By Karen Hills

A frequently used—at least, by soil scientists—definition for soil health is “the continued capacity of soil to function as a vital living system […] to sustain biological productivity, maintain the quality of air and water environments, and promote plant, animal, and human health” (Doran et al. 1996). Many different indicators—chemical, physical, and biological—are used to assess soil health.

Figure 1. Potatoes are economically important crops in many irrigated areas of the Pacific Northwest. Here, potatoes are harvested near Pasco, Washington. Photo: Athena Loos.

Growing potatoes is notoriously hard on the physical and biological health of soil (Figure 1). Potato production in many areas of the Pacific Northwest involves seven or more soil disturbance operations, leaves little residue on the field, and often involves the use of fumigants to control soilborne diseases. The economics of potato production often drive growers to utilize short rotations. But a suite of strategies are possible to improve soil health in potato production, including cover crops, rotating with perennial crops and crops that contribute high levels of residues, and incorporation of organic amendments. While growing green manure crops for biofumigation has probably achieved the most success and adoption in the region (see producer Dale Gies as an example), in this article I focus on a more challenging strategy that has received limited attention, but may have more direct climate change implications: tillage reduction. Continue reading →

by Georgine Yorgey

Managing crop residue is essential to reduced and no-till farming systems. These farming systems store more carbon than conventional farming systems, thereby mitigating climate change, enhancing soil health, and reducing soil erosion. In work described in a recent project report, Arron Carter and colleagues have been working to make it easier for growers with diverse needs across the Pacific Northwest to manage wheat residues. While the work is still in progress, it is an illustration of the kind of creative, applied work that is needed to make reduced-tillage systems easier to manage, and more widely adopted across the region.

Wheat residue in a field in early July near Bickleton, WA. This area is part of the drier winter wheat-fallow area, where slower decomposing residues are preferred. Photo: Hilary Davis.

Growers in different parts of the dryland Pacific Northwest are seeking different residue characteristics. Continue reading →