Bioenergy from plants and the sustainable yield challenge.
Bioenergy from plants, particularly from perennial grasses and trees, could make a substantial contribution to alleviation of global problems in climate change and energy security if high yields can be sustained. Here, yield traits in a range of key bioenergy crops are reviewed, from which several targets for future improvement can be identified. Some are already the focus of genetically modified (GM) and non-GM approaches. However, the efficient growth strategies of perennial bioenergy crops rely on newly assimilated and recycled carbon and remobilized nitrogen in a continually shifting balance between sources and sinks. This balance is affected by biotic (e.g. pest, disease) and abiotic (e.g. drought) stresses. Future research should focus on three main challenges: changing (photo)thermal time sensitivity to lengthen the growing season without risking frost damage or limiting remobilization of nutritional elements following senescence; increasing aboveground biomass without depleting belowground reserves required for next year's growth and thus without increasing the requirement for nutrient applications; and increasing aboveground biomass without increasing water use.
Karp
Angela
A
Centre for Bioenergy and Climate Change, Plant and Invertebrate Ecology Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
Shield
Ian
I
Centre for Bioenergy and Climate Change, Plant and Invertebrate Ecology Department, Rothamsted Research, Harpenden, Hertfordshire AL5 2JQ, UK.
D018533:Biomass; D018556:Crops, Agricultural / Q000254:growth & development / Q000378:metabolism*; D004736:Energy-Generating Resources; D017752:Greenhouse Effect; D006109:Poaceae / Q000254:growth & development / Q000378:metabolism*; D012621:Seasons; D014197:Trees / Q000254:growth & development / Q000378:metabolism*