Evaluation Of Heating Value And Biomass Production Of Eucalyptus Plantations For Fuelwood Supply To Tea Factories In Nandi County, Kenya

Abstract

Trees and woodlots in plantation establishments produce biomass for energy supply. In developing countries where fuelwood is the main source of energy, the properties of wood in relation to energy supply are important. However, little is known about the proximate value and biomass production for energy supply of several species of trees in plantation establishments. The objective of this study was to determine the biomass energy supply of eucalyptus plantations from Eastern Produce Kenya (EPK) to Nandi Tea Factories. Specifically, the study determined the standing volume of the existing eucalyptus plantations of ages ranging from 1 years to 15 years old at EPK, the within tree variation in proximate and calorific values as a function of age and developed tree biomass and volume models above ground biomass equation. Four trees were randomly selected from each age group for destructive sampling to enable biomass and proximate value determination. The results revealed significant differences among age (P = 0.0001), calorific value (P = 0.0001), volatile matter (P = 0.0001), ash content (P = 0.0001), fixed carbon (P = 0.0001), desorption (P = 0.0001) and absorption (P = 0.0001). The mean ash content, desorption and absorption of E. grandisplantation decreased with increasing age of the trees while the volatile content, fixed carbon and calorific values increased with increasing age of the trees. Tree volume was best described by the function Tree biomass increased with volume of the forest plantation, where the biomass was fitted using the equation Y = bx + cx2with estimates for b and c being 601.7 and c being -147.6. The tree biomass and volume were positively correlated with a regression coefficient (R2) of 0.9736. There was a sigmoid relationship between the standing volume and tree age. Further research is needed to know the contribution of the soil organic components and plantation management practices in Eucalyptusplantations as they impact on the amount of biomass and hence the energy content