The objective of this work was to assess the vegetative population and to determine the number of viable seeds and their distribution in the soil profile under two soil management systems. Thus, two assays were conducted at the Department of Vegetable Production of ESALQ/USP using two types of soil preparation systems: tillage and no-tillage. For statistical analysis 28 samples of each type of soil handling were removed (tillage and pousio), being the averages compared by the test t to 5% of probability. The identification of the vegetative population and the amount of viable seeds and their distribution in the soil profile was determined by collecting the soil samples at depths of 0.0-2.5, 2.5-5.0, 5.0-10.0, 10.0-15.0 and 15.0-20.0 cm, placing them in aluminum trays and evaluating them in 15, 30, 60 and 90 days under greenhouse conditions. In the no-tillage system area, a smaller number of weed species and viable seeds occurred in the soil. The dominant families were Compositae and Amaranthacea and the seeds concentrated on the superficial layers of the soil (0-2.5 cm). In the tillage system area the dominant families were Compositae and Cruciferaceae and the viable seeds were dispersed in the soil profile.
seed bank; soil profile; weeds
