Weed emergence as affected by soil disturbance and moisture in a controlled environment

Emergence of weeds is influenced by disturbance of the top soil layer which, in general, creates favourable environmental conditions for the germination of seeds and consequent plant emergence. This study reports the influence of soil disturbance on the emergence of weeds under different soil moisture levels. The experiments were carried out under controlled environment conditions, using rings containing undisturbed soil cores collected from the top soil layer (0-2.5 cm and 0-5.0 cm depths) of a Luvisol. The treatments comprised two depths and four moisture levels in disturbed and undisturbed soil. The results showed that both moisture level and soil disturbance greatly influence weed seedling emergence. Emerged seedlings in the disturbed soil, which had been subject to a moisture level greater than or equal to two thirds field capacity, was higher in number than in the undisturbed soil. However, soil subject to saturation followed by desiccation produced fewer seedlings when the soil was disturbed.