Fertilizer Use and Functional Quality of Fruits and Vegetables.

The contribution of mineral nutrients to crop productivity is well-established. Adequate nutrient supply combined with proper placement, timing, and application methods often results in higher yields and improved crop nutrient use efficiency. Less well-studied is the influence of fertilizers on retail quality, and the nutritional/functional properties of foods. Consumers are increasingly aware of the health benefits of Functional Foods (particularly fruits and vegetables), since these are excellent sources of essential nutrients and plant secondary compounds (phytonutrients) that have been linked with disease prevention and promotion of good health and wellbeing. However, consumption of functional foods often falls short of recommended guidelines, and many staple foods tend to have low phytonutrient densities. Breeding, genetic engineering, and post-harvest fortification are some of the strategies that have been proposed and/or implemented to help improve the functional properties for foods and indirectly enhance intake.  Besides genetics, pre-harvest farming practices, particularly fertilizer management, can have a strong influence on the functional properties of foods, and thus represent a sustainable and inexpensive complement to breeding and biotechnology. However, major gaps still exist in the knowledge regarding interactive effects among fertilizers, and among phytonutrients in foods. Selected case studies where macro- and micro-nutrient management has enhanced the functional quality of fruits and vegetable crops will be discussed. It is concluded that carefully-planned site/crop-specific fertilizer management practices, embracing the concepts of proper amounts, timing, placement, and application method, can be a cost-effective approach for enhancing the functional quality of fruits and vegetable crops.