Time magazine highlights a report in the Journal of HortScience, which states that the average vegetable found in today's supermarket is anywhere from 5% to 40% lower in minerals (including magnesium, iron, calcium and zinc) than those harvested just 50 years ago. One of the given reasons is the "Industrialization" of Agriculture.

"Thanks to the growing rise of chemical fertilizers and pesticides, modern crops are being harvested faster than ever before. But quick and early harvests mean the produce has less time to absorb nutrients either from synthesis or the soil, and minerals like potassium (the "K" in N-P-K fertilizers) often interfere with a plant's ability to take up nutrients. Monoculture farming practices - another hallmark of the Big Ag industry - have also led to soil-mineral depletion, which, in turn, affects the nutrient content of crops."

Time Magazine 18/2/09