Abstract:

To explore the influences of N, P, K fertilizer treatment and N, P, K effects on yield characters of rapeseed in high yield field, the rapeseed varieties ‘Qinyou 2’ and ‘Zhongyou 821’ were used as materials. Pure nitrogen was applied at 0 and 180 kg/hm², while phosphorus (P₂O₅) and potassium (K₂O) was 0 and 90 kg/hm² respectively to analyze the effects of N, P, K and their interaction on economic characters of rapeseed by split plot design. The results showed that the combined application of N and P increased the yield by 25.7% compared with control (blank) and increased the yield by 21.6%, 18.0% and 37.9% respectively compared with the single application of N, P and K. The best yield of the two varieties was achieved by N 180 kg/hm² + P 90 kg/hm², 3850.70 kg/hm² of ‘Qinyou 2’ and 3096.26 kg/hm² of ‘Zhongyou 821’. The yield of ‘Qinyou 2’ increased significantly compared with that of ‘Zhongyou 821’ in all the nine treatments, with an average increase of 22.2%, which was due to the difference of nutritional genotypes. Comprehensive effect analysis showed that the interaction effect of N and P was positive on yield, but it did not reach a significant level, while the individual effect of N and P was significant respectively. Further analysis of the yield increase showed that the interaction effect of N and P had a great influence on the silique number per plant of ‘Qinyou 2’, and significantly increased the plant height and 1000-grain weight of ‘Zhongyou 821’. The single effect of P was the most significant on 1000-grain weight of ‘Qinyou 2’ and the silique number per plant of ‘Zhongyou 821’. The study indicates that the yield under the combined application of N and P is significantly higher than that under their single application, and the accumulation of individual effect contributes the most to the yield increase, N application rate of 180 kg/hm² with P application rate of 90 kg/hm² is suitable in Guanzhong high yield field of rapeseed.

Key words: rapeseed, NPK, high yield field, effect, yield character