A Pretty Penny: Pennycress Cover Crop Could Play a Part in Helping Solve the Climate Puzzle

Crop Puzzle GraphicIn solving a puzzle, sometimes it’s the smallest pieces that can help complete the big picture. In the climate change puzzle, a once-underappreciated plant called pennycress just may prove itself a beneficial piece.

As a plant that has spent most of its evolutionary history as a weed, pennycress is gaining new interest as an oilseed crop that can help us piece together solutions to many environmental challenges.

This oilseed plant, with pods shaped like a penny, captured my interest as a scientist once I began to understand both its novelty and potential. Pennycress has the potential to provide financial, environmental and industrial advantages for decades to come. If farmers one day choose to adopt it on a widescale as a cover crop and feedstock source for biodiesel, it could make contributions towards the improvement of our environment while providing extra income to farmers.

In 2015, the United Nations put forth 17 Sustainable Development Goals (SDGs). These goals serve as a global call to action to recognize that ending poverty must go together with strategies that improve health and education, reduce inequality, and spur economic growth — all while confronting climate change and working to preserve our oceans and forests.

Agriculture is sure to play a major role in achieving these goals.

In fact, at his confirmation hearing in February, U.S. Secretary of Agriculture Tom Vilsack not only pledged to focus on climate change but stressed the role of the U.S. Department of Agriculture and American farmers in leading efforts to mitigate the effects of climate change.

It all starts with the soil — a fact noted by a new study by the UN’s Food and Agriculture Organization, which found that soil biodiversity is at the heart of achieving those SDGs.

As a cover crop, pennycress can play a role in restoring soil biodiversity on the farm. Growing cover crops is one of the farming practices that helps remove carbon dioxide from the atmosphere and convert it to soil organic matter. Pennycress is well-positioned to become an enticing option, with many benefits to soybean farmers and others.

Cover crops and soil have a symbiotic relationship of sorts.

Grown during the off-season to fill the fallow period between major summer annuals like soybeans and corn, cover crops hold valuable organic matter in the soil during a particularly vulnerable period. The benefits include the following:

  • Holding the topsoil in place, preventing unwanted nutrient loss and protecting water quality
  • Suppressing weeds (leading to reduced chemical spraying)
  • Taking carbon dioxide out of the air and returning it to the soil
  • Providing support for pollinators in early spring, when their food source is most limited

In turn, organic matter makes the soil healthier, helping it to retain moisture more efficiently while preventing unwanted losses of precious topsoil and nutrients.

Unlike most other cover crops, there’s more to the pennycress story. In the 1940s, scientists discovered its potential as an oilseed. But nothing really came of it until biodiesel, an advanced biofuel with lower carbon intensity for diesel engines, emerged on the scene and began to rise in popularity. Since biodiesel, and more recently renewable diesel, can be made from any fat or vegetable oil, the industries pursue a diverse array of feedstocks. In addition to soybean oil, which is anticipated to continue to fill the majority of U.S. biodiesel demand, biodiesel producers will likely need more oilseed options to achieve the ambitious goal of 6 billion gallons in the U.S. by 2030 — more than double today’s production.

My Ph.D. research at the University of Minnesota aims to understand how we can achieve high-yielding and high-oil pennycress that complements the soybean cropping system. I hope my research will play a role in this potential transformation. Since pennycress was long deemed a common weed, it has not had the history of human selection and improvement as have other crops like soybeans, corn, and wheat. The domestication and breeding efforts are merely a decade old, and two big consequences of the lack of human improvement for an oilseed crop are the small seed size and lower than achievable oil content. My research aims to change that.

At least one startup company, CoverCress Inc., has plans to commercialize pennycress — calling it the “cash cover crop,” producing new farm income and low carbon intensity feedstocks while delivering cover crop benefits. This is exciting and groundbreaking.

Let’s go back to the farm. In the land of cover crop options, the potential of pennycress as a cash crop is a game changer. If farmers can capture value from the cover crop, they reap not only the sustainability benefits, but also more profit. In the U.S., cropland shrinks every year. Farmers grow more with less, largely thanks to technology. The idea of sustainable agriculture intensification is that farmers use the same amount of land for more output — and pennycress can help achieve just that.

There’s another opportunity for pennycress to help farmers become more profitable. Emerging carbon markets aim to reduce greenhouse gas emissions by enabling the trading of emission units. Climate gains through financial incentives empower farmers and rural America to join this effort. Major agribusinesses such as Bayer, Nutrien, and Cargill have launched startups to encourage farmers to adopt climate-friendly practices in this system and reward them for it.

I can’t think of a more fitting culmination to a pennycress crop’s lifecycle than to be transformed into cleaner burning, renewable biofuel. Through biodiesel and renewable diesel, this plant’s benefits will live on, providing lifecycle greenhouse gas emissions reductions and another tool in the battle to combat climate change.

Pennycress shows us that if we see all the pieces, even the hardest puzzles have a solution.

The National Biodiesel Board is funded in part by the United Soybean Board and state soybean board checkoff programs.

Zenith Tandukar Headshot
Zenith Tandukar
Zenith Tandukar is a Ph.D. candidate in the department of Agronomy and Plant Genetics at the University of Minnesota. He serves as a co-chair of the Next Generation Scientists for Biodiesel.
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