Optimal Nutrition and Diagnosis for Abies fraseri Christmas Trees in Michigan
Abstract Fraser fir (Abies fraseri) is a species with a highly restricted native range that is now planted widely for Christmas tree production throughout the eastern US. The southeastern US has a long history of research on nutritional demands of Fraser fir, but growers in the Upper Midwest have limited locally based nutrition research on which to draw. A survey of foliar nutrition and soil properties in Fraser fir Christmas tree plantations throughout the state of Michigan was conducted to accomplish the following objectives: 1) identify relationships between tree nutrition and tree performance, 2) identify relationship between soil properties and tree nutrition, and 3) develop Diagnosis and Recommendation Integration System (DRIS) norms for Fraser fir Christmas trees in Michigan. Foliar N, P, and K levels were all positively associated with tree performance. In contrast, Ca, Mg, and Fe levels in foliage were negatively associated with tree quality. DRIS analysis indicated nutrient imbalances resulting from excess Ca, Mg, and Fe in comparison to N, P, K, and S. High pH and base saturation of young, calcareous soils of Michigan appear to be the most important site factor limiting the production of Fraser fir in Michigan.