ARTICLE: GMO Sustainability Frontier: Helping Crops Acquire Their Own Nitrogen

The following is an excerpt of an article by David Warmflash at the Genetic Literacy Project on the possibility of using biotechnology to enable food crops to make their own nitrogen.

It comprises 78 percent of our atmosphere, yet it enters and leaves your lungs unchanged. That’s partly because the triple bond holding its two atoms together is really hard to break up, and that’s why most plants don’t do anything with it either.

Molecular nitrogen (N2) has loads of chemical energy packed into that triple bond, and nature has ways to break it up. In a process called nitrogen fixation, energy is consumed to convert atmospheric N2 into compounds like ammonia (NH3), ammonium (NH4+), and nitrate (NO3–), which plants are equipped to utilize in their growth. Physical forces that can do this include volcanism and lightning strike, but certain bacteria and certain archaea also can fix nitrogen using an the enzyme nitrogenase, which breaks up N2 and adds hydrogen, producing ammonia. In another process, called nitrification, soil bacteria can convert ammonia to nitrate, which plants love, though plants also can utilize ammonium, the ionic form of ammonia.

Despite these mechanisms, however, nitrate is not concentrated enough in most soils to produce the kind of agricultural yields needed to support the human population — plus the livestock that many humans prefer as a source of protein. Consequently, farmers must enrich soils with nitrogen fertilizers, which go into the roots of plants where they’re needed, but also end up in places where they’re not wanted. Furthermore, their production is costly and energy consuming.

So this raises a question: Might we instead use our biotechnology to enable food crops to fix their own nitrogen?

The answer is yes; people are working on it with potential benefits not only in terms of cost, but also in terms of environmental stewardship. But, somewhat analogous to new generation nuclear power, advocates of nitrogen fixation biotech are also tasked to win over the public in a political and cultural landscape that has been plagued with an intense distrust of any biotechnology.

Click on the article to read more.