  • Non agricultural uses
    • Construction site protection
    • Sediment / holding-pond treatment
  • Dryland - the real challenge

39. Furrow on PAM39. This is your irrigated furrow. . . This is your furrow on PAM!

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Last Updated on April 7, 1997 by Jim Foerster


Last Modified: 8/18/2009
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