Figure 5. Predicted effects of altering oil or protein (grain) or lignin (stover) on bioproductivity in maize. Starting composition for grain was taken as 90 g kg^–1 protein, 40 g kg^–1 oil, 20 g kg^–1 ash, and by subtraction, 850 g kg^–1 carbohydrates (starch and fiber). Initial composition for stover was 730 g kg^–1 carbohydrates, 180 g kg^–1 lignin, 40 g kg^–1 protein, and 50 g kg^–1 ash. Replacement of lignin, oil, or protein only by carbohydrates is assumed. Although oil requires most energy for its synthesis, relatively steeper slopes for lignin and protein are a result of their higher initial amounts (180 and 90 g kg^–1, respectively, compared with 40 g kg^–1 for oil) in the respective tissues.