Soil microbiome characteristics and soilborne disease development associated with long-term potato cropping system practices

Authors: Larkin, Robert - Bob

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 5/26/2018
Publication Date: 7/22/2018
Citation: Larkin, R.P. 2018. Soil microbiome characteristics and soilborne disease development associated with long-term potato cropping system practices. Abstracts of the 2018 Annual Meeting of the Potato Association of America, Boise ID. 31-32.

Interpretive Summary:

Technical Abstract: Potato cropping system practices substantially affect soil microbial communities and the development of soilborne diseases. Cropping systems incorporating soil health management practices, such as longer rotations, disease-suppressive crops, reduced tillage, and/or organic amendments can potentially alter the soil microbiome, reduce soilborne potato diseases, and increase productivity. In field trials originally established in 2004, different 3-yr potato cropping systems focused on specific management goals of soil conservation (SC), soil improvement (SI), and disease-suppression (DS) were evaluated and compared to a 2-yr standard rotation (SQ) and a non-rotation control (PP) for their effects on soilborne diseases and soil microbial communities over time. After 12-14 years, the SI system, which included regular compost amendments to enhance organic matter content, produced higher potato yield and greater microbial activity than all other systems. DS, which included disease-suppressive Brassica green manures, maintained significantly lower disease (black scurf and common scab) severity than all other systems. Characteristics and composition of the soil microbiome, as determined by fatty acid methyl ester (FAME) profiles and taxon identification from 16S rRNA (bacterial) and ITS2 (fungal) amplicon sequencing, were uniquely different for each cropping system. SI generally resulted in the greatest abundance and diversity of bacterial and fungal taxons among systems, with PP the lowest, and more closely associated with potential plant pathogens. These results indicate that soil health management practices incorporated into potato cropping systems can alter soil microbial communities and sustainably reduce soilborne diseases and enhance productivity.