Short rotation coppices along watercourses - an innovative combination of sustainable agriculture and water protection

Abstract

The multiple advantages of short rotation coppices (SRC) such as sustainable energy wood production, income diversification, and ecological services are well known and investigated in various projects. Additionally, strips of SRC present an innovative instrument to buffer nutrient and pesticide contamination of watercourses induced by soil erosion. Through extensive management, provision of permanent plant cover, soil improvement, and long rotations, SRC-strips on arable land could help to achieve the goals of the EU Water Framework Directive (i.e., reduction of nutrient contamination of water bodies). In comparison to near-natural buffer strips, SRC also provides monetary benefits for farmers and therefore is a sustainable combination of agriculture production and water pollution control. SRC-strips represent a special form of agroforestry systems. From the aspect of erosion control and runoff reduction, strips should have a width of 12 - 18 m; therefore, the SRC-strips are small in comparison to conventional SRCs. This circumstance requires adapted planting strategies such as a reduced tree number (3.000 trees/ha), a rotation period of at least 10 years and manual harvest to optimise labour input and revenues. The project “Short rotation coppice along a watercourse” investigates the anticipated environmental advantages of SRC-strips. The study site, installed in 2011, is situated near Wolferschwenda in Thuringia on the edge of a field, slightly sloping towards the Bennebach stream. The experiment compares three management options for the buffer strip: cropland, grassland, and SRC (willow). Two main objectives of the project are (i) simulation of potential soil input by erosion on the study site under different crops and (ii) investigation of the retention capacity of SRC, grassland, and cropland. Intensive soil measurements carried out from 2012 until present show initial trends that SRC may be a more effective nutrient buffer than grassland. More detailed results are expected from irrigation experiments in spring 2014.