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Sources of Variation in Home Lawn Soil Nitrogen Dynamics
Author(s) -
Martinez Noelle G.,
Bettez Neil D.,
Groffman Peter M.
Publication year - 2014
Publication title -
journal of environmental quality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.888
H-Index - 171
eISSN - 1537-2537
pISSN - 0047-2425
DOI - 10.2134/jeq2014.03.0103
Subject(s) - lawn , environmental science , variation (astronomy) , nitrogen , hydrology (agriculture) , agronomy , ecology , biology , chemistry , engineering , geotechnical engineering , physics , astrophysics , organic chemistry
Urban, suburban, and exurban lawns are an increasingly important ecosystem type in the United States. There is great concern about the environmental performance of lawns, especially nitrate (NO 3 − ) leaching and nitrous oxide (N 2 O) flux associated with nitrogen (N) fertilizer use. Previous studies of lawn N dynamics have produced conflicting results, with some studies showing high NO 3 − leaching and N 2 O flux and others showing lower losses and high retention and cycling of N inputs. We hypothesized that this variation is caused by differences in lawn management and soil properties that control root and soil organic matter (SOM) dynamics that influence N cycling processes. We tested these hypotheses by making measurements of soil NO 3 − , root biomass, rates of potential net N mineralization and nitrification, N 2 O flux, and SOM levels in samples from the front and backyards of residential homes in suburban and exurban neighborhoods with contrasting soil types in the Baltimore metropolitan area. There were no differences between front and backyards, between suburban and exurban neighborhoods, or between different soil types. Further, there were no significant relationships between root biomass, SOM, soil NO 3 − levels, and N 2 O fluxes. These results suggest that lawns have uniformly high rates of plant productivity that underlies high levels of SOM and N retention in these ecosystems across the Baltimore metropolitan area.