Effects of different potassium fertilizers on chlorophyll fluorescence parameters of alfalfa under waterlogging conditions

Waterlogging is animportant abiotic factor that restricts the production of alfalfa in waterlogged areas globally. The addition of elements, for example N, P, and K, can alleviate the damage to plants caused by waterlogging. Thus, the objective of the present study was to investigate the effect of different potassium fertilizers (KCl and KNO₃) on chlorophyll content, prompt fluorescence, and delayed fluorescence parameters of alfalfa under waterlogging. The results showed that the addition of KCl and KNO₃ can significantly alleviate the damage caused by waterlogging. Both the chlorophyll (Chl) a fluorescence induction transient (OJIP) curve and the delayed fluorescence further indicate that the application of KCl and KNO₃ can aleviate damage. The results of this study may provide some suggestions to prevent waterlogging stress in alfalfa and inform further research in the area.