How Iron Levels in Maize Have Changed Over 2000 Years

According to a study by Ale Vidal Elgueta et al, researchers from Chile and France, the intensification of agricultural production over the past two millennia has led to a reduction in the level of iron in maize.

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There is no consensus among nutritional and chemical scientists on the changes in levels of micronutrients such as iron, zinc, copper and manganese in grain crops. The unequal conditions of the experiments, difficult comparisons, discrepancies in statistical methods, and the lack of historical data cause these contradictory positions.

The controversy deepens when it comes to the accumulation of iron in maize, as the element is quite variable in modern cultivars. Moreover, despite the nutritional importance of maize, with annual global production standing at more than a billion tons in 2021/22, there are limited studies on the physiological changes associated with the absence or presence of micronutrients during the history of the maize production.

MODIFYING MAIZE IN THE ATACAMA DESERT

Intensive agriculture for thousands of years among prehispanic agricultural communities in Tarapacá in the Atacama Desert led to changes in maize morphology.

Thus, our previous studies indicated that Tarapacá’s prehispanic farmers phenotypically modified their ancient maize.

These modifications included the significant augmentation of the sizes of cobs and kernels, from a mean length of 5cm to more than 15cm for cobs, and from 5mm to over 10mm for kernels.