Nitrogen is the most important mineral nutrient in almond production.  It is absorbed as nitrate or ammonium by active roots.  Mature almond trees use 80% of their total annual N requirement between March (full leaf out) and mid-May – June (kernel fill).    If the N isn’t available in this key application window, yield can be lost. To maximize yield (income) while minimizing N losses from the root zone ($ losses) that hurt growers wallets and may harm the environment attention to the four R’s – Right Rate, Right Time, Right Place, and Right Material — is needed in all orchard fertility programs.  Different nutrients are needed at different times and amounts by almond trees.  Spring is a key time for almond orchard nutrient management and the key time for nitrogen inputs.