Evaluating Best Management Practices for Bermudagrass Fairways to Protect Surface Water Quality

1
Evaluating Best Management Practices for
Bermudagrass Fairways to Protect Surface Water
Quality
2
Investigators

• Horticulture Landscape Architecture
• James H. Baird, Dennis L. Martin
• Agronomy
• Nicholas T. Basta, Gordon V. Johnson
• Biosystems Agricultural Engineering
• Raymond L. Huhnke, Daniel E. Storm,
  Michael D. Smolen, Deborah A. Bazay
• Statistics
• Mark E. Payton

3
Introduction

• The potential for runoff of pesticides and
  nutrients from turf, especially on golf courses,
  into surface water is the subject of increasing
  environmental concern.
• Objective
• Evaluate management strategies that are both
  practical and effective in reducing pesticide and
  nutrient runoff from golf courses and other turf
  areas.

4
Specific Objectives

• Evaluate Best Management Practices to reduce
  surface runoff losses of pesticides and nutrients
  
• Characterize surface runoff loss potential of
  pesticides and nutrients
• Site Parameters
• Stillwater,Oklahoma
• Kirkland Silt Loam
• Bermudagrass (Cynodon dactylon)
• 6 Slope

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Treatment Summary

• Vegetated Buffer Strips
• Vegetation Height
• Aeration
• Fertilizer Formulation
• Pesticide Formulation

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Vegetated Buffer StripsBuffer Vegetated area
between treated turf and waterway

• 1995 Experiments
• Buffer Length
• Buffer Length 0, 1.2, 2.4, 4.9 m
• Turf Height 1.3 m
• Mowing Height
• Buffer Length 4.9 m
• Turf Height 1.3, 3.8, 7.6 m

• 1996 Experiments
• Buffer Length
• Buffer Length 0, 1.2, 2.4, 4.9 m
• Turf Height 3.8 cm
• Mowing Height
• Buffer Length 4.9 m
• Turf Height 1.3, 3.8, 7.6 cm

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Chemical Treatments

• Chemical Formulation
• Fertilizer
• Urea (1995) vs. Sulfur Coated Urea Slow Release
  (1996)
• Triple Super Phosphate
• Pesticides
• Mecoprop
• Dicamba
• Chlorpyrifos
• 2,4-D
• Wettable Powder (1996) vs. Granular (1995)
  Pesticides

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Fertilizer
Specified as kg/ha or mg as N or P
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Pesticides
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1995 Field Experiment

• Simulated Rainfall Events
• July 11-14
• August 8-10
• Randomized Incomplete Block
  4 Replications/ Treatment
• Simulated rainfall
• 51mm/hour for 75 - 140 min. (July)
• 64mm/hour for 75 min. (August)

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1995 Treatments
Control Plot (No Pesticides or Nutrients Applied)
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1995 Conclusions

• Buffers can significantly reduce pesticides and
  nutrients runoff losses
• Buffer mowing height and aerification did not
  significantly contribute to reduced chemical
  runoff losses
• Use of slow release N fertilizers, wettable
  powder pesticides, and pesticides with lower
  water solubilities and stronger adsorption will
  reduce surface runoff potential

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1996 Field Experiments

• Simulated Rainfall Events
• July 31 and August 1
• August 13 - 14
• Two Experiments
• Buffer Mowing Height
• Buffer Length
• Randomized Complete Block
  4 Replications/ Treatment
• Simulated Rainfall
  64mm/hour for 75 min.

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Buffer Mowing Height1996 Experiment
Plot 2
Plot 3
Plot 4
Plot 1
Legend
Treated Area
Buffer Length
Downslope
Numbers with the same letter not significantly
different at a 0.05
Rainfall Simulator
1.3 Yes 8 c 897 a
3.8 Yes 12 b 919 a
Mowing Height (cm) Chemical Applied Time to
Runoff (min.) Runoff Volume (L)
3.8 No 15 a b 695 a b
7.6 Yes 19 a 619 b
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Buffer Mowing HeightAverage Runoff Concentration
(ppb)
Plot 2
Plot 3
Plot 4
Plot 1
Legend
Treated Area
Buffer Length
Downslope
Numbers with the same letter not significantly
different at a 0.05
Rainfall Simulator
1.3 Yes 95 a 46 a 7.5 a 0.58 a
3.8 Yes 116 a 53 a 8.6 a 0.75 a
7.6 Yes 91 a 44 a 8.1 a 0.48 a b
3.8 No 4.7 b 1.8 b 0.33 b 0.17 b
Mowing Height (cm) Chemical Applied 2,4-D Mecopro
p Dicamba Chlorpyrifos
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Buffer Mowing HeightMass Loss in Runoff (ug)
Plot 2
Plot 3
Plot 4
Plot 1
Legend
Treated Area
Buffer Length
Downslope
Numbers with the same letter not significantly
different at a 0.05
Rainfall Simulator
1.3 Yes 88,000 a b 42,000 a b 6,900 a
540 a b
3.8 Yes 107,000 a 48,000 a b
7,900 a 700 b
3.8 No 9,000 c 3,800 c 630 b 130 c
7.6 Yes 56,000 b 27,000 b 5,300 a b
290 a c
Mowing Height (cm) Chemical Applied 2,4-D Mecopro
p Dicamba Chlorpyrifos
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Buffer Length 1996 Experiment
Plot 4
Legend
Treated Area
Buffer Length
Plot 3
Downslope
Plot 2
Plot 1
Numbers with the same letter not significantly
different at a 0.05
Rainfall Simulator
Buffer Length (m) Time to Runoff Runoff Volume
0.0 17 a b 280 b
2.4 21 a 420 a
1.2 15 b 360 a b
4.9 20 a 460 a
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Buffer LengthAverage Runoff Concentration (ppb)
Plot 4
Legend
Treated Area
Buffer Length
Plot 3
Downslope
Plot 2
Plot 1
Numbers with the same letter not significantly
different at a 0.05
Rainfall Simulator
Buffer Length (m) 2,4-D Mecoprop Dicamba Chlorp
yrifos
0.0 190 a 80 a 14 a 1.4 a
1.2 120 b 54 a 9.2 b 0.2 b
2.4 110 b 45 b 8 b 0.3 b
4.9 94 b 42 b 7 b 0.2 b
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Buffer LengthMass Loss in Runoff (ug)
Plot 4
Legend
Treated Area
Buffer Length
Plot 3
Downslope
Plot 2
Plot 1
Numbers with the same letter not significantly
different at a 0.05
Rainfall Simulator
Buffer Length (m) 2,4-D Mecoprop Dicamba Chlorp
yrifos
0.0 51,000 a 22,000 a 3,800 a 380 a
1.2 43,000 a 19,000 a 3,600 a
81 b
2.4 44,000 a 19,000 a 3,300 a 120 b
4.9 43,000 a 19,000 a 3,200 a 95 b
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Project Summary

• Buffers tend to reduce mass and concentration of
  nutrients and pesticides in surface runoff
• No statistical difference between the 1.3 and 3.8
  cm buffer mowing heights in nutrient and
  pesticide surface runoff losses
• 7.6 cm buffer mowing height was most effective in
  reducing nutrient and pesticide runoff

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Suggested Best Management Practices

• Avoid apply pesticides and nutrients when high
  soil moisture conditions exist
• Choose pesticides and nutrients with low runoff
  potential based on their physical and chemical
  properties
• Vegetated buffers can reduce nutrient and
  pesticide losses to surface waters