%0 Journal Article
%T Biological Fixation of N2 in Mono and Polyspecific Legume Pasture in the Humid Mediterranean Zone of Chile Fijaci車n Biol車gica de N2 en Praderas Mono y Poliespec赤ficas de Leguminosas en la Zona Mediterr芍nea H迆meda de Chile
%A Soledad Espinoza
%A Carlos Ovalle
%A Alejandro del Pozo
%A Erik Zagal
%J Chilean Journal of Agricultural Research
%D 2011
%I 
%X Despite annual legume pasture are of great importance for dryland agricultural systems in Mediterranean environments, there are few studies of N2 biological fixation (NBF) reported in Chile. In this study the NBF of four annual legume species: subterranean clover (Trifolium subterraneum L.), yellow serradella (Ornithopus compressus L.), arrow-leaf clover (T. vesiculosum L.), and crimson clover (T. incarnatum L.) (Experiment 1), as well as seven mixtures of these species (Experiment 2) were assessed. The NBF was measured by the 15N natural abundance technique. The objective was to determine NBF in the legume species and in distinct mixtures used. The study was carried out in an Andisol of the Andean Precordillera located in the humid Mediterranean zone of Chile. Pasture was evaluated for biomass; and total N and natural abundance of 15N were analyzed in plant material samples. In Experiment 1 (monospecific legume species pasture), N derived from fixation ranged between 43 and 147 kg N ha-1 and where T. vesiculosum and T. subterraneum presented statistical differences (P ≒ 0.05) in connection with the other species. In the legume mixtures (Experiment 2), N derived by fixation varied between 97 and 214 kg N ha-1 where the 50-50 mixtures (T. subterraneum and O. compressus, or T. subterraneum and T. vesiculosum, respectively) had the highest N fixation. Fixed N ranged between 12 and 25 kg N t-1 DM, showing significant differences among mono and polyspecific legume species. A pesar de la gran importancia que las praderas de leguminosas tienen en los sistemas agr赤colas de secano en ambientes mediterr芍neos, existe muy poca informaci車n sobre la fijaci車n biol車gica de N2 (FBN) reportada en Chile. En este estudio se evalu車 la FBN en cuatro leguminosas forrajeras anuales: tr谷bol subterr芍neo (Trifolium subterraneum L.), serradela amarilla (Ornithopus compressus L.), tr谷bol vesiculoso (T. vesiculosum L.) y tr谷bol encarnado (T. incarnatum L.) (Experimento 1), adem芍s de siete mezclas de estas especies (Experimento 2). La FBN se midi車 mediante la t谷cnica de la abundancia natural de 15N. El objetivo fue determinar la FBN en las especies de leguminosas como en las diferentes mezclas. El estudio se llev車 a cabo en un suelo Andisol, de la Precordillera Andina, localizada en la zona mediterr芍nea h迆meda de Chile. En la pradera se evalu車 producci車n de biomasa y en submuestras se analiz車 N total y abundancia natural de 15N. En el Experimento 1, el N derivado de la fijaci車n fluctu車 entre 43 y 147 kg N ha-1; siendo T. vesiculosum y T. subterraneum los que presentaron diferencias e
%K abundancia natural de 15N
%K praderas mediterr芍neas
%K suelo volc芍nico
%K Natural abundance of 15N
%K Mediterranean pastures
%K volcanic soil
%U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392011000100016