Table 3 Mean and standard error (SE) of crop C export and input, total C input (= crop C input + mulch C + compost C) accumulated over ten years, and soil organic carbon (SOC) stock down to 1 m depth separated for treatments (P: plough; C: compost; M: mulch, where M1 and M2 refer to the first and second mulching, respectively, M3 to the double mulched treatments; RT: reduced tillage). Letters indicate significant differences between treatments; significance levels of model effects are given below.
Treatment | Crop C export (sum over 10 years) [Mg C ha−1] | Crop C input (sum over 10 years) [Mg C ha−1] | Total C input (sum over 10 years) [Mg C ha−1] | SOC stock [Mg SOC ha−1] | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
Mean | SE | Mean | SE | Mean | SE | Mean | SE | |||||
P | 17.5 | ± 0.3 | a | 37.9 | ± 0.7 | a | 37.9 | ± 0.7 | a | 88.6 | ± 4.1 | ab |
P.C | 17.7 | ± 0.5 | a | 38.5 | ± 0.9 | a | 47.1 | ± 1.1 | b | 95.8 | ± 3.7 | abc |
P.M2 | 17.3 | ± 0.5 | a | 40.3 | ± 0.9 | ab | 47.6 | ± 0.9 | b | 86.3 | ± 3.8 | a |
P.M2C | 18.1 | ± 0.4 | a | 42.9 | ± 0.9 | b | 58.8 | ± 1.0 | d | 95.5 | ± 3.5 | abc |
RT.M1 | 16.3 | ± 0.5 | a | 37.5 | ± 1.6 | ab | 43.8 | ± 1.9 | b | 99.1 | ± 4.9 | bc |
RT.M1C | 16.4 | ± 0.4 | a | 38.0 | ± 1.2 | ab | 53.0 | ± 1.9 | c | 102.7 | ± 3.8 | c |
RT.M3 | 17.2 | ± 0.5 | a | 40.5 | ± 1.3 | ab | 54.0 | ± 1.6 | c | 96.3 | ± 3.7 | abc |
RT.M3C | 17.2 | ± 0.6 | a | 40.6 | ± 1.2 | ab | 62.8 | ± 1.9 | d | 103.2 | ± 4.2 | c |
Significance levels of model effects | ||||||||||||
0.097 | < 0.001 | < 0.001 | < 0.001 | |||||||||
