On the other hand, weed seeds present on the soil surface are more prone to desiccation and greater predation activity of insects, especially ants. Crop residues, when uniformly and densely present, under CA could suppress weed seedling emergence, delay the time of emergence, and allow the crop to gain an initial advantage in terms of early vigor over weeds. Where pre-emergence herbicides are applied, crop residues may also intercept a considerable proportion of the applied herbicide and may result in lower herbicide efficacy.