Abstract:

The study aimed to clarify the optimal fertilizer management scheme for winter rapeseed of the Chinese cabbage type in northern regions, and to understand the effects of different types and application rates of compound fertilizers on the dry matter accumulation and yield of winter rapeseed, thereby achieving green and efficient production. The experiment was conducted using winter rapeseed cultivar ‘Tianyou 1358’, a registered variety in Hebei Province, as the test material. Two compound fertilizer types were set: balanced fertilizer (C1) and rapeseed-specific fertilizer (C2), alongside seven application rates: 150 kg/hm² (N1), 300 kg/hm² (N2), 450 kg/hm² (N3), 600 kg/hm² (N4), 750 kg/hm² (N5), 900 kg/hm² (N6), and 1050 kg/hm² (N7). The responses of dry matter accumulation and yield of winter rapeseed to fertilizer management were examined during the 2023-2024 growing season. The results indicated that: (1) the balanced fertilizer applied at the N₅ rate and the rapeseed-specific fertilizer applied at the N₄ rate significantly enhanced yield components, thereby increasing seed yield. (2) At the same application rate, the dry matter accumulation of rapeseed treated with rapeseed-specific fertilizer was higher than that with balanced fertilizer. The application of rapeseed-specific fertilizer promoted dry matter accumulation at the maturity stage to a certain extent and increased its contribution to seed yield; however, excessive fertilizer application failed to further improve dry matter accumulation in various vegetative organs. (3) Dry matter in winter rapeseed plants was primarily distributed in stems/branches, pod shells, and seeds, with the order of dry matter accumulation across organs being stems/branches> pod shells> seeds> roots. In conclusion, considering the yield-determining factors of winter rapeseed, rapeseed-specific fertilizer is more favorable for dry matter accumulation related to yield, thereby facilitating yield improvement. Among the seven fertilizer rates tested, the application rates of 750 kg/hm² for balanced fertilizer and 600 kg/hm² for rapeseed-specific fertilizer resulted in the highest rapeseed yield and dry matter accumulation, effectively promoting seed yield formation.

Key words: winter rapeseed, compound fertilizer, fertilizer amount, agronomic traits, dry matter accumulation, yield components, fertilizer management