Turfgrass Runoff

1
Turfgrass Runoff

• Dr. John Stier
• University of Wisconsin-Madison
• Dept. of Horticulture

2
Public Awareness of Environmental Contamination
Growing

• News stories
• Urban sprawl
• Nutrients and chemicals in ground and surface
  waters
• Scientific literacy of public
• Fear what is unknown
• Special interest groups
• Only voice heard

3
Why Public Perception Matters

• Politicians seek re-election
• Laws difficult to change
• Well-intentioned laws may not help
• Diverts attention from true problem
• Base laws on scientific data when possible

4
Lake Eutrophication

• Eutrophication-Transformation of barren lake into
  nutrient-laden lake full of aquatic organisms
• Natural process
• Civilization accelerates it
• Phosphorus is limiting nutrient
• 0.02 ppm
• Terrestrial plants require 0.2 ppm P in soil
  moisture

5
Stages of Eutrophication

• Oligotrophic Clear water, minimal organic matter
  or sediment, minimum biological activity
• Mesotrophic More nutrients, more biological
  activity
• Eutrophic Nutrient-rich, high biological
  activity, change in aquatic species
• Hypereutrophic Murky, highly productive, closest
  to wetland many clearwater species cannot survive

6
Understanding P types

• Soluble (dissolved) P pass through fine filter,
  used by algae
• Particulate P attached to sediments, solubilizes
  in water unless water P high
• 10-90 bioavailable (Sharpley et al. 1994)
• Total P Soluble Particulate P

7
Watersheds

• Drainage region
• Size and type vary according to geography,
  climate
• Lakes water sources
• Rainfall
• Rivers, streams, creeks
• Groundwater (springs)

8
How Our Environment Has Changed

• Impervious vs Pervious surfaces
• Pre-Development Forests, Fields, Wetlands
• Post-Development Rooftops, driveways, sidewalks,
  streets, parking lots
• Post-Development Lawns, Rain Gardens, Ditches,
  Detention Ponds
• Stormwater fees

9
Runoff

• Definition Water that is discharged laterally on
  or through the ground
• Surface runoff
• Seepage flow from ground water
• Both Runoff Volume and Contamination must be
  considered
• Concentration level has little impact if only few
  ounces or quarts runoff from large area

10
Problems with Runoff

• Sediment
• Deposits in surface waters, sewers, etc.
• Carries adsorbed chemicals nutrients (P)
• Nutrients
• N P
• Algal blooms oxygen deprivation
• Pesticides
• Water treatment plants cant remove
• Agricultural not distinguished from turf

11
Runoff Depends on

• Rate of precipitation/irrigation
• Pre-existing soil moisture
• Slope
• Infiltration percolation capacity of soil
• Soil type (sand gt loam gt clay)
• Time of year (frozen vs. unfrozen)
• Vegetation height and density

12
Soil and Phosphorus

• Acre-furrow slice 1 acre soil, 6-8 deep,
  2,000,000 lbs
• P is 100-1000 ppm
• P bound tightly to soil, other molecules (P
  fixation)
• Unavailable to plants
• 0.01 in soil solution (inorganic P)
• P Mineralization Microbes degrade organics

13
Soil Tests for P

• Soil tests measure P levels needed for crop
  growth, not based on how much P can be adsorbed
  to soil

14
Phosphorus

• Essential to all life (DNA and ATP-energy)
• Natural compound in soil

15
Phosphorus Sources in Runoff

• Organic sources
• Pollen, seeds
• Leaves (living and dead)
• Animal waste
• Manure spread on frozen fields
• Wildlife
• Aquatic animals/plants

16
Phosphorus Sources in Runoff

• Inorganic sources Soil particles/dust
• Bare/exposed soil
• Agricultural operations
• Building construction
• Geography of area

17
The Scientific Method

• Observe a condition
• Read existing information
• Develop theory
• Test theory
• Accept, reject, or alter theory

18
Good vs Bad Science

• Good science has
• Scientifically accepted methods
• Multiple replications (repeated treatments)
• Minimal variation of conditions
• 2 years field data
• Validate statistically
• Publish in peer-reviewed journal

19
Why Data Vary Runoff from 6 Grassland Plots
(Sharpley et al., 1992)
Scientists seek uniformity among plots and
replicate for statistical validation to overcome
natural variation in data.
20
Similar Studies Not Always Agree

• Different methods
• Bray vs Olsen for Phosphorus
• Time of year, soil type, etc.
• Environment!
• Body of Knowledge important
• Not just one experiment
• .cold fusion?

21
Multiple Runoff Studies Conducted

• 1970 current
• Water quantity, nutrients, pesticides
• Crops, turf, fields/prairies

22
Water Runoff from Crops, Turf, and Grasslands
23
Sediment in Runoff from Crops, Turf, and
Grasslands
24
Phosphorus in Runoff from Crops, Turf, and
Grasslands
25
Seasonal Effects of Lawn Runoff
Source Kussow, 1995
26
Fertilization Effect on Phosphorus Losses from
Lawn Turf
Source Kussow, 1997
27
Turf Type Affects Runoff

• Penn State Univ., Linde et al., 1995
• Creeping bentgrass vs. perennial ryegrass
• Fairway height, sloped plots
• 6 inch irrigation/hr to force runoff
• Bentgrass intercepted 113 more water
• 6 times more tillers, thatch
• High water holding capacity, hydraulic resistance

28
Tree Leaf Phosphorus

• Waschbusch et al., 1999
• Madison, WI
• P in street runoff
• No trees lt0.1 ppm P
• 80 tree canopy 0.8 ppm P

29
Pollen Phosphorus

• Banks and Nighswander (1999)
• Pollen of 11 tree spp., Ontario Canada lake study
• Averaged 0.82 P
• Total atmospheric deposition 0.23 lb P/acre
• 43 occurred during May/June

30
Tree Phosphorus on Streets

• Kluesner and Lee (1974)
• High P in runoff (May) elm seeds in
  streets/gutters
• High P in fall (November) P leached from street
  leaves
• Dorney (1986)
• Avg soluble P, 13 tree spp., 148 ppm
• Shapiro and Pfannkuch, 1973 (Univ. Minn.)
• Weekly street sweeping ? P runoff by 42

31
Storm Water Runoff, Lake Wingra, WI (Kluesner and
Lee, 1974)
This study indicated that the amount of runoff
from the storm sewer basin could be accounted
for by summing the area of streets in the basin
(and in some cases driveways also). Thus, unless
fertilizers were carelessly strewn on
the impervious surfaces, it seems unlikely that
the home gardener would be guilty of adding
appreciable amounts of nitrogen or phosphorus to
urban runoff with the types of soils found in
Madison.
Kluesner, J.W., and G.F. Lee. 1974. Nutrient
loading from a separate storm sewer in
Madison, Wisconsin. J. Water Poll. Control Fed.
46(5)920-936.
32
What Happens to Pesticides?
Photodecomposition
(Volatilize)
Pesticide Applied
(Drift)
Runoff ?
Plant Uptake Degradation
Thatch Adsorption
Microbial decomposition
Soil Chemistry Reactions and Decomposition
Leaching?
33
Ultimate Fate of Organic (Synthetic) Pesticides

• Degradation!
• Microbes, soil chemistry, sunlight
• Enhanced degradation
• Half-life Time to degrade 1/2 of compound
• Varies by compound and situation
• Soil
• Foliar
• Water
• Laboratory

34
Pesticides in Runoff Depend on

• Pesticide rate
• Solubility
• Formulation
• Soil adsorption
• Timing of application
• Liquid dries before rainfall?
• Dormant versus actively growing turf
• Placement of pesticide
• Thatchy turf versus pavement

35
Solubility May Impact Pesticides in Runoff

• Greater than 10 mg/L high solubility
• Phenoxy herbicides
• 2,4-D 300,000 - 790,000 mg/L
• MCPP 660,000 mg/L
• Dicamba 850,000 mg/L
• Organophosphate insecticide
• Chlorpyrifos 2.0 - 4.8 mg/L
• Dursban, banned in 2002!

36
Soil and Thatch Adsorption

• Soil and thatch bind (sorb) many compounds
• Determined by adsorption coefficient (Koc)
• Large Koc strong binding
• Chlorpyrifos 6,070 to 14,000
• 2,4-D 20
• Dicamba 2

37
Research

• Numerous studies on turf pesticide runoff and
  leaching
• Fate and Management of Turfgrass Chemicals. 2000.
  J.M. Clark and M.P. Kenna (ed.) American Chemical
  Soc., Washington, D.C.
• Summarizes studies

38
Do Turf Pesticides Runoff?

• Watschke Mumma, 1989
• 2 yr study, 29 sampling dates
• Kentucky bluegrass lawn-type turf
• 9-15 slope, clay soil

39
Materials and Methods

• Both natural and artificial (irrigation)
  precipitation analyzed
• Irrigation conducted within 24 hr application
• Water collection devices at bottom of slope
• Volumes measured
• Pesticide concentrations percents

40
Results

• Irrigation 6 in/hr for 1-1.5 hr to cause runoff
• Only 1 natural runoff event occurred

41
Small Percentage of Pesticides Applied Detected
in Turf Runoff
42
Why So Little Leachate and Runoff?

• 90-100 turf cover
• prevents sediment loss
• intercepts pesticides
• Abundant, contiguous root system
• absorbs nutrients and stabilizes soil
• Diverse microbial population
• degrades pesticides
• Thatch retains nutrients, pesticides until used
  or degraded

43
Therefore,

• Data indicate pesticide losses from turf are
  minor
• Nonpoint source pollution continued concern
• Urban landscapes targeted by legislation
• Careless lawn applications end up on driveways
• Hypothesis Pesticide losses from urban settings
  are minimal from both impervious and pervious
  surfaces

44
Pesticide Runoff from Urban Landscapes

• Dr. John Stier
• Dept. of Horticulture
• University of Wisconsin-Madison

45
Objectives Univ. of Wisconsin 1999-2001

• Estimate relative proportion of pesticide losses
  from impervious (concrete) and pervious (turf)
  surfaces
• Compare professional versus retail formulations
• Products
• Granular versus liquid

46
Plot Construction

• 2.4 x 4.3 m
• Concrete and KBG turf
• 6 slope
• Silt loam soil
• Irrigation 2x weekly, 50 ET
• Zn-plated weir channeled runoff into covered
  plastic collection vessel
• Randomized complete block, 3 reps

47
Treatments

• Professional pesticide program
• Pre-emergent Barricade (prodiamine) (g)
• Surface insect Dursban Pro (chlorpyrifos) (l)
• Grubs Merit (Imidacloprid) (wp)
• Post-emergent HorsePower (Dicamba, MCPA,
  triclopyr) (l)
• Retail pesticide program (homeowner)
• Pre-emergent Pendimethalin (g)
• Surface insect Ortho Diazinon (g)
• Grubs Scotts Grub EX (Imidacloprid) (g)
• Post-emergent Weed-B-Gone (Dicamba, MCPP,
  2,4-D) (l)
• Untreated control

48
Sample Analysis

• Aliquots extracted and held on Carbograph tubes
  until analysis
• HPLC/Mass Spectrometry
• Standard curves to estimate concentrations
• Runoff volumes to determine true pesticide
  amounts
• Proc Mix (SAS) to determine treatment effects

49
Runoff 1999-2000
50
Runoff 2000-2001
51
Pre-Emergence Herbicide Losses ( recovery)
DAT Days after treatment. Data averaged over
2000 and 2001.
52
Post-Emergence Herbicide Losses ( recovery)
DAT Days after treatment. Data averaged over
2000 and 2001.
53
Surface Insecticide Losses ( recovery)
DAT Days after treatment. Data averaged over
2000 and 2001.
54
Grub Insecticide Losses ( Recovery)
DAT Days after treatment. Data averaged over
2000 and 2001.
55
Synopsis

• Negligible runoff of granular pre-emergent
  herbicides
• Partial (17-28) runoff of liquid post-emergent
  herbicides from concrete
• Imidacloprid losses approximately 90 from
  concrete (new chemistry)
• Chlorpyrifos and diazinon had negligible losses
  (old, now banned)

56
Synopsis

• Pesticide runoff from concrete dependent on type
  retail similar to professional
• Winter thaws and excessive precipitation
• (gt 2 in/hr) cause turf runoff

57
Conclusions

• Avoid misapplication to impervious surfaces
• Use drop spreaders
• Sweep up missapplications
• Turf not major source of nonpoint pollution

58
Prevent Environmental Contamination

• Use pesticides w/ low solubility and high Koc in
  sensitive areas
• Do not apply to saturated soils or when 0.5 inch
  or more rainfall expected
• Avoid inadvertent deposition into surface waters
• Reduce urban runoff use pervious surfaces
  (turf, prairie, woodlots, turf pavers, etc.)