The effect of biochar in the growth of Sphagnum papillosum

The cultivation of Sphagnum mosses is being developed both as a commercial product and for the restoration of peatlands, for example, in peat extraction areas that have been removed from production. Understanding the factors influencing the growth of Sphagnum mosses, and especially those that promote it, plays a key role in intensive farming. It is also crucial that grown mosses are healthy and robust when transferred to sowing areas.

 

We planted Sphagnum papillosum capitula in small plastic mugs on top of peat collected from old peat extraction area. On top of the peat, we spread willow and birch biochar. Straw was spread on top of the mosses to even out the moisture conditions. The irrigation water came through holes in the bottom of the mugs and there were three different types of water: from a raised bog, spring and a mixture of these. The mugs were in a growth chamber under standard conditions for three months. Subsequently, the mosses were imaged using Pulse-Amplitude-Modulation (PAM) to detect photosynthetic activity. For mosses, length, number of capitulum and fresh and dry weight were measured separately from capitula and stems. The aim of the study was to investigate the effect of different biochars and irrigation water on the growth of S. papillosum.

 

The best growth results were achieved in mugs with added willow biochar (232 ± 30.1 g m ^-2). The growth of mosses was almost half that of mugs without added char (126 ± 27.9 g m ^-2). Birch biochar also promoted moss growth in length, weight and number of capitula. Different irrigation waters did not have a statistically significant effect on moss growth (paired t-test, t = -0.400, p = 0.697, df = 11). The PAM measurement results were interpreted using "healthy" pixels identified in the image. When comparing the number of pixels, willow char, birch char and control treatments differed significantly, and the control mugs had lower photosynthesis activity.

 

The experiment gave promising results on the development of Sphagnum farming and possible guidelines for what can be studied next in field experiments.