Date of Award
12-2024
Document Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
Department
Plant and Environmental Science
Committee Chair/Advisor
Rongzhong Ye
Committee Member
Christopher Saski
Committee Member
Barbara Campbell
Committee Member
Anthony Keinath
Committee Member
Christopher Mcmahan
Abstract
The objectives of this study were to understand how continual organic amendment inputs improve Nitrogen (N) cycling, microbial diversity and functional traits. Fully crossed factorial experiments were designed to test four cover crop treatments (cereal rye, hairy vetch, mixture of the rye and vetch, and no cover crop fallow) and two levels of manure compost application (with manure application and blank control) in organic vegetable production from 2020 to 2023. Cover crop biomass, soil chemical and biological properties were analyzed for the distribution and availability of soil labile N (Chapter 2), the abundance of N-cycling genes (Chapter 3), the structure and composition of microbial communities (Chapter 4), and the functional traits associated with organic decomposition (Chapter 5). Both hairy vetch and its mixture with rye had higher organic N inputs than cereal rye; manure application also increased cover crop biomass carbon (C) and N input compared to the non-manure treatment. Hairy vetch treatment had the highest soil N availability and abundance of microbial nitrifiers. Cover crop incorporation modified the microbial community structure, which is correlated to the continual inputs of organic C and N. In addition, hairy vetch treatments upregulated the abundance of cellulose and lignin decomposing genes compared to cereal rye treatments. Most of the treatment effects differed between hairy vetch and cereal rye treatments, likely due to distinguishing biochemical properties. The diverse changes in soil microbial taxonomy and functional traits created an opportunity to optimize the organic inputs to maximize agronomic outcomes and environmental benefits in sandy soils.
Recommended Citation
Wang, Zhine, "The Diverse Effects of Continual Organic Inputs on Soil Biogeochemical Properties and Microbial Communities in Sandy Ultisols Under Organic Production" (2024). All Dissertations. 3788.
https://open.clemson.edu/all_dissertations/3788
Author ORCID Identifier
0000-0001-9841-1905
