%A Jing LI,Jin-Yao YAN,Wen-Shi HU,Xiao-Kun LI,Ri-Huan CONG,Tao REN,Jian-Wei LU %T Effects of combined application of nitrogen and potassium on seed yield and nitrogen utilization of winter oilseed rape (Brassica napus L.) %0 Journal Article %D 2019 %J Acta Agronomica Sinica %R 10.3724/SP.J.1006.2019.84146 %P 941-948 %V 45 %N 6 %U {https://zwxb.chinacrops.org/CN/abstract/article_6700.shtml} %8 2019-06-12 %X

The imbalance inputs of nitrogen (N) and potassium (K) fertilizer in current agricultural production severely restricts fertilizer use efficiency and crop yield potential. In order to estimate the influence of K fertilizer application on rapeseed yield and N fertilizer use efficiency under different nitrogen application rates, field experiments using two-factor experimental design were conducted at Wuxue county, Hubei province in 2016/2017 and 2017/2018 winter oilseed rape growing seasons. Four levels of N and K fertilizer application rates were set up, which were 0, 90, 180, 270 kg N ha -1 and 0, 60, 120, 180 kg K2O ha -1, respectively. Seed yield, shoot N and K accumulation and N fertilizer use efficiency were measured at the harvest of winter oilseed rape. When K supply was insufficient (K0 and K60), the average increase rate of seed yield was 113.7%, while under sufficient K supplies (K120 and K180), the average seed yield increase rate was 172.9%. In contrast to the K0 treatment, the K120 treatment increased N fertilizer use efficiency by 16.6% on average; nevertheless, further increase K fertilizer application rate played minor role in the improvement of N fertilizer use efficiency. Considering the regional average rapeseed yield, adequate K supply could reduce the N fertilizer application rate with the average of 33.9% compared with insufficient K fertilization (K60). Consequently, the combined application of N and K fertilizers could significantly enhance rapeseed yield and N fertilizer use efficiency. In practices, besides paying more attention to N fertilizer application, K fertilizer input also should be strengthened. Optimizing N and K fertilizer application could be beneficial to further achieving higher seed yield and higher fertilizer use efficiency.