Table1_Effects of NH4+-N: NO3–N ratio on growth, nutrient uptake and production of blueberry (Vaccinium spp.) under soilless culture.docx

Blueberry (Vaccinium corymbosum) is a small pulp shrub, which prefers to grow on a soilless culture. For soilless culture, nutritional management remains typically vital for blueberry production. However, the effect of different nutritional treatments on blueberry growth and production is largely unknown. This study was designed to investigate to formulate a specific nutritional treatment for blueberry. The results showed that NH4+-N: NO3−-N ratios significantly affected the growth, nutrient uptake, physiological characteristics, and flowering, as well as the fruiting characteristics of blueberry plants. The number of shoots and top projection area was increased considerably by 25:75 treatment. In contrast, 50:50 treatment promotes plant height, shoot length, and stem thickness, increasing chlorophyll contents, photosynthetic capacity, and P, Ca, and Mg in leaves. In contrast, 50:50 treatment promotes the flowering fruiting rate and prolongs the blueberry flowering period. The maximum soluble sugar contents were noted in 25:75, while maximum starch contents were reported in the 50:50 treatment. The treatments 100:0 and 75:25 promote early flowering and accelerate fruit set. Notably, NH4+-N: NO3−-N ratios; 50:50 treatment significantly encourages plant growth, nutrient uptake, chlorophyll contents, photosynthetic capacity, and fruit setting rate in blueberry plants. These findings suggested that NH4+-N: NO3−-N ratios 50:50 is the most appropriate treatment that significantly promotes vegetative growth and enhances production in blueberry plants. This study provides valuable information for improved blueberry production under a controlled environment.

蓝莓（Vaccinium corymbosum）为小型浆果灌木，偏好无土栽培（soilless culture）模式。在无土栽培中，养分管理始终是蓝莓生产的关键环节。然而，目前不同养分处理对蓝莓生长与产量的影响仍未得到充分阐明。本研究旨在明确适配蓝莓的专用养分调控方案。研究结果表明，铵态氮（NH4+-N）与硝态氮（NO3−-N）的比例显著影响蓝莓植株的生长、养分吸收、生理特性、开花及坐果特性。其中，25:75处理可显著提升新梢数量与冠幅投影面积；相较而言，50:50处理可促进株高、新梢伸长与茎秆增粗，同时提升叶片叶绿素含量、光合能力以及叶片内磷（P）、钙（Ca）、镁（Mg）的含量，还可提高开花坐果率并延长蓝莓花期。可溶性糖含量在25:75处理下达到峰值，而淀粉含量的最大值则出现在50:50处理组中。100:0与75:25处理可促进蓝莓提早开花，并加快坐果进程。值得注意的是，铵态氮与硝态氮比例为50:50的处理，可显著促进蓝莓植株生长、养分吸收，提升叶绿素含量、光合能力与坐果率。综上结果表明，该比例为最适配的养分处理方案，可显著促进蓝莓营养生长并提升产量。本研究可为设施可控环境下的蓝莓高效生产提供重要参考依据。