Compost Amendment to Control

Runoff From Turf

Rob HarrisonUniv of Washington

Rob Harrison RobH@u.washington.edu http://128.95.36.3/robh

Ecosystem Sciences DivisionCollege of Forest ResourcesUniversity of WashingtonSeattle WA 98185 USA

Phil Cohen, Bruce Jensen, Kyle Kolsti, Steve Burgess, Mark Grey and Chuck Henry

Big Problems:

Rob HarrisonUniv of Washington

Lake Sammamish is increasingly polluted and subject to eutrophication

P in runoff is considered the problem

direct sources of P:soil erosionhuman and animal wastefertilizers

lower infiltration of water

aggravating problems:

increased peak runoff

septic tanks

“turf on till” phenomenon on Alderwood and related soil types

aggravating problems:

highest native P soil concentrations in the U.S.lack of permanence in turf establishment

large amounts of water used to establish and maintain turf

turf industry estimates that...

did you know?

18 $billion per year spent on turfestablishment and maintenance

growth rate for industry is 35%per year

very little recycled material is used,but use is growing rapidly

1)

2)

3)

increase water percolation

primary needs:

decrease erosion and runoff

reduce use of phosphorus fertilizer

establish plots to turf

approach:

run natural and manmade storm events

evaluate runoff1) total amounts2) periodicity3) chemistry

sites:

8'

32'control soil 1

soil 1

soil 1

soil 1

2:1 CG fine

2:1 CG coarse

4:1 CG fine

soil 2control

soil 2

soil 2

2:1 GroCo

3:1 CG fine

weatherstation

1 2 4 876

5

3

2'8'

1'

16'

2'5'

9'

4'

Detail of Soil Sampling Scheme

Turf runoff study at UW Center for Urban HorticultureTurf runoff study at UW Center for Urban Horticulture

2:1 “Clean 2:1 “Clean GreenGreen””

controlcontrol

3:1 “Clean Green”3:1 “Clean Green”

2:1 GroCo2:1 GroCo

4:1 “Clean Green”4:1 “Clean Green”

weather station weather station and recordersand recorders

3:1 GroCo3:1 GroCo

till soiltill soilonlyonly

2:1 Soil:2:1 Soil:““Clean Green”Clean Green”

2:1 2:1 Soil:GroCoSoil:GroCo

2:1 Soil:2:1 Soil:““Clean Green”Clean Green”

till soiltill soilonlyonly

Grass Appearance, August 15, 1996Grass Appearance, August 15, 1996

Sampled in August, 1994Field Field

total total Capacity Capacity Total BulkSample designation C N g/g ml/ml Porosity Density

% % % % % g/cm3amended average 2.8 0.27 35 37 50 1.08

no compost average 0.3 0.12 19 24 49 1.28

changes in soil:

Summary of Run Collection Times

Field Collector placed Collector taken Sampling durationRun On Off (hours)

1 03/07/95--10:30 03/15/95--09:00 1912 04/25/95--09:00 04/26/95--09:00 24.03 04/27/95--10:00 04/28/95--11:00 25.04 05/01/95--10:18 05/03/95--18:00 565 05/04/95--09:30 05/08/95--09:30 966 05/08/95--09:30 05/12/95--09:00 957 05/12/95--09:00 05/15/95--09:00 728 05/15/95--09:00 05/15/95--12:45 3.89 05/15/95--12:45 05/15/95--13:15 0.510 05/15/95--13:15 05/16/95--10:10 20.911 05/16/95--10:14 05/16/95--12:15 2.012 05/16/95--12:15 05/16/95--12:30 0.313 05/16/95--12:30 05/16/95--13:00 0.514 05/16/95--13:00 05/24/95--12:00 19115 05/24/95--12:05 05/25/95--11:30 23.416 05/25/95--11:45 05/25/95--15:20 3.617 05/25/95--15:30 05/25/95--18:06 2.618 05/25/95--18:06 05/25/95--18:21 0.219 05/25/95--18:21 05/26/95--21:15 26.920 05/26/95--21:15 05/26/95--21:30 0.321 05/26/95--21:30 06/03/95--10:10 18122 05/27/95--09:00 05/27/95--12:20 3.323 05/27/95--12:20 05/27/95--15:15 2.924 05/27/95--15:15 05/27/95--15:46 0.525 05/27/95--15:46 05/27/95--21:10 5.426 05/27/95--21:10 05/31/95--09:55 8527 05/31/95--10:00 05/31/95--16:30 6.528 05/31/95--16:30 06/03/95--10:10 6629 05/27/95--21:10 05/31/95--09:55 8530 05/31/95--10:00 05/31/95--16:30 6.531 05/31/95--16:30 06/03/95--10:10 6632 06/03/95--10:10 06/06/95--19:52 8233 06/06/95--19:52 06/09/95--10:00 6234 06/09/95--10:00 06/09/95--20:10 10.235 06/09/95--20:10 06/10/95--20:16 24.136 06/09/95--10:00 06/10/95--20:16 34.3

total 1554

EventCollectionPeriods

0

20

40

60

RainfallRunoffstorage

0 5 10 15 20 25 30 35

withcompost

soil only

0

20

40

waterflux(l/hr)

0

500

1000

1500

2000

2500

0 5 10 15 20 25 30 35 40

control unamendedcompost-amended

total runoff

Hours from start of event

control unamended and compost-amended

total rainfall

May 25-26, 1995 two storm eventstotalstorage(liters)

0

200

400

600

800

1000

1200

1400

0 5 10 15 20 25 30 35 40start 11:00 AMMay 25, 1995

control unamendedcompost-amended

rainfall storage

Hours from start of event

May 25-26, 1995 two storm eventstotalstorage(liters)

Water balance for storm event

Rainfall Runoffunamended amended unamended amended–––––– liters –––––– –––––– liters ––––––

total liters per plot 2,432 2,432 1,749 1,214percent runoff 72 50

percent retention 28 50inches storm event 4.03 4.03

inches runoff 2.90 2.01inches retention 1.13 2.02

Hydrological characteristics of a simulationadditional

hydrologic control compost lag withcharacteristic unamended amended compost

––––––––– simulation 1, storm 1 –––––––––total input 2.33 in 2.46 in

rainfall rate 0.28 in/h 0.30 in/hrunoff > 0.01 in/hour 0.50 h 1.00 h 0.50 hrunoff > 0.1 in/hour 0.75 h 1.75 h 1.00 h

runoff rate > 90% input rate 2.00 h 5.25 h 3.25 hrunoff < 10% of input rate† 0.75 h 1.50 h 0.75 h

runoff < 0.01 in/hour 1.75 h 6.50 h 4.75 h––––––––– simulation 1, storm 2 –––––––––

total input 2.09 in 2.29 inrainfall rate 0.26 in/h 0.29 in/h

runoff > 0.01 in/hour 0.25 h 0.50 h 0.25 hrunoff > 0.1 in/hour 0.50 h 1.00 h 0.50 h

runoff rate > 90% input rate 0.75 h 1.25 h 0.50 hrunoff < 10% of input rate† 0.75 h 1.50 h 0.75 h

runoff < 0.01 in/hour 1.75 h >2.00 h

Summary statistics for solution chemistry analyses

totalreactive Total Nitrate-

P P nitrogenTreatment SRP TP NO3-N

–––––average conc. (mg/l) –––––overall average 1.14 2.72 1.55

control unamended 1.19 2.54 1.39compost amended 1.08 2.87 1.70

May 25-26, 1995 two storm events

TotalPhosphorus

0

2000

4000

6000

8000

10000

12000

14000

0 5 10 15 20 25 30 35 40

12,657

3,257

Time from start of first storm event (hours)

till soil onlytill with compost amendment

start 11:00 AMMay 25, 1995

Soluble Phosphate

0

1000

2000

3000

4000

5000

60005,189

1,880

0

100

200

300

400

0 20 40 60 80 100 120

0

400

800

1200

0 20 40 60 80 100 120

Time from start of first storm event (hours)

till soil onlytill with compost amendment

till soil onlytill with compost amendment

Soluble Phosphate

1405

849

392

466

start 8:00 AMMay 31, 1995

TotalPhosphorus

May 31-June 3, 1995 two storm events

Conclusions:

Rob HarrisonUniv of Washington

Compost amendment increased water retention in soil and lag times of response to storms, though antecedent conditions are important

Compost amendment appears to be a permanent improvement, not so with inorganic fertilizer amendment

Total P runoff from compost-amended sites was less, though P concentrations were sometimes higher

Future directions:

Rob HarrisonUniv of Washington

What are implications on a watershed basis?

Will the properties of the unamended site improve with time?

Is the compost treatment permanent?