Impacts of flooding induced salinity on soil hydrology and nutrient leaching from a poorly drained marl soil

Abstract. Soil salinity due to flooding or saltwater intrusion could be a big threat to South Florida‘s agriculture. The shallow and coarse soils and the highly permeable limestone bedrock hydrologically connect surface and groundwater resources. This leads to a greater risk of salt accumulation due to flooding or saltwater intrusion. In this study, freshwater and seawater were used to conduct a greenhouse flooding experiment to study the effects of flooding and salinity on soil health indicators such as soil hydrology and nutrient leaching. The flooding was conducted for a length of 28 days and porewater samples were collected for nutrient analysis on the 1^st, 7^th, 14^th, and 28^th day after flooding. Soil moisture and soil water relationships of fresh soil and saltwater flooded soils were measured using the HYPROP and WP4C equipment (METER Group, Inc., Pullman, WA, USA). Saltwater flooding affected both soil hydraulic properties and nutrient leaching. Saltwater flooding decreased soil moisture retention near saturation and field capacity while increasing soil moisture retention at the dry end of the soil moisture retention curve. Additionally, as a result of saltwater flooding the concentration of P, K, and Ca in soil porewater increased and resulted in the decline of Mg concentration.