Two field experiments were carried out with peanut in the same area on a limed and fertilized "cerrado soil" (originally acidic and low fertility). The first experiment was carried out in the autumn/winter (dry season), and the second one in the subsequent spring/summer (wet season), in Campinas, State of São Paulo, Brazil. Plant development and production of inoculated (three Rhizobium strains) and nitrogen fertilized treatments (at planting 25 and 45 days after planting) were compared with non-inoculated and non-N-fertilized control. Nodulation of inoculated plants was similar to those of non-inoculated, with or without nitrogen. Greater accumulations, and rates for average daily uptake of nitrogen were observed for inoculated as well as for nitrogen fertilized plants, as compared to the control. In the autumn/winter experiment there was no increase in pod production neither due to nitrogen or to inoculation. In the spring/summer experiment however, the pod production was higher with nitrogen (30kg/N/ha) at planting, although higher nitrogen accumulations in plant shoots (sampled 84 days after planting) were observed treatments with two of the three inoculated strains.
inoculation; Rhizobium; peanut; Arachis hypogaea L. nitrogen