Insights on Molecular Characteristics of Hydrochars by <sup>13</sup>C-NMR and Off-Line TMAH-GC/MS and Assessment of Their Potential Use as Plant Growth Promoters
Laís G. Fregolente,
João Vitor dos Santos,
Giovanni Vinci,
Alessandro Piccolo,
Altair B. Moreira,
Odair P. Ferreira,
Márcia C. Bisinoti,
Riccardo Spaccini
Affiliations
Laís G. Fregolente
Laboratório de Estudos em Ciências Ambientais, Campus São José do Rio Preto, Instituto de Biociências, Universidade Estadual Paulista (Unesp), Letras e Ciências Exatas, Rua Cristovão Colombo 2265, Jardim Nazareth, São José do Rio Preto 15054-000, Brazil
João Vitor dos Santos
Laboratório de Estudos em Ciências Ambientais, Campus São José do Rio Preto, Instituto de Biociências, Universidade Estadual Paulista (Unesp), Letras e Ciências Exatas, Rua Cristovão Colombo 2265, Jardim Nazareth, São José do Rio Preto 15054-000, Brazil
Giovanni Vinci
Interdepartmental Research Centre on Nuclear Magnetic Resonance (NMR) for the Environment, Agro-Food and New Materials (CERMANU), Università degli Studi di Napoli Federico II, Via Università 100, 80055 Portici, Italy
Alessandro Piccolo
Interdepartmental Research Centre on Nuclear Magnetic Resonance (NMR) for the Environment, Agro-Food and New Materials (CERMANU), Università degli Studi di Napoli Federico II, Via Università 100, 80055 Portici, Italy
Altair B. Moreira
Laboratório de Estudos em Ciências Ambientais, Campus São José do Rio Preto, Instituto de Biociências, Universidade Estadual Paulista (Unesp), Letras e Ciências Exatas, Rua Cristovão Colombo 2265, Jardim Nazareth, São José do Rio Preto 15054-000, Brazil
Odair P. Ferreira
Laboratório de Materiais Funcionais Avançados (LaMFA), Universidade Federal do Ceará, Fortaleza 60455-900, Brazil
Márcia C. Bisinoti
Laboratório de Estudos em Ciências Ambientais, Campus São José do Rio Preto, Instituto de Biociências, Universidade Estadual Paulista (Unesp), Letras e Ciências Exatas, Rua Cristovão Colombo 2265, Jardim Nazareth, São José do Rio Preto 15054-000, Brazil
Riccardo Spaccini
Interdepartmental Research Centre on Nuclear Magnetic Resonance (NMR) for the Environment, Agro-Food and New Materials (CERMANU), Università degli Studi di Napoli Federico II, Via Università 100, 80055 Portici, Italy
Hydrochar is a carbon-based material that can be used as soil amendment. Since the physical-chemical properties of hydrochar are mainly assigned to process parameters, we aimed at evaluating the organic fraction of different hydrochars through 13C-NMR and off-line TMAH-GC/MS. Four hydrochars produced with sugarcane bagasse, vinasse and sulfuric or phosphoric acids were analyzed to elucidate the main molecular features. Germination and initial growth of maize seedlings were assessed using hydrochar water-soluble fraction to evaluate their potential use as growth promoters. The hydrochars prepared with phosphoric acid showed larger amounts of bioavailable lignin-derived structures. Although no differences were shown about the percentage of maize seeds germination, the hydrochar produced with phosphoric acid promoted a better seedling growth. For this sample, the greatest relative percentage of benzene derivatives and phenolic compounds were associated to hormone-like effects, responsible for stimulating shoot and root elongation. The reactions parameters proved to be determinant for the organic composition of hydrochar, exerting a strict influence on molecular features and plant growth response.
