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Isothermal microcalorespirometry is a non-destructive technique widely used to study terrestrial activity in ecosystems by measuring the heat and the carbon dioxide (CO2) released by metabolic reactions of soil organisms. Therefore, microbial communities naturally present in the soil play a key role in the C and N cycle thereby releasing heat and CO2 which are quantitatively related to the matter fluxes via the law of Hess. In order to measure both quantities simultaneously, current methods follow mainly a purely calorimetric approach (absorbent method or GC analysis) [1]. In the absorbent method, CO2 is measured indirectly via the heat released during the absorption reaction in a NaOH-solution (CO2-trap), which is placed in the sample vessel together with the soil sample. This approach presents a few disadvantages, e.g. indirect CO2 measurement, small sample size, low sample throughput, low CO2 partial pressure and oxygen limitation. To overcome the drawbacks of the current calorespirometric approach, a newly designed isothermal macrocalorespirometer (IMCR) was developed by combining a classic respirometer and the proven concept of isothermal microcalorimetry. The IMCR is composed of 10 mobile channels placed in a thermally isolated box, water-thermostated at 20°C. Each channel is composed of a heat sink and a heat sensor directly in contact with the sample vessel (calorimetric unit), plus a vessel with a KOH-solution (CO2-trap) in which a pair of electrodes is immersed (respirometric unit) connected to the channel’s lid. The spatial separation between the two units, the use of electrodes and the size of the channel, make it possible to overcome the disadvantages of the absorbent method (NaOH-solution) mentioned above. The new approach has been successfully tested with glucose-induced microbial metabolic activity in soil samples, allowing the quantification of the calorespirometric ratio . Additionally, TGA-DSC-MS and GC-MS analysis will be performed, necessary to close balances of mass and energy fluxes.This newly designed IMCR will be applied in the wider frame of calorimetric environmental soil studies, aiming at understanding the carbon dynamics in soil, the latter being known as the biggest carbon pool among the natural matrix. New knowledge in this area support potential solutions for climate change, intimately connected to the global carbon fluxes.[1] Wadsö L., A method for time-resolved calorespirometry of terrestrial samples, Methods 76 (2015) 20–2

Graphical abstract The ability of tobacco (Nicotiana tabacum L. cv. Badischer Geudertheimer) for phytomanaging and remediating soil ecological functions at a contaminated site was assessed with a potted soil series made by fading an uncontaminated sandy soil with a contaminated sandy soil from the Borifer brownfield site, Bordeaux, SW France, at the 0%, 25%, 50%, 75%, and 100% addition rates. Activities of sandblasting and painting with metal-based paints occurred for decades at this urban brownfield, polluting the soil with metal(loid)s and organic contaminants, e.g., polycyclic aromatic hydrocarbons, in addition to past backfilling. Total topsoil metal(loid)s (e.g., 54,700 mg Zn and 5060 mg Cu kg−1) exceeded by seven- to tenfold the background values for French sandy soils, but the soil pH was 7.9, and overall, the 1M NH4NO3 extractable soil fractions of metals were relatively low. Leaf area, water content of shoots, and total chlorophyll (Chl) progressively decreased with the soil contamination, but the Chl fluorescence remained constant near its optimum value. Foliar Cu and Zn concentrations varied from 17.8 ± 4.2 (0%) to 27 ± 5 mg Cu kg−1 (100%) and from 60 ± 15 (0%) to 454 ± 53 mg Zn kg−1 (100%), respectively. Foliar Cd concentration peaked up to 1.74 ± 0.09 mg Cd kg−1, and its bioconcentration factor had the highest value (0.2) among those of the metal(loid)s. Few nutrient concentrations in the aboveground plant parts decreased with the soil contamination, e.g., foliar P concentration from 5972 ± 1026 (0%) to 2861 ± 334 mg kg−1 (100%). Vulnerability to drought-induced embolism (P50) did not differ for the tobacco stems across the soil series, whereas their hydraulic efficiency (Ks) declined significantly with increasing soil contamination. Overall, this tobacco cultivar grew relatively well even in the Borifer soil (100%), keeping its photosynthetic system healthy under stress, and contaminant exposure did not increase the vulnerability of the vascular system to drought. This tobacco had a relevant potential to annually phytoextract a part of the bioavailable soil Zn and Cd, i.e., shoot removals representing here 8.8% for Zn and 43.3% for Cd of their 1M NH4NO3 extractable amount in the potted Borifer soil. Supplementary Information The online version contains supplementary material available at 10.1007/s11356-021-16411-y.