Table 1.
Effect of cover crops on annual above-ground CC C content from 2007 to 2015 at site A and 2008 to 2016 at site B at Ridgetown, Ontario.
| Cover crop (CC) | Annual above-ground CC C inputs | ||
|---|---|---|---|
| Mg C ha−1 | |||
| Site A | Site B | ||
| No cover | –z | – | |
| Oat | 0.795b | 0.699d | |
| Oilseed radish (OSR) | 1.04a | 1.180a | |
| OSR + Rye | 0.978a | 0.989b | |
| Cereal rye | 0.695b | 0.869c | |
| SEy | 0.030 | 0.027 | |
| Year | Main crop followed by CC | ||
| 2007/08 | Pea fbx CC | 1.94a | 1.93a |
| 2008/09 | Sweet corn fb CC | 0.716 cd | 1.31b |
| 2009/10 | Spring wheat fb CC | 0.852bc | 0.892 cd |
| 2010/11 | Tomato fb CC | 1.01b | 0.759d |
| 2011/12 | Grain corn | – | – |
| 2012/13 | Squash fb CC | 0.645d | 0.584e |
| 2013/14 | Soybean | – | – |
| 2014/15 | Winter wheat fb CC | 1.02b | 1.03c |
| 2015/16 | Tomato fb CC | 0.106e | 0.224f |
| SE | 0.046 | 0.037 | |
| Effects | P values | ||
| CC | < 0.0001 | < 0.0001 | |
| Year | < 0.0001 | < 0.0001 | |
| CC × year | < 0.0001 | < 0.0001 | |
a−fIn each column and each effect, means followed by a different letter indicate statistical significance at P < 0.05 per protected LSD test.
zNo cover crop was planted in control plots or all plots after grain corn or soybean harvest.
ySE = standard error of mean.
xfb = followed by.
Bold font indicates statistical significance at P < 0.05.
OSR + Rye = mixture of oilseed radish and cereal rye.