Location: Soil, Plant and Nutrient ResearchTitle: Cover crops can improve potato tuber yield and quality) Author
Submitted to: HortTechnology
Publication Type: Peer reviewed journal
Publication Acceptance Date: 1/4/2012
Publication Date: 4/10/2012
Citation: Essah, S., Delgado, J.A., Dillon, M., Sparks, R. 2012. Cover crops can improve potato tuber yield and quality. HortTechnology. 22:185-190. Interpretive Summary: The purpose of the 2005-2008 studies was to evaluate the effects of certain types of cover crops on tuber yield, as well as to obtain new, additional information on the effects of cover crops on tuber size distribution and/or external defects. This unique set of studies has enormous implications for sustainability. The results suggest that although there is not yet a clear understanding of the mechanism (e.g., possible mechanisms such as soil biology impacts, suppression of diseases, biogeochemistry pathways and/or availability of macro and micro nutrients, and the physiological responses by the potato at the root, aboveground and/or tuber development stages that can even influence the external appearance of a tuber), cover crops can potentially contribute to a sustainable system that can improve potato tuber yields and quality and minimize external tuber defects. Additionally, positive results from the sorghum sudan crop suggest that there is even potential to use cover crops for hay production while still keeping the sustainability and tuber quality benefits of these crops. Due to the interrelated factors of limited soil and water resources, continuing population growth, and global climate change, there is a need to apply conservation practices that will contribute to sustainable systems and help conserve soil and water quality, as reported by Delgado et al. (2011). We suggest that the use of the summer cover crops–potato systems with limited irrigation (< 200 mm) discussed in this paper, which were found to contribute to higher yields and tuber quality while conserving water resources, is among the potential practices that can used to mitigate climate change and adapt to it effects. Additional studies will be needed to understand the mechanism causing these potato systems to respond positively to these cover crops.
Technical Abstract: There is the need to develop sustainable systems with higher yields and crop quality. We conducted studies with cover crops grown under limited irrigation (< 200 mm) to assess the effects of certain types of cover crops on tuber yield and quality. On a commercial farm operation prior to the 2006 and 2007 potato season, we planted mustard (Brassica spp.), canola (Brassica napus), and two varieties of sorghum-sudan (Sorghum sudanensis). A wet fallow ground treatment where no cover crop was planted, was used as a control. Prior to the 2007 season, barley (Hordeum vulgare L), barley plus applied compost, sunflower (Helianthus annus), peas (Pisum sativum), and annual rye grass (Lolium spp.) cover crops were added. The results of these 2005-2008 studies show that cover crops have potential to contribute to sustainable food production while increasing potato tuber yields and quality, as measured by tuber size (larger tubers) and appearance (e.g., tubers with reduced defects such as cracks, knobs, and misshapes). In two of the three years, most of the cover crops, especially sorghum sudan, increased yields and/or tuber quality. Positive results from sorghum sudan suggest there is potential to harvest hay from cover crops and still obtain tuber benefits.