In the heart of the Great Plains, a revolution is brewing, and it’s not about oil or wind turbines. It’s about a grain that could change the way we think about soil health, carbon sequestration, and sustainable agriculture. Meet Kernza, the first commercially available perennial grain in the United States, and the subject of a groundbreaking study led by Laura K. van der Pol at Colorado State University’s Natural Resource Ecology Laboratory.
Kernza, a domesticated form of intermediate wheatgrass (Thinopyrum intermedium), is not your average grain. With its deep, robust root system, it’s a champion of soil organic matter (SOM) formation, a critical component in the fight against climate change and for sustainable food production. But how exactly does Kernza work its magic? That’s what van der Pol and her team set out to discover.
The researchers quantified the formation of SOM over two years, using continuously 13C- and 15N-labeled plant material from Kernza grown alone and in an alfalfa (Medicago sativa) intercrop. They compared SOM formation under three different agronomic environments: unfertilized Kernza monoculture, unfertilized Kernza intercropped with nitrogen-fixing alfalfa, and fertilized Kernza monoculture.
The results were striking. Kernza promoted new SOM formation with 14% of roots and 8% of shoot-derived carbon recovered in bulk soil after 27 months. This is compared to just 5% for alfalfa roots and shoots. “Kernza’s deep root system allows it to access nutrients and water that annual crops can’t, and this seems to translate into a significant advantage in terms of soil organic matter formation,” van der Pol explained.
But the story doesn’t end with Kernza’s impressive soil-building capabilities. The study also found that legume intercrops, like alfalfa, can support Kernza cropping systems with minimal synthetic inputs. This is a game-changer for the energy sector, which is increasingly looking to invest in sustainable, low-carbon agriculture.
“The energy sector is always looking for ways to reduce its carbon footprint,” said a spokesperson for a major energy company, who wished to remain anonymous. “If we can support crops like Kernza that sequester carbon and build soil health, it’s a win-win.”
The study, published in the journal ‘Frontiers in Soil Science’ (translated from the original German title ‘Frontiers in Bodenkunde’), also found that root tissues contributed to SOM formation primarily as occluded particulate organic matter (oPOM). This means that a significant portion of root tissue carbon inputs may be stabilized in the soil, further enhancing Kernza’s soil-building capabilities.
So, what does this all mean for the future of agriculture and the energy sector? It’s clear that Kernza has the potential to revolutionize the way we think about soil health and carbon sequestration. As van der Pol puts it, “Kernza is more than just a grain. It’s a tool for building resilient, sustainable agricultural systems.”
As the energy sector continues to look for ways to reduce its carbon footprint, crops like Kernza could play a significant role. By sequestering carbon and building soil health, Kernza offers a unique opportunity for the energy sector to invest in sustainable, low-carbon agriculture. And with the backing of cutting-edge research, the future looks bright for this remarkable grain.