The Importance of Climate Friendly Soil

Posted on Thursday, 23 July 2020 under Farmer Story Series

The key to climate-friendly soil is healthy soil. Soil health is a top priority for farmers who rely on good soil for nutrient-rich foods, it also has the capacity to act as a carbon sink, making it an important climate initiative. Trials in Europe have demonstrated that “soil carbon sequestration is regarded as one of only a few strategies that could be applied at large scales and at a relatively low cost” (Paustian et al., 2016). Sequestering carbon refers to removing carbon from the atmosphere and storing it in a stable way that won’t be easily released back into the atmosphere. Carbon dioxide and nitrous oxide are two out of three main greenhouse gases that threaten our climate. Through the management of agricultural soils, there is great potential to capture carbon in the ground as well as reduce or eliminate nitrogen fertilizer inputs.

Having a greater presence of soil organic matter benefits the environment and farmers. #FFCFClimateAction Share on X

When soil is in a healthy state, there is a heavy presence of soil organic matter (carbon) which includes living organisms, decomposing material, and fresh reside. Jo Tobias is the creator of RootShoot Soils, an agriculture consulting agency and extension service based in Vancouver, BC. Tobias is a regenerative soils consultant and provided an in-depth description of what ‘living soils’ means. When she studies soil samples for clients to determine its health she said, “I look at bacteria, the fungi, protozoa, nematodes, microarthropods, things like that.” Tobias uses this criteria, quantifying these organisms based on what crops farmers are growing. She checks if the soil hosts these microbes and microorganisms and how diverse they are within the soil system. She adds, “The main idea is understanding biological diversity because there is a relationship that happens between plants and soil organisms and the services that soil organisms provide the plants and vice versa. Plants exude carbon compounds, so they release these carbon compounds as part of the photosynthetic process, from there they feed microorganisms in the soil and the microorganisms will then provide them nutrients in return.” Good quality compost is one of the best ways to create life in the soil, Tobias states, “A lot of these living organisms can be found in our compost pile, but we have to make and manage these compost piles properly. At the end of the day, when we want to put compost back into the soil it’s not just about the organic matter that is in the compost. What we also want to bring back are the microbes that are in that organic matter”. She continues, “Maximizing the use of the compost pile produced on the farm and understanding how we go about inoculating soil with the microbes from your compost is important for farmers.”

Having a greater presence of soil organic matter benefits the environment and farmers. Healthier soil increases the ability of the land to retain water and nutrients, resulting in greater resilience to climate shocks. Higher levels of soil organic matter improve soil structure and reduce the chances of erosion. Healthier soils improve the quality of surrounding ecosystems and the plants that feed off that soil. Lastly, capturing carbon in soil by building up soil organic matter can help reduce agriculture-related emissions. While Tobias admits that she’s not sure if the scientific community has agreed on measuring how much carbon can be sequestered in soils, she sees the potential for it. “With carbon sequestration, one of the discussions that the scientific community tends to talk about is increasing organic matter. That is one of the ways to help sequester carbon, is increase organic matter, reduce tillage, or reduce disturbance in soil,” she says. Tobias adds it’s important to, “Incorporate these practices in order to have those checks and balances when you’re removing nutrients from the soil on your farm. You have to be able to bring those nutrients back and consider in what form you are bringing those nutrients back. Is it through cover cropping, through integrated livestock management, through composting and inoculating your soil with biology?”

One of the biggest benefits of having a diverse microbial community in the soil is that it reduces fertilizer inputs and reduces chemical inputs because those services are already being established from that connection.

A few practices that increase carbon sequestration and create healthier soil include, but are not limited to, cover cropping, no or reduced tillage, compost application, no synthetic pesticides, long term field cropping, diversified crop rotation, maintaining soil cover, and agroforestry. Ensuring agricultural soils are healthy reduces the amount of fertilizer inputs necessary for growing food. Tobias stresses, “one of the biggest benefits of having a diverse microbial community in the soil is that it reduces fertilizer inputs and reduces chemical inputs because those services are already being established from that connection.” She clarifies services to mean “providing the plants with the nutrients that they need at the time that they need them. We can then start to step back and reduce the amount of inputs that we have to put into the ground. Those microbes retain the nutrients that are in the soil, keeping them for themselves to multiply and reproduce or, exchange it with another plant or organism.”

Increasing organic matter in soil provides resiliency to unpredictable changes in climate. These climate strategies can be implemented on animal farms, crop farms, and mixed farming systems. Arzeena Hamir, co-owner of Amara Farm, a fruit and vegetable farm in the Comox Valley, has noticed her farms’ capacity for dealing with climate shocks. Arzeena explains, “As we’ve been noticing the organic matter in the soil increase and increase every year, we’re noticing we have to water less. We know that we don’t have to water as often because the soil is holding onto water so much better because that’s what the organic matter does, it acts as a sponge.” As changes in climate continue and impact farming more and more, there is potential for adaptation and mitigation, especially through building healthy soil. At Amara Farm, they are adding trees and woody perennials into their crop plan as a way to capture more carbon in a permanent way. Read the full farmer profile here.

Another beneficial way of creating healthy, regenerative soil is through animal grazing. Animals are a natural part of the earth’s healthy ecosystems, introducing them onto a farm can help create balance and nutrient-rich soils. With proper management practices, poultry has the potential to have immense benefits on the land. Andrea Gunner, owner and operator of Rosebank Farms, works on 9 acres, with her turkeys and chickens regenerating the land. When they first bought the property, it was all glacial till and had just been clearcut, leaving the land severely lacking nutrients and structure. Through years of farming the land with animals, they have managed to build incredible amounts of topsoil and transform parts of their land into nutrient-dense soil that continues to capture carbon as they rotate their animals. Pasture-raised animals benefit the climate by reducing the amount of feed needed for them and, by spreading their own manure, fertilizing the land, and eliminating the need for other fertilizers to be brought in. Read the full farmer profile here.

References:

Paustian, K., J. Lehmann, S. Ogle, D. Reay, G. P. Robertson, and P. Smith (2016) Climate-smart soils. Nature 532.

RootShoot Soils mandate is about, “how can we improve the health of our soils, and one of the best ways to do that is to improve biological diversity. Soil biology. Because they have this immense set of services that people are not capable of providing to our plants. Everything is covered in microbes. We need to bring those microbes back to the soil and re-establish that connection”. Follow RootShoot Soils on Instagram @rootshoot_soils and visit their website, www.rootshootsoils.com to learn more about Jo’s work.