Abstract:
Tillage erosion is the dominant soil erosion process in hummocky landscapes. The topsoil lost from the convex upper slope positions (i.e., hilltops knolls, ridges) gradually makes its way to the concave lower slope positions (i.e., foot slopes, toe slopes/depressions), while reducing yield capability in the knolls. The accumulation of topsoil in the concave lower slope positions does not increase yield potential. Landscape restoration is a process by which organic-rich topsoil is removed from lower slope positions and is moved to the knoll positions where it is applied and incorporated as additional topsoil. Field studies on this matter have shown increases in crop yield productivity due to land restoration on the convex upper slope positions.
Using a model developed in STELLA ®, this research examines the net monetary benefit of landscape restoration in specific landscape scenarios modeled after areas in Manitoba which are prone to tillage erosion. This study demonstrates that farming operations in hummocky landscapes, experiencing topsoil loss at knolls benefit from landscape restoration as it can lead to positive net returns. In this study, the research shows that landscape restoration, in the Rural Municipality of Lorne (South Western Manitoba), led to revenues greater than restoration costs for arable land used for agricultural purposes. Depending on soil conditions and tillage choices the payback period for landscape restoration ranged from 8 to 18 years.
