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ARS Home » Midwest Area » Morris, Minnesota » Soil Management Research » Research » Publications at this Location » Publication #339395
Research Project: Stewardship of Upper Midwest Soil and Air Resources through Regionally Adapted Management Practices

Location: Soil Management Research

Title: Influence of fertilization on mycorrhizal dynamics in a perennial biomass production system

Author
item Brockamp, Rachel
item Weyers, Sharon
item KUCHENREUTHER, MARGARET - University Of Minnesota
item Zaharick Jr, John
item Wilts, Alan

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/9/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Interest among landowners in diversified production systems is growing in the Upper Midwest. Diversification in the form of perennial biomass production systems from converted cropland is supported by developments in livestock integration as well as cellulosic and gasification energy platforms. Management strategies are needed that balance productivity with the ecosystem services perennial systems often offer. Within a low-diversity, native perennial production system, we established a randomized block experiment to evaluate the impact of four whole plot fertilizer treatments (zero, composted cattle manure, half rate (30-10-30 NPK) and full rate (60-20-60 NPK)) and two split-plot harvest rates (annual fall harvest versus no-harvest) on biomass production dynamics, soil health, and associated ecosystem services. Mycorrhizal inoculum potential (MIP) was evaluated as an indicator of soil health benefits. Big bluestem (Andopogon gerardii) seed was used to bioassay the MIP of soil collected within the four different fertilizer treatments under annual fall harvest. To support bioassay results field collected roots were also assessed for mycorrhizal colonization. The MIP, measured as fraction of infection in the bioassay roots, was significantly lower in treatments that had received fertilizer at the recommended rate than treatments receiving no fertilizer or composted cattle manure. In field collected big bluestem roots, mycorrhizal colonization was not significantly different among fertilizer treatments, but did reflect a trend similar to the bioassay. Despite colonization of field-grown hosts, the bioassay results in conjunction with established reduction in plant diversity under recommended fertilizer management may have unforeseen consequences for mycorrhizal diversity and abundance.