This post will highlight some of the points I have presented at recent gatherings like the Spokane Farm & Food Expo and the WSU Grain Gathering at The Bread Lab in Mt. Vernon.
This past June my wife, Lois, and I led a tour of the Baltic countries which provided an opportunity to see first-hand American and European farming systems and to meet agronomists from abroad. Of course agriculture in any single nation is an exceedingly diverse enterprise, so meaningful comparisons invariably require considerable explanation and generalization. At the same time, trends in nutrition and crop production are evident in important studies conducted in places like the Swedish University of Agricultural Sciences in Alarp.
Cereal researchers there conducted chemical analysis using plasma spectrometry on several hundred spring and winter wheats. In order to determine nutritional variations among the genotypes, these were divided into groups including primitive “pre-wheats” like emmer, landrace “heritage” grains like we raise at Palouse Colony Farm, old cultivars (1900-1960s releases/hybrids), and new cultivars (varieties released since 1970). The grains were grown at several locations in Sweden and under organic conditions in order to provide comparative results without influence of synthetic soil amendments, herbicides, or other chemical inputs. Results of the study were published in “Mineral Composition of Organically Grown Wheat Genotypes” in the International Journal of Environmental Research and Public Health (September 2010) and indicate substantial variation among the various groups.
Primitive and landrace grains were found to have the highest concentrations of the most minerals with selections highest in manganese, phosphorus, and selenium. Landrace wheats showed the highest concentration of calcium and high levels of boron and iron. Spelts were highest in sulfur and high in copper. The Alnarp researchers suggest that the negative correlation between recent cultivars and mineral density indicated in their study and similar investigations elsewhere is likely due to a dilution effect given the increased yield of most modern varieties. In other words, available minerals are dispersed more widely so require higher amounts of food to receive similar amounts. Another factor may be the deeper root systems of pre-wheats and landrace grains which enable the plant to tap minerals available at greater depth.
These studies indicate that mineral levels in whole grain kernels depend on absorption in the soil by the plant’s roots and subsequent redistribution to the kernels through vegetative tissues that are also influenced by photosynthesis. Higher chlorophyll content, for example, is positively correlated to iron concentration, as is availability of nitrogen which facilitates photosynthesis. The Alnarp study also indicates that grain type is more influential than location for mineral content in primitive grains. Finally, growing environments significantly contribute to variations for others, and high organic matter and increased soil pH also favor mineral concentration.
Research by cereal chemists and soil scientists are contributing to new understandings of the complex biological systems that contribute to healthy crops and people. We at Palouse Heritage look forward to sharing news with you about this vital work and doing our part to promote health, heritage, and rural renewal.