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ARS Home » Plains Area » Temple, Texas » Grassland Soil and Water Research Laboratory » Research » Publications at this Location » Publication #315644
Title: Allometric models for predicting aboveground biomass and carbon stock of tropical perennial C4 grasses in Hawaii

Author
item YOUKHANA, ADEL - University Of Hawaii
item OGOSHI, RICHARD - University Of Hawaii
item Kiniry, James
item MEKI, MANYOWA - Texas Agrilife Research
item NAKAHATA, MAE - Hawaiian Commercial And Sugar Company
item CROW, SUSAN - University Of Hawaii

Submitted to: Frontiers in Plant Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/2017
Publication Date: 5/2/2017
Citation: Youkhana, A.H., Ogoshi, R.M., Kiniry, J.R., Meki, M.N., Nakahata, M.H., Crow, S.E. 2017. Allometric models for predicting aboveground biomass and carbon stock of tropical perennial C4 grasses in Hawaii. Frontiers in Plant Science. 8:650. doi:10.3389/fpls.2017.00650.

Interpretive Summary: Biomass represents a promising renewable energy opportunity. Equations to estimate biomass and plant carbon (C) and plant nitrogen (N) (allometric models) will allow the rapid prediction for tropical warn season grasses being considered as potential feedstocks in subtropical and tropical locations. The objective of this study was to develop optimal models to predict aboveground biomass, biomass C and N content of individual stalks of one-year sugarcane, energycane, Napier grass, and two-year sugarcane cultivated as biofuel feedstock. For all equations, a simple power model provided the optimal prediction of aboveground biomass and its C and N stocks. Stalk diameter (D) and dewlap height (H) were the most effective predictors for aboveground biomass, biomass C and N stocks. Generalized models were either poor predictors or required similar effort for destructive harvesting and data collection that was used to develop site-specific models. These equations can be applicable for establishing aboveground reference levels of potential feedstock quantities and C content which can be used for measuring, reporting and verifying the C footprint and C budget for other, similar biofuel cropping systems.

Technical Abstract: Biomass represents a promising renewable energy opportunity that mayprovide a more sustainable alternative to the use of fossil resources by minimizing the net production of greenhouse gases. Yet, allometric models that allow the prediction of biomass, biomass carbon (C) and nitrogen (N) stocks rapidly and non-destructively have not yet been developed for tropical perennial C4 grasses currently under consideration as potential feedstocks in Hawaii and other subtropical and tropical locations. The objective of this study was to develop optimal allometric relationships and site-specific models to predict aboveground biomass, biomass C and N content of individual stalks of one-year sugarcane (Saccharum officinarum cv. 65-7052), energycane (Saccharum officinarum x Saccharum rubustom cv. MOL-6081), Napier grass (Pennisetum purpureum cv. bana grass), and two-year sugarcane cultivated as biofuel feedstock. For all allometric equations, a simple power model provided the optimal prediction of aboveground biomass and its C and N stocks. Stalk diameter (D) and dewlap height (H) were the most effective predictors for aboveground biomass, biomass C and N stocks (R2 for all crops was more than 90%). Generalized models were either poor predictors or required similar effort for destructive harvesting and data collection that was used to develop site-specific models. Although optimal prediction required the development of site-specific allometric relationships, these equations can also be applicable for establishing aboveground reference levels of potential feedstock quantities and C content which could be used for measuring, reporting and verifying the C footprint and C budget for any biofuel cropping system.