%0 Journal Article
%T Soil Management and Efficiency of Rhizobia Strains of Cowpea Vigna unguiculata (L.) Walp. in the Tropics Manejo de Suelo y Eficiencia de Cepas de Rizobio de Frijol Vigna unguiculata (L.) Walp. en los Tr車picos
%A Jos谷 Geraldo Donizetti dos Santos
%A Alana das Chagas Ferreira Aguiar
%A Edilson M芍ximo Silva Junior
%A Danubia Lemes Dadalto
%J Chilean Journal of Agricultural Research
%D 2011
%I 
%X In the humid tropics, the largest obstacle to the implementation of sustainable farming systems is the reduced efficiency of nutrient use by crops. This study assesses the effectiveness of five selected rhizobia strains in symbiosis with cowpea (Vigna unguiculata (L.) Walp.), with the objective of replacing N fertilization in the predominant agricultural system used by smallholder farmers. The study was carried out in three adjacent areas with distinct agricultural uses: conventional tillage, itinerant agriculture, and a no-till system. The experimental design was in randomized complete blocks with four replicates and seven treatments: five rhizobia strains (BR3262, BR3267, BR3299, INPA3-11B, and UFLA 3-84) and two controls without inoculation (one without mineral N and another fertilized with 74 kg N ha-1). We measured the dry mass of 100 grains, nodules and shoots, as well as cowpea yields and calculated relative and absolute efficiency indices for dry biomass production of cowpea shoots. Agricultural uses affected the number and dry mass of the nodules and, consequently, the mass of the dry plant matter and bean yield. In terms of yield, there was a major difference between the conventional and the itinerant systems. Yield was around four times as high in the itinerant system (1009.9 kg ha-1 compared to 243.7 kg ha-1). Under conditions of cohesion-prone soils, the system of conventional tillage reduces the possibility of cultivation of a second harvest in the year even with inoculation or N fertilization. En los tr車picos h迆medos, el mayor obst芍culo para la aplicaci車n de sistemas de agricultura sostenible es la reducci車n de la eficiencia del uso de nutrientes por los cultivos. Este estudio eval迆a la eficacia de cinco cepas de rizobios seleccionados en simbiosis con frijol (Vigna unguiculata (L.) Walp.), con el objetivo de sustituir la fertilizaci車n nitrogenada en el sistema de uso de suelo predominante utilizado por los peque os agricultores. El estudio se llev車 a cabo en tres zonas adyacentes de distintos usos agr赤colas: labranza convencional, agricultura itinerante, y un sistema de no laboreo. El dise o experimental fue en bloques al azar con cuatro repeticiones y siete tratamientos: cinco cepas de rizobios (BR3262, BR3267, BR3299, INPA3-11B y UFLA 3-84) y dos controles sin inocular (uno sin N mineral y otro fertilizado con 74 kg de N ha-1). Se midi車 el peso en seco de 100 granos, de los n車dulos y de los brotes, as赤 como los rendimientos de frijol y se calcularon los 赤ndices de eficiencia relativa y absoluta para la producci車n de biomasa seca de los
%K Vigna unguiculata
%K Vigna unguiculata
%K agroecosistemas
%K bacterias fijadoras de nitr車geno
%K leguminosas
%K Agroecosystem
%K nitrogen-fixing nodule bacteria
%K legumes
%U http://www.scielo.cl/scielo.php?script=sci_arttext&pid=S0718-58392011000400015