Profiling Microbial Communities in Soils from Organic, Sustainable, and Conventional Cropping Systems

Profiling Microbial Communities in Soils from Organic, Sustainable, and Conventional Cropping Systems

Summary

This project investigates the effect of cover crops and fertilizers on soil bacterial community structure and function in organically managed soils. Field plots were established at three collaborating farms in southern Minnesota and the Southwest Research and Outreach Station in Lamberton. The experiment has eight treatments: four cover crops (rye, hairy vetch, buckwheat, and tillage radish), three fertilizers (uncomposted dairy manure, composted poultry manure, and Sustane), and a no-amendment control. Extraction and sequencing of 16S rDNA from soil samples will be used to generate a census of bacterial taxa present in the samples. Several soil functions of interest to growers, including decomposition and nutrient cycling, will be measured by laboratory assays of sampled soil.

Objectives/Performance Targets

This project has two objectives: 1) to investigate the effects of cover crop and fertilizer amendments on soil bacterial community structure, and 2) to determine whether bacterial community structure is correlated with assayed values of soil function.

Accomplishments/Milestones

Cover crops were established in August 2012 and fertilizer treatments were applied in October 2012. Because the price of sequencing has dropped during the time since we wrote this grant, we have held off on extracting and sequencing the fall-collected samples while are assessing how best to take advantage of the increased capacity now available to us. We expect to take further samples in April, May, and August.

Impacts and Contributions/Outcomes

This project will contribute to the ability of growers to make informed decisions about appropriate practices for achieving specific desired goals for improvement of soil microbial diversity and function. It will also contribute to the scientific understanding of whether information on soil microbial community structure is useful for prediction of soil function.

Collaborators: