ABSTRACT: Measured field scale data are increasingly used to
guide policy and management decisions based on comparative
pollutant load information from various land management alter-
natives. The primary objective of this study was to compile
measured annual nitrogen (N) and phosphorus (P) load data
representing field scale transport from agricultural land uses.
This effort expanded previous work that established an initial
nutrient export coefficient dataset. Only measured annual N and
P load data published in scientific peer-reviewed studies were
included in the present compilation. Additional criteria for inclu-
sion were: spatial scale (field scale or farm scale, minimum
0.009 ha); land use (homogeneous, either cultivated agriculture
or pasture/rangeland/hay); natural rainfall (not rainfall simula-
tion); and temporal scale (minimum one year). Annual N and P
load data were obtained from 40 publications, resulting in a
163-record database with more than 1,100 watershed years of
data. Basic descriptive statistics in relation to N and P loads
were tabulated for tillage management, conservation practices,
fertilizer application, soil texture, watershed size, and land use
(crop type). The resulting Measured Annual Nutrient loads from
AGricultural Environments (MANAGE) database provides readi-
ly accessible, easily queried watershed characteristic and nutri-
ent load data and establishes a platform suitable for input of
additional project specific data.
(KEY TERMS: databases; nitrogen; nonpoint source pollution;
phosphorus; water quality.)
Harmel, Daren, Steve Potter, Pamela Casebolt, Ken Reckhow,
Colleen Green, and Rick Haney, 2006. Compilation of Measured
Nutrient Load Data for Agricultural Land Uses in the United
States. Journal of the American Water Resources Association
(JAWRA) 42(5):1163-1178.
INTRODUCTION
Growing demand for land use specific nutrient
export information to inform regulatory and educa-
tional programs and to support water quality model-
ing has highlighted the need for a comprehensive
database