Phosphorus (P) is a structural component of DNA, RNA, and cell membranes in living organisms. Phosphorous has limited mobility in the soil and in acidic or alkaline soils, P can become strongly absorbed to soil particles thereby reducing the availability of P to the plant roots. Plants have developed a variety of strategies to improve P availability. Phosphorous may be a limiting nutrient in canola production. However, in the majority of P research studies conducted in Washington it was found that P replacement strategies common in wheat production were adequate for supplying canola P needs. Anecdotal evidence indicates that soil test P can be increased through the frequent use of canola in rotation.