HARVEST FREQUENCY OF SWITCHGRASS IN A CIRCULAR ECONOMY ALTERS SOIL ECOLOGY

Abstract

Modern agricultural management has disrupted the balance of agroecosystems, as reflected in widespread nutrient disequilibrium. Ecosystems have the capacity to restore balance when provided with appropriate ecological conditions that support nutrient cycling, soil structure formation, and plant-microbe interactions. This thesis begins by proposing the implementation of a circular economy on the Lower Eastern Shore of Maryland to address two pressing local issues: the overabundance of nutrients and increasing rates of marginal land. An important component of the proposed circular economy is planting and harvesting switchgrass (Panicum virgatum). The second and third chapters investigate how different harvest frequencies of switchgrass affect soil ecology. Chapter 2 investigates how harvest frequencies impact arbuscular mycorrhizal fungal (AMF) diversity. The third chapter investigates the relationship among harvest frequency, soil organic carbon, soil aggregation, and AMF. Together, the results show that switchgrass harvest frequency influences AMF community composition, small macroaggregate formation, and soil carbon.