Scientific literature reports mixed results in terms of crop yields grown in soils amended with biochar and compost. These discrepancies are mainly attributed to the heterogeneity of waste materials used, the production processes, and the application rates. To address the challenge of reducing synthetic fertilizer inputs in the Mediterranean area, three experiments were conducted to evaluate the effect of biochar, compost, and...

Remediation of metal-contaminated soils by aqueous washing is actually done using synthetic surfactants, calling for safer alternatives such as biosurfactants. Here we tested coffee-based humic substances extracted from various composts for soil washing of agricultural, industrial and urban soils contaminated by heavy metals. Molecular-level characterization of humic substances was done by 13 C-nuclear magnetic resonance and t...

Humic substances play empirically several essential functions in biogeochemical cycles such as storage of carbon, pollutants, nutrients and water, yet the underlying mechanisms remain poorly known because their precise molecular structure is largely unknown so far. Here, we extracted humic substances from biomass waste of bell pepper, fennel, artichoke, coffee ground, coffee husks, and nursery residues. We analyzed humic extra...

Background and aims Higher plants represent an optimal tool to regenerate resources while producing food in Space. However, the configuration of fertile cultivation substrates based on extraterrestrial resources is still a challenge. We evaluated the adaptability of potato ( Solanum tuberosum L., cv. ‘Colomba’) to the growth on six substrates: the MMS-1 Mars regolith simulant, alone (R100) and in mixture with 30% in vol. of gr...

Background and aims Biostimulants of natural origin represent a growing ecological strategy to increase crops productivity, especially when applied in combination with microbial bioeffectors. We studied the effect of biostimulants such as Potassium Humates (KH) from Leonardite and Compost Tea (CT) from green compost on both productivity and nutritional status of lettuce plants, as well as on the primary and secondary metabolis...