Unlocking fertilizer-free agriculture through dormant plant traits

Plants made their terrestrial debut approximately 460 million years ago, transitioning from their aquatic origins to brave the barren landscapes. Today, our cultivated crops are grappling with climate extremities, prompting a resurgence in the study of their ancient resilience.

To sustain life, plants necessitate 17 nutrients, with nitrogen, phosphate, and potassium taking precedence. A deficiency in any of these elements hampers plant growth. Over millennia, humankind has strategized agricultural practices to ensure optimal nutrient availability. From the rudimentary spreading of night soil to the global synthetic nitrogen fertilizer trade, human progress has been significantly interlinked with agricultural advancements.

However, common perceptions often reduce plants to mere green vegetables, essential for oxygen but otherwise simplistic. Current research is contesting this perspective, illustrating plants’ intricacies and complexity.

While our practices might have augmented food production, they have inadvertently detached plants from their natural alliances.

The ancient symbiotic tapestry

Historically, plants innovated evolutionary strategies to thrive on land. A vital move was the symbiotic bond with arbuscular mycorrhizal fungi, facilitating nutrient absorption from soil. While plants did evolve their roots around 350 to 400 million years ago, they continued to leverage this fungal affiliation.

Furthermore, roughly 100 million years ago, the legume family cultivated a bond with rhizobia, soil bacteria, enabling nitrogen conversion from the atmosphere to a usable form.

These age-old symbiotic alliances still support wild plants in nutrient acquisition. Unfortunately, such traits are predominantly dormant in our current global food production systems.

Redefining agriculture: the scientific frontier

To cater to an expanding global populace, we need enhanced food production methods. Presently, nearly half of the global population relies heavily on fertilizers, a situation that’s unsustainable. The synthetic nitrogen supply chain was responsible for about 10% of 2018’s agricultural greenhouse gas emissions, making it inaccessible to many small-scale African farmers.

However, advancements in plant genetics have unveiled that our grain crops share a genetic pathway with legumes, enabling interaction with nitrogen-fixing bacteria.

Current research reveals the potential of transferring legumes’ nitrogen-fixing abilities to other crops. Through laboratory conditions simulating fertilized fields, grains can be trained to interact effectively with beneficial fungi and replicate processes evident in legumes.

This knowledge signifies a turning point for developing grains capable of self-reliant nitrogen fixation and nutrient absorption via fungal interactions. Essentially, cereals can be re-engineered to be more self-sufficient, using existing fundamental mechanisms previously exclusive to legumes.

Yet, transitioning to these practices won’t be straightforward. The endeavor demands intricate processes to transpose nitrogen-fixing capabilities to cereals, such as fostering a recognition function for beneficial bacteria.

Looking ahead

The future might see crops cultivated devoid of excessive chemical fertilizers. Such a shift holds the promise of not only elevating the prospects for small-scale farmers without fertilizer access but also curtailing pollution and agricultural greenhouse gas emissions.

Despite the obscured nature of plants’ subterranean symbiotic dynamics with microorganisms, these relationships might be pivotal for the future trajectory of agriculture.