Soils of 49 agricultural and 2 "native condition" sites in the Lower Umatilla Basin,
Oregon were sampled for nitrate-nitrogen, ammonium-nitrogen, chloride, and pH
beginning in Fall of 1992. Several sites were sampled in Spring and Fall 1993 in order to
indicate movement or loss of residual soil nitrogen over time. This study was prompted
by current concern over contamination of public drinking water supplies by nitrate and the
designation of over 550 square miles of this region as a Ground Water Management Area.
This study sought to identify links between agricultural management practices-primarily
irrigation, fertilization, and crop rotation systems, and deep soil nitrate levels.
Soil profiles were divided into 3 "management zones:" 0-3', 3-6', and beyond 6' in depth.
These depths represent average rooting depths for the major agricultural crops of the
study area. In general, the effective rooting depth of most area-crops does not extend
beyond 6', therefore, it was determined that residual soil-nitrate found at this depth or
beyond may be a potential source of ground water contamination if not managed
correctly.
Results of the study indicate that proper management of irrigation, fertilization,
and cropping rotation can significantly reduce the potential for contaminating ground
water. Deep soil nitrate levels under most agricultural fields were consistent with the
concept that some loss of nitrate below the root zone is inevitable, however, this condition
can be minimized through intensive crop management.
This study concludes that responsible management of agriculture can minimize
impacts on ground water, while providing quality food and fiber products to an ever-growing
population. In addition, more research is needed in the area of crop physiology
and response to intensively managed systems. Such research may provide insight into
more efficient methods of crop production and environmental protection. / Graduation date: 1995
| Identifer | oai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/35247 |
| Date | 14 July 1994 |
| Creators | del Nero, Zachary Augustus |
| Contributors | Warkentin, Benno |
| Source Sets | Oregon State University |
| Language | en_US |
| Detected Language | English |
| Type | Thesis/Dissertation |
Page generated in 0.0016 seconds