Plant diversity (and drought) affect legacy effects on soil fertility

We investigated the effect of grassland diversity, drought and higher nitrogen level on legacy effects. Legacy effects (measured as yield of a follow-on crop, which reflect the influence of the preceding crop) were strongly positively affected by the proportion of legumes. Drought can impact legacy effects, but is modest relative to the effect of plant diversity. Aggregated across both ley and follow-on crop phases, the high-diversity, lower-nitrogen grassland community yielded more than the higher-nitrogen grass monoculture. 

Fig. 1. Overhead shot of the field site with the experimental design and plot management to track the effect of plant diversity, drought and fertiliser level on the legacy effect within plots.

Assessing the habitat quality of Irish field margins

 

We developed a methodology to assess the habitat quality of field margins in a set of more intensively managed farms in Ireland. Overall, we found that over half of the field margins surveyed had low or very low levels of habitat quality.

Field margin with very low habitat quality (dominated by negative indicator species)