Organic Farming is a system that is based on building soil health through the use of compost, manure, cover crops and crop rotations and other natural methods. Organic principles are based on the belief that if the natural microbial life in the soil is given an opportunity to be prolific, the plants grown in that soil will also be healthy and resistant to pest and disease, and provide high quality nutrition to those that eat those plants.
Organic food is based on an agricultural growing method and is not intended to be a health claim. USDA's organic rules specifically state that they do not address food safety or nutrition. But researchers have documented health and quality implications: fewer pesticide residues, less groundwater contamination, and apparently higher levels of some nutrients.
A number of studies have concluded that organic food, particularly produce, has fewer and less toxic pesticide residues.
As far as nutritional value, published research that has compared organic versus conventional fruits, vegetables, and grains, finding that organic crops contained significantly more vitamin C, iron, magnesium, and phosphorous.