Runoff and Nutrient Losses from Constructed Soils Amended with Compost

Table 6

Comparison of runoff concentration of NO₃-N among contrasting roadside treatments for selected rain events on an 8.5% slope. Rain amounts for the respective events were 23, 5, 18, 29, and 50 mm. See Table 2 caption for description of treatments and compost sources.

Treatment

Compost

Rain event

Rate

1 (5 Jun)

3 (14 Jun)

6 (4 Jul)

8 (11 Aug)

10 (31 Aug)

(m^3 m^−3)

(mg L^−1)

(mg L^−1)

(mg L^−1)

(mg L^−1)

(mg L^−1)

Control

NA

NA

0.59

d

0.22

a

0.25

a

0.55

b

0.25

bc

CMT

CDM

0.125

1.20

bcd

0.48

a

0.51

a

0.64

b

0.23

c

CMT

CMB

0.125

1.10

cd

0.32

a

0.17

a

0.41

b

0.21

c

CMT

CDM

0.25

2.38

a

0.69

a

0.40

a

0.41

b

0.23

c

CMT

CMB

0.25

1.65

abc

0.47

a

0.25

a

0.40

b

0.21

c

ECC

CDM

0.50

1.41

bcd

0.28

a

0.46

a

1.15

a

0.30

ab

ECC

CMB

0.50

2.01

ab

0.45

a

0.45

a

1.42

a

0.34

a

^†Different letters in columns represent significant differences using Fisher’s LSD means separation test.