Thursday, 29 June 2017

Final publication of EU COST Action TD1107 ("Biochar") published!

Eventually the final publication of the EU COST Action "Biochar as option for sustainable resource management" (2012-2017) is published in the journal Journal of Environmental Engineering and Landscape Management, please see the open access papers from the journal website.

The nine articles cover the main results of the COST Action, some arer highlighted here. The first one published,  Tammeorg et al. 2017 explored the research priorities for the future biochar research. The highest future research priorities regarding biochar’s effects in soils were: functional redundancy within soil microbial communities, bioavailability of biochar’s contaminants to soil biota, soil organic matter stability, GHG emissions, soil formation, soil hydrology, nutrient cycling due to microbial priming as well as altered rhizosphere ecology, and soil pH buffering capacity.

The Kern et al. (2017) paper focused on the question to what extent peat may be replaced in growing media by biochar. First positive results from laboratory and greenhouse experiments have been reported with biochar content in growing media ranging up to 50%. Various companies have already started to use biochar as an additive in their growing media formulations. Biochar might play a more important role in replacing peat in growing media, when biochar is available, meets the quality requirements, and their use is economically feasible.

 Frenkel et al. (2017), on the other hand, concluded that even low rates of biochar addition (less than 1%) can have positive effects on plant health. Kammann et al. (2017) reviewed the current state of knowledge on the potential of biochar to reduce N2O and CH4 emissions from agriculture. The found that the largest future research needs lay in conducting life-cycle GHG assessments when using biochar as an on-farm management tool for nutrient-rich biomass waste streams.

The representetativeness of European biochar research was analyzed by Verheijen et al. (2017) for field experiments and Sakrabani et al. (2017) for pot and lab experiments. They concluded that the potential of different biochars for remediation of contaminants need more research attention and that it is crucial to contextualize the effects of biochar on soil properties.

The Biochar COST Action was an efficient initiative to make the network of biochar researchers in Europe more coherent and I am sure several new projects and synergistic future steps will follow! 

Wednesday, 21 June 2017

Long-term effects of biochar as a soil amendment material on soil biota

We are investigating the long-term effects of spruce and pine- based biochars (BC) on earthworm and microbial community structures in fertile Stagnosol and nutrient deficient Umbrisol soils in Helsinki. BC was applied at rate of 0 and 10 or 30 t ha-1.

The field sampling campaign in 2015: from morning haze to late night!
Earthworm sampling conducted in autumn 2015, four and five years after BC application, showed no significant differences between the biochar and control treatments. The species composition of earthworms was in both sites typical for Finnish arable soils, dominated by endogeic Aporrectodea caliginosa Sav. Total earthworm density in Stagnosol was double the amount than in Umbrisol, but interestingly, we saw evidence of biochar particles being ingested by earthworms. This may suggest its enhancement of the microbial processes in earthworm digestive system.

Soil microbial samples were collected, and soil DNA was already extracted from 2015 samples, and is currently in a process of sequences analysis. In addition we measured soil CO2, CH4 and N2O fluxes in autumn 2015, using a closed dynamic chamber method. Preliminary analyses shows no significant effect of biochars on above mentioned gas fluxes.

In addition to above study, Mr. Jure Zrim has recently started working on effect of recycled organic fertilizers (including BC) on soil properties, crop growth and microbial community structures in (Tila)Hykerrys project, where four new experimental sites have been established since June 2016.

Read more from: Zrim, J., Nuutinen, V., Simojoki, A. & Tammeorg, P. 2017. Effects of biochar on earthworms in two long-term field experiments in Finland. IX Maaperätieteiden päiviät (Conference poster), Pro Terra, 71: 99-100.