Spatial and Temporal Variability of Leached Nitrate From Field Core Lysimeters and Hummocky Prairie Landscape.

Spatial and temporal variability of leached nitrate from field core lysimeters and hummocky prairie landscape

Akinremi O.O,  R.K. Dehkordi, S.O. Olatuyi, F. Zvomuya, D. Flaten and D. Lobb

Department of Soil Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2  Email: akinremi@cc.umanitoba.ca

The field core lysimeter study is located at the Ian N. Morrison Research Farm in Carman, Manitoba Canada and is part of the NCLE (National Center for Livestock and Environment) long-term rotation that attempts to understand the impact of agricultural production on the environment using a system approach. The objective was to compare the traditional liquid swine manure and solid manure production systems in combination with perennial and annual cropping systems on the loss of nutrients from the soil. The study was launched in the fall of 2006 with the installation of 40 field core lysimeters at the corner of each experimental plot that measured 10 m by 10 m. Leachate samples collected in 2007 and 2010 are used to demonstrate temporal and spatial variability of nitrate leaching on the prairies. The second study was carried out on a no-till hummocky landscape near Brandon, Manitoba, during the growing seasons of 2007 and 2008.  The plot was delineated into three discrete landscape positions as upper (UPP), middle (MID) and lower (LOW) slopes. A microplot demarcated at each landscape position received ¹⁵N labelled fertilizer in form of KNO₃ at the rates of 0, 90 and 135 kg N ha^-1, and Br^- (KBr) at the rate of 200 kg Br^- ha^-1. The results of bromide, fertilizer derived nitrate-nitrogen, and soil nitrate-nitrogen will be used to show that the trend of leaching in both years followed LOW>UPP>MID slope positions.