Ajay K. Bhardwaj*, P. Jasrotia, S.K. Hamilton and G.P. Robertson Great Lakes Bioenergy Research Center (GLBRC), Michigan State University, W.K.

Transcription

1 Ajay K. Bhardwaj*, P. Jasrotia, S.K. Hamilton and G.P. Robertson Great Lakes Bioenergy Research Center (GLBRC), Michigan State University, W.K. Kellogg Biological Station, 37 E. Gull lake Drive, Hickory Corners, MI 496

2 Fossil fuels vs. Biofuels: Lower emissions Potential for mitigation of droughts and desertification Cellulosic vs. Grain based: Carbon sequestration potential Rehabilitation of degraded lands Water Quality benefits One biofuel is not same as another.

3 Through climate change : Changes in the hydrological cycle Glacial melt and sea level rise Increased water temperatures Through increased climate variability: more serious and frequent extremes, such as floods, droughts, typhoons * IPCC WG 2 Fourth Assessment Report, April 27: Climate Change Impacts, adaptation and vulnerability

4 Water footprint is the amount of water used to generate a product Includes temporal and spatial dimensions: when and where water was used Crop Water Requirement (CWR)= Evapotranspiration/Yield Water footprint is critical to both human health and economic growth. Water Footprints of Biofuels= d c CWR Land Requirement of Biofuels = d c Yield D = Density of fuel, c = feedstock biofuel conversion ratio

5 Water Footprint ( m 3 /L) Water Consumed ( m 3 /MWh) Electricity < Ethanol < biodiesel Cellulosic ethanol < grain ethanol < algal ethanol* Source: UNESCO Hydro power Corn Biofuel Sugarcane Biofuel How do and how should the water footprints of different energy types impact our? 18 2 Wind Wind Gas Gas Gasoline Coal Nuclear Coal Nuclear Gasoline Energy Source Hydro Power Corn Biofuel Sugarcane Biofuel 15 How will impact on the? 12 9 If we don t have enough water for both, how do we? 6 3 * Source: Clarens et al. 21, Env. Science and Technology Corn Sugarcane Soybeans Crop

6 WHAT? Ethanol or Biodiesel Cellulosic or Grain based Mixed species or monocultures Trees or Grasses WHERE? Land Quality-marginality Prime Agricultural land Grassland, forest land Bromegrass Poplars Wheat Prairie grasses Soybean Canola HOW? Soil Management: Tillage, Residue Input Use: Fertilizer, Pesticides Harvesting Time Switchgrass Miscanthus

7 SWC (v/v) Rainfall (mm) SWC (v/v) Rainfall (mm) SWC (v/v) Rainfall (mm) Continuous Corn Soil Depth (cm) Miscanthus Soil Depth (cm) DOY Deeper roots: Better utilization of water from deeper layers vs. lesser ground water recharge Poplars DOY Soil Depth (cm) Denser canopy: Greater light interception and biomass production vs. greater water interception and losses Every Feedstock has different water footprint and hydrological implications. DOY

8 Prime Agricultural lands Marginal lands Forest lands Scale-up sites in GLBRC sustainability thrust to investigate landscape level processes CRP-S3 CRP-S2 CRP-REF LUC- carbon debt CRP-S1 Fragility-Environment AGR-S1 Food vs. Fuel Cellulosic bioenergy feedstocks(mixed sp., grasses) can provide substantial environmental and socioeconomic benefits AGR-S2 AGR-S3 Eddy-covariance flux towers

9 Land Marginality: Soil Quality Land slope and erodibility potential Land Capability Scale-Up Sites under KBS GLBRC: Net Ecosystem Exchange Land use change and land quality scenarios Landscape level production effects of switch grass-corn-mixed prairie grasses. Evaluating the potential of marginal and degraded lands for bioenergy production is important Soybean Grain Yield (Mg ha -1 )

10 Land Erodibility Factor Soil Quality Index Management can have a large influence over the inherent land quality/ marginality Agriculture CRP Land AG-S1 AG-S2 AG-S3 CRP-S1 CRP-S2 CRP-S3 CRP-REF Site Agriculture CRP Land AG-S1 AG-S2 AG-S3 CRP-S1 CRP-S2 CRP-S3 CRP-REF Site Water Footprint (m 3 / ton) Water footprints are affected by land use history as well as land quality Grain Total biomass AG-S1 AG-S2 AG-S3 CRP-S1 CRP-S2 CRP-S3 CRP-REF Site

11 Water Footprint (m 3 GJ -1 ) Soybean Biodiesel/ ethanol Burning CRP Grasses Burning as a method of energy production is >1 times more water efficient than ethanol or biodiesel production Water footprints will be lower if existing CRP grasses are used for bioenergy production compared to land use change to agricultural crops like soybeans.

12 Mean Leachate NO 3 (mg/l) Mean Leachate NH 4 (mg/l) Tillage management Fertilizers and pesticides 14 Nitrate Ammonium 1.2 Harvesting time and strategy Consumptive Use Canopy Interception Biomass processing and transportation Fertilizer rate (lb/a) Environment vs. Economics Mixed Species vs. monocultures Till-No Till Water Conservation Water Quality

13 Changes in land use and production practice will have consequences for water use, landscape hydrology and water quality in the backdrop of uncertainties of climate change effects The technology will influence consequences The extent of these changes will vary regionally The agricultural landscapes that eventually emerge will depend on incentives and programs which are yet to be defined