Nitrogen release, uptake, and yield of wheat in the Brown Soil Zone at the landscape-scale as influenced by tillage treatments

Non-Peer ReviewedComparison of the effects of short-term mechanical and no-till fallow managements on nitrogen (N) availability was conducted in an undulating landscape in the Brown Soil Zone in southwestern Saskatchewan. The effects of these fallow managements were assessed by i) crop N uptake and yield and ii) l5N tracer technique (A value approach) and in situ burial of anion exchange membrane (AEM) probes. No significant differences in spring soil nitrate or mean soil temperature were observed between the treatments. However, spring moisture content of the surface soil samples was significantly higher under no-till compared to mechanical fallow. At the landform scale, shoulder positions of the respective tillage systems had significantly lower crop N uptake, yield and apparent N mineralization compared to other slope positions. The contribution of shoulders under no-till towards N uptake and grain yield were 8.25 and 445 kg/ha higher compared to shoulders in mechanical fallow. Soil N supplying capacity as determined by A value and AEM techniques along with crop N uptake and yield was not significantly different between the tillage treatments, indicating that N availability is not likely to be greatly affected in initial years by switching to no-till in these soils