OLS : Record


Main Title Field-to-stream transport of agricultural chemicals and sediment in an Iowa watershed. Data base for model testing (1976-1978) /
Author Johnson, H. P.
Publisher U.S. Environmental Protection Agency, Environmental Research Laboratory,
Place Published Athens, Ga.
Year Published 1982
Report Number EPA-600/S3-82-032
OCLC Number 456547909
Subject Added Ent Watersheds--Iowa.; Water--Pollution--Iowa.; Erosion--Iowa.
Internet Access
Description Access URL
Library   Call Number Additional Info Location Date Modified
EJBD EPA 600-S3-82-032 c.1 Headquarters Library/Washington,DC 08/09/2011
EJBD ARCHIVE EPA 600-S3-82-032 Headquarters Library/Washington,DC 10/19/2009
Collation 4 p. : ill. ; 28 cm.
Notes Caption title. At head of title: Project Summary. Distributed to depository libraries in microfiche. "EPA-600/S3-82-032". "Sept. 1982".
Contents Notes Data on the field-to-stream transport of sediment and chemicals from an agricultural watershed were collected in a three-year study to provide information for testing and evaluating mathematical models under development for predicting agricultural non-point source pollution. These models are prepared as tools to evaluate the effectiveness of different farm management practices in controlling losses of nutrients, pesticides, and sediment in field drainage to receiving waters. In the study, data were collected for small corn, soybean, and pasture fields; for two larger mixed-cover watersheds; and at three drainage-stream sites. During the study (1976-1978), annual rainfall (753 mm) and streamflow (124 mm) averaged a little below normal. Sediment losses were also low because of a lack of intense rains, averaging 2.6 t/ha from row-crops and 0.9 t/ha from the watershed as a whole. Soluble chemical losses (NH4-N, NO3-IM, PO<-P, Cl and TDS) in surface runoff were less than that deposited with rainfall. Because IMO3-N, Cl and TDS were concentrated in subsurface drainage, losses from the watershed as a whole due to streamflow (surface plus subsurface drainage) were significantly larger than losses from surface runoff alone. Average annual pesticide losses from the field were least for the shortest-lived herbicide (0.2% of that applied) and greatest for the most persistent (1.6%). No runoff event occurred within a week of application. On the basis of percentage applied, losses or export from the watershed as a whole were about 25% of the losses from the two individual fields studied. With the exception of the strongly adsorbed paraquat, at least 80% of the losses occurred in the water phase as opposed to that adsorbed on sediment.
Author Added Ent
Baker, J. L.
Corporate Au Added Ent Environmental Research Laboratory (Athens, Ga.)
Alternate Title Data base for model testing (1976-1978)
PUB Date Free Form 1982
BIB Level m
OCLC Time Stamp 20091015104212
Cataloging Source OCLC/T
Language eng
Origin OCLC
Type CAT
OCLC Rec Leader 03028nam 2200349Ia 45020