An ecological effort by a nonprofit organization has targeted abandoned farms as a way to help local farmers earn more money. One particular region in the foothills, which had been over-farmed, now has plants and a few young trees growing there. Which of the following strategies should the organization implement as sustainable practice(s) to promote soil quality?

I. Utilize pesticides generously to ensure that vegetation isn't lost
II. Encourage planting of crops in rows perpendicular to the hill slope
III. Plow deeply to access the richer soil under the depleted topsoil

II only
III only
I and II only
II and III only