EFFECTS OF NITRAPYRIN ON NITRATE MOVEMENT IN SOIL COLUMNS

Possible benefits of a nitrification inhibitor to control nitrate leaching in soils was studied. Sandy loam soil cores were taken in 1-m-long polyvinyl chloride cylinders. After prewetting the cores, nitrapyrin (a nitrification inhibitor)-treated urea was incorporated into the top 10 cm of 3 cores and untreated urea was incorporated into the top 10 cm of 3 cores. The columns were leached periodically with distilled water. After 91 days, 1 and 9.7% of applied N had leached from the nitrapyrin-treated and untreated cores, respectively; after 144 days, 41.9 and 53.0%, respectively, of applied N was leached. Short-term studies indicated that further work using a nitrification inhibitor to reduce nonpoint source nitrate additions to ground water was justified.