Tuesday, July 28, 2009

more grain, fewer nutrients

Farmonline | SINCE the Green Revolution of the 1960s, the world has produced a lot more grain—but there may be a lot less in it, a unique experiment in the United Kingdom has revealed.

Recent analysis of 160 years of crop samples from Rothamsted Research Station near London discovered that levels of essential micronutrients remained consistent in wheat grain from 1844 to the late 1960s, but then began a decline that continues to this day.

The nutrient decline began when traditional long-straw wheat varieties where phased out in favour of higher-yielding semi-dwarf varieties.

As wheat plants have grown smaller since the 1960s, grain nutrient density has continued to decrease.

Compared to the old long-straw varieties, Rothamsted’s modern dwarf wheat grain carries on average 20-30 per cent less zinc, iron, copper and magnesium.

For zinc, a critical human nutrient, the decline is even more pronounced if the most recent five years of data are compared, with average nutrient levels in wheat harvested from 1844-1967.