Several studies of fruits, vegetables and grains have suggested a decline in nutritional value over time. According to research, this decline is due to factor such as selected varieties (trade-off between yield and nutritional value), soil depletion, changes in farming methods, including the extensive use of chemical fertilizers, as well as food processing and preparation.

SILT farmers use practices that guarantee soil health and provide nutritious foods.

Read more here: https://www.nytimes.com/2015/09/15/science/a-decline-in-the-nutritional-value-of-crops.html?ref=topics&_r=0