Kevin Tiessen1, David Lobb2, Guy Mehuys3, Sheng Li2, Herb Rees4, and Lien Chow4. (1) Macdonald Col.-McGill Univ., Dept of NRS, McGill University, 21 111 Lakeshore Road, Ste. Anne de Bellevue, QC H9X 3V9, CANADA, (2) University of Manitoba, Department of Soil Science, University of Manitoba, Winnipeg, MB R3T 2N2, Canada, (3) CANADA,McGill U., Dep. of Natural Resource Sci., Macdonald Campus Mcgill University, Ste Anne De Bellevue, QC H9X 3V9, CANADA, (4) Agriculture and Agri-Food Canada, Potato Research Centre, 850 Lincoln Road, P.O. Box 20280, Fredericton, NB E3B 4Z7, Canada
Total soil erosion is the result of all soil erosion agents – wind, water and tillage. In Canada, the risk of soil erosion (in particular by tillage and/or water) is expected to be greatest in regions where highly erosive cropping practices are used on highly erodible landscapes – such as the potato growing regions of northwestern New Brunswick. However, no previous studies have looked at the combined impacts of tillage and water erosion on soil and crop quality in Atlantic Canada. The objectives of this project were to: 1) estimate the relative contributions of tillage and water erosion using caesium-137 (137Cs) as a tracer; and 2) assess the impact of tillage and water erosion on soil and crop productivity within intensive potato production in Atlantic Canada.
Depth incremental soil samples were collected at an Agriculture and Agri-Food Canada benchmark site (20NB) located in New Brunswick. Site 20NB is 3.5 ha in size and is under conventional up and down slope potato production (slope gradients: 2 to 17 %). Soil samples were collected across the landscape using two grid patterns (25 x 25 m over the entire field and 12.5 x 12.5 m at the most convex part of the field) and were analyzed for 137Cs, total C, total N, and Mehlich-available nutrients. Preliminary analyses suggest that both tillage and water erosion are major erosive agents at this field site, but that tillage erosion is the dominant soil redistribution process. Current inventories of 137Cs will also be compared to those previously taken at 20NB in 1990 and 1996 to compare soil redistribution over a shorter timescale (ca. 10 – 15 years). It is clear that both water and tillage erosion must be considered when choosing implements and developing best management practices for potato production in Atlantic Canada.
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