Biochar for the win: a greenhouse-raised wetland grass grows better with added biochar

Biochar is the matter that is leftover after organic materials (for example, wood) are heated at very high temperatures without oxygen. It is purposefully made and sometimes used in agricultural settings to help plants grow, because like fertilizers you buy at the local hardware store, biochar can be used as an amendment to soil.

The ability to grow robust native plants in greenhouses for reintroduction into native habitats is crucial for wetland restoration work. The wetland grass, Fowl mannagrass, is one example of a native plant that is of interest because it grows well in various habitats (e.g., in dry or wet areas of marshes). It is also found along the salty coasts of Nova Scotia — the Canadian province where our research was conducted.

We tested whether biochar can improve the growth of Fowl mannagrass grown in a greenhouse. We found that when Fowl mannagrass is grown in soil with 50% biochar that has also been “charged” with a boost of extra nutrients, plants had greener leaves and grew significantly more in both height and mass. Plants reached 4.4 times greater heights and were 85 times heavier compared with plants without any biochar treatment.

We also tested whether adding arbuscular mycorrhizal fungal spores to soil would also lead to greater growth. Such fungi can help some plants acquire nutrients from the soil. Interestingly, adding such typically helpful fungal spores to the roots of growing Fowl mannagrass did not produce any measured benefit. We are excited to continue exploring this plant–fungal interaction with biochar for native wetland plant propagation.

Read the full paper — Determining the effects of biochar and an arbuscular mycorrhizal inoculant on the growth of fowl mannagrass (Glyceria striata) (Poaceae) by Sadie Moland, Brent M. Robicheau, Robin Browne, Ruth Newell and Allison K. Walker on the FACETS website.