Analysis of the soil food web structure under grass and grassclover

Summary

The below ground biodiversity of soil organisms plays an important role in the functioning of the the soil ecosystem, and consequently the above ground plant production. The objective of this study is to investigate the effect of grass or grass-clover in combination with fertilisation on the soil food web structure.
In 2003 a fertilisation trial on grass and grassclover was sampled for soil organisms. Data were agglomerated in seven trophic groups, and classified by means of TWINSPAN.
TWINSPAN clearly distinguished three main soil food web structures:
Type 1: Grass plots with a high biomass of bacteria and fungi;
Type 2: Grass-clover plots with a high biomass of earthworms;
Type 3: Grass and grass-clover plots, that received relativily high fertilisation, with a high number of nematodes.
Results suggest a microbial oriented soil food web for grass and an earthworm orientated soil food web for grass-clover.