DATA - Pyrolysis temperature controls carbon stability and micronutrient bioavailability in vineyard-trimming biochar

Published: 27 January 2026| Version 1 | DOI: 10.17632/rgtsx6xs4b.1
Contributors:
PEDRO GARZON CAMACHO,
,

Description

This dataset contains the complete experimental data supporting the study “Pyrolysis temperature controls carbon stability and micronutrient bioavailability in vineyard-trimming biochar”. The data were generated to evaluate how contrasting pyrolysis temperatures (300 °C and 600 °C) regulate biochar yield, physicochemical properties, carbon stability, and the total and bioavailable fractions of key micronutrients. Biochars were produced from vineyard pruning residues (Vitis vinifera) collected in northwestern Spain using slow pyrolysis under controlled laboratory conditions. The dataset includes raw and processed measurements for biochar yield, pH, electrical conductivity, moisture content, volatile matter, ash content, fixed carbon, oxidizable organic carbon, elemental composition (C, H, N, S, and O), and derived atomic ratios (H/C, O/C, and (O+N)/C) used as indicators of carbonization degree and chemical stability. In addition, the dataset provides total concentrations of macro- and micronutrients (Na, Mg, P, Ca, K, Mn, Fe, Cu, and Zn) determined by acid digestion and ICP-MS analysis, as well as chemically extractable (DTPA-extractable) fractions of Mn, Fe, Cu, and Zn representing potential bioavailability. Relative bioavailable fractions are included to enable direct comparison between total and extractable pools. The repository also includes the data matrix used for multivariate analysis (principal component analysis, PCA), summary statistics (mean ± standard deviation, n = 3), and the complete R scripts employed for statistical analyses and figure generation. All data are provided in open, reusable formats to ensure transparency, reproducibility, and reuse. These data support the identification of a functional trade-off between carbon stability and micronutrient bioavailability in vineyard-derived biochars and are intended for reuse in studies on biochar design, soil amendment strategies, circular economy applications, and climate-smart agriculture.

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Steps to reproduce

Feedstock preparation Collect vineyard pruning residues (Vitis vinifera) from a representative viticultural area. Air-dry the biomass, then oven-dry at 60 °C for 48 h until constant mass is achieved. Mechanically reduce the dried material to fragments smaller than 2 cm to ensure homogeneous thermal conversion. Biochar production Produce biochar by slow pyrolysis in a laboratory-scale electric furnace under controlled atmospheric conditions. Apply two target temperatures: 300 °C and 600 °C, using a constant heating rate of 3 °C min⁻¹ and a residence time of 1 h at the final temperature. Allow samples to cool naturally to ambient temperature, sieve to < 2 mm, and store in airtight containers under dry conditions. Label samples as BVT300 and BVT600. Biochar yield determination Determine biochar yield (%) on a dry-mass basis by relating the mass of biochar obtained after pyrolysis to the initial dry mass of the feedstock. Physicochemical characterization Measure pH and electrical conductivity (EC) in a 1:2.5 (w/v) biochar-to-water suspension after shaking for 1 h. Determine moisture content gravimetrically at 105 °C. Perform proximate analysis to quantify volatile matter, ash content, and fixed carbon. Quantify oxidizable organic carbon using the Walkley–Black method. Elemental and stoichiometric analysis Determine elemental composition (C, H, N, and S) by dry combustion using an elemental analyzer. Estimate oxygen content by difference. Calculate atomic ratios (H/C, O/C, and (O+N)/C) to assess carbonization degree and chemical stability. Macro- and micronutrient analysis Digest biochar samples using an HCl:HNO₃ (3:1, v/v) solution. Quantify total concentrations of Na, Mg, P, Ca, K, Mn, Fe, Cu, and Zn by ICP-MS following internationally recognized protocols. Micronutrient bioavailability Assess chemically extractable (potentially bioavailable) Mn, Fe, Cu, and Zn using a DTPA extraction (pH 7.3). Equilibrate 3.0 g of biochar with 20 mL of DTPA solution, agitate at 240 rpm for 2 h at room temperature, filter, and analyze extracts by ICP-MS. Express bioavailable fractions relative to total concentrations. Statistical and multivariate analysis Perform statistical analyses using R software (version 4.5.2). Apply ANOVA followed by Tukey’s post hoc test (p < 0.05). Conduct principal component analysis (PCA) on standardized variables to assess multivariate differentiation between BVT300 and BVT600. Data visualization and reproducibility Use the provided datasets and R scripts included in this repository to reproduce all statistical outputs, tables, and figures reported in the associated publication.

Institutions

Categories

Natural Sciences, Materials Science, Soil Science, Agricultural Soil Science

Funders

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