Soil Erosion: Plants get their nutrients from the soil and animals get their nutrients from plants. Thus, the more nutrient depleted the soil is, the fewer nutrients the vegetation growing on it will have. The food that we now eat is about 30% less nutritious than the same food from 1940. That means you literally need to eat 30% more food to get the same level of minerals that someone used to get who lived just 80 years ago.