Soil Column Simulation of Natural Nutrient Flux after Short‐term Inundation

Abstract

Core Ideas Intact soil column flood studies inaccurately capture short‐term nutrient flux. Filter paper creates barrier to physical disturbance of soil into water column. Filters are permeable to dissolved nutrients to chemically flux into water column. Cone filters prevent floating soil and organic materials from entering water column. Intact soil column studies have been widely used as laboratory simulations in determining the effects of long‐term inundation on nutrient flux in soils, but preliminary studies on total Kjeldahl N (TKN) have shown that physical disturbance associated with current flooding techniques causes an overestimation of TKN flux after short‐term inundation. Therefore, the objective of this study was to create a laboratory protocol that would minimize the effect of physical disturbance associated with current flooding procedures. To determine physical disturbance, total P concentrations were measured as a proxy for soil particles. Within 3 h of inundation, results found that total P concentrations in the water column were significantly reduced when using flat or cone‐shaped filter paper on the soil surface compared with blanks. By adapting the Collins‐filter barrier technique to short‐term flooding simulations, we were able to more accurately predict TKN flux to represent a natural real‐world response to short‐term inundation.