The Effects of Fertilizers on Rabbiteye Blueberry (Vaccinium ashei Reade.) Root Distribution and Fruit Yield

The root system plays an important role in the growth and development of blueberry. The aim of this study was to assess the impacts of different fertilizers on the root growth and root–yield relationship of blueberry to provide insight into the regulation of root growth and fruit yield by fertilizing from the perspective of the root system. Rabbiteye blueberry variety ‘Britewell’ as the test material, and six fertilizers, including BF, OR, CF, SF, HF, and RT were used in single-factor fertilization experiments to analyze the effects of different fertilizer treatments on the root morphology, root distribution, and fruit yield of blueberry. Fertilization overall increased the root length density and root surface area in most soil layers, and the RT treatment significantly increased the total root length density and total root surface area 98.6% and 98.5%, respectively, compared with a control lacking fertilizer. In addition, the effect of fertilization on the blueberry root system was mainly observed in the 0–20 cm layer. Fruit yield was positively correlated with total root length density and total root surface area, and negatively correlated with average root diameter. In summary, the SF and RT treatments increased the morphological indexes of the root system, particularly in the shallow soil layers, leading to an increase in blueberry fruit yield.