Life cycle assessment of a system under no-tillage and ploughing

No-tillage and conventional plough tillage have been compared on a soil of medium heavy texture in a crop rotation without fallow period at the Inforama Ruetti in Zollikofen (Berne) since 1994. For the crop rotation period from 1999 to 2005 the environmental impact of both systems was calculated via life cycle assessment. With regard to resources, nutrients and pollutant management, the environmental impact of the no-tillage system is more favourable than the conventional system involving periodical tillage operations, both per hectare of arable land and annum, and per kilogram of harvested dry matter. For the no-tillage system positive changes were also found in the assessment of soil quality. It is essential to follow up the impacts of the slightly higher herbicide requirement characterizing the no-tillage system. In both systems, however, pollutant management is strongly influenced by the choice of the active ingredient applied. According to model calculations in which slope gradient was varied, the risk of soil erosion and P-runoff remained constantly low up to a gradient of 18 % in the no-tillage system. In contrast, the risk of runoff increased steeply with increasing slope gradient in the conventional tillage system.