Economic evaluation of tillage management practices at the watershed scale in southern Manitoba

The costs, risk, and additional management associated with the conversion of agricultural land from conventional tillage to conservation tillage play a significant role in the producers’ likelihood of adoption of such practices. A local watershed organization in the South Tobacco Creek (STC) watershed in southern Manitoba has been collecting land management data for almost 20 years. As part of the national Watershed Evaluation of Beneficial Management Practices (WEBs), a tillage index and model were developed based on field tillage operations and production costs, and net incomes. The index and model quantified economic impacts of land management practices for three crop rotations under three tillage systems at the watershed scale. Based on a tillage index to define tillage levels for zero, minimum, and conventional tillage, a tillage cost function related tillage cost to tillage passes and crop residue management. Net income of crops and typical rotations under three tillage systems has been estimated. For canola, the greatest net income was generated in the conventional tillage (CT) system, which is attributed to the yield response to the tilled seedbed. As tillage frequency decreased, net income for canola declined. In contrast, the income response for cereals, such as wheat, was highest under minimum tillage (MT) due to reduced fuel and depreciation costs relative to conventional tillage. However net income for cereals managed with zero tillage (ZT) was significantly reduced due to increased equipment costs. Using the same tillage index, the model has produced results suggesting that for a wheat–canola rotation there is a significant difference between cropping system costs in areas of labour, oil and fuel, chemical and tillage costs; however, there is no significant difference between the three tillage levels in areas of total costs and net income. Although MT overall performed better compared to ZT or CT, net income of these three different tillage systems was offset between crops of the wheat–canola rotation and generally no statistically significant differences were observed. These results explained why most farmers in the STC watershed prefer conventional or minimum tillage to zero tillage-due to increased machinery investment and lower net returns for zero tillage. If conservation tillage is to be promoted in this region of Manitoba, additional incentives may be required to encourage its further adoption. However, increased net income for conservation tillage of cereals provides a clear incentive to adopt this practice.