Commentary on Current economic obstacles to biochar use in agriculture and climate change mitigation' regarding uncertainty, context-specificity and alternative value sources

A recent study in Carbon Management, by Bach etal., argues that biochar amendments' positive impacts on crop yields and soil carbon sequestration have been overestimated, and biochar amendment to soil is hence unlikely to be an economically viable technique for cropping system management or C abatement. We question the data selection and analysis techniques that the authors used to assess the effect of biochar on crop yield, biochar stability in soil, and biochar production cost. Although the research article was not intended as a meta-analysis - and hence the data reported need not be analyzed with the full rigor of a systematic review - we assert that the employed data set, while containing a sufficient quantity of data, requires closer inspection and a more careful interpretation to avoid significant bias in the conclusions. Furthermore, we assert that proper implementation of biochar and inclusion of non-yield benefits in the analysis would render it more economically viable for both cropping system enhancement and C sequestration than portrayed by Bach etal.