Abstract:

To provide a theoretical basis for water-fertilizer integration in the greenhouse cultivation of B. pekinensis, this study set up four treatments: conventional fertilization (CK), and conventional topdressing amount (T1), 33.4% reduction of topdressing fertilizer (T2) and 66.7% reduction of topdressing fertilize (T3) under drip irrigation and fertilizer integration, and used potted substrate cultivation method to explore the effects of reducing the amount of topdressing on growth, yield, partial factor productivity of fertilizer (PFP) and substrate environment. The results showed that compared with CK, T1, T2 and T3 increased the yield by 51.61%, 44.15% and 29.28%, respectively, and the yield increase was significant. PFP in T3 treatment group was the highest, reaching 139.55 kg/kg, which was 2.4 times that of CK. The water-fertilizer integration is beneficial to increasing the number of leaves, leaf divergence and the maximum leaf area, and the treatments under water-fertilizer integration after topdressing have a faster effect. High water-fertilizer can significantly increase the alkali-hydrolyzable nitrogen content of the substrate, but at the same time it will cause the concentration of soluble ions in the substrate to be too high. In conclusion, the application of water-fertilizer integration can effectively improve the yield, growth index and PFP of B. pekinensis. It is recommended that 33.4% reduction in topdressing fertilizer application can not only significantly improve the yield and PFP but also be less likely to cause salt damage.

Key words: water-fertilizer integration, partial factor productivity of fertilizer, Brassica pekinensis Lour. Rupr., yield, fertilizer reduction