Aluminum

Aluminum is very common in soils around the world, including those common in North Carolina. In fact, the earth's crust is about 7% aluminum, and most soils are over 1% aluminum![36] The aluminum is generally unavailable to plants as long as the soil pH is above about 5.5. In acidic soils many forms of aluminum become more bio-available to plants; this can be toxic to many plant species.[37] This effect is one of the major reason many plants do not tolerate very acidic soils. The use of aluminum building materials releases negligible amounts of aluminum during their useful life because the material is so corrosion resistant.[38] The aluminum frames of PV modules are anodized which adds a very thin hard coating of aluminum oxide to the exterior of the aluminum that greatly improves aluminum's already-high resistance to corrosion. Therefore, any minute amount of aluminum that could be released by corrosion from aluminum construction materials during the life of a solar project will not materially add to the thousands or millions of pounds of aluminum naturally present in the soil of a typical N.C. solar facility. The common practice of liming soils to maintain appropriate soil pH for crop systems alleviates most, if not all, concerns about aluminum impacting crop growth in the future.

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References
  1. ^ NC State Cooperative Extension Service.Extension Gardener Handbook.February 2015. Accessed June 2017.https://content.ces.ncsu.edu/extension-gardener-handbook/1-soils-and-plant-nutrients..
  2. ^ Spectrum Analytics.Soil Aluminum and Soil Test Interpretation.Accessed March 2017. http://www.spectrumanalytic.com/support/library/ff/Soil_Aluminum_and_test_interpretation.htm
  3. ^ Aluminum Design.Aluminum Corrosion Resistance.Accessed March 2017.http://www.aluminiumdesign.net/design-support/aluminium-corrosion-resistance/.Resource explains aluminum's corrosion resistance, including the corrosion resistant benefits of anodized aluminum.
NC State Credit