Assessment of the cup plant based on soil biodiversity

Background and Objective

The general aim is to investigate the impact of the cup plant (Silphium perfoliatum) on agroecosystems with a focus on functional aspects of biodiversity. The project will provide scientific guidance for a sustainable establishment of the cup plant cropping system. This project focusses on soil biodiversity with following aims:

(i) Monitoring of soil fauna communities regarding the structural diversity of nematodes, collembolans and earthworms in crop stands of different age during the vegetation period;

(ii) Assesment of the functional role of soil biodiversity rearding decomposition dynamics of crop residues and C- and N- dynamics in soil.

Approach

Twelve fields of S. perfoliatum from experimental and farming sites were sampled for nematodes, collembolans and earthworms to investigate long-term effects of this new cropping system on soil fauna communities and functions. Sampling and extraction of soil fauna took place in spring and autumn 2012 and 2013 and followed standardized ISO-guidelines. The fields represented an artificial timeline with fields established in 2004/05, 2007, 2009, and 2011 with 3 field replicates each. Maize fields (n=3) served as control. Earthworms are identified at species level, collembolans at family level. For nematodes feeding-type determination and calculation of NCR (nematode channel ratio) is performed.

Results

The results show a trend towards higher functional complexity and biodiversity in older S. perfoliatum fields. Younger fields show small differences compared to maize. The perennial cropping system of S. perfoliatum seems to build niches for a greater variety of life forms in agroecosystems and consequently facilitates decomposition processes.