Occurrence and efficiency of populations of nitrogen fixing bacteria in cowpea in Marabá, PA

Abstract

Cowpea is a common legume in the northern and northeastern regions of Brazil. It has a
great ability to form symbiosis with bacteria fixing atmospheric nitrogen as one of the ways
to increase crop productivity and to replace nitrogenous fertilizers. The present work aims to
evaluate the occurrence and efficiency of populations of bacteria that nodulate legumes and fix
N2 in seed of cowpea and cultivar BR 17 Gurgéia in an agroforestry system in Marabá, Pará.
Of Pará Campus Marabá Rural in December 2016, in a Yellow Latosol, medium texture, in an
area without previous use of any type of inoculant with implantation of agroforestry system. It
was used the seeds of cowpea creole known in the region as owl and the cultivar BR 17 Gurguéia.
The nodulation and the biomass production of cowpea plants were evaluated at the time
of flowering. The plants cultivated with creole seeds and cultivar BR 17 Gurguéia presented
nodulation. The efficiency of native populations in N2 fixation was similar regardless of seed
type. It is suggested the capture of strain in the study area for the evaluation of plant growth
promotion.