Intercropping Hydroponic Lettuce with Cherry Radish for Bioregulation of Yield and Quality

Abstract:

Hydroponics contributes to food security and sustainable agriculture. However, achieving high crop quality and yield through artificial light and temperature control increases energy consumption, while multi-factor interactions introduce regulatory uncertainties. Three hydroponic systems, nutrient film technique (NFT), deep-water culture, and aeroponics were evaluated under sole cropping and lettuce/radish intercropping (a quantity ratio of 2∶1) in a non-strictly controlled environment. Results demonstrated that intercropping significantly enhanced lettuce dry matter yield (up to 19.18%) and nitrogen use efficiency (up to 21.54%), while reducing nitrite content in both lettuce (up to 31.32%) and radish (up to 33.36%). Vitamin C and soluble protein contents were also notably increased. Among different intercropping hydroponic systems, the NFT exhibited the strongest interspecific competition (LEC=0.22). Additionally, intercropping led to a decrease in the total nitrogen (TN) content of lettuce and an increase in the TN, molybdenum (Mo), and calcium (Ca) contents of radish, with the highest improvement in Ca content reaching 31.94%. These changes may have balanced crop yield and quality by influencing carbon and nitrogen metabolism. The findings can provide a theoretical basis for optimizing intercropping in hydroponic vegetable cultivation.