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🌳 "Soil Carbon & Cover Crops"

Carbon Removal Newsroom

Photo by Red Zeppelin | Unsplash

Host: Radhika Moolgavkar
Guests: Dr. Holly Jean Buck | Assistant Professor in Environment & Sustainability | University at Buffalo &
Dr. Jane Zelikova | Executive Director | Soil Carbon Solutions Center
Category: 🌳 Carbon Capture

Podcast’s Essential Bites:

[3:55] JZ: “The majority of global agriculture is in these rain fed, non-irrigated systems. And so these systems are potentially more vulnerable to the impacts of drought and other kinds of extreme weather events like extreme heat. We know climate change is affecting and increasing incidence of both. And so it's really important to kind of assess the relationship between soil organic matter, which is something we're trying to manage for agricultural lands. […] Increasing or bolstering soil organic matter helps mitigate and provide some resilience to climate change.

[4:47] JZ: “Soil organic matter is just dead and decomposing stuff, plant material, animal matter, that is decomposing on and in soils. […] It's sort of like the next stage of decomposition where you can't really see and physically distinguish the specific things that are decomposing anymore. They’ve broken down enough to where they don't have a specific shape, you can easily recall. And about half of soil organic matter is or consists of carbon.

[10:23] JZ: “The main […] result that I took away from this specific paper is that the response to drought conditions, especially as drought severity increases, is modulated by soil organic matter. So the more soil organic matter rich soils and systems and agricultural operations have experienced less loss of […] crop yields under more severe drought conditions. […] What it says is in these […] sort of natural rain fed systems, soil organic matter buffers against future drought conditions, […] with clear implications […] for programs like crop insurance.”

[20:30] HB: “Cover cropping [is about] plant[ing] a crop in between the crops that you're going to harvest, whether that's corn or soy, or whatever. There's a variety of crops that can be planted. It's becoming more and more popular. There's one statistic that the US acreage increased 43% between 2017 and 2021. There are a number of reasons for why it's become more popular. Companies that have these carbon farming programs, have some incentive payments […]. There are also federal conservation programs that for many years have been paying farmers to set aside land and some incentives federally for cover cropping as well.”

[21:34] JZ: “In this study, the […] biggest impact [on carbon] had to do with the growing window. So how long the cover crops were being grown and at what period of time. […] The continuous cover cropping had the biggest […] positive effect on carbon, and then growing cover crops in the fall and over winter had […] the second biggest effect on carbon. […] While the incorporation of cover crops is increasing at a pretty high level in the US, it's still pretty low in most of the US. It’s somewhere in the 1 to 5% of acres are under cover crops. […] It's often […] state or even more local programs that are the incentives that drive adoption. I feel like the carbon markets payment side hasn't kind of had enough time yet to be implemented. And few farmers that implement cover crops have actually seen any payments to date.”

[25:06] HB: “My understanding is that cover crops that are harvested, typically you can't insure them. And if you harvest it, it creates insurance issues down the line. Plus, if a crop is harvested, it's not considered a cover crop under USDA rules. So they can't get these incentive payments. So from the farmers point of view, they're planting seed, and […] they can't harvest it and get a profit from it. […] It could be a mental roadblock.”

Rating: ⚡⚡⚡

🎙️ Full Episode: Apple | Spotify
🕰️ 36 min | 🗓️ 01/07/2022
✅ Time saved: 34 min

Additional Links:
Paper: “Soil organic matter protects US maize yields and lowers crop insurance payouts under drought” (Daniel A Kane et al. 2021, Environmental Research Letters, March 2021)
Paper: “Management of cover crops in temperate climates influences soil organic carbon stocks: a meta-analysis” (McClelland et al. 2020, Ecological Applications, December 2020)