This publication provides information on the timing and pattern of biomass accumulation and nitrogen (N) uptake for a variety of Pacific Northwest crops. You can use this information to schedule N fertilizer applications for maximum efficiency. To achieve near-maximum crop yields, an adequate supply of available N must be present during the period of rapid N uptake by the crop. Supplying N when it's most needed usually reduces the amount of N lost via nitrate leaching, denitrification, and other processes. Improving the timing of N applications can provide three benefits: It can improve crop yield and quality, it can reduce fertilizer costs, and it can help protect the environment.