Title : Use of biochar as peat replacement in ornamental containerized bedding plant production
Abstract:
An increase in atmospheric CO2 concentration may change Earth's mean temperature and precipitation. Whilst soil carbon sequestration is widely recognized, much of the research on greenhouse gas emissions and carbon sequestration has been conducted in row crop and forest systems. Notwithstanding, managing soils of ornamental horticultural crops judiciously may reduce emissions and increase soil organic carbon stocks.Therefore, three greenhouse experiments were designed to test the hypothesis that “it is possible to grow commercial quality plants of Petunia hybrida and Pelargonium peltatum using biochar and vermicompost as partial substitutes of peat based growing media”. The first experiment focused on determining the feasibility of growing these plants with commercial quality using 24 different biochar / vermicompost mixes. The second experiment was conducted on the 5 best growing media from the first experiment, and evaluating the physiological plant attributes when growing those species with the selected mixtures. During the third experiment, leachates from the containers were collected to determine whether less nutrients were lost by irrigation when growing species on the selected media. The results from the first experiment indicated that the best biochar and vermicompost mixture could store up to 88.7 g of CO2e per each 800 cm3 container, first in the container itself, and then in the garden's soil after transplanting. The second experiment demonstrated that some of the best 5 mixes showed a similar or better physiological response than that of the plants grown in the control. Using the best media resulted in a significant reduction in both the amount of nitrates and the volume of leachate from the irrigation in the third experiment. The results suggest that vermicompost and biochar can be used as peat substitutes in the ornamental containerized bedding plant production to store carbon in garden soils for adaptation, and mitigation of anthropogenic climate change.
