A water table management field experiment was established and conducted on a sandy loam soil in 1991 and 1992. The effects of two water tables levels, as well as conventional drainage, on nitrate levels in drainage outflow were studied. The controlled water table levels were 25 and 50 cm above the drain. The experimental setup consisted of 9 monitored drains and 6 buffer drains. Plots were centred over the drains and were 115 m long by 18.69 m wide. Drain outflow, nitrate concentration in the drainage water, soil temperature, rainfall, and water table elevations were measured during the 1992 growing season. In July a solid set sprinkler irrigation system was installed and operated for a period of 2 weeks, to raise water table levels and induce nitrate leaching. / It was impossible to maintain the 25 and 50 cm controlled water table levels for the entire 1992 growing season. Controlled drainage had a significant effect on subsurface dynamic outflow. The 25 and 50 cm controlled water tables were effective in reducing total drainage volume by 60% and 77%, respectively, compared to conventional drainage. Controlled drainage also had a significant effect on nitrate loss. The 25 and 50 cm controlled water tables reduced nitrate loss by 85% and 58%, respectively, during the July irrigation period, compared to conventional free outlet drainage. This was due to the reduced drainage volumes associated with controlled drainage.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.69663 |
| Date | January 1993 |
| Creators | Lalonde, Vincent |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Science (Department of Agricultural Engineering.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 001382297, proquestno: AAIMM91758, Theses scanned by UMI/ProQuest. |
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