Ion exchange resin based soil solution lysimeters and snowmelt solution collectors

Abstract

Conventional soil solution lysimeters and snowmelt solution collectors suffer from a number of limitations when used to estimate yearly nutrient fluxes. This study describes an alternative technique to directly measure soil and snowmelt solution fluxes utilizing ion exchange resin-based collectors. Resin-lysimeters were constructed by enclosing a layer of resin between two layers of nutrient-free silica sand within a polyvinyl chloride tube. Nitrogen (N) and phosphorus (P) fluxes from resin based collectors were compared against buried resin bags, ceramic cup lysimeters, and traditional snowmelt solution collectors co-located in an eastern Sierra Nevada forest. Ammonium and P accumulation in resin lysimeters were one- to two orders of magnitude smaller than in buried resin bags placed in direct contact with the soil. Resin lysimeters and resin snowmelt collectors measured NH4–N and P fluxes that were three times greater than those estimated from ceramic cup lysimeters and solution snowmelt collectors. We hypothesize that this difference was due to spoilage of the solution sample in solution collectors between collections. Resin lysimeters are easy to construct, provide a direct measurement of nutrient fluxes, and are an alternative to solution snowmelt collectors and ceramic cup lysimeters, especially in areas where poor winter accessibility precludes constant maintenance.