John Reganold and Jonathan Wachter reviewed 40 years of science and numerous scientific studies to understand the long-term prospects of organic and conventional farming. This analysis considered four main metrics of sustainability identified by the US National Academy of Sciences. These are productivity, economic profitability, environmental soundness, and social justice. For a farm to be sustainable, all four parameters should be in balance.
The research shows that the average yield in organic farming systems is 10 to 20% less than conventional agriculture. These farms are more profitable and environmentally friendly. Higher profitability is attributed to the willingness of the customer to pay more for organic products.
It is also understood that organic farm produce is more nutritious, contains little or no pesticide residues, provides more employment, improves soil biodiversity, shows better crop pollination. It has a better soil structure and, therefore, less soil erosion and is more energy-efficient.
The nutritional value, sensory qualities, and food safety of organically and conventionally produced foods have been compared. Except for nitrate content, there is no strong evidence that organic and conventional foods differ in carious nutrients or contaminants (Bourn et al., 2002).
On the other hand, a nutritional quality comparative assessment study for fruits, vegetables, and grains raised in organic and conventionally grown crops showed that the former contained significantly more vitamin C, iron, magnesium, and phosphorus and considerably fewer nitrates (Worthington, 2001).
Phenols are important to human health. The total content of this class of metabolites was studied in marionberries, strawberries, and corn cultivated in organic and conventional farms. In the three most common post-harvest processing treatments — freezing, freeze-drying, and air-drying the phenol content was higher in organically raised crops (Asami et al., 2003).
162 studies, of which 137 examined nutrient quality in crops and 25 livestock products, were analyzed. Conventionally produced crops had a significantly higher nitrogen content, and organic crops had a higher content of phosphorus and higher titratable acidity. The scientists also noted no evidence of a difference in nutrient quality between organically and conventionally produced foodstuffs. Small differences in nutrient content between the two could be related to differences in production methods (Dangour et al., 2009).