Carbon from Methane Plasmalysis in Agriculture: from Low-emission Hydrogen to Soil-health

Abstract The utilisation of carbon materials as soil amendments has seen a notable increase, with the aim of enhancing plant growth and facilitating carbon sequestration. Carbon from methane plasmalysis (CMP) may soon become widely available as a result of this hydrogen production process with low specific energy input. This study presents the initial evaluation of CMP’s properties and its effects on soil quality and plant growth. CMP was characterised as being of a purity level of ≥ 98% carbon (C), with a specific surface area of approximately 25.0 m 2 g⁻ 1 . In a greenhouse experiment, the application of CMP (w CMP = 0.1–1%) as a soil amendment to three Austrian soils with contrasting pH resulted in enhanced Zea mays biomass, chlorophyll content, and nutrient uptake, particularly under slightly acidic conditions and even at the lowest rate (0.1%). A 29-month field trial was conducted in order to confirm the positive effects of CMP under real-world conditions. This trial revealed increases in plant-available phosphorus (+ 60% at 11 months) and microbial activity (+ 25% at 25 months; + 15% at 29 months). The present study demonstrates that CMP has the potential to function as a beneficial soil amendment, with its effectiveness subject to variation depending on soil and site-specific conditions.