@article{balota_machineski_truber_auler_2011,  title={Effect of tillage systems and permanent groundcover intercropped with orange trees on soil enzyme activities},  volume={54},  ISSN={1516-8913},  url={https://doi.org/10.1590/S1516-89132011000200001},  DOI={10.1590/S1516-89132011000200001},  number={2},  journal={Brazilian Archives of Biology and Technology},  publisher={Instituto de Tecnologia do Paraná - Tecpar},  author={Balota, Elcio Liborio and Machineski, Oswaldo and Truber, Priscila Viviane and Auler, Pedro Antonio Martins},  year={2011},  month={Mar},  pages={221–228} }