@article{sacomori_cassol_mafra_erdemann_almeida_2021,  title={Accumulation of humic substances in an Oxisol fertilized with pig slurry for 15 years},  volume={25},  ISSN={1415-4366},  url={https://doi.org/10.1590/1807-1929/agriambi.v25n2p109-115},  DOI={10.1590/1807-1929/agriambi.v25n2p109-115},  number={2},  journal={Revista Brasileira de Engenharia Agrícola e Ambiental},  publisher={Unidade Acadêmica de Engenharia Agrícola},  author={Sacomori, Wagner and Cassol, Paulo C. and Mafra, Maria S. H. and Erdemann, Luiza F. and Almeida, Jaime A. de},  year={2021},  month={Feb},  pages={109–115} }