The response of the peanut plant to lime has been associated with calcium nutrition, but a higher nitrogen uptake has been observed in limed plots. A greenhouse experiment was conducted using a Red Latosol (Rhodic Hapludox) to study the effects of molybdenum, cobalt and liming on the nodulation and N uptake by peanut. A randomized block design was used, with four replicaties, in a factorial 4x3 scheme. Seed treatments (0.16 g kg-1 of Co, 0.58 g kg-1 of Mo, 0.16 g kg-1 of Co + 0.58 g kg-1 of Mo and no treatment) were applied to the peanut, cv. "Tatu", grown receiving three rates of lime (0, 4 and 6 t ha-1). There was no effect of seed treatment with Co on the nodulation and N uptake of peanut. Liming increased N uptake due to the formation of a larger number of nodules in the plant. The dry matter of peanut nodules was increased by Mo, but N uptake was not affected, showing that the decrease in Mn toxicity due to liming was more important than the increase in Mo availability for nodule formation and symbiotic N2 fixation.
Arachis hypogaea; symbiotic fixation; manganese
