LONG-TERM LAND MANAGEMENT PRACTICES AND THEIR EFFECT ON SOIL HEALTH AND CROP PRODUCTIVITY

• Main Author: Muratore, Thomas Joseph, Jr.
• Format: Others
• Published: UKnowledge 2019
• Subjects: PLFA; Microbial Community Structure; Crop Rotation; Corn Yield; Temporal Dynamics; Agricultural Science; Environmental Microbiology and Microbial Ecology; Soil Science
• Online Access: https://uknowledge.uky.edu/pss_etds/115; https://uknowledge.uky.edu/cgi/viewcontent.cgi?article=1127&context=pss_etds

Agricultural intensification reliant on monocrops could change soil health in a way that does not support maximum crop productivity. Twenty-nine-year-old no-till field plots at the University of Kentucky Spindletop research farm showed a significant reduction in corn yields from continuous corn plots compared to those from plots in various types of rotation. The objective of this study was to determine what role soil microbes might play in yield reduction and how management and time effects microbial community structure. Samples were collected from the following treatments: continuous corn (CC), continuous soybean (SS), a 2-year corn/soybean rotation (CCSS), Corn in rotation with soybean with winter wheat cover (C/W/S), and sod controls (SOD). Soil health-related parameters were determined along with microbial community structure using phospholipid fatty acid analysis (PLFA). Results show that there is a strong seasonal dynamic in microbial communities with May, July and September showing the greatest differentiation between treatments. Nonparametric multidimensional analysis (NMDS) shows that microbial communities under SS, CC treatments were significantly different from the CS and CWS treatments across all four years of the study. My findings will prove useful for assessing the contribution of biological indicators to agroecosystem function and will aid in making recommendations of when and how to manage these parameters to improve soil health and maximize yield.