Growth of Inga vera Willd. subsp. Affinis under rizobia inoculation.

Nitrogen, in general, is the largest limiting plant growth nutrient in the tropics and is required as a synthetic fertilizer to improve plants productivity. Therefore, studies aiming in understanding and using nitrogen fixation by leguminous trees have been done as a low-cost alternative for chemical fertilizer. Native legume trees such as Inga vera have been recommended in the rehabilitation of degraded areas due their ability to establish symbiosis with nitrogen fixation organisms replacing nitrogen fertilization. These species are able to increase soil organic matter, nitrogen and phosphorus availability. Thus, the present study aims to assess the inoculation effects of native rhizobia strains on nodulation, dry matter production, nitrogen and phosphorus leaf incorporation in I. vera seedlings. With this purpose, four strains were obtained from inga nodules and tested in a greenhouse. The inoculation of I. vera seedlings with native rhizobium strains promoted an increase in shoot dry mass as well as in leaf nitrogen content. According to symbiotic efficiency equation, this approach ranged from 50 to 80% indicating that the nitrogen fertilization for this species can be partially replaced by rhizobia inoculation.