Date of Defense
4-1-2024
Date of Graduation
4-2024
Department
Biological Sciences
First Advisor
Kathryn Docherty
Second Advisor
James Friedrich
Keywords
Soil health, soil degradation, microbial, extracellular enzyme activity, restoration, soil management practices, prairies, agriculture.
Abstract
Prior to European colonization, a large portion of North America was covered by grasslands that were slowly replaced by agroecosystems. This impacted soil health because it interfered with soil microbial interactions that influence soil fertility and quality. To understand how soil microbes are affected by different restorative management practices, we investigated microbial extracellular enzyme activity. Extracellular enzymes play a critical role in nutrient cycling and organic matter decomposition, making them good indicators for soil quality. This study focuses on four microbial extracellular enzymes: N-acetylglucosaminidase, phosphatase cellobiohydrolase and β-glucosidase. We studied these enzymes to determine how their activity varies on four soils that were managed differently (conventionally managed cropland, abandoned cropland (old fields), and two types of restored prairies that were previously old fields). We expected that: H1) extracellular phosphatase and N-acetylglucosaminidase activities, which mobilize phosphorus and nitrogen respectively, would be lowest in the conventionally managed cropland due to frequent use of fertilizers; H2) extracellular cellobiohydrolase activity would be highest in the two restored prairies, due to perennial organic inputs at those sites. H3) extracellular β-glucosidase activity would be lowest in agricultural sites due to reduced soil organic matter inputs and limited availability of substrates for hydrolysis. Our results revealed significant differences in β-glucosidase and phosphatase activities between the agricultural fields and the high-richness prairies. Cellobiohydrolase and N-acetylglucosaminidase were not different across the soil sources. Our results provide insights about soil microbial activity, an important indicator of soil health, which can help guide development of restoration practices that mitigate the effects of anthropogenic disturbances and climate change on soil degradation.
Recommended Citation
Solis-Sarat, Angela, "Restorative Land Management Practices Can Alter Soil Microbial Enzyme Activities" (2024). Honors Theses. 3851.
https://scholarworks.wmich.edu/honors_theses/3851
Access Setting
Honors Thesis-Restricted
Restricted to Campus until
6-20-2026