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Access Type

Open Access Thesis

Document Type


Degree Program

Plant & Soil Sciences

Degree Type

Master of Science (M.S.)

Year Degree Awarded


Month Degree Awarded



Soils provide many essential functions that support the world. With a decline in soil health, these functions also decrease in efficiency, and can threaten the health of billions of people around the world. Typically, soil health tests do not use biological indicators, however microbes drive and perform vital functions to increase soil health. One way to increase soil health is through the use of cover crops to reduce soil erosion during fallow periods, increasing soil organic matter, as well as collecting nutrients from soil into their biomass. These cover crops are then terminated through various methods such as herbicides, disk tillage, or no tillage. The termination method can have an impact on soil health, by chemically affecting soil microbes with herbicides, disturbing soil, microbial communities, and fungi with tillage, or creating residue barriers on the surface of soil such as with using roller crimping (no tillage). Fertilization can also affect soil health, controlling rates of nutrient turnover and decomposition through the needs of microbes for carbon and nitrogen. This study quantifies the effects of four termination methods and four fertilization treatments on soil biological indicators during one growing season of sweet corn. Plots that were not tilled and terminated using roller crimping showed highest rates of decomposition, as well as increased labile carbon pools to feed microbes slowly throughout the growing season. Microbial activity was also observed to respond to fertilization, as patterns in activity spiked directly after fertilization. This study informs agricultural land management by the usage of biological indicators to further support the use of cover crops to increase soil health along with using no-till termination methods. Root biomass contributions toward soil health was also investigated, and how they may be affected by tillage.


First Advisor

Ashley Keiser

Second Advisor

Rachel Hestrin

Third Advisor

Masoud Hashemi