Factor

Terms

Average marginal effect

P-value

Pre-treatment (reference = 1 h)

10 mn

0.2756

0.0000

30 mn

0.4578

0.0000

Substrate (reference = fine sand)

Sawdust

0.0222

0.5326

Sawdust and fine sand

0.2481

0.0000

Sawdust and black earth

0.3370

0.0000

Black earth

0.3185

0.0000