Nitrogen management and nitrification inhibitor effects on nitrogen-15 urea: 2. Nitrogen leaching and balance

Journal Article · · Soil Science Society of America Journal; (United States)

DOI:https://doi.org/10.2136/sssaj1990.03615995005400010019x· OSTI ID:5466561

Walters, D T ^[1]; Malzer, G L ^[2]

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1. Univ. of Nebraska, Lincoln (USA)
2. Univ. of Minnesota, St. Paul (USA)

Nitrification inhibitors (NI) may reduce N leaching losses, and should have the greatest effect on sandy soils where leaching potential is high. This study used 27 lysimeters to evaluate the effect of a NI, nitrapyrin (2-chloro-6(trichloromethyl) pyridine), on soil water percolation (SWP) and N leaching losses from an irrigated sandy loam soil (Typic Hapludoll) planted with corn (Zea mays L.), and monitor the fate of a single application of {sup 15}N-enriched urea over a multiyear period. Urea was applied at 90 and 180 kg N ha{sup {minus}1} yr{sup {minus}1} for a 3-yr period, with and without NI, and with and without incorporation. Urea + NI reduced SWP between planting and silking in 2 out of 3 yr when growing degree days (GDD) were high. After silking, SWP was reduced when urea + NI was incorporated and leaching load was high. A twofold increase in N rate resulted in an average of 3.4 times more N leached over 3 yr. The NI influenced time of N loss but not total N loss. Leaching losses of fertilizer-derived N (FDN) were delayed 25 to 50d when urea + NI were incorporated. The leaching load required to reach the maximum rate of FDN loss was higher with urea + NI. Leaching losses of fertilizer N were three times greater when determined by the difference method than by isotope-ratio analysis. Differing results with these two calculations are attributed to isotope dilution with indigenous soil N as a result of microbial activity. Nitrification inhibitors may reduce the potential for nonpoint-source pollution by delaying NO{sub 3} leaching, but will be most effective if coupled with proper N rates and conservative irrigation water management.

• OSTI ID: 5466561
• Journal Information: Soil Science Society of America Journal; (United States), Journal Name: Soil Science Society of America Journal; (United States) Vol. 54:1; ISSN SSSJD; ISSN 0361-5995
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540211 -- Environment
Terrestrial-- Basic Studies-- Radiometric Techniques-- (1990-)
540220* -- Environment
Terrestrial-- Chemicals Monitoring & Transport-- (1990-)
AMIDES
CARBONIC ACID DERIVATIVES
CEREALS
CHEMICAL EFFLUENTS
CHEMICAL REACTIONS
CHEMICAL WASTES
CHEMISTRY
DISSOLUTION
EFFICIENCY
FERTILIZERS
GRAMINEAE
GROUND WATER
HYDROGEN COMPOUNDS
IRRIGATION
ISOTOPES
LEACHING
LIGHT NUCLEI
LILIOPSIDA
LOAM
LYSIMETERS
MAGNOLIOPHYTA
MAIZE
MEASURING INSTRUMENTS
METABOLISM
MONITORING
NITRIFICATION
NITROGEN 15
NITROGEN CYCLE
NITROGEN ISOTOPES
NONRADIOACTIVE WASTES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
OXYGEN COMPOUNDS
PERMEABILITY
PLANTS
POLLUTANTS
SAND
SEPARATION PROCESSES
SOIL CHEMISTRY
SOILS
STABLE ISOTOPES
UREA
WASTES
WATER