Measurement of net nitrogen and phosphorus mineralization in wetland soils using a modification of the resin-core technique

Biogeochemistry
By:

Links

Abstract

A modification of the resin-core method was developed and tested for measuring in situ soil N and P net mineralization rates in wetland soils where temporal variation in bidirectional vertical water movement and saturation can complicate measurement. The modified design includes three mixed-bed ion-exchange resin bags located above and three resin bags located below soil incubating inside a core tube. The two inner resin bags adjacent to the soil capture NH4+, NO3-, and soluble reactive phosphorus (SRP) transported out of the soil during incubation; the two outer resin bags remove inorganic nutrients transported into the modified resin core; and the two middle resin bags serve as quality-control checks on the function of the inner and outer resin bags. Modified resin cores were incubated monthly for a year along the hydrogeomorphic gradient through a floodplain wetland. Only small amounts of NH4+, NO3-, and SRP were found in the two middle resin bags, indicating that the modified resin-core design was effective. Soil moisture and pH inside the modified resin cores typically tracked changes in the surrounding soil abiotic environment. In contrast, use of the closed polyethylene bag method provided substantially different net P and N mineralization rates than modified resin cores and did not track changes in soil moisture or pH. Net ammonification, nitrifi cation, N mineralization, and P mineralization rates measured using modified resin cores varied through space and time associated with hydrologic, geomorphic, and climatic gradients in the floodplain wetland. The modified resin-core technique successfully characterized spatiotemporal variation of net mineralization fluxes in situ and is a viable technique for assessing soil nutrient availability and developing ecosystem budgets.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Measurement of net nitrogen and phosphorus mineralization in wetland soils using a modification of the resin-core technique
Series title Biogeochemistry
DOI 10.2136/sssaj2010.0289
Volume 75
Issue 2
Year Published 2011
Language English
Publisher Soil Science Society of America
Publisher location Madison, WI
Contributing office(s) National Research Program - Eastern Branch
Description 5 p.
Larger Work Type Article
Larger Work Subtype Journal Article
Larger Work Title Biogeochemistry
First page 760
Last page 770
Additional Online Files (Y/N) N