Preferential movement of oxygen-18-labeled water and nitrogen-15-labeled urea through macropores in a nicollet soil

Journal Article · · Journal of Environmental Quality; (USA)

DOI:https://doi.org/10.2134/jeq1989.00472425001800010012x· OSTI ID:6946673

Priebe, D L; Blackmer, A M ^[1]

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1. Iowa State Univ., Ames (USA)

Studies were conducted to evaluate the possibility that preferential movement of water through soil macropores was an important factor in previously observed losses of surface-applied urea and nitrate from Iowa soils. Granules of {sup 15}N-labeled urea were applied to the surfaces of undisturbed soil columns at their water-holding capacities, and then {sup 18}O-labeled water was applied to simulate a 25-mm rainfall event. Effluent from the bottoms of the columns was incrementally collected and analyzed. Soil from the columns was removed in layers 24 h after initiation of the rainfall, and each layer was analyzed to determine depths of movement of labeled water and N. Significant amounts of labeled water and urea were present in the first increment of effluent from some columns. Labeled water and urea moved much deeper and were more dispersed in all soil columns than would be expected in absence of preferential movement of water through macropores is more important as a factor affecting the movement and fate of nitrogen in Iowa soils than generally has been recognized. A better understanding of where and when this preferential movement occurs and how it influences leaching of N and other solutes in soils is needed to advance efforts to identify management practices that reduce losses of N and other chemicals from agricultural soils to the environment.

• OSTI ID: 6946673
• Journal Information: Journal of Environmental Quality; (USA), Journal Name: Journal of Environmental Quality; (USA) Vol. 18:1; ISSN JEVQA; ISSN 0047-2425
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540211* -- Environment
Terrestrial-- Basic Studies-- Radiometric Techniques-- (1990-)
AGRICULTURE
AMIDES
ATMOSPHERIC PRECIPITATIONS
CARBONIC ACID DERIVATIVES
DISSOLUTION
ELEMENTS
ENVIRONMENTAL TRANSPORT
EVEN-EVEN NUCLEI
HYDROGEN COMPOUNDS
INDUSTRY
ISOTOPE APPLICATIONS
ISOTOPES
LEACHING
LIGHT NUCLEI
MASS TRANSFER
NITROGEN
NITROGEN 15
NITROGEN ISOTOPES
NONMETALS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN 18
OXYGEN COMPOUNDS
OXYGEN ISOTOPES
RAIN
SEPARATION PROCESSES
SIMULATION
SOILS
STABLE ISOTOPES
TRACER TECHNIQUES
UREA
WATER