Environmental effects of energy crop cultivation in Sweden--I: Identification and quantification

摘要

This paper presents an analysis of how energy crop cultivations in Sweden, consisting of short-rotation forest (Salix)and energy grass (reed canary grass),can be located and managed to maximise environmental benefits. The overall conclusion is that substantial environmental benefits ,ranging from global to site-specific, could be achieved when traditional annual food crops produced with current agriculture practices are replaced by dedicated perennial energy crops. The emission of greenhouse gases could be reduced by reduced carbon dioxide emissions from organic soils, by reduced nitrous oxide emissions caused by the use of fertilisers and through accumulation of soil carbon in mineral soils, which also leads to increased soil fertility. Nutrient leaching could be reduced by using energy crop cultivations as buffer strips along open streams and wind erosion could be reduced by using Salix plantations as shelter belts. Cultivation of Salix and energy grass can also be sued to purify municipal waste, such as waste water, landfill leachate, and sewage sludge .Furthermore ,the content of heavy metals in the soil can be reduced through Salix cultivation. The biodiversity is estimated to be almost unchanged, or slightly increased in open farmland. These environmental benefits, which could be achieved on up to 60 of current Swedish arable and last for 25 years of or more, will increase the value of the energy crops. The economic value of these benefits is calculated in Part II of the analysis, which is presented in second paper.