Abstract

The response of pepper (Capsicum annuum L.) to Ammonium-N was studied in a multispan greenhouse under soilless culture using coir fiber as substrate. Ammonium-N application rates were 0, 2, 4, 6 and 8 mM with a total-N concentration of 13 mM. The total content of the rest of all macronutrients in the nutrient solution was maintained from the beginning of the experiment until the end. The highest water uptake was recorded at 2 mM ammonium concentration in the nutrient solution. Compared to nitrate, ammonium nitrogen caused a decrease in nitrate absorption, but led to an increase when applying 8 mM ammonium. Despite a progressive increase in ammonium content in the nutrient solution, potassium absorption was constant below the ammonium concentration of 8 mM. Under a high N-NH₄ content (from 6 to 8 mM) in the nutrient solution, high toxicity was found, deriving in the appearance of deformed or noncommercial fruits. There was a significant benefit by the use of ammonium as a component in the nutrient solution. The optimum yield ammonium concentrations were found in the range from 2 to 4 mM. Nevertheless, concentrations higher than 6 mM led into a decrease in commercial production, with the production of increasing deformed fruit, out of size and/or blossom-end rot.

摘要

辣椒（Capsicum annuum L.）对氨氮的反应在无土栽培的多跨温室中使用椰壳纤维作为基质进行了研究。氨氮施用率为 0、2、4、6 和 8 mM，总氮浓度为 13 mM。从实验开始到结束，营养液中其余所有常量营养素的总含量保持不变。在营养液中铵浓度为 2 mM 时记录到最高吸水量。与硝酸盐相比，铵态氮导致硝酸盐吸收降低，但在施用 8 mM 铵时导致吸收增加。尽管营养液中的铵含量逐渐增加，但在低于 8 mM 的铵浓度时，钾的吸收是恒定的。在高 N-NH ₄营养液中的含量（从 6 到 8 mM），发现高毒性，源于变形或非商业水果的外观。使用铵作为营养液中的成分有显着的好处。最佳产量铵浓度范围为 2 至 4 mM。然而，高于 6 mM 的浓度会导致商业产量下降，导致畸形果实、尺寸过大和/或开花期腐烂的产量增加。