Biochar as a plant growth substrate amendment
University College Cork
Biochar (BC) is an alternative growth media, a potential soil health ameliorant and climate change mitigation strategy. The effects of an oak BC (OBC) with peat-free compost (PFC) and a rush BC (RBC) with PFC treatments were tested on plant growth of perennial ryegrass (Lolium perenne L.) and oilseed rape (Brassica napus) in potted glasshouse trials. Overall, plant height and yield of L. perenne and B. napus were not affected by OBC+PFC. RBC+PFC had no effect on plant height and yield of B. napus, but did have significant positive height and yield effects on L. perenne. OBC+PFC and RBC+PFC were ‘charged’ over 6-months of outdoor incubation and re-tested as charged OBC (COBC) + PFC and charged RBC (CRBC) +PFC on the same plants concurrently in the presence of abiotic stressors. The effects of both charged treatments and stressor combinations on both plants were shown to be individually statistically different with varying results between group interactions. The control (PFC) treatment had the most positive effect on plant height and yield for both plant species. Soil Plant Analysis Development (SPAD) measurements on B. napus plant health showed that COBC+PFC was most effective at alleviating abiotic stress. The structural and elemental components of OBC and RBC were analysed using a scanning electron microscope (SEM). The vastly porous nature of a hardwood OBC and its elemental constituents compared to a RBC was confirmed, strengthening other findings in the scientific literature.
Biochar , Plant growth , Peat replacement , Biochar SEM , Structural analysis , Elemental analysis , Organic peat replacement , Oilseed rape , Perennial ryegrass , Potted trials , Charging biochar , Peat-free compost
Hynes, E. 2021. Biochar as a plant growth substrate amendment. MRes Thesis, University College Cork.