Table 5. Integrated ecosystem carbon flux and its components and dry biomass increments in maize fields at different growth stages of 2011–2013.
| Year | Treatments | Growing stages | Period | Days | Ecosystem net CO2 flux (kg CO2 /m2) | Ecosystem respiration flux (kg CO2 /m2) | Canopy photosynthesis (kg CO2/m2) | Dry biomass increments (kg/m2) |
|---|---|---|---|---|---|---|---|---|
| 2011 | CK | Seedling | 5.01–5.31 | 30 | 0.205 | 0.208 | -0.003 | 0.015 |
| Shooting | 6.01–7.03 | 33 | -0.076 | 0.301 | -0.376 | 0.165 | ||
| Heading | 7.04–7.23 | 20 | -0.611 | 0.390 | -1.002 | 0.505 | ||
| Filling | 7.24–9.06 | 45 | -1.260 | 1.115 | -2.375 | 0.864 | ||
| Maturity | 9.06–9.29 | 23 | -0.212 | 0.253 | -0.465 | 0.091 | ||
| Total | 5.01–9.29 | 151 | -1.954 | 2.267 | -4.221 | 1.640 | ||
| MFR | Seedling | 5.01–5.28 | 28 | 0.117 | 0.145 | -0.013 | 0.028 | |
| Shooting | 5.29–6.28 | 31 | -0.170 | 0.316 | -0.501 | 0.432 | ||
| Heading | 6.29–7.16 | 18 | -0.565 | 0.410 | -0.994 | 0.538 | ||
| Filling | 7.17–8.28 | 42 | -1.370 | 1.173 | -2.549 | 1.151 | ||
| Maturity | 8.29–9.18 | 21 | -0.237 | 0.383 | -0.620 | 0.111 | ||
| Total | 5.01–9.18 | 140 | -2.225 | 2.426 | -4.677 | 2.260 | ||
| 2012 | CK | Seedling | 5.03–5.31 | 29 | 0.239 | 0.247 | -0.008 | 0.030 |
| Shooting | 6.01–6.30 | 30 | -0.110 | 0.240 | -0.350 | 0.370 | ||
| Heading | 7.01–7.19 | 19 | -0.527 | 0.384 | -0.911 | 0.937 | ||
| Filling | 7.20–8.31 | 43 | -1.284 | 1.000 | -2.284 | 0.764 | ||
| Maturity | 9.01–9.22 | 21 | -0.283 | 0.276 | -0.559 | 0.323 | ||
| Total | 5.03–9.22 | 142 | -1.965 | 2.148 | -4.113 | 2.424 | ||
| MFR | Seedling | 5.03–5.28 | 26 | 0.122 | 0.139 | -0.010 | 0.030 | |
| Shooting | 5.29–6.26 | 29 | -0.165 | 0.242 | -0.395 | 0.660 | ||
| Heading | 6.27–7.13 | 17 | -0.442 | 0.339 | -0.784 | 1.069 | ||
| Filling | 7.14–8.23 | 41 | -1.317 | 1.032 | -2.365 | 1.104 | ||
| Maturity | 8.24–9.10 | 18 | -0.394 | 0.314 | -0.728 | 0.093 | ||
| Total | 5.03–9.10 | 131 | -2.196 | 2.066 | -4.282 | 2.956 | ||
| 2013 | CK | Seedling | 4.28–5.28 | 31 | 0.191 | 0.184 | 0.007 | 0.015 |
| Shooting | 5.29–6.28 | 31 | -0.122 | 0.177 | -0.299 | 0.251 | ||
| Heading | 6.29–7.19 | 22 | -0.497 | 0.372 | -0.868 | 0.644 | ||
| Filling | 7.20–9.01 | 42 | -1.560 | 1.106 | -2.666 | 1.736 | ||
| Maturity | 9.02–9.25 | 23 | -0.306 | 0.320 | -0.669 | 0.148 | ||
| Total | 4.28–9.25 | 150 | -2.294 | 2.158 | -4.495 | 2.794 | ||
| MFR | Seedling | 4.28–5.25 | 28 | 0.091 | 0.103 | -0.009 | 0.045 | |
| Shooting | 5.26–6.24 | 30 | -0.171 | 0.216 | -0.371 | 0.310 | ||
| Heading | 6.25–7.14 | 20 | -0.589 | 0.468 | -1.093 | 0.654 | ||
| Filling | 7.15–8.25 | 41 | -1.532 | 1.101 | -2.545 | 1.991 | ||
| Maturity | 8.26–9.15 | 21 | -0.393 | 0.370 | -0.755 | 0.260 | ||
| Total | 4.28–9.15 | 140 | -2.594 | 2.258 | -4.773 | 3.260 | ||
| Averages | CK | Seedling | 30.0 | 0.212 | 0.213 | -0.001 | 0.020 | |
| Shooting | 31.3 | -0.103 | 0.239 | -0.342 | 0.262 | |||
| Heading | 20.3 | -0.545 | 0.382 | -0.927 | 0.695 | |||
| Filling | 43.3 | -1.368 | 1.074 | -2.442 | 1.121 | |||
| Maturity | 22.3 | -0.267 | 0.283 | -0.564 | 0.187 | |||
| Total | 147.7 | -2.071 | 2.191 | -4.276 | 2.286 | |||
| MFR | Seedling | 27.3 | 0.110 | 0.129 | -0.011 | 0.034 | ||
| Shooting | 30.0 | -0.169 | 0.258 | -0.422 | 0.467 | |||
| Heading | 18.3 | -0.532 | 0.406 | -0.957 | 0.754 | |||
| Filling | 41.3 | -1.406 | 1.102 | -2.486 | 1.415 | |||
| Maturity | 20.0 | -0.341 | 0.356 | -0.701 | 0.155 | |||
| Total | 137.0 | -2.338 | 2.250 | -4.577 | 2.825 |
Notes: CK and MFR stand for planting in non-mulching with flat tillage and partial plastic film mulching with furrow-ridge tillage, respectively.