This is our second in a series of blog posts on improving nitrogen (N) use efficiency in California small grains. This post focuses on the use of N-rich reference zones to assess in-season N status and make management decisions based on crop need. Our goal is to help growers and consultants learn how to use N-rich zones to improve small grain N fertilizer use efficiency and reduce negative environmental outcomes. To demonstrate what we know about this practice across the small grain growing regions of the state, our team has helped growers establish N-rich zones in their fields across a wide range of soil and climatic conditions. These demonstration sites are in the Sacramento Valley, Delta Region, San Joaquin Valley, and the...