Plants require certain levels and ratios of nutrients from the soil to grow properly. A nutrient deficiency, such as nitrogen, will show up in farm fields as yellow leaves in the plant and can lower the nutritional quality of harvested foods (e.g. lowered protein in wheat). Nutrient density refers to the amount of nutrients contained in a serving of food, or a given amount of food (e.g., 100 grams). Nutrient density is also sometimes expressed per calorie of food – an approach helpful to people looking to increase their nutrient intake without also increasing overall calories.
Unfortunately, USDA data show an incremental decline in nutrient density for many foods and nutrients over the past 50 years. As plant breeders and farmers focus on increasing yields, nutritional quality and taste often suffer as a result.
There is growing research interest on whether and how agricultural management can play a role in reversing the observed decline in nutrient density. In addition to nutrients (e.g. minerals, vitamins), many foods contain other compounds such as antioxidants that may have important health properties. Again, researchers are studying whether and how different plant genetics and growing conditions interact to drive upward (or sometimes down) the levels of health-promoting compounds in food.
Other critical research focuses on how to preserve the nutrients in food when it is harvested, as the food moves along the value chain to consumers. Advances in food storage, preservation, and manufacturing methods are steadily reducing the percent of nutrients lost between harvest and consumption.
Quality of Organically and Conventionally Grown Apples and Strawberries
Research on apple and strawberry by Dr. Preston Andrews, Dr. John Reganold, and Dr. Neil Davies.
Effect of thermal treatments on phytochemicals in conventionally and organically grown berries
Sablani, S. S., Andrews, P. K., Davies, N. M., Walters, T., Saez, H., Syamaladevi, R. M., and Mohekar, P. R. 2010. Journal of the Science of Food and Agriculture 90: 769-778
Influence of processing on phytonutrient content of organic and conventional raspberries and blueberries
Poster presentation – BIOAg Research Symposium 2008.
High Tunnels: Improving Crop Quality, Extending the Season, and Increasing Farm Profitability – Summer 2007
Article in Sustaining the Pacific Northwest Newsletter
Apple orchard productivity and fruit quality under organic, conventional, and integrated management.
Peck GM, Andrews PK, Reganold JP, Fellman JK. 2006. HortScience 41:99-107.
Soil and winegrape quality in biodynamically and organically managed vineyards.
J. R. Reeve, L. Carpenter-Boggs, J. P. Reganold, A. L. York, G. McGourty, and L. P. McCloskey. 2005. Amer. J. Enol. Vitic. 56: 367-376.
Biodynamic Management of Wine Grapes
Study by Jennifer Reeve as part of MS degree, WSU Crops & Soils. Examined the effect of biodynamic preparations on wine grape, soil, and compost quality. Major professor Dr. John Reganold.
Soil and plant mineral nutrition and fruit quality under organic, conventional, and integrated apple production systems in Washington State, USA.
P.K. Andrews, J.K. Fellman, J.D. Glover, J.P. Reganold. 2001. Acta Hort. 564:291-298.