Tillage Practices and Nitrogen Leaching to Groundwater Across Canada. (A03-yang303763-oral)
Authors:
J.Y. Yang* - AAFC-ECORC R. De Jong - AAFC-ECORC E.C. Huffman - AAFC-ECORC
Abstract:
Soil Residual Nitrogen (RSN) and Indicator of the Risk of Water Contamination by Nitrogen (IROWCN) are environmental indicators calculated by the Canadian Agricultural Nitrogen Budget (CANB) model. To improve the model’s sensitivity to local and temporal variation, we need to define the effect of tillage practices on RSN and IROWCN, but unfortunately this is not a clear relationship because of the numerous mechanisms which influence soil processes. As a starting point, we used EPIC to simulate conventional tillage (CT) and no-till (NT) in dry and wet climatic zones, with two rotations and three soils using 31-year weather data. Results indicate that in the dry Canadian Prairies (Swift Current, SK), RSN is significantly lower under NT than under CT, and IROWCN is less than 5 kg N/ha in both CN and NT. In the humid region (Harrow, ON), no difference between CT and NT was found in either RSN or IROWCN, but both RSN and IROWCN results are higher under a
corn-soybean-wheat rotation (60, 100, 130 kg N/ha in clay, loam and sand soils) than under continuous-barley (less than 26 kg N/ha in all soils). Using further such simulations, the relationship between tillage and soil N is being defined and incorporated into CANB. Results are discussed in the paper.
Speaker Information: Jingyi Yang, AAFC-ECORC, Room 4105 Central Experimental Farm, K.W.
Neatby, Ottawa, ON K1A 0C6; Phone: 613 759 1412; E-mail: [email protected]
Session Information: Wednesday, November 5, 2003, 1:55 PM-4:15 PM Presentation Start: 3:30 PM
Keywords: tillage practices; nitrogen leaching; groungwater contamination; modelling
