Unexpected N and K nutrition diagnosis in oil palm smallholdings using references of high-yielding industrial plantationsSylvain Rafflegeau, Isabelle Michel-Dounias, Bertrand Tailliez, Benjamin Ndigui and François PapyAgron. Sustain. Dev., 30 4 (2010) 777-787DOI: https://doi.org/10.1051/agro/2010019