Abstract Interest in the production of USDA-certified organic tobacco continues to increase. Limited research exists that focuses on organic production practices specific to tobacco. Float beds, a semi-hydroponic system, are commonly used to germinate seed and produce healthy transplants. High bicarbonate concentrations in the float bed solution are a common issue and can greatly affect seedling health. A greenhouse experiment was conducted to evaluate OMRI-certified acidifier treatments for their effects on float bed media and solution nutrient status and plant health. Treatments included acetic acid, liquid citric acid, granular citric acid, a sulfuric acid conventional check, and stagnant and aerated controls. Miniature float beds were constructed to which the acidifier treatments were applied, each containing a single 288-cell tray and fertilized with seabird guano. The aerator treatment was the only one to consistently maintain bicarbonate levels below the recommended 100 mg L−1. Aeration also created an environment that favored high nitrate and low ammonium concentrations compared to all other treatments. Dissolved oxygen remained at or above 6 mg L−1 with aeration, while the remaining five treatments resulted in concentrations below 4 mg L−1. No significant differences were found among the acidifier treatments for percent of usable transplants produced. Media selection may play a role in buffering the extreme bicarbonate concentrations, as the pH in the media tended to be lower than the more alkaline solution. The use of an aerator proved to be an effective means to manage high bicarbonate and appears to promote higher rates of nitrification of the organic fertilizer source material.

中文翻译：

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评估有机酸化剂作为有机烟草 (Nicotiana tabacum L.) 浮床系统中高碳酸氢盐浓度的纠正措施

摘要 对美国农业部认证的有机烟草生产的兴趣持续增加。有限的研究侧重于烟草特有的有机生产实践。浮床是一种半水培系统，通常用于发芽种子和产生健康的移植物。浮床溶液中的高碳酸氢盐浓度是一个常见问题，会极大地影响幼苗的健康。进行了一项温室实验，以评估 OMRI 认证的酸化剂处理对浮床介质和溶液养分状态和植物健康的影响。处理包括乙酸、液体柠檬酸、颗粒柠檬酸、硫酸常规检查以及停滞和充气控制。建造了微型浮床，并对其进行了酸化处理，每个包含一个 288 细胞的托盘，并用海鸟鸟粪施肥。曝气器处理是唯一一种将碳酸氢盐水平始终保持在推荐的 100 mg L-1 以下的方法。与所有其他处理相比，曝气还创造了一个有利于高硝酸盐和低铵浓度的环境。通过曝气，溶解氧保持在或高于 6 mg L-1，而其余 5 个处理导致浓度低于 4 mg L-1。对于产生的可用移植物的百分比，酸化剂处理之间没有发现显着差异。介质选择可能在缓冲极端碳酸氢盐浓度方面发挥作用，因为介质中的 pH 值往往低于碱性溶液。