Search

BACKGROUND: Despite the optimal characteristics of peat, more environmental‐friendly materials are needed in the nursery sector, although these must guarantee specific quantitative and qualitative commercial standards. In the present study, we evaluated the influence of biochar and compost as peat surrogates on yield and essential oil profile of two different varieties of basil (Ocimum basilicum var. Italiano and Ocimum basilicum var. minimum). In two 50‐day pot experiments, we checked the performances of biochar from pruning of urban trees and composted kitchen scraps, both mixed in different proportions with commercial peat (first experiment), and under different nitrogen (N) fertilization regimes (second experiment), in terms of plant growth and volatile compounds profile of basil. RESULTS: Total or high substitution of peat with biochar (100% and 50% v.v.) or compost (100%) resulted in seedling death a few days from transplantation, probably because the pH and electrical conductivity of the growing media were too high. Substrates with lower substitution rates (10–20%) were underperforming in terms of plant growth and color compared to pure commercial peat during the first experiment, whereas better performances were obtained by the nitrogen‐fertilized mixed substrates in the second experiment, at least for one variety. We identified a total of 12 and 16 aroma compounds of basil (mainly terpenes) in the two experiments. Partial replacement of peat did not affect basil volatile organic compounds content and composition, whereas N fertilization overall decreased the concentration of these compounds. CONCLUSION: Our results support a moderate use of charred or composted materials as peat surrogates. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

There is considerable interest devoted to old-growth forests and their capacity to store carbon (C) in biomass and soil. Inventories of C stocks in old-growth forests are carried out worldwide, although there is a lack of information on their actual potential for C sequestration. To further understand this, soil organic carbon (SOC) was measured in one of Italy’s best-preserved old-growth forests, the Sasso Fratino Integral Nature Reserve. This reserve is on the World Heritage List along with other ancient beech forests of Europe, and it is virtually untouched due to the steepness of the terrain, even before legal constraints were imposed. Although the sandstone-derived soils are often shallow, they are rich in organic matter. However, no quantification had been carried out. By systematically sampling the topsoil across the forest, we accurately determined the average amount of SOC (62.0 ± 16.9 Mg ha–1) and nitrogen (4.0 ± 1.2 Mg ha–1) in the top 20 cm. Using the CENTURY model, future dynamics of SOC stocks were predicted to 2050 according to two climate scenarios, A1F1 and B2, the first of high concern and the second more optimistic. The model projected an increase of 0.2 and 0.3 Mg ha–1 a–1 by 2030 under the A1F1 and B2 scenarios, respectively, suggesting that the topsoil in old-growth forests does not reach equilibrium but continues accumulating SOC. However, from 2030 to 2050, a decline in SOC accumulation is predicted, indicating SOC net loss at high altitudes under the worst-case scenario. This study confirms that soils in old-growth forests play a significant role in carbon sequestration. It also suggests that climate change may affect the potential of these forests to store SOC not only in the long term but also in the coming years. [ABSTRACT FROM AUTHOR]