Hållbar sockerrörsodling för etanolframställning i Brasilien : Hur slagkraftig är dagens hållbarhetscertifiering och kan den förändra mark- och vattenpåverkan från odlingarna?

Sammanfattning: Climate changes today are mainly caused by anthropogenic activities and the increased emissions of greenhouse gases to the atmosphere and this has raised questions on how to reduce the usage of fossil fuels. Ethanol is a good alternative to conventional gas and has been used in Brazil since the 1970 ́s. In Sweden several newspapers has written about the poor working conditions on many farms thus making the Swedish company SEKAB design a certification for their ethanol to ensure that it can be considered to be a sustainable alternative. Furthermore WWF has developed a certification tool called Bonsucro in cooperation with Coca Cola, Ferrero group, BP and Shell. This is due to the fact that no global certification tool has been available up until now. In year 2014 3.6 % of the sugar cultivation in the world was certified by Bonsucro. The aim with this report is to investigate the level of sustainability of the sugar cultivation today and how it affects soil and water. The study was isolated to the area Sao-Paolo in Brazil and only investigated the cultivation process, excluding parts as transport and processing of the yield to ethanol. In addition the aim is also to investigate Bonsucro as certification tool to recognize its strengths as well as its weaknesses. The study was performed using a literature study and the simulation software Coup Model. These simulations showed five different scenarios where the cultivation differed in harvest type and how much fertilizers were added. This was to distiguince potential differences in the budgets of carbon and nitrogen. The largest environmental impacts is due to leakage of nutrients and sedimentation of water streams as well as accumulation of pesticides in the ground, local acidification, compaction of soil, erosion and degradation of the quality of the soil. The level of microorganisms and organic carbon is also likely to decrease. Pre harvest burning result in loss of biodiversity. The result from the simulations show that the model where all the leaves and the crown with no fertilizers added get the biggest yield and more important there is no leakage of nitrogen. The lowest yield was found in the model where pre harvest was implemented. The average yield is lower than the average in Brazil today, and also lower than Bonsucros standards. The results show that fertilizers are very effective during the first years after a new plant has been planted. In conclusion the study shows that the amount of fertilizers added affects the cultivation more than the choice of harvest. On the other hand excessive use of fertilizers will contribute strongly to nutrient leakage. Bonsucro is considered a good certification tool in countries where laws and regulations leave much to ask for and are not necessarily implemented. In countries such as Brazil and especially Sao Paolo where the producers follow the law relatively well, Bonsucro functions more as a tool to further ensure the sustainability of the cultivation. Since Bonsucro demands use of mechanical harvest, this certification contributes to the national adaption from manual to mechanical harvest. However Bonsucro is lacking in its ability to give clear directions on exact numbers on the levels of nutrients allowed in cultivation depending on area and soil type thus making the certification tool less transparent than what is desirable.