Studies Of Dynamics Of Biomass And Cloric Value For Miscanthus Floridulus

Energy crisis is a big challenge that mankind will be faced to.The exploitation of biological energy has been becoming a hot issue in the present world.Miscanthus floridulus is a C₄ rhizomatous perennial grass.The characteristics,such as rapid growth, great adaptability to different environments,high yielding,and good combustion quality makes it to be one of the most ideal crops for energy production.In order to obtain the biggest energy output for M.floridulus,the basic biological traits,for instance,both biomass and caloric value yearly dynamics;biomass characteristics;a comparison the caloric value of M.floridulus with other tall energy crops and other indicators have been researched,and based on this research,some conclusions have been obtained:(1) The phonological period of M.floridulus can be divided into 6 stages: leaf-expansion stage,stem-elongation stage,ear sprouting stage,flowering stage,seed setting stage and dry yellow stage.It grows slow in leaf-expansion stage,accelerates its growth gradually in stem-elongation stage and ear sprouting stage,reaches the fastest growth rate in flowering stage,then decreases its growth till to stop gradually.(2) The seed propagation methods should be applied when we cultivate M. floridulus on a large-scale.It has strong ability of tillering with peaks in spring and autumn.It grows very fast during the growing season,and the dry matter accumulation is quite rapid.(3) When the height of M.floridulus is up to 170～200 cm,it is appropriate time for harvesting because of obtaining the most aboveground biomass,the biggest ratio of stem to leaf and the best biomass characteristics.(4) For M.floridulus leaf the average year-round gross caloric value,the average ash content and the average ash free caloric value is 17.44 kJ·g^-1,7.03%and 18.77 kJ·g^-1 respectively;for stem the average year-round gross caloric value,the average ash content and the average ash free caloric value is 17.76 kJ·g^-1,2.55%and 18.23 kJ·g^-1 respectively. The caloric value changes with season,and it is associated with its biological and ecological characteristics.(5) Compared with the other tall grasses,M.floridulus has the higher caloric value and lower ash content.(6) There is significant effect of fertilization on the biomass characteristics of M. floridulus.Nitrogen fertilizer,phosphate fertilizer,kotassium fertilizer affect significantly the caloric values in the leaf of M.floridulus.Nitrogen fertilizer affects significantly the ash content.Kotassium fertilizer affects significantly the ash content of stem.(7) There is no significant effect of elements in M.floridulus on its caloric values.(8) Biomass energy changes with season,which was greatly affected by the aboveground biomass.Although the biomass energy vary with the biomass change, caloric value has a little significant effect on it.