The difference between management treatments is likely to be due to the application of organic fertilisers (at up to 11.25 Mg ha−1 year−1), as no significant differences were found between these subplot treatments for total inputs of above-ground biomass to the soil in the form of senescent leaf litter and pruned material (p = 0.24). Further, there was a positive correlation between the mass of organic fertiliser inputs and changes in 0–10 cm depth SOC (r2 = 0.18, p < 0.01). Both conventional and organic managements showed a consistent decline in SOC stocks at the two lower soil depths with no significant between-treatment differences (Fig. 3). Changes in total 0–40 cm depth SOC stock showed no significant correlations with either pruning or organic fertiliser inputs.
organic fertilisers
up to 11.25 Mg ha−1 year−1
Mg ha−1 year−1
no significant differences
p
0.24
SOC
depth
0–10 cm
cm
positive correlation
r2
0.18
positive correlation
p
< 0.01
lower soil depths
two
SOC
depth
0–40 cm
cm