Effect of nitrogen application on biomass yield and quality of forage rape after clipping

Using 1315 plants as testing material, a field trial was conducted to study the effect of nitrogen fertiliser application on biomass yield and quality of forage rapeseed after clipping, with the ultimate aim of providing a theoretical reference for its cultivation in fallow fields of Hubei Province during winter. The results showed that after the first clipping, nitrogen fertiliser could significantly increase the biomass yield. Compared with that of the nitrogen-free control (N0), the dry weight of rape increased by 50.0% and 75.0% under N1(17.25 kg·ha-1) and N2(34.5 kg·ha-1) treatments, respectively, than that in N0. Simultaneously, the crude ash yield increased by 45.7% and 53.2%, the cellulose yield by 50.7% and 90.4%, the protein yield by 84.5% and 159.3%, the crude fat yield by 53.9% and 83.8%, and the soluble sugar yield by 64.7% and 68.5%, in the N1 and N2 treatments, respectively, than in N0. These indicated that rapeseed feed production was increased by nitrogen fertiliser application. After the first clipping, topdressing 30 kg·ha-1 is recommended for improving the yield and quality of rapeseed in the forage rapeseed test planting area.