A study conducted by researchers on the seasonal harvest of switch grass in winter and spring indicates that the seasonal harvest time does affect the plant’s biomass and biofuels yield. As stated in the article, seasonal time of harvest affects switchgrass yield where maximum yield was observed in mid-September or mid-August in the South Central USA and Midwest respectively. However, according to Casler and Boe, harvesting in mid-August in north-central USA reduced the stand density over time and hence a much later harvest time was predicted for this site.
Since different conversion systems require different quality of biomass to produce bio fuels, “the composition of the biomass affects the quality of bio fuels”, as stated in the article. For instance, more water composition in the biomass may hinder in its safety in storage, the cost of its transportation and its combustion efficiency; more mineral concentration/chemical composition may lead to corrosion, slagging, and fouling of boilers and increased emissions in direct combustion system. Moreover, the composition of C in the biomass can affect ethanol production from it. Therefore, the importance of seasonal harvest of switch grass is important since it is one of the crops considered to be a potential use for bio fuels, and hence the time of seasonal harvest thus affects its biomass and its composition which eventually affects bio fuels yield.
Switch grass yield reduced when the harvest was shifted from winter to spring; this depended on the snowfall. If there was a higher snowfall during the winter, the harvest reduced greatly in the spring. Although the switchgrass yield decreased, the bio fuels quality either increased or decreased depending on the assessment parameter and the target method of energy generation. High water concentration was present in the fall harvest while reduced concentration of selected minerals was found in the spring harvest. No impact was seen on the energy yield from the delay in harvest. However, each seasonal harvest had a negative effects to it and so I think this article is helpful in determining the best time to harvest switch grass such that highest bio fuels yield is obtained for the right conversion system.