Abstract: In this study, a field experiment was conducted to study the balance and cycling characteristics of nitrogen(N) and phosphorus(P) under the integrated planting and breeding system in the vegetable field(VE mode) using an input-output method, with the conventional singly planting system as the control(CK mode). And the corresponding parameters were determined and analyzed: farming soil, ditch bottom mud, side ditch soil, cauliflower, aquatic products(crab, eel, fish), and water in the ditch. The results showed that the total nitrogen(TN) and total phosphorus(TP) were the largest in the fertilizer input, accounting for 89.09% and 99.73%(VE mode) and 89.20% and 99.86%(CK mode) of the total input, respectively. In the harvest season, the TN and TP of cauliflower curd, of the total output, accounted for 37.74% and 33.69% in the VE mode and 38.26% and 34.50% in the CK mode. The TN and TP input/output ratios of VE system were 67.01% and 39.51%, which both were higher than those of CK system(66.75% and 38.82%), indicating that VE mode decreased the apparent loss of N and P in the system(35.19kg and 24.38kg). Under the current input levels, the apparent balance of both TN and TP in the whole VE and CK systems were in deficit, so appropriate amount of fertilizer was needed for the two modes to guarantee crop yield and system balance. The research will be helpful to provide references for N and P cycling mechanism and balance management of the integrated plantation and breeding system in the vegetable field.

Key words: Integrated planting and breeding system, Vegetable field, Nutrient balance, Nitrogen and phosphorus