1. Compost Application Practices Improve Quality of Turfgrass and a Degraded Urban Soil
Virginia Recycling Association Annual Meeting
Organics Session
Hotel Roanoke
May 16, 2012
Shea Dunifon, Greg Evanylo, Michael Goatley, Rory Maguire, Shan Dexin, and Xunzhong Zhang
Crop and Soil Environmental Sciences Department
Virginia Tech

2. Introduction: Disturbed Soils
Urbanization contributes greatly to soil disturbance.
Permanent vegetation is most effective practice to stabilize soil and reduce water impairment.
Compost has been demonstrated to improve disturbed soils for vegetation establishment.

3. Objective
To compare various compost application and turfgrass seeding practices for revegetating disturbed urban land.

4. Methods and Materials: field study
The Summit, Lynchburg, VA
Cullen Loam
Slope 3-5%
Study established March 2009

5. Initial Soil Test Analysis and Fertilizer Recommendations: March 2009
Property
Soil Test Value
Fertilizer Recommendations
(kg ha-1) N 45 P
3 mg kg-1 78 K
80 mg kg-1
112 Ca
1221 mg kg-1 Mg
>120 mg kg-1 pH
7.1
CEC
7.3 cmol(+) kg-1

6. Field study Treatments
1: Fertilizer and seed
No cover (Control)
Straw blanket
Compost blanket: 0.6 cm (1/4”) depth
2: Compost - broadcast: 2.5 cm depth
3: Compost - broadcast & incorporated: 2.5 cm depth
4: Compost - broadcast & incorporated: 5.0 cm depth

7. Compost Source and Methods
Compost source: Royal Oak Farm, Evington, VA
Compost feedstock
Papermill sludge
Woody waste
Wood ash
Food processing residuals
Turned windrow processing

8. Compost composition Parameter Result ¼ in screen size (%) 94
Moisture (g kg-1)
430
EC (dS m-1)
2.97 pH
7.9
C:N
18:1
Total Organic C (g kg-1)
300
Total N (g kg-1) 17
NO3-N (g kg-1)
9.7
P (g kg-1) 10
K (g kg-1) 14
Maturity (Solvita)
Very Mature
(low CO2, NH3)
Small amounts of NPK… pH a little high, but not bad; Solvita test indicates it is a very stable form… Solvita – plastic vials with compost, put in absorbent papers to the vial that change colors on the paper according to CO2, NH3 levels

9. Applying and Incorporating Compost1
Compost 2
Aerovate 3
Seed, roll
3/28/2009

10. Nutrients Recommended and Applied by TreatmentsK
kg ha-1
Fertilizer 45 78
112
0.64 cm compost
3,200
131 98
157
2.5 cm compost
12,800
524
392
627
5.0 cm compost
25,600
1048
784
1254
Fert trt according to standard soil test results; different levels of compost are what were delivered to the plots… a lot of C is being added as well as a lot of N, but Compost N is only about 10% available (must be microbially decomposed for release); high amounts of P could be of concern… when compost is used as an amendment, is this creating a potential problem… if it ran off in surface water, possibly… the P levels can be a concern… would be more of a concern on very high sand content soils but not on heavy textured clays.

11. http://connect.ag.vt.edu/compostforturf/ SCT+Straw Mat (back)
0.64 cm com blanket (fore)
2.5 cm compost blanket
5 cm compost PPI
2.5 cm compost PPI
Standard Fert
Photo taken April 17, 2009; Plots Seeded March 24, 2009. 11 11

12. Visual Treatment comparisons
Four weeks after establishment
6.3 cm of rainfall
Straw mat
Control
0.25” compost broadcast

13. Treatment Effects on turf biomass with time

14. http://connect.ag.vt.edu/compostforturf/ SCT+Straw Mat (back)
Feb. 9, 2012
Standard fertility treatment based on soil test, rep 3
SCT+Straw Mat (back)
¼” com blanket (fore)
2” compost, incorporated ,
Rep 3
1” compost blanket
2” compost PPI
1” compost PPI
Standard Fert
1” compost, incorporated ,
Rep 3
Photo taken April 17, 2009; Plots Seeded March 24, 2009.
July 5, 2011
CVNLA Short Course 14 14

15. Effects of treatments on mean seasonal turfgrass density (averaged over Time)
Density assessed visually using a scale of 1 to 9 where 1 = bare ground to 9 = dense turf.

16. Soil properties two years after treatment applications (summer 2011)
Soil Test Extractable
Treatment P K TN
TOC
bulk density
mg kg-1 soil
g kg-1 soil
g/cc
Fertilizer
16 c
145 b
0.8b
12.2c
1.25 b
2.5 cm compost,
surface
15 c
180 a
1.1 ab
18.9b
1.33 c
2.5 cm compost, incorporated
22 b
172a
1.5 a
28.2a
1.24 ab
5.0 cm compost, incorporated
26 a
202 a
1.7 a
32.0a
1.18 a
In general, P – despite large amounts we don’t see a high increase in P

17. Conclusions
Slow release of compost nitrogen likely improved turfgrass biomass with time.
Incorporated compost performed better than compost blanket.
Greater turfgrass density with compost than with standard fertilizer practices.
Soil properties improvements: compost > fertilizer.

18. Thanks to our supporters
National Fish and Wildlife Foundation
Mark Maslow and Southern Landscape Group, Inc., Lynchburg, VA
John Hicks, Augusta Co-op, Lynchburg/Bedford, VA
Mr. Ken Burger, Executive Director ,The Summit, Lynchburg, VA