Selected Enzyme Activities Under Different Land Use Management in Lower Missouri River Floodplain Soils

Abstract

ABSTRACT Floodplains are vital and productive ecosystems that provide essential biological, and hydrologic functions. However, human modifications to floodplains, such as urbanization, and agriculture have increased the need to assess the impacts of land use changes on the sustainability of their functions. Riparian forest (RF), agroforestry (AF), and row-crop agriculture (AG) are among common land-use systems in the lower Missouri River Floodplain (MRF) region in New Franklin, MO. This study tested the hypothesis that variations in soil physicochemical and biological parameters in relation to land management could affect soil enzyme activities. Soil samples were collected from three land use systems, and enzyme activities were measured in three seasons fall 2019, summer 2020, and spring 2021. Soil properties such as soil C and N, bulk density, organic matter, and water-holding capacity were measured. The results revealed significantly higher levels of β-glucosidase, β-glucosaminidase, and dehydrogenase activity in agroforestry (AF) and riparian forest (RF) treatments relative to agriculture (AG) management in all three studied seasons. No substantial differences in total PLFA were detected among land use systems. This research demonstrated that tree-based systems can substantially enhance soil bulk density and organic matter concentration, leading to increased activity of the selected enzymes. Efforts to incorporate agroforestry systems help to create a more diverse and complex ecosystem compared to monoculture cropping systems. This, in turn, stimulates connections among diverse plant species, microorganisms, and soil fauna, leading to improved nutrient cycling, organic matter decomposition, and overall soil health.