Aerated drip irrigation improves watermelon yield, quality, water and fertilizer use efficiency by changing plant biomass and nutrient partitioning

Collaborative implementation of agricultural yield and fertilizer input has been a fundamental issue of sustainable and green production. Aerated drip irrigation (ADI) could potentially overcome the aforementioned conflict by enhancing crop yield, quality, and water/fertilizer use efficiency in a synergistic manner. However, its effects on the accumulation and distribution of plant biomass and nutrients are still elusive. Two consecutive years of ADI experiments were conducted to investigate the effects of irrigation frequency and fertilizer amount on agronomic performance. The results indicated that watermelon yield and IWUE were increased by 7.7–52.9% and 4.7–53.5%, respectively, compared to no-aerated (CK) treatment, and that there was a positive correlation between irrigation frequency and these increases. In addition, the application of ADI and increasing the frequency of irrigation increased the total dry matter and plant nutrient (N, P, K) contents. There was no discernible difference in watermelon performance when 20% of fertilizer was reduced in ADI conditions. ADI promoted plant biomass buildup and nutrient absorption and forced nutrient partitioning from vegetative organs (root, stem, leaf) to reproductive organs (fruit), resulting in synergistic benefits in crop yield, quality, and water/fertilizer use efficiency. ADI application once every 3 days with 80% traditional fertility application was suggested as a viable regulatory method for greenhouse watermelon. Our research sheds fresh light on the putative regulatory pathway of ADI’s beneficial effects on crop agronomic performance, with potential implications for crop production strategy.