Carbon dioxide emission from an organic soil amended with straw and wood chips

F. L’Heureux-Bilodeau, J. Dessureault-Rompré, A.N. Rousseau
Drained and cultivated organic soils represent an important part of vegetable production in North America. However, the drainage required to cultivate these soils induces annual soil loss of 1 to 5 cm, which also leads to CO2 emissions due to peat decomposition. One potential conservation strategy is adding plant-based amendments to organic soils to compensate for carbon loss. However, little is known about the impact of this conservation strategy on CO2 fluxes. A greenhouse experiment was developed, using soil columns filled with organic soils collected from southwestern Quebec. Treatments were assigned to each column in a full block factorial experiment. Four types of biomasses (birch, willow, panicum, and miscanthus) at two different rates (6%, 20% v/v) constituted the treatments, in addition to an intact control and a disturbed control without amendment. The CO2 fluxes emitted by soils were measured weekly using the static chamber method and infrared sensors over a period of 9 weeks, for a total of 1228 degree-days. Results showed that CO2 emitted from the control soil columns (intact and disturbed) were 4.9 and 5.2 t C-CO2 ha-1 year-1, respectively. Wood biomass amendment (birch and willow) had higher CO2 emissions than straw biomass (panicum and miscanthus) with values of 6.5 to 9.1 t C-CO2 ha-1 year-1 compared to 5.9 to 6.7 t C-CO2 ha-1 year-1, respectively. Some treatments differ significantly from each other. The mass balance shows that only the 20% (v/v) amendments led to a positive net carbon balance or equilibrium.
L’Heureux-Bilodeau, F., Dessureault-Rompré, J. and Rousseau, A.N. (2024). Carbon dioxide emission from an organic soil amended with straw and wood chips. Acta Hortic. 1389, 329-334
DOI: 10.17660/ActaHortic.2024.1389.37
cultivated organic soils, soil conservation, soil restoration, CO2 emissions, amendment

Acta Horticulturae