Growth of Crotalaria juncea L. supplied with mineral nitrogen

Plants of Crotalaria juncea inoculated with Rhizobium were treated with nutrient solution containing 10 or 20mg of either N/NO3 or N/NH4-plant(-1). week(-1). The control plants received nutrient solution without N. An investigation was conducted on the effect of these sources of N on growth and nitrogen fixation of plants with 30, 60 and 90 days after sowing (DAS). Those that received mineral N presented higher growth than -N plants, but the presence of nodules occurred in all the treatments. Plants treated with NH4 presented higher N content until 60 days. The highest concentrations of leghemoglobin and protein in nodules were found at 30 DAS and there was no difference in for any age and in protein from 60 DAS. Nitrogenase activity did not leghemoglobin content between treatments vary from 60 to 90 days, with the exception of plants that received 20mg N/NO3, where it was higher at 60 days.