There are a wide variety of opinions regarding the contribution that agriculture makes worldwide to climate change.  Environmentalists tend to emphasize the role of farmers and ranchers as CO2 emitters, as if humanity has another way to feed itself other than by growing crops and livestock.  After spending years on the defensive, the agricultural community has finally shifted to a focus on the role that farming plays in offsetting everyone else’s carbon emissions, and potential ways to expand that role.

Farmers have little influence over what people eat.  For the most part, we try to grow the crops that we are able to produce well and sell at a reasonable price so that we can stay in business.  We can try to farm in a way that reduces carbon emissions, but the customers — humans and the food industry — really don’t care.  In fact, humanity as a whole seems to on a trajectory to increase the carbon footprint of food by consuming more meat and increasing food miles by growing crops farther away from where they are eaten.

Still, there are tantalizing opportunities to achieve broad-scale reduction of carbon emissions in agriculture.  One is by using cover crops that pull carbon from the air and lock it up in the soil.  Some cover crops also pull nitrogen from the atmosphere and make it available for cash crops planted afterwards.  Until recently, though, very few resources have been devoted to developing new varieties of cover crops to achieve this goal.  There are many thousands of varieties of cash crops available to farmers, bred for very specific parameters including geography, planting season, size, shape, flavor, etc. But there are only a handful of commercially available varieties of cover crops, and they are decades if not centuries old.

And even within the catalog of existing cover crops, many of them are not always available.  One example is Vetch, a leguminous plant similar to lentils that grows over the cool season here.  There are several varieties of vetch that can be used as a cover crop, but they do not perform equally.  “Common Vetch” produces a fairly small amount of biomass (I.e., carbon) and competes poorly with weeds.  “Purple Vetch” does better.  But far and away the best performing variety is called “Hairy Vetch” or “Lana Vetch”.  It tolerates a wider range of temperatures and precipitation amounts while producing far more biomass and outcompeting weeds.  Yet it is often unavailable  for  purchase because it produces fewer seeds than the “Common”, thus making it unprofitable for the farmers who grow and sell the seeds. Ironically, when Lana Vetch is available, it most often comes from Australia — which makes it more expensive and less carbon-neutral.

The Federal government has only recently begun subsidizing farmers who plant cover crops, finally recognizing the environmental benefit that confers from doing so.  But in order to maximize the potential for carbon sequestration, they also need to finance a breeding program for new cover crop varieties as well as providing financial incentives for farmers to grow the seed.  Over the last thirty years, development of new crop varieties has shifted to the private sector, but they are unlikely to finance research into low-profit cover crop seed.  Using new, modern breeding techniques, land-grant universities could likely develop dozens of new, innovative cover crops that be more useful for farmers as well as better at sequestering carbon.

Another area with huge potential for reducing the carbon footprint of food production is to explore ways to reduce fertilizer usage directly.  Most farmers use nitrogen fertilizers that are produced directly or indirectly from natural gas.  Some cover crops, such as the vetch I mentioned above, reduce the need for fertilizer by “fixing” nitrogen from the atmosphere.  But there is also the potential to use cash crops to do the same.

Here at Terra Firma we recently began using a new microbial product called “Utrisha”.  Sprayed directly onto the crops when they are still small, the microbes form a symbiotic relationship with the plants that allows them to pull nitrogen from the air and make it available to the plant.  It’s not technically a fertilizer, but it has the potential to dramatically reduce the amount of fertilizer the crops would require.  This affordable product is being mass-produced and marketed to farmers who grow thousands of acres of crops.  It, and other similar technologies, have the potential to dramatically reduce the carbon footprint of agriculture through fertilizer reduction — which has other benefits including reducing ground and surface water pollution.

Here again, publicly funded research and plant breeding has a role to play.  Only recently have plant breeders begun to identify the different fertilizer requirements of different crop varieties and promote the ones that need less.  Universities can help expand breeding for so-called “nitrogen scavenging” varieties of both annual and perennial crops, with the goal of completely eliminating the need for fertilizer in agriculture.

The time is long past where assigning blame for carbon pollution  is a useful or productive exercise.  Humans have a collective responsibility for climate change, and we all need to roll up our sleeves and figure out solutions.  Farmers are tasked with growing everyone’s food, and we need help to do it in a way that reduces carbon dioxide pollution.