Canola As A New Crop For California: A Simulation Study

The agricultural sector of California is one of the most economically valuable and diverse in the world, but is dominated by perennial tree, vine and forage crops, as well as warm-season annual species that are dependent on irrigation. The diversity of less water-intensive annual cool-season crops is limited and wheat (Triticum aestivum L.) is the primary crop. Canola (Brassica napus L.) could diversify annual cool-season cropping in the state. Our study used field data from a multi-environment canola variety trial to test the ability of the Agricultural Production Systems Simulator (APSIM) model to simulate canola production in California. APSIM was able to accurately simulate canola yields in diverse regions, and consequently was used to investigate the yield potential of canola in California, using different irrigation management strategies, under both current and anticipated future climate scenarios. These simulations predict that canola should have high mean yields throughout California, given suitable management and variety selection. The long-term mean yield for short-season, spring-type, canola in the central valley of California is predicted to be more than 4800 kg/ha with supplemental irrigation. Under rain-fed conditions in the northern central valley mean yields are predicted to be 3500 kg/ha. This should make canola economically competitive with cool-season cereals. Without additional improvements in variety adaptation or management changes, our simulations suggest the yield of canola in California will decline modestly, but remain economically viable, under future climate scenarios.