|
|
||||||||
USDA-ARS, National Soil Tilth Lab., 2150 Pammel Dr., Ames, IA 50011-3120
Dep. of Agronomy, Iowa State Univ., Ames, IA 50011
*Corresponding author (jaynes{at}nstl.gov).
ABSTRACT
Point injection of N fertilizers within the ridge of ridge-tilled soils has shown promise in reducing nitrate leaching in short-term rainfall simulation studies, but it has not been studied under natural rainfall throughout the growing season. At two uncropped locations, we measured the leaching of tracers injected into different ridge positions in established ridge-tilled plots that were leached by natural rainfall. A point injector was used to inject conservative anionic tracers 100 mm below the soil surface every 38.1 mm along ridge-top, ridge-shoulder, and furrow positions. Movement of tracers was measured four times after tracer application by triplicate soil sampling with a 38.1-mm-diam. soil probe to a maximum depth of 1.22 m. Sample collection spanned a period of 102 d with 282 mm of cumulative precipitation after tracer application at the Boone site and 97 d with 314 mm of precipitation at the Treynor site. Mass recoveries of furrow-applied tracer was significantly lower (P = 0.05) than ridge-applied tracer on the last two sampling dates at both sites. There was no consistent difference in mass recoveries between tracers applied at ridge top compared with shoulder positions. Furrow-applied tracer had lower concentrations in the soil profile than tracers applied to ridge-top and shoulder positions after 40 d and 76 to 129 mm of precipitation. Tracer movement was essentially vertical below the ridges, with
96% of the recovered ridge-applied tracer found below the ridges. Lateral spreading was more pronounced under the furrows, with
49% of the recovered furrow-placed tracer found below the furrows. Fertilizer injection within the ridge shows promise for reducing leaching and potentially increasing nutrient availability to plants.
Received for publication December 1, 1997.
This article has been cited by other articles:
![]() |
W. B. Stevens, A. D. Blaylock, J. M. Krall, B. G. Hopkins, and J. W. Ellsworth Sugarbeet Yield and Nitrogen Use Efficiency with Preplant Broadcast, Banded, or Point-Injected Nitrogen Application Agron. J., August 10, 2007; 99(5): 1252 - 1259. [Abstract] [Full Text] [PDF] |
||||
![]() |
J.F. Power, R. Wiese, and D. Flowerday Managing Farming Systems for Nitrate Control: A Research Review from Management Systems Evaluation Areas J. Environ. Qual., November 1, 2001; 30(6): 1866 - 1880. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. A. Lehrsch, R.E. Sojka, and D.T. Westermann Nitrogen Placement, Row Spacing, and Furrow Irrigation Water Positioning Effects on Corn Yield Agron. J., November 1, 2000; 92(6): 1266 - 1275. [Abstract] [Full Text] |
||||
![]() |
B. Bargar, J.B. Swan, and D. Jaynes Soil Water Recharge under Uncropped Ridges and Furrows Soil Sci. Soc. Am. J., September 1, 1999; 63(5): 1290 - 1299. [Abstract] [Full Text] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| The SCI Journals | Agronomy Journal | Crop Science | |||
| Journal of Natural Resources and Life Sciences Education |
Vadose Zone Journal | ||||
| Journal of Plant Registrations | Journal of Environmental Quality |
The Plant Genome | |||