Topographic influence on the variability of soil properties within an undulating Manitoba landscape

As soil properties influence productivity, it is of interest to characteriz e their distribution for the purpose of intensified agricultural management in variable landscapes. Soil proper-ties (soil organic C content, soil pH, A horizon thickness, solum thickness and depth to carbonates) were studied in 10 intensively sampled transects in a gently undulating glacial till la ndscape near Miniota, Manitoba. Using a landform. description model, the st udy site was delineated into upper, mid and lower elevation landform. eleme nt complexes (LEC) The program used a digital elevation model created from relative elevation data collected on a 10-m grid. Sample points were also s tratified by soil series; Newdale (Orthic Black Chernozem), Varcoe (Gleyed Rego Black Chernozem) and Angusville (Gleyed Eluviated Black Chernozem) soi ls of the Newdale association were identified. Landform element complexes w ere ranked lower > mid > upper with respect to convergent landscape charact er. The eluviated Angusville profiles occurred under more convergent landsc ape character than the Newdale or Varcoe series. There was a consistent ran k of lower > mid > upper with respect to depth to carbonates, A horizon thi ckness, solum thickness and soil organic C content. Relative ranking of the pH in the Ap horizon was the opposite. In all cases, the lower LEC emerged as most clearly distinct. There was substantial variability in soil profil e development, and, therefore, soil series membership, within individual LE C. This indicated that the scale at which LEC are delineated is broader tha n that at which soil series variability occurs. Nonetheless, LEC were usefu l in capturing gross variability in soil properties within the landscape at a scale that would allow unique agricultural management practices.