Exponential Nutrient Loading as a Means to Optimize Bareroot Nursery Fertility of Oak Species

摘要: Conventional fertilization in nursery culture of hardwoods may involve supply equal fertilizer doses at regularly spaced intervals during the growing season, which create a surplus available nutrients beginning and deficiency nutrient availability by end season. A method termed "exponential loading" has been successfully used propagation several conifer species, but this technique not tested hardwood culture. By supplying an exponential manner, more closely matches plant demand, improve uptake use efficiency. The amount needed to maximize reserves growth before inducing toxicity is "optimum" loading level. Because optimum levels have established for hardwoods, we examined response northern red oak (Quercus rubra) white (Q. alba) range treatments bareroot Indiana. Ammonium nitrate was applied rates ranging from 0X 4X current conventional rate. Seedling morphological nutritional parameters exhibited responses consistent with conceptual model depicting points deficiency, sufficiency, luxury consump- tion, toxicity. Maximum seedling biomass production occurred 1.0X seasonal rate, establishing sufficiency nitrogen (N) content tissues peaked 2.0X rate reflecting Toxicity 3.0X above, increased tissue N concentration, reduced dry mass content. This type analysis assist nurseries refining practices producing high quality seedlings outplanting.