Evaluation of the Effect of Agricultural Management on Energy Yield and Greenhouse Gas Emission Reduction of Bioenergy Production Chains

Sjaak Conijn, Wim Corré, Hans Langeveld, Jacques Davies

Biomass Research, Wageningen, The Netherlands.
Plant Research International, Wageningen University and Research Centre (WUR), Wageningen, The Netherlands.

DOI: 10.4236/nr.2014.57030                

Abstract

The role of energy crops in reducing fossil energy use and greenhouse gas emission is much debated. To improve decision making on the use of crops for producing bioenergy, a tool (Energy Crop Simulation Model or E-CROP) has been developed to calculate 1) sustainable crop dry matter yield levels as function of agricultural inputs, and 2) gross and net energy yield and greenhouse gas emission reduction, covering the entire bioenergy production chain from sowing to distribution of bioenergy. E-CROP can be applied to a wide range of crops, soils, climatic conditions, management choices, and conversion technologies. This paper describes E-CROP and focuses on its application on four arable crops, as cultivated on two contrasting sites in the Netherlands (potato and sugar beet for bioethanol, winter oilseed rape for biodiesel and silage maize for bioelectricity) and on the effect of crop management (viz. irrigation and nitrogen fertilisation). In all situations, gross energy output exceeded total energy input. Calculated for an average situation, net energy yield ranged from 45 to 140 GJ.ha^-1. Lowering irrigation and/or fertilisation input levels generally resulted in a reduction of net energy yields. The net reduction of greenhouse gas emissions in the average situation ranged from 0.60 to 6.5 t CO₂-eq.ha^-1. In general, N₂O emission from nitrogen fertiliser caused large variations in the net reduction of greenhouse gas emission, which even became negative in some situations. Lowering nitrogen fertilisation to levels that are suboptimal for net energy yields enhanced the net reduction in greenhouse gas emission, implicating that both goals cannot be optimised simultaneously. Agricultural knowledge is important for optimising the outputs of bioenergy production chains.

Keywords

Energy Crops, Biodiesel, Bioethanol, Bioelectricity, Sustainable Production, Energy Yield, Greenhouse Gas Emission

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	Statistical Information. http://www.iea.org
[2]	Taschner, K. (1993) Who Needs Biofuels? European Environmental Bureau, Brussels.
[3]	Commission of the European Communities (2003) Directive 2003/30/EC of the European Parliament and of the Council of 17 May 2003 on the Promotion of the Use of Biofuels or Other Renewable Fuels for Transport. Brussels.
[4]	Commission of the European Communities (2009) Directive 2009/28/EC of the European Parliament and of the Council of 23 April 2009 on the Promotion of the Use of Energy from Renewable Sources. Brussels.
[5]	Hammerschlag, R. (2006) Ethanol’s Energy Return on Investment: A Survey of the Literature 1990-Present. Environmental Science & Technology, 40, 1744-1750. http://dx.doi.org/10.1021/es052024h
[6]	Kavanagh, E., Ed. (2006) This Weeks Letters. Science, 312, 1743-1738. http://dx.doi.org/10.1126/science.312.5781.1743a
[7]	Kim, S. and Dale, B.E. (2005) Life Cycle Assessment of Various Cropping Systems Utilized for Producing Biofuels: Bioethanol and Biodiesel. Biomass and Bioenergy, 29, 426-439. http://dx.doi.org/10.1016/j.biombioe.2005.06.004
[8]	Hanegraaf, M.C., Biewinga, E.E. and van der Bijl, G. (1998) Assessing the Ecological and Economic Sustainability of Energy Crops. Biomass and Bionenergy, 15, 345-355. http://dx.doi.org/10.1016/S0961-9534(98)00042-7
[9]	Fischer, G. and Schrattenholzer, L. (2001) Global Bioenergy Potentials through 2050. Biomass and Bioenergy, 20, 151-159. http://dx.doi.org/10.1016/S0961-9534(00)00074-X
[10]	Faaij, A.P.C. (2006) Bio-Energy in Europe: Changing Technology Choices. Energy Policy, 34, 322-342. http://dx.doi.org/10.1016/j.enpol.2004.03.026
[11]	Commission of the European Communities. http://ec.europa.eu/energy/renewables/studies/land_use_change_en.htm
[12]	Commission of the European Communities. http://ec.europa.eu/energy/renewables/biofuels/land_use_change_en.htm
[13]	ECS (2006) Environmental Management—Life Cycle Assessment—Principles and Framework, European Standard ISO 14040. European Committee for Standardisation, Brussels.
[14]	ECS (2006) Environmental Management—Life Cycle Assessment—Requirements and Guidelines. European Standard ISO 14044. European Committee for Standardisation, Brussels.
[15]	Kramer, K.J., Moll, H.C. and Nonhebel, S. (1999) Total Greenhouse Gas Emissions Related to the Dutch Crop Production System. Agriculture, Ecosystems & Environment, 72, 9-16. http://dx.doi.org/10.1016/S0167-8809(98)00158-3
[16]	van Ministerie, L.N.V. Brochure Mestbeleid 2006: Het Stelsel van Gebruiksnormen. http://www.hetlnvloket.nl
[17]	Jongschaap, R.E.E. (1996) ROTASK 1.0—A Dynamic Simulation Model for Continuous Cropping Systems. Reference Manual. Report No. 70, DLO Research Institute for Agrobiology and Soil Fertility Research, Wageningen.
[18]	Ten Berge, H.F.M., Withagen, J.C.M., de Ruijter, F.J., Jansen, M.J.W. and van der Meer, H.G. (2000) Nitrogen Responses in Grass and Selected Field Crops: QUADMOD Parameterisation and Extensions for STONE-Application. Report No. 24, Plant Research International, Wageningen.
[19]	Schr?der, J.J., Aarts, H.F.M., van Middelkoop, J.C., Schils, R.L.M., Velthof, G.L., Fraters, B. and Willems, W.J. (2007) Permissible Manure and Fertilizer Use in Dairy Farming Systems on Sandy Soils in the Netherlands to Comply with the Nitrates Directive Target. European Journal of Agronomy, 27, 102-114. http://dx.doi.org/10.1016/j.eja.2007.02.008
[20]	Statistical Information. http://www.cbs.nl
[21]	Dalgaard, T., Halberg, N. and Porter, J.R. (2001) A Model for Fossil Energy Use in Danish Agriculture Used to Compare Organic and Conventional Farming. Agriculture, Ecosystems & Environment, 87, 51-65. http://dx.doi.org/10.1016/S0167-8809(00)00297-8
[22]	KWIN-AGV (2006) Kwantitatieve Informatie Akkerbouw en Vollegrondsgroenteteelt 2006. PPO Publication No. 354, Praktijkonderzoek Plant & Omgeving, Lelystad.
[23]	Elsayed, M.A., Matthews, R. and Mortimer, N.D. (2003) Carbon and Energy Balances for a Range of Biofuel Options. Report B/B6/00784/REP, Energy Technology Support Unit, Harwell.
[24]	Edwards, R., Larivé, J.F., Mahieu, V. and Rouveirolles, P. (2007) Well-to-Wheels Analysis of Future Automotive Fuels and Powertrains in the European Context. JRC/Concawe/Eucar Report, Ispra.
[25]	van den Broek, R., van Walwijk, M., Niermeijer, P. and Tijmensen, M. (2003) Biofuels in the Dutch Market: A Fact-Finding Study. Report 2GAVE03.12, SenterNovem, Utrecht.
[26]	KTBL (2009) Faustzahlen Biogas. Kuratorium für Technik in der Landwirtschaft (KTBL), Darmstadt.
[27]	Vreuls, H.H.J. (2004) Nederlandse lijst van Energiedragers en Standaard CO2 Emissiefactoren. SenterNovem, Utrecht.
[28]	Jenssen, T.K. and Kongshaug, G. (2004) Energy Consumption and Greenhouse Gas Emissions in Fertiliser Production. Proceedings No. 509, The International Fertiliser Society, York.
[29]	IPCC 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol. 4, Agriculture, Forestry and Other Land Use. http://www.ipcc-nggip.iges.or.jp/public/2006gl/
[30]	Rathke, G.W., Christen, O. and Diepenbrock, W. (2005) Effects of Nitrogen Source and Rate on Productivity and Quality of Winter Oilseed Rape (Brassica napus L.) Grown in Different Crop Rotations. Field Crops Research, 94, 103-113. http://dx.doi.org/10.1016/j.fcr.2004.11.010
[31]	Nevens, F. and Reheul, D. (2001) Crop Rotation versus Monoculture; Yield, N Yield and Ear Fraction of Silage Maize at Different Levels of Mineral N Fertilization. NJAS—Wageningen Journal of Life Sciences, 49, 405-425.
[32]	Conijn, J.G., Corré, W.J., de Ruijter, F.J. and Rutgers, B. (2012) Improvements of Environmental Performance of Oilseed Cropping Systems for Biodiesel Production. The Case of Rapeseed and Sunflower Cultivation in the European Union. Report No. 435, Plant Research International, Wageningen.
[33]	Commission of the European Communities. Directive 2000/60/EC of the European Parliament and of the Council Establishing a Framework for the Community Action in the Field of Water Policy. Brussels.
[34]	Dewulf, J., van Langenhove, H. and van de Velde, B. (2005) Exergy-Based Efficiency and Renewability Assessment of Biofuel Production. Environmental Science & Technology, 39, 3878-3882. http://dx.doi.org/10.1021/es048721b
[35]	Commission of the European Communities. Directive 91/676/EEC Concerning the Protection of Waters against Pollution Caused by Nitrates from Agricultural Sources. Brussels.
[36]	BioGrace (2010) Harmonised Calculations of Biofuel Greenhouse Gas Emissions in Europe. http://www.biograce.net