The black oat (Avena strigosa Schreb.) seeds are able to remain alive in soil from a culture to another. The objective of this study was to evaluate the number of black oat seeds resulting from two management, harvesting, and natural reseeding, which could form the seed bank of soil. The experiments were conducted in Jari-RS, Brazil, the cultivation system is "No Tillage". Were collected 50 samples in each management, at a spacing of 10mx20m, using a sampler diameter of 0.05m and depth of 0.1m. The evaluation of the number of seeds and seedling emergence was accomplish at the Laboratory of Seeds Analysis of the Faculdade de Agronomia "Eliseu Maciel" (UFPEL). It was found that both as the crop as the natural seeding allow large quantities of seeds in the soil for the upper area suitable for planting. The harvest area is heterogeneous in the number of seeds in soil and plants in the area. The natural seeding results in a large amount of seed in soil and seedling.
Avena strigosa Schreb; forage specie; natural seeding; integrated crop-livestock
