79 AGRO PRODUCTIVIDAD https://doi.org/10.32854/agrop.v0i0.1440 Agroproductividad: Vol. 12, Núm. 7, julio. 2019. pp: 79-85. Recibido: febrero, 2019. Aceptado: junio, 2019. Vertical root distribution in six agroecosystems in a savanna's acrisol of Huimanguillo, Tabasco, Mexico Distribución vertical de raíces en seis agroecosistemas en un acrisol de la sabana de Huimanguillo, Tabasco, México Murillo-De la Rosa, Arnulfo 1 ; Obrador-Olán, José J. 1 ; Castelán-Estrada, Mepivoseth 1 ; García-López, Eustolia 1 ; Carrillo-Ávila, Eugenio 2 ; Guerrero-Peña, Armando 1 1 Colegio de Postgraduados, Campus Tabasco. Periférico Carlos A. Molina km 3.5. H. Cárdenas Tabasco. CP. 86500. 2 Colegio de Postgraduados, Campus Campeche, Carretera Federal Haltun- chén-Edzná Km 17.5, C.P. 24450, Sihochac, Champotón, Campeche, Mexico. *Autor de correspondencia: rogarlopez@colpos.mx ABSTRACT Objective: We studied the density of length of thin roots (DLRD), less than 6 cm thick, in six agroecosystems that develop in an acid soil characteristic of the Sabana de Huimanguillo, Tabasco, Mexico, an “acahual” was taken as a reference and characterized floristically, identifying 33 species. Design/methodology/approach: A description of a soil profile was made, taking samples from each horizon to perform physical and chemical analyzes. The DRLD was estimated by the monolith method, considering four depths (0-10, 10-20, 20-30 and 30-40 cm), six samples were taken per agroecosystem. Results: The soil corresponded to a Chromic Acrisol (Loamic, Cutanic, Hyperdystric, Humic). The highest values of DRLD occurred in the first 20 cm, being 67, 69.1, 66.5, 81.4, 82.8 and 77.6% for pineapple, eucalyptus, acacia, rubber, grass and acahual, respectively. It was notorious that from 40 cm of depth the DLRD values decreased considerably in all agroecosystems. 33 plant species were identified. Limitations of the study/implications: It is necessary to do more research of the DLRD at greater depth and in other savanna soils to establish clear differences of vertical exploration of the radical biomass. Findings/conclusions: The greatest development of DLRD occurs in the first 20 cm in the six agroecosystems, decreasing considerably according to depth. Grass presented the highest values of DLDR in general there were statistical differences between the first and the rest of the depths. No homogeneity of DLRD was observed in the arboreal agroecosystems in the studied depths. Keywords: acid soils, root exploration, root length density. 79 AGRO PRODUCTIVIDAD Imagen de felipellsalek en Pixabay