A number of our articles this year discussed using biochar in agriculture and in forestry. These earlier articles did not delve into the methods to apply biochar on large tracts of forests. You’d expect this to be a much more challenging task than spreading biochar on croplands. Researchers and technology developers are tackling this particular issue, developing a specialized forest biochar spreader. Take a few minutes to check out their Science Spotlights article and their video. Among the details they discuss in the video is a point Chris Schnepf and Darren McAvoy made in their AgClimate article: biochar can use—and store the carbon that is in—those “leftovers” that otherwise get burned, releasing that carbon into the atmosphere.
Topsoil has often been referred to as the “thin skin” of our planet, essential for producing the food that feeds us. Because it’s not easy to create new topsoil, conserving the soil that we have is essential for maintaining our region’s agricultural productivity. Reducing tillage, and leaving residue on the soil surface, is a proven way to reduce erosion. As residues break down, they increase the concentration of soil organic matter at the surface of the soil and help to form soil aggregates—a composite of soil particles that clump or bind together, giving soil its structure. Soil that is aggregated in larger particles is less prone to being eroded by the wind. And soils with more organic matter also benefit the climate, by storing more carbon.
Planting the wheat cover crop in strips makes planting corn easier, as the planter does not encounter roots and leaves in the planting strip. Photo: Darrell Kilgore
In non-irrigated areas that are too dry to support annual cropping, fallow (the practice of leaving land unplanted) preserves soil moisture for future crops. However, annual fallow combined with conventional tillage has resulted in a net decrease in soil carbon over time in our region, with negative impacts to soil health across large areas. And even when tillage is eliminated, it is very difficult to maintain soil carbon over time in a wheat-fallow system. For this reason, the impact of climate change on the frequency of fallow in crop rotations has important future implications both for soil health and for opportunities for carbon sequestration.
Two papers published last year by Kaur et al. and Karimi et al. use modeling to project the impacts of climate change on dryland cropping systems. Continue reading →
What are the climate impacts of a given farm practice? While we know lots of strategies for reducing greenhouse gas emissions on farms, quantifying that impact can be difficult. However, there is at least one farm in our region – one that uses some pretty neat practices – for which scientists have attempted to answer that question. And the farmer just happens to be a long-time member of the Center for Sustaining Agriculture and Natural Resources’ advisory committee, Dale Gies. Continue reading →
Biochar as a soil amendment has been the subject of much attention in recent years because of its ability to sequester carbon and to improve aggregation, water holding capacity, and organic matter content of soil amended with it (Lehmann, 2007; Marris, 2006). A recent post discussed what’s needed to economically produce forest to farm biochar. In contrast, researchers at Washington State University are investigating what we could call waste to farm biochar. Waste to farm biochar, if deployed on a larger scale, could offer a two-part benefit – removal of wood from the municipal solid waste stream and creation of a valuable product from this wood. In recent work, researchers are looking at two possible wastes that could be made into biochar: wood-based fractions of municipal solid waste and the large woody material remaining after compost production—referred to as “compost overs.”
Figure 1: Images of the woody biomass sources used to create biochar for this project, including compost overs and wood-based products from municipal solid waste. (source: WTFT 2015-2017 report; photo credit: M. Ayiania)
Beginning Thursday, July 12 at 9:00 am Pacific Standard Time – and occurring weekly at that time through Tuesday, August 28 – the OneNOAA seminar series will be hosting an 8-part suite of talks on different aspects of the National Climate Assessment 4 Volume I – the Climate Science Special Report. This is a fantastic opportunity to learn about the latest climate science from some of the nation’s most eminent scientists!
Biochar is being used in a variety of agricultural and home and garden applications. Photo: C. Schnepf.
Biochar has many possible agricultural benefits. Given the large role that fire plays in western forests, biochar has likely also already played a significant role in Northwest forests, as evidenced by the charcoal commonly found on top of or buried in our forest soils. Biochar shows promise in providing additional benefits in restoring heavily disturbed forest sites, such as forest roads, skid trails, and landings. For more information, see a chapter in a recent biochar book detailing the current state of North American forest biochar research.
Most of the enthusiasm around biochar in the forestry community, however, is related to using forest management residues to create biochar and useable fuels, such as bio-oil and syngas. Continue reading →
By Kristin Trippe, USDA Agricultural Research Service, Forage Seed and Cereal Research Unit
Farmers across the globe are grappling with the challenges of a changing climate. In the Pacific Northwest, loss of snow pack has diminished the availability of water resources, causing increased drought stress (see this article, for example). Our program is focused on biochar, a rather non-descript product that can help farmers both sequester carbon and prolong the availability of soil moisture in their agricultural soils to address drought stress.
Biological Science Technicians Sarah Light (left) and Stephanie Chiu (right) collect soil cores from soil amended with biochar to determine if biochar can help prevent drought. Photo: Claire Phillips, USDA ARS FSCRU.
Swathed cover crop that will be fed to cattle in the field, Nez Perce, ID. By Darrell Kilgore
Across the dryland areas of the inland Pacific Northwest, soil erosion and the use of near monocultures of wheat have long been serious sustainability challenges, ones that we have been working on for decades, including over the last seven years through regional collaborations. Reducing or eliminating tillage has been one important strategy for reducing erosion across the region in recent decades. Improving diversity by including crops such as canola, peas, chickpea and quinoa in rotations is another approach, but across the inland Pacific Northwest from 2007-2014, 53% of dryland crop acreage was used for winter or spring wheat, while an additional 31% was fallow (meaning that to preserve moisture for the following crop, no crop was grown) (Kirby, E. et al., 2017). Continue reading →