ABSTRACT

Recycled hydroponic solutions used for growing crops can accumulate allelochemicals that inhibit plant growth. We applied alternating current electrodegradation (AC-ED) to fresh nonrenewed nutrient solutions (i.e. solutions remaining unchanged throughout the culture period) and once-used nonrenewed solutions (i.e. solutions that had been used for a previous culture) for detoxifying autotoxic chemicals. Four experiments were conducted in which lettuce plants were grown in different nonrenewed solutions treated with AC-ED and in renewed solution that was not treated with AC-ED. Renewed solution (50% ‘Enshi’ solution) was changed at 14-day intervals. In fresh starting solutions, no substantial difference was found in shoot fresh weight (SFW) between renewed and AC-ED-treated nonrenewed solutions at different intervals (experiment I) and frequencies (experiment III), but notably, the lowest yield was recorded in non-renewed solution. In contrast, in the case of once-used nonrenewed solution, weekly (experiment II) and thrice-weekly and continuous (experiment IV) AC-ED application showed significantly higher SFW compared to values for other solutions, and the lowest value was also found in nonrenewed once-used culture solution. Therefore, we recommend the application of AC-ED to non-renewed solution either thrice weekly or continuously for efficient detoxification of accumulated allelochemicals to improve the growth, yield and quality of lettuce under two or more successive cultivations in recycled hydroponics.

摘要

用于种植作物的循环水培溶液会积累抑制植物生长的化感物质。我们对新鲜的未更新的营养液（即在整个培养期间保持不变的溶液）和曾经使用过的未更新的溶液（即用于先前培养的溶液）应用交流电电分级 (AC-ED) 来解毒自体毒性化学物质。进行了四个实验，其中莴苣植物生长在用 AC-ED 处理的不同非更新溶液和未用 AC-ED 处理的更新溶液中。更新溶液（50% '恩施'溶液）每 14 天更换一次。在新的起始解决方案中，在不同的时间间隔（实验 I）和频率（实验 III），更新和 AC-ED 处理的非更新溶液之间的芽鲜重 (SFW) 没有显着差异，但值得注意的是，在非更新溶液中记录的产量最低。相比之下，在使用一次的非更新溶液的情况下，每周（实验 II）和每周三次和连续（实验 IV）应用 AC-ED 的 SFW 显着高于其他溶液的值，并且还发现了最低值在未更新的一次性培养液中。因此，我们建议每周三次或连续将 AC-ED 应用到非再生溶液中，以有效解毒累积的化感物质，从而在循环水培中连续两次或更多次培养下提高生菜的生长、产量和质量。