REZENDE, F. C.; RIBEIRO, V. B.; ÁVILA, L. F.; FARIA, M. A. DE; SILVA, E. L. DA. Spatial variability of pH in coffee plants under fertigation and traditional system of fertilizing. Coffee Science - ISSN 1984-3909, v. 7, n. 3, p. 198-207, 5 Oct. 2012.