|Larkin, Robert - Bob|
|HONEYCUTT, C - Natural Resources Conservation Service (NRCS, USDA)|
|GRIFFIN, T - Tufts University|
Submitted to: Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/28/2016
Publication Date: 8/11/2016
Citation: Larkin, R.P., Halloran, J.M., Honeycutt, C.W., Griffin, T.S., Olanya, O.M., He, Z. 2016. Cumulative and residual effects of different potato cropping system management strategies on soilborne diseases and soil microbial communities over time. Plant Pathology. 66:437-449. doi: 10.1111/ppa.12584.
Interpretive Summary: Potato production faces numerous constraints to productivity, including high potential for soilborne diseases, high pesticide and fertilizer requirements, soil erosion, degrading soil quality, and variable rainfall during the growing season. Improved cropping systems (CS) can potentially address some of these constraints to enhance crop productivity. In this research, four different potato cropping systems, designed to address specific management goals of soil conservation (SC), soil improvement (SI), disease suppression (DS), and a status quo standard rotation control (SQ), were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics over time. Because the effects of such systems are not fully realized for several years, studies were continued and analyzed over 9 field seasons. Results showed that all rotations reduced disease initially, but only the DS rotation maintained low disease throughout the study. SI and irrigation both resulted in higher yields, but also higher levels of soilborne disease. CS effects tended to increase over time, and were significant even after systems were no longer maintained. Soil microbial community data also showed significant changes associated with CS, and differences among systems increased over time. Overall, improved cropping system approaches had significant and lasting effects on soil microbiology and soilborne diseases, and can be used to effectively enhance potato production. This research is useful for scientists, extension personnel, growers, and consumers, providing information on the development of cropping systems that address the major constraints to potato production.
Technical Abstract: Four different potato cropping systems (CS), designed to address specific management goals of soil conservation (SC), soil improvement (SI), disease suppression (DS), and a status quo standard rotation control (SQ), were evaluated for their effects on soilborne diseases of potato and soil microbial community characteristics over time. SQ system was a standard 2-yr barley-potato rotation. SC system featured an additional year of forage grass and reduced tillage (3-yr, barley/timothy-timothy-potato). SI system added yearly compost amendments to the SC rotation, and DS system featured diverse crops with known disease-suppressive capability (3-yr, mustard /rapeseed-sudangrass/rye-potato). Each system was also compared to a continuous potato control (PP) and evaluated under both irrigated and non-irrigated conditions. Systems were established in 2004 and managed through 2010, with assessments continuing through 2012. All rotations reduced the soilborne diseases black scurf and common scab, and increased yield after one rotation cycle (3 yrs), but diseases increased overall after two rotation cycles. DS maintained lower soilborne disease levels than all other rotations, as well as high yields, throughout the study. CS effects tended to become more pronounced after two rotation cycles (6 yrs). SI and irrigation both resulted in higher yields, but also higher levels of soilborne disease. CS and irrigation effects were significant even after systems were no longer maintained. Soil microbial community data, based on FAME profiles, showed significant changes associated with CS, and these changes among systems increased over time. Overall, cropping system strategy had significant, lasting effects on soil microbiology and soilborne diseases, and can effectively enhance potato production.