Nutrient density in food has decreased due to the switch to synthetic fertilizers used by intensive farming practices. Man-made fertilizers contain only the big three (phosphorus, potassium, and nitrogen) nutrients, leading to the slow depletion of micronutrients in the soil. Without an abundance of those other elements, plants cannot incorporate them and the resulting crops will lack them. As a result, modern industrial food contains a fraction of the micronutrients as compared to the same food from a century past, and there has not been a widespread effort to fix the problem.