This morning was a seasonal milestone on the farm: our first hard frost. We’ve had pockets of frost a couple of times in recent weeks, but these cold temperatures definitely mark a changing of the seasons, even though we haven’t been harvesting frost-sensitive crops from the fields for some time now. We still have some tomatoes and sweet peppers and our sweet potato crop protected under plastic, but everything else we have growing right now laughs at these slightly-chilly temperatures (it was 26 F last night). If anything, light frosts in October are great because they knock back the aphids a little bit and help harden off everything for colder temperatures to come.
Growing nutritious food. We all know that vegetables are better for our bodies than Cheetos, and it’s also widely recognized that a diet based on whole foods is healthier than a diet comprised primarily of processed foods. For many folks, this is at least one motivating factor for incorporating as many fresh fruits and vegetables and whole grains into one’s diet as possible.
We’ve thought a lot about the nutrient content of the food we grow, both because our fields make up a large proportion of the food we eat as a family, and because there is plenty of evidence that the best way to obtain your vitamins and minerals (not to mention a whole range of plant-based protective substances) is through the diet as opposed to from supplemental pills. As a result, we are motivated to grow produce that is as nutritious as possible. The fact that we have a child on the way motivates us further, as does our own increasing reliance on our own crops in our diet as we are able to grow more of our own staples, such as legumes (dried beans) and grain (dried corn). Of course, we also care a lot about providing nutritious produce to our CSA members, and since all of you eat from the same fields that we do, our attempts to grow more nutritious crops serve a double purpose. So does the farmer have any control over the nutrient quality of his or her crops? Fortunately, we’re not the first people to wonder about this.
In the middle part of the last century, William Albrecht, a professor at the University of Missouri, conducted pioneering research on this very topic. By analyzing the foraging patterns of livestock, as well as investigating the draft records for military service in WWII in an era when most Americans still ate locally, Albrecht came to the conclusion that the soils plants were grown on did in fact play a role in the nutritional quality of those crops and that this crop quality was expressed in the health of the animals or people that consumed these crops. He concluded that soil fertility patterns followed rainfall patterns: the drier mid section of the country (the Great Plains) had balanced soils that produced nutritious forages while the wetter east, with its soils leached out by heavy rainfall were deficient in many plant nutrients and unbalanced for most crops. Since Albrecht’s time, soil scientists and agronomists have further developed guidelines that farmers can use in areas with deficient soils. These guidelines allow farmers to increase the fertility of their soils by bringing the major plant nutrients and micronutrients in balance like they are in the Midwest. This benefits both the crops themselves and the health of the humans or animals that consume them.
This approach to agronomy is not without controversy, however. It turns out that balancing the soils for healthy crops does not necessarily maximize yield. Because farmers are generally paid by quantity and appearance and not for nutritional value the agricultural establishment hasn’t given this topic the attention it deserves in the decades since Albrecht and others developed this idea. As a result, balancing soils for healthy crops has become an alternative method, generally favored by those who lean towards more natural farming methods.
Western Oregon is a great place to grow most vegetables. However, this isn’t because our soils are well endowed, as we initially learned when we got our first soil reports back from our fields over four years ago. As Albrecht would have predicted based on our wet climate, our wet winters leach many important nutrients. We’re quickly learning that to grow healthy crops that produce well and are resistant to many pests, we need to amend our soils at least to some degree. So, since the inception of our farm, we’ve decided to go whole hog and to fully balance our soils according to the guidelines of Albrecht so we can grow the most nutritious food (and the most resilient plants) possible.
There are a couple of drawbacks to this approach. First, amending soils with minerals brought from far away increases the embodied energy in the food we grow. For example, limestone that is the basis of agricultural lime isn’t available in the Willamette Valley, and must come from at least east of the Cascades. Phosphate rock deposits are even rarer, and come from as far away as Montana or even Florida. To boot, some of the companies that mine phosphorous are not the most environmentally sensitive ones out there. This means that our soil balancing program does have an environmental impact. Secondly, achieving balance in our soils through mineral amendments as opposed to simply adding sufficient amounts that conventional agronomy would call for, is more expensive. Because this approach doesn’t necessarily increase yields, we won’t necessarily see a short-term profit from the investments we make in our soils, especially because it will take a number of years to bring the soils on all of our fields up to snuff.
But, because our family’s health and the well-being of our CSA members are our first priorities, we’ll continue to import mineral supplements. We believe the environmental and financial costs of these supplements are at least partially offset by the many benefits nutritious crops provide – not only are they healthier, but they taste better and may be more resistant to some pests. While no food comes without its costs, we believe this system strikes the best balance for everyone involved.
Have a great week and enjoy the taste of your healthy veggies!