Organic vs. Conventional Growing

By Erika Shaver, University of Michigan Dietetics Intern

The Farm at St. Joes follows organic practices, and I wanted to find out if organic produce was healthier and more nutritious than conventional produce, or produce that was grown using non-organic practices. This has been a hotly debated topic in the last decade, and during my rotation here at the St. Joes Farm, I wanted to explore the pros and cons so that I could make a conscious decision for myself.

Before we begin with the debate, let’s talk about organic farming. According to the USDA, organic crop production is a set of practices that support the cycling of on-farm resources, promote ecological balance, and conserve biodiversity (1). Examples of organic crop production include maintaining or improving soil and water quality; conserving wetlands, woodlands, and wildlife; and avoiding use of synthetic fertilizers, sewage sludge, irradiation, and genetic engineering (such as GMOs). In general, organic growers aim to use natural processes and materials on their farm (1).

To enhance soil quality at the St. Joes Farm, the Farm applies compost, organic fertilizer, and a natural supplement called azomite once per year. Compost is organic material, such as food scraps and yard waste, that is broken down by microorganisms to give nutrients to soil (2,3). St. Joes also tests its soil each year. This helps reduce the use of fertilizer because the farmer knows how much nutrients are needed in the soil for the upcoming season (4). St. Joes also helps maintain its soil quality by practicing crop rotation, which essentially means that the type of crop grown in one plot rotates each year (1). This prevents pests from becoming too comfortable with a particular area of land and can prevent soil erosion (1).

To control pests, the St. Joes Farm practices integrative pest management, which is an environmentally friendly way to reduce pest problems. The first goal of this practice is to prevent pests by following practices such as removing overgrown and rotten crops. If this does not work, then the goal is to control pests by physically removing them, trapping them, or applying pesticides if these methods do not work (5).  Yes, it is true! Organic farmers are allowed to use organic pesticides if needed. However, they must use organic pesticides, not synthetic pesticides. Weed problems are handled with a similar mindset. One practice St. Joes Farm used to control weeds was good old-fashioned weeding. I had some experience with this one afternoon on the farm! St. Joes also tries purchasing organic seeds when possible. Organic seeds are seeds that have not come in contact with conventional growing practices that may have exposed them to pesticides (1).


The carrot beds we weeded for an afternoon. It took some time!

Pros and cons of organic produce

In the past decade, the academic community has debated whether organic produce is more nutritious than conventional produce.  Some review articles support this argument (6,7). One article describes that there is 12 percent more vitamin C and most phytochemicals, such as phenols, in organic produce compared to conventional produce. These nutrients often have antioxidant properties that can help reduce the risk of diseases such as cancer and heart disease (8,9). However, other review articles suggest that conventional produce is as nutritious as organic ones (10, 11). The challenge with review articles is that they include studies with many different crops from different years. Nutrient content can vary greatly by weather and variety (7), and, thus, it can be hard to tell how much impact the growing practice (conventional or organic) has on nutrient content when it’s being compared to produce of a different variety or season (7). However, there does seem to be enough information to demonstrate that organic produce provides more nutrients than conventional.


An example of  variety on the farm. These are red, orange, and yellow snack peppers.

In regards to pesticides, there is general agreement that organic produces has less about 30% less pesticides than conventional produce (11,12). However, most conventional produce has pesticides levels below the allowable limits for consumption (12). Yet, the greatest exposure to pesticides is not by eating produce that is sprayed but by being a farm worker on a farm spraying chemicals regularly. Farm workers exposed to pesticides can develop breathing problems, skin rashes, miscarriages, birth defects, depression, and neurological diseases such as Parkinson’s (12). Lastly, pesticide exposure also has environmental impact. Certain insect and bird populations and the balance of predators and prey in the environment, for example. In particular, honeybees’ immune systems are weakened in the presence of pesticides, which make them more vulnerable to their enemies (13).

So which should you choose? It is a challenging question that often comes down to personal choice. This rotation with the St. Joes market has reminded me how close and personal a worker gets with the plants he or she harvests from. This is humbling for me, and reminds me to try purchasing organic as often as I can. Even if it doesn’t affect my health as much, it affects others, whether that’s the farm worker or the honey bee. From a dietitian’s perspective, however, I want to mention that buying any produce, whether organic or conventional, is better for you than choosing to buy none at all. I know I struggle at times to purchase organic over conventional, particularly when the price is higher. However, I often find certain produce, such as organic carrots, to be comparable to their conventional counterpart. These are the small wins I always shoot for, and if I can purchase more, I will definitely try.


  1. US Department of Agriculture. (2015). “Introduction to Organic Practices.” Retrieved from
  2. Environmental Protection Agency. (n.d.) “Compositing Basics.”
  3. Rueb, E. (2017). How New York is turning food waste into compost and gas. New York Times. Retrieved from
  4. Oklahoma State Soil, Water, and Forage Analytical Laboratory. (n.d.). “Benefits of Testing.” Retrieved from
  5. Environmental Protection Agency. (n.d.) “Introduction to Integrated Pest Management.” Retrieved from
  6. Baranski, M. et al. “Higher Antioxidant and Lower Cadmium Concentrations and Lower Incidence of Pesticide Residues in Organically Grown Crops : A Systematic Literature Review and Meta-Analyses British Journal of Nutrition British Journal of Nutrition.” British Journal of Nutrition (2014): 1–18.
  7. Brandt, K et al. “Critical Reviews in Plant Sciences Agroecosystem Management and Nutritional Quality of Plant Foods : The Case of Organic Fruits and Vegetables Agroecosystem Management and Nutritional Quality of Plant Foods : The Case of Organic Fruits and Vegetables.” Critical Reviews in Plant ScienceDecember (2015): n. pag. Web.
  8. Higdon, J. V., Delage, B., Williams, D. E., & Dashwood, R. H. (2007). Cruciferous Vegetables and Human Cancer Risk: Epidemiologic Evidence and Mechanistic Basis. Pharmacological Research : The Official Journal of the Italian Pharmacological Society, 55(3), 224–236.
  9. Cornelis, M. C., El-Sohemy, A., & Campos, H. (2007). GSTT1 genotype modifies the association between cruciferous vegetable intake and the risk of myocardial infarction. The American Journal of Clinical Nutrition, 86, 752-8.
  10. Dangour, Alan D et al. “Nutritional Quality of Organic Foods : A Systematic Review 1 – 4.” The American Journal of Clinical Nutrition 90 (2009): 680–685.
  11. Smith-Spangler, Crystal et al. “Are Organic Foods Safer or Healthier than Conventional Alternatives.” Annals of Internal Medicine 157 (2012): 348–366. Print.
  12. Forman, J., and J. Silverstein. “Organic Foods : Health and Environmental Advantages and Disadvantages Abstract.” Pediatrics 130 (2012): e1406–e1415. Web.
  13. Horrigan, Leo, Robert S Lawrence, and Polly Walker. “Review How Sustainable Agriculture Can Address the Environmental and Human Health Harms of Industrial Agriculture.” Environmental Health Perspectives5 (2002): 445–456. Print.


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