influence of roadside establishment practices on sediment and nutrient loss kyle r. briscoe g....
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Influence of Roadside Establishment Practices on Sediment and Nutrient Loss
Kyle R. Briscoe G. Munshaw, J.J. Varco, B.R. Stewart
Plant and Soil SciencesMississippi State University
Research Motivation• Mississippi Nonpoint Source Management Plan lists sediment as
a potential surface water pollutant, nutrients are not mentioned (MDEQ, 2000)
• Mississippi Department of Transportation specifications:– 13-13-13 fertilizer applied during seeding at 1123 kg ha-1
• N and P can contribute to eutrophication of surface water
Objectives• Determine the influence of nitrogen (N) and
phosphorus (P) sources and rates, and fertilizer application timing on sediment and nutrient losses during runoff
• Evaluate species establishment under various fertility programs
MDOT Specifications • MS Department of Transportation (MDOT)
– Soil tests – Lime applied as needed– Fertilizer: 13-13-13 applied at 1123 kg fertilizer ha-1
– Seed Mixture:• Bahiagrass 28 kg seed ha-1
• Tall fescue 28 kg seed ha-1
• Sericea lespedeza 28 kg seed ha-1
• Common bermudagrass 23 kg seed ha-1
• Crimson clover 23 kg seed ha-1 (fall planting only)• Hay or wheat straw applied at 4490 kg ha-1
Runoff Field Site• Plot area disked and tilled• Weather station - rainfall, wind speed, air
temp., relative humidity, photosynthetically active radiation
Runoff Experimental Design• Randomized complete block, 4 replicates• Stainless steel frames (0.75 x 2 m) and plastic collection
containers were used to collect runoff from simulated and natural rainfall
Half Rates
Simulated Rainfall • Simulated rain events conducted 14, 28, and 56 days after
seeding• Simulated rainfall intensity = 66 mm hr-1
• Total runoff volume determined on a weight basis • Runoff samples collected every 5 minutes after runoff began and
continued for 30 minutes
Nutrient Loss Evaluation
• Runoff water analyzed for total sediment (TS), dissolved reactive P (DRP), total P (TP), NH4-N, NO3-N, and total N (TN)
Vegetative Cover Evaluation
• Weekly percent cover data collected visually and by digital image analysis
Vegetative Coverage
Natural Rainfall - DRP
Simulation 1 – DRP
Simulation 2 – DRP
Simulation 3 – DRP
Simulated Rainfall – Total DRP
Conclusions• Establishing vegetation on roadsides can be difficult due to
infertile disturbed soils – MDOT fertilizer specifications could potentially lead to nutrient
loss• No significant differences in vegetative coverage were
observed between fertilizer sources or rates• Phosphorous source may have an influence on DRP lost during
runoff events– Significantly more DRP was lost from plots treated with a
mixture of poultry litter and TSP • A second project is evaluating the influence of various
mulches on sediment and nutrient losses
Influence of Roadside Establishment Practices on Sediment and Nutrient Loss
Dr. Jac VarcoProfessor
Plant and Soil SciencesMississippi State University
jvarco@pss.msstate.edu
Kyle BriscoeGraduate Research Assistant
Plant and Soil SciencesMississippi State University
kb371@msstate.edu
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