1a. Objectives (from AD-416):
1) Improve current decision making capabilities on HC&S land by building robust data on current practices (Temple, Parlier); 2) Create management plans to maximize yield and stability of feedstock production (Temple, Hilo); 3) Maximize bioenergy biomass stability and yield while minimizing environmental impacts at watershed scale (Temple, Parlier, Hilo); and 4) Improve water resource management and optimize biomass production for other production areas in the Hawaiian Islands and Pacific Basin (Temple, Hilo).
1b. Approach (from AD-416):
Objective 1: Develop spatial and temporal data sets form historic data for baseline analyses. Objective 2: Simulate current management impacts on feedstock yields and resource inputs. Objective 3: Demonstrate applicability of simulation approaches with validated present practices and explore watershed scale impacts of changes. Objective 4: Improve decision support for assessment of resource conditions, and utilize parallel computing and deep hydrology water balance. Documents Reimbursable with Department of Navy. Log 43854.
3. Progress Report:
The goal of this research is to develop a unified modeling framework for assessing the dependability of biomass supplies for use in the production of biofuels for the Navy. These simulation models are being developed, calibrated, and validated for use across Pacific Basin volcanic islands and globally which contributes to subobjective 3c of the inhouse parent project, "Develop improved practices for sustainable, tropical/subtropical, diversified crop production that will serve as an industry model for zero waste". Progress has been made to gather key ALMANAC model parameterization data for the evaluation of candidate high biomass energy crops; sugarcane, energy cane, energy sorghum, and banagrass; (1) Crop parameters - the basic plant growth processes that need to be parameterized to simulate bioenergy crop growth and yields. Model simulations of growth processes, such as leaf area index (LAI) over time, and dry matter accumulation, are currently being conducted to fine-tune the parameters and test the accuracy of model simulated vs. measured data; (2) Crop management - this includes information on land preparation, fertilizer application, planting, irrigation and harvesting. For sugarcane, historical crop management data for 8 fields over a 13-year period (1999-2012) will be used to further validate model performance; (3) Soils data – Currently, the ALMANAC model uses the USDA-NRCS Soil Survey Geographic (SSURGO) database for soil parameter inputs. Soil parameter data gathered by project co-operating partners (University of Hawaii at Manoa, Hawaii, and USDA, ARS, Parlier, California) has proved invaluable in correcting soil parameter errors in some specific test field sites; (4) Weather data - For more accurate model testing, field-specific weather data (18 stations) was obtained from HC&S and processed into ALMANAC compatible input formats. Given the competition for the water resources in Hawaii, sustainable production of bioenergy feedstocks will be driven by management strategies that optimize water use efficiency, enhance feedstock yields, while minimizing environmental impacts. By working closely with project co-operators, we were able to obtain crucial model parameterization data for evaluating water use efficiency and potential bioenergy cropping systems’ impacts on ecosystems services; soil organic carbon by depth, greenhouse gas fluxes (CO2, N2O and CH4 and related soil moisture and temperature), pH, soil nutrient content, etc. Simulations to compare the productivity and global warming potentials (GWPs) of sugarcane (a crop with a high water-demand) and banagrass (a relatively drought tolerant bioenergy crop) at three irrigation levels; full irrigation-100%, 75% and 50% are being conducted. Set to begin in 2014, we will adapt and apply the generated technologies to the southern USA, a region which has the perfect agroclimate for optimizing bioenergy feedstock production.