Submitted to: International Symposium on Soil Erosion and Dryland Farming
Publication Type: Proceedings
Publication Acceptance Date: September 19, 1997
Publication Date: N/A
Technical Abstract: A prototype N-fertilizer applicator was designed and constructed, to apply N-fertilizer to locally tilled soil, construct a hydraulic barrier (compacted soil) over the fertilizer, and form a surface dome or ridge. This localized compaction and doming (LCD) applicator was compared with a conventional knife applicator by investigating soil physical properties of the injection zone, nitrate redistribution during a growing season, corn yield response, and leaching to subsurface drains. Data from these evaluations suggest that N applied by the LCD applicator is less susceptible to water percolation and leaching than N injected by a conventional knife injector. Soil nitrate concentrations were closer to the surface and less dilute when fertilizer was applied by the LCD versus the conventional knife. Subsurface drain water concentrations show that after 10 cm of drainage, 5% of knife injected chemicals were recovered, compared to just 1% of LCD applied chemicals. Modifying surface soils to alter water flow paths is a valuable tool to guard against ground water or tile drain contamination by N-fertilizers.