DOI: 10.18150/av5z37
title: Utilization of post-fermentation sludge as a soil structure and strength conditioner

description: The deposited dataset was collected as part of the research project “Wpływ biowęgla wzbogaconego mikrobiologicznie na właściwości fizykochemiczne i biologiczne agregatów glebowych – badania modelowe” (“The influence of microbiologically enriched biochars on the physicochemical and biological properties of soil aggregates – model studies”), funded by the National Science Centre, Poland, under the SONATA 17 program (project no. 2021/43/D/ST10/01656). The project is based on model aggregates prepared from biochar and biochar enriched with microorganisms (Trichoderma), mixed with soils of different texture classes and physicochemical characteristics. The research in the project covers bulk density, aggregate structure and pore characteristics, water and mechanical stability of aggregates, wettability, microbial activity, as well as a range of other physicochemical and biological parameters of soils.The study was carried out between December 2023 and June 2024 at the Institute of Agrophysics, Polish Academy of Sciences, in Lublin.The dataset includes results for six soil types, post-fermentation sludge, and mixtures of soils amended with digestate at various proportions (1–15%). The deposited data comprise the following parameters:Total carbon content;pH measured in H2O and KCl;Organic carbon content;Solid-phase density;Bulk density;Specific surface area;Cation exchange capacity;Average pore diameter;Pore surface area;Total pore volume;Total porosity; Granulometric composition;Ash content;Content of available macronutrients and heavy metals;Maximum force causing aggregate destruction;Young’s modulus;Mercury intrusion porosimetry cumulative curves;Mercury intrusion porosimetry differential curves;Stress-strain curves.The dataset consists of the following *.xlsx files: A_1 – pH measured in H₂O for six soils (Abruptic Luvisol (A), Brunic Arenosol (B), Haplic Cambisol (C), Haplic Chernozem (D), Haplic Fluvisol (E), Stagnic Luvisol (F)), post-fermentation sludge, and soil–digestate mixtures at proportions of 0, 1, 3, 5, 10, and 15%; A_2 – pH measured in KCl for the same soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_3 – Total carbon content of six soils and post-fermentation sludge; A_4 – Organic carbon content of six soils; A_5 – Solid phase density of six soils and post-fermentation sludge; A_6 – Bulk density of six soils, post-fermentation sludge and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_7 – Specific surface area of six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_8 – Cation exchange capacity (CEC) of six soils; A_9 – Average pore diameter obtained by mercury intrusion porosimetry for six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_10 – Surface area of pores obtained by mercury porosimetry method for six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_11 – Pore volume obtained by mercury porosimetry method for six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_12 – Total porosity obtained by mercury porosimetry method for six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_13 – Granulometric composition of six soils; A_14 – Organic carbon content of post-fermentation sludge; A_15 – Ash content of post-fermentation sludge; A_16 – Content of available macronutrients and heavy metals in post-fermentation sludge; A_17 – Cumulative mercury intrusion porosimetry curves for six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_18 – Differential mercury intrusion porosimetry curves for six soils, post-fermentation sludge and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_19 – Stress–strain curves for six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_20 – Maximum force required to destroy aggregates obtained for six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%); A_21 – Young’s modulus determined for six soils, post-fermentation sludge, and soil–digestate mixtures (0, 1, 3, 5, 10, and 15%);Summary of methods and equipment: A_1, A_2 – CX-505 digital pH meter (Elmetron); A_3 – TOC MULTI N/C 2000 analyzer with HT 1300 module (Analytik Jena); A_4 – Dichromate oxidation method; A_5 – Helium Ultrapycnometer 1000 (Quantachrome); A_6 – Bulk density calculated by dividing aggregate mass by aggregate volume measured via mercury immersion; A_7 – 3Flex surface area analyzer (Micromeritics, Norcross, GA, USA); A_8 – CEC was determined using an indirect method by separately measuring the sum of basic cations (Ca²⁺, Mg²⁺, K⁺, and Na⁺) and exchangeable hydrogen (H⁺); A_9–A_12, A_17, A_18 – Autopore IV 9500 mercury porosimeter (Micromeritics, Norcross, GA, USA); A_13 – The aerometric method with the Prószyński modification; A_14 – The Alten method, based on the oxidation of organic matter in a sulfuric acid (VI) environment; A_15 – Ash content determined by heating samples at 550 °C for 6 h in a muffle furnace (FCF 12 SP, Czylok); A_16 – Phosphorus: UV–Vis spectrophotometry (SPECORD 50 PLUS, Analytik Jena); Potassium, magnesium, calcium: atomic absorption spectrometry (AAS contra AA 300, Analytik Jena); Zinc, lead, chromium, cadmium, copper: acid digestion (HNO₃–H₂O₂–HCl) followed by AAS (contra AA 300, Analytik Jena); A_19–A_21 – Mechanical testing machine LabTest 6.10.1 (LABORTECH s.r.o., Opava, Czech Republic).