Initial Results For Three Years (2008-10)
The first three seasons of field sampling have been completed. Nutrient dynamics in fruiting and non-fruiting leaves suggests that leaves of fruiting spurs may exhibit nutrient deficiencies when non-fruiting leaves on the same tree may have “adequate” leaf concentrations. (Figure 1).
This result implies that current sampling strategies may be inadequate to effectively describe tree nutrient status. Predictable change rates in nutrient concentrations through the year and consistent shape of the phenological changes in nutrient status clearly curve suggest that early season leaf analysis may be useful for nutrient management. There is substantial variability in nutrient concentration within fields, between fields, and within trees. The diversity in nutrient status and the concomitant yield data will provide valuable insight into yield and nutrient interactions.
The nutrient budget for a tree provides a calculation of plant demand for a nutrient--the amount of the nutrient required by the tree to maximize production. The amount of the nutrient lost to the environment can also be calculated. They also quantify the time course of these processes. Nutrient budgets nitrogen and potassium for the four locations under study are shown (Figure 2).