Weed Control J 2022; 21: e202200761

Research Article

Dynamics of the weed seed bank in soil under no-tillage

DOI: 10.7824/wcj.2022;21:00761

Abstract

Background

Knowledge of the seed bank present in soil of agricultural areas is essential for choosing the most appropriate management strategies for weed control.

Objective

Our objective was to evaluate the immediate viability of weed seed germination of soil conducted in a consolidated no-tillage system. However, there is uncertainty about the composition of the seed bank in no- tillage areas.

Methods

The soil was collected at a depth of 0 to 40 cm, stratified: 0-10 cm, 10-20 cm and 20-40 cm. The viability of weed seeds was evaluated through the emergence of viable seeds incubating the soil in a completely randomized design with five replicates per treatment, at 25ºC with a photoperiod of 12 hours daily for 56 days. The weed seedlings were quantified and the species were identified, resulting in 11.2, 4.0, 1.6 seedlings at depths of 0-10, 10-20 and 20-40 cm, respectively.

Results

Four species were identified: Pigweed ( Amaranthus spp.) representing 54%, horseweed ( Conyza bonariensis ) with 36%, greater beggarticks ( Bidens pilosa ) with 8.8% and milkweed ( Sonchus oleraceus ) with 1.2%.

Conclusions

The depth of 0-10 cm show a greater quantity of seeds with immediate viability for the germination of pigweed and horseweed weeds in soil. The milkweed and black pick have less seeds with immediate viability, however with uniform distribution in the depth of the soil under no-tillage system management.