Skip to main content

Table 2 Flow velocities and chemical parameters at start (t = 0 h) and the end (t = 280 h) of the experiment among four treatments

From: Flow velocity and nutrients affect CO2 emissions from agricultural drainage channels in the North China Plain

Treatment

Abbreviation

Flow velocity (m s−1)

Time (h)

NO3−–N concentration (mg L−1)

NH4+–N concentration (μg L−1)

DIC concentration (mg L−1)

Alkalinity (μmol L−1)

pCO2 (μatm)

Add + high

A + H

0.37 ± 0.21

0

0.33 ± 0.01

5.6 ± 0.4

9.53 ± 4.79

721.2 ± 83.8

3537 ± 2670

280

0.06 ± 0.07

0.03 ± 0.03

6.21 ± 3.18

571.2 ± 14.5

43.3 ± 34.8

Add + low

A + L

0.11 ± 0.07

0

0.33 ± 0.03

6.3 ± 1.2

10.11 ± 5.06

794.8 ± 17.0

3270 ± 2259

280

0.13 ± 0.05

0.11 ± 0.12

6.40 ± 0.86

629.3 ± 60.4

439 ± 612

Non + high

N + H

0.32 ± 0.22

0

0.01 ± 0.01

6.2 ± 1.6

9.85 ± 4.94

758.3 ± 53.0

1889 ± 1349

280

0.01 ± 0.00

0.01 ± 0.00

7.02 ± 3.51

588.9 ± 22.1

15.2 ± 15.8

Non + low

N + L

0.09 ± 0.06

0

0.02 ± 0.00

5.8 ± 0.9

9.33 ± 4.78

719.6 ± 81.9

3549 ± 1943

280

0.01 ± 0.00

0.03 ± 0.05

7.25 ± 3.64

591.1 ± 25.1

383 ± 605