The effects of agricultural forages on soil biology - linking the plant-soil-invertebrate ecosystem

Soil biology is key to maintaining soil health, and soil health is fundamental to the sustainability of agricultural systems. Alternative forages have higher concentrations of essential nutrients, and different rooting patterns, potentially affecting soil-plant-animal interactions. Soil fauna have significant effects on belowground processes and are a vital part of carbon/nitrogen cycling, litter decomposition and the redistribution of nutrients. It is unknown how the soil food web will be affected by different forages, whilst all other environmental variables remain the same, under field conditions. An experiment was set up to test the hypothesis that alternative forages would alter the soil habitat leading to changes in soil biology. To investigate this, plots of chicory (Cichorium intybus), red clover (Trifolium pratense) white clover (Trifolium repens) and perennial ryegrass (Lolium perenne) were established in 2009. Plots were maintained over a three year period, before soil biology samples were taken including soil mesofauna, nematodes, and earthworms. Significant differences were found between the forages and earthworm abundance, as well as some of the microarthropod groups. The implication of these results in relation to the soil food web and sustainable grassland systems is discussed.