Eficiência da fixação biológica de nitrogênio no feijão-caupi a base de extrato de nódulos

Abstract

Biological nitrogen fixation is essential for the cultivation of cowpea, reducing the need for nitrogen fertilizers and promoting sustainable agricultural practices. The use of nodule extracts with native soil bacteria, adapted to local conditions, emerges as an effective alternative to commercial inoculants, stimulating biological nitrogen fixation. The objective of this study was to evaluate the use of nodule extract as an alternative inoculant for biological nitrogen fixation in cowpea cultivars. The experiment was conducted in pots in the greenhouse of the Department of Farm School at the Federal Institute of Education, Science, and Technology of Piauí – Uruçuí Campus, in a completely randomized design arranged in a 4 x 3 factorial scheme with four replications. The treatments consisted of four nitrogen sources (control without N, nodule extract inoculant, commercial inoculant, nitrogen fertilization) and three cowpea cultivars (BRS Tumucumaque, BRS Xiquexique, and Pratinha). At the beginning of flowering, the following were evaluated: number of nodules per plant, number of viable nodules per plant, dry mass of nodules, plant height, and dry mass of the aerial part. The results showed that the nodule extract led to significant increases in nodulation and biomass, being equivalent or superior to the other nitrogen sources, especially for the cultivars BRS Xique-xique and BRS Tumucumaque. The Pratinha cultivar showed greater efficiency in the dry mass of nodules. The nodule extract stood out as an efficient alternative, promoting greater nodulation and favoring biological nitrogen fixation in cowpea, especially in the Tumucumaque and Xique-xique cultivars