北京地区柳枝稷产量和品质的变化规律

Dynamic change of biomass and quality of switchgrass in different growing seasons

通过田间试验研究了北京地区不同生长期柳枝稷(Panicum virgatum)产量和品质变化规律。结果表明,在北京地区,柳枝稷品种Alamo地上部生物量在8月末达到最高值,此后开始下降,到10月末约降低23%,到11月末约降低30%。不同生长时期,柳枝稷品质变化明显,其纤维素、木质素含量逐渐升高,半纤维素含量逐渐降低;热值、挥发分逐渐升高;水分、灰分和固定碳含量逐渐降低;氮、氯元素含量先升高后降低,在开花期达到最高值,磷、钾、硫元素含量均逐步降低。北京地区,一般10月底,霜期到来,柳枝稷地上部已衰老枯萎,养分回流过程完成,生物质品质达较高水平,此时开始收获,比较适宜。

Switchgrass( Panicum virgatum) has the potential to produce biofuel from its lignocellulosic feedstock.A field experiment was conducted to evaluate the dynamic change of biomass yield and qualities of switchgrass( P.virgatum cv. Alamo) in different growing seasons in Beijing,China. The results showed that the aboveground biomass of switchgrass was highest in late August,and gradually decreased by 23%( from 20. 3 to 15. 2 t·ha- 1) in late October and decreased by 30% in late November. There were significant dynamic various for switchgrass qualities in different growing seasons. The nitrogen and chlorine concentrations increased firstly and then decreased with a peak value at anthesis stage in late August. The heat value,volatile,hemicellulose,lignin contents increased,and the water,ash,fixed carbon,cellulose,phosphorus,potassium,sulphur contents decreased. The offtake of all elements measured in this experiment reached the peak value in late August which suggest that late October was optimal for harvest with better qualities and higher biomass yield for Alamo in Beijing.