Drip irrigation provides a trade-off between yield and nutritional quality of tomato in the solar greenhouse

Abstract

To address the twin issues of food and nutrition security, the focus of agricultural production should be shifted from biomass productivity to nutritional gains. The objectives of this study were to evaluate the impact of conversion from furrow to drip irrigation on the yield components, water productivity (WP), nutritional yield (NY) and nutritional water productivity (NWP) of tomato during two consecutive growth cycles (2017–2018) in a greenhouse in the arid area of Northwest China. Results showed that the environment under drip irrigation was more beneficial to the accumulation of phytochemicals and the formation of total antioxidant activity in tomato fruits, which also significantly increased the NWP. However, the notable decline in single fruit fresh weight reducing the tomato yield significantly under drip irrigation in summer, while the WP and NY were similar to furrow irrigation. This indicated that the NY of tomato was mainly determined by the fruit yield, while the NWP was strongly affected by the mass concentration of nutrients. In contrast, no difference was found in the single fruit fresh weight and tomato yield between drip and furrow irrigation in winter, which related to the similar environmental conditions, while the WP and NY were significantly higher under drip irrigation. In summary, the potential and water use efficiency in nutrient production of tomato were enhanced under drip irrigation, and the improvement of fruit quality can offset the negative effect of yield reduction. Therefore, drip irrigation can achieve a good balance between the high yield and superior quality of tomato fruits, meanwhile reducing the pressure on the environment caused by horticultural production. We propose that the drip irrigation should be employed in the greenhouse in arid areas for tomato production, and the concepts of NY and NWP can be further applied to other horticultural crops with high nutritional value.