Crops Features Insights

Subterranean secrets are key to unlocking crop potential

Published:

With just a few exceptions, plants are the energetic envy of the world. No “higher” organisms are graced with the gift of photosynthesis — seemingly making sugars from scratch.

But all these textbook praises about self-sufficiency are being charitable. While plants may be the consummate carb loaders, they’re also freeloaders. They can’t conjure up everything from thin air. Biological alchemy has its limits.

Plant building takes a tremendous amount of raw materials. Problem is, there’s rarely enough to satisfy the appetite of the green monsters. We can amend the soil with fertilizers and manures, but plant roots can only intercept so much as nutrients get kicked around on the way down.

The final destination of those nutrients is the concern. Whether they leach into groundwater or runoff into surface water, we frequently see headlines about syrupy algal blooms and “dead zones” fueled by a relentless stream of fertilizer. While this is prone to gross exaggeration — farmers aren’t the only contributing party by a longshot — we do need to reflect downstream, literally and figuratively.

Agriculture’s calling card is to do more (production) with less (land). Thanks to high-yield ag, countless acres have been spared the plow. But we can always do better. Any earnest attempt to do so needs to think outside the box. Or more appropriately, below it.

Roots are a critical vulnerability that desperately need a fix. For decades, we’ve snubbed the behind the scenes heroism of roots in favor of above-ground gains. It’s time to rewrite the narrative of the “supercrop.” From wishlist to in-progress, here are some options.

You’ve probably heard of annuals and perennials in a landscape setting. Annuals are kind of a pain — plant once, ooh and aah, and watch them die. Rinse and repeat. Perennials seemingly die over the winter, only to regenerate every season. What if we could use this strategy for crops? Sort of like creating a long-term orchard, grove, or vineyard, only in a field setting. There is considerable interest to “perennialize” cereal grains like corn. These wouldn’t last quite as long (maybe several years before having to replant), but consider all of the potential time and resources saved. The major hitch is that they don’t yet yield as well as annuals.

Breeding for — or swapping in — perennial crops would go a long way toward our march to environmental quality. How? For one, more efficient “harvest” of nutrients from the soil. The roots take up so much volume that nutrients are almost guaranteed to get ensnared by their generous netting. The deep roots also protect against erosion and surface runoff.

For decades, we’ve snubbed the behind the scenes heroism of roots in favor of above-ground gains. It’s time to rewrite the narrative of the “supercrop.”

We hear a lot about resiliency in the face of climate change — stressors like drought. No problem. Water in the deepest recesses can be tapped. All the while, nutrients entombed in those catacombs are pumped to the surface to replace (at least in part) what’s been lost.

Speaking of roots, some plants will often tag team with bacteria or fungi in the soil to form a superteam of dynastic proportions. Rather than a seedy soil underworld, it’s a sultry one [cue Kenny G soprano sax]. A seductive come-hither between the microbe and the plant suitor.

Through a series of affirmative “nods,” a bacterium called Rhizobium (among others) signals its intent to embed itself in the plant roots and set up a nitrogen-making factory. Portions of the roots swell, forming factories called nodules. The bacterium pull nitrogen gas from pockets of soil air and create fertilizer, shipping most of it off to the plant. A textbook case of self-help called fixation. The plant gives up some sugar from photosynthesis in the process. In a nutshell, this means the less fertilizer humans need to make industrially using fossil fuels!

One problem: Only legumes (anything in the bean family) can form the partnership. But what if we expanded the slate of potential suitors? Turns out, many plant families used to be able to partner. It was lost over time, possibly because the carb fee was “too expensive” to the plant in the wild. But what about in a more controlled setting? Re-engineering this ability back to lovelorn species would go a long way to shore up food security, especially in the developing world, where fertilizer is a luxury.

A similar effort could take place with certain fungi called mycorrhizae. In this case, they act as root extenders, allowing the roots to better harvest nutrients like phosphorous. Unfortunately, some major plants families are biologically blind to their advancements — or is it the other way around?

So in the quest to build the perfect plant, we have a number of options: from perennial crops to biological mashups and inter-species pillow talk. Or perhaps all of the above. Activist-dreaded genetic modification seems to be the most promising option for at least some of these goals. In fact, the Bill and Melinda Gates Foundation is onboard for GMO nitrogen fixing cereals.

“…we can rebuild [it]. We have the technology.”

But will it be unfairly demonized? The tired protestation for the sake of protestation approach continually used by well-fed activists? In my view, how we decide to proceed isn’t as important as why. The environmental benefits and alleviation of suffering entreats us to move forward.

 

Tim Durham’s family operates Deer Run Farm — a truck (vegetable) farm on Long Island, New York. As an agvocate, he counters heated rhetoric with sensible facts. Tim has a degree in plant medicine and is an Assistant Professor at Ferrum College in Virginia.

Any views or opinions expressed in this article are those of the author and do not reflect those of AGDAILY. Comments on this article reflect the sole opinions of their writers.
Previous Article Next Page