Revised July 1983. Reprinted January 2000. Please check for active titles in the OSU Extension Service Catalog: http://extension.oregonstate.edu/catalogGood management practices are essential if optimum fertilizer responses are to be realized. These practices include adequate irrigation, use of recommended varieties, selection of adapted soils, weed control, disease and insect control, proper seeding methods, and timely harvest. It is important that the soil be sampled and tested as a guide to fertilization. Follow recommended soil sampling procedures to estimate fertilizer needs. The Oregon State University Extension Service agent in your county can provide you with soil sampling instructions, soil sample bags, and information sheets