Reducing nitrogen fertilizer and splitting its application can improve sweetpotato growth by enhancing photosynthesis. In a two-year experiment, researchers found that splitting nitrogen fertilizer into two applications increased photosynthetic efficiency, delayed leaf aging, and boosted biomass production compared to conventional methods. This approach led to higher chlorophyll content and improved electron transfer rates, resulting in better overall plant health and yield. Overall, splitting nitrogen fertilizer application is more beneficial for sweetpotato growth than applying it all at once.