Life cycle and economic assessment of Western Canadian pulse systems: The inclusion of pulses in crop rotations

The introduction of a pulse crop into a cereal production rotation has been widely recognized for the rotational benefits resulting from nitrogen fixation and crop diversification. Pulses are the dry, edible seeds of pod-bearing plants in the legume family, such as dry pea and lentil. Both dry pea and lentil are widely grown across Western Canada and provide an important source of food and feed worldwide. In addition, these pulse crops demonstrate positive returns over and above the production of traditional crops in most situations except when their prices are low. Although the economic and environmental benefits of pulse crops have been examined in many different capacities, an examination of the rotational implications of including pulse crops in a cereal-based rotation in Western Canada has not been conducted on a life cycle basis. In this study, life cycle and economic assessments were used to examine the environmental and economic implications of including dry pea and lentil crops in an oilseed-cereal rotation in Western Canada. An analysis was performed in which dry pea or lentil replaced a spring wheat crop in a canola – spring wheat – spring wheat – spring wheat rotation. Pulses were ultimately produced for their protein content. Results suggested that introducing dry pea or lentil in the rotation reduced environmental effects in all impact categories examined (Global Warming and Resource Use: −17% to −25%; Ecosystem Quality: −1% to −24%; and Human Health: −3% to −28%). In addition, the economic benefits of this practice suggested that the farm level returns over variable costs improved for both the dry pea and lentil rotations (from $−20.43ha−1 for the traditional rotation to $110.45 and $138.78ha−1, respectively, for dry pea and lentil rotation). These reductions were a result of reduced fertilizer requirements for the pulse-containing rotations (i.e. no application of nitrogen fertilizer to the pulse crop and reduced application to the succeeding cereal crop) as well as higher cereal yields. Based on these results, improved returns to producers and reduced amounts of material and energy inputs can be realized with optimized crop management that can include dry pea and/or lentil in rotation with other high yielding crops. Including pulse crops in an oilseed-cereal rotation is an effective method to enhance the economics and environmental effects of crop production.