Miscanthus Biochar had Limited Effects on Soil Physical Properties, Microbial Biomass, and Grain Yield in a Four-Year Field Experiment in Norway

Abstract

The application of biochar to soils is a promising technique for increasing soil organic C and offsetting GHG emissions. However, large-scale adoption by farmers will likely require the proof of its utility to improve plant growth and soil quality. In this context, we conducted a four-year field experiment between October 2010 to October 2014 on a fertile silty clay loam Albeluvisol in Norway to assess the impact of biochar on soil physical properties, soil microbial biomass, and oat and barley yield. The following treatments were included: Control (soil), miscanthus biochar 8 t C ha−1 (BC8), miscanthus straw feedstock 8 t C ha−1 (MC8), and miscanthus biochar 25 t C ha−1 (BC25). Average volumetric water content at field capacity was significantly higher in BC25 when compared to the control due to changes in BD and total porosity. The biochar amendment had no effect on soil aggregate (2–6 mm) stability, pore size distribution, penetration resistance, soil microbial biomass C and N, and basal respiration. Biochar did not alter crop yields of oat and barley during the four growing seasons. In order to realize biochar’s climate mitigation potential, we suggest future research and development efforts should focus on improving the agronomic utility of biochar in engineered fertilizer and soil amendment products.

Corn and hardwood biochars affected soil microbial community and enzyme activities

“…Typically, pyrolysis leads to structural modifications including shrinkage and loss of volatile organics (Chia, Downie, & Munroe, 2015) with higher temperatures decreasing the yield (Lehmann et al, 2006) while increasing C concentration (Lehmann et al, 2006) and surface area (Lehmann et al, 2006;Novak et al, 2009). The latter was higher in HB than CB, nonetheless the values were similar to those reported in the literature for wood-derived biochar (e.g., Sun et al, 2014) and plant materials (e.g., O'Toole et al, 2018).…”

“…(2014) found a significant decrease in EA in soils treated with biochar, while O'Toole et al. (2018) found no changes in microbial biomass after 4 yr of application of Miscanthus biochar. Application rates of biochar to soil can adversely affect soil microorganisms by reducing both their activity and abundance (Ameloot et al., 2014; Palansooria et al., 2019).…”

Pongamia pinnata L. Leaves Biochar Increased Growth and Pigments Syntheses in Pisum sativum L. Exposed to Nutritional Stress

“…Biochar can contribute to better colonization of plant growth promoting bacteria (PGPR) [26]. The PGPR act as an allied factor for better availability of nutrients and contribute to increasing chlorophyll pigments in wheat plant [73].…”

“…Biochar is well known to optimize the availabilities of water and nutrients to roots, resulting in significant increases in pigments syntheses and assimilations in plant leaves [74]; however, contrary findings are not uncommon [73]. These findings are attributed to contrasting feedstocks, soils, and environmental conditions [73,74].…”

Marginal Agricultural Land Low-Input Systems for Biomass Production

“…This leads to a more 'closed' cycle of production (and less external inputs) [37]. Note, that this more closed production cycle requires both more advanced agronomic skills [38,39] and additional links within the value chain, such as application of biochar [40][41][42][43][44][45][46][47][48][49] or phosphate salt recovery from the digestates [50,51]. Therefore, practical guidelines for industrial crops are also under development within the MAGIC project.…”