ABSTRACT
Seeds can absorb N from mineral supplementation, thus stimulating seedling development in soybeans (Glycine max (L.) Merrill). This study aimed to evaluate the contribution to soybean seedlings of N derived from mineral supplementation in seeds with different nutritional contents. Seeds of the cultivar BMX Potência RR received mineral supplementation enriched with 2.5% excess 15N. The treatments were performed in seeds in two lots, one with high and one with low nutritional content. At 2, 6 and 10 days after sowing on paper towels, the seedlings were collected and separated into cotyledons, roots and shoots. Dry matter production, root length and root volume were assessed. Total N and 15N values were analyzed in the seedling organ tissues. The seeds from the lot with lower nutritional content absorbed more N from the mineral supplement, which was accumulated in the cotyledons and redistributed to the root systems and cotyledons. At 10 days after sowing, most of the N in the organs of soybean seedlings was derived from the seed reserves, regardless of nutritional content. Thus, application of N through mineral supplementation is of low importance for the development and nutrition of seedlings.
Index terms:
Glycine max (L.) Merrill; absorption; distribution; 15N.