Wednesday, 30 November 2022

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.

Friday, 4 November 2022

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)

Thursday, 3 March 2022

Semi-natural habitats and Ecological Focus Areas on Irish farmland

HIighlights: We surveyed farmland habitats on tillage and more intensive beef and dairy farms. Habitat area was lower than that found in the general countryside, and was dominated by linear features (especially hedgerows). All tillage farms and the majority of pastoral farms in our sample met the current 5% EFA requirement, and the vast majority (93%) met a scenario with a 7% EFA requirement. There is a considerable amount of a broader range of wildlife habitats already present on intensively managed farms that was not included in EFA in Ireland, and is not reflected in policy or legislation. 

Open Access data: landscape classification of Ireland

The FarmForBio project has developed a landscape classification map of the Republic of Ireland. 

The map and the GIS data are now available on Teagasc’s TStor repository

Wednesday, 23 February 2022

Lower nitrous oxide emissions intensity from multi-species swards

Recent Teagasc research shows that multispecies grasslands can potentially reduce both nitrous oxide (N2O) emissions and emissions intensities, and can contribute to more sustainable grassland production. Greenhouse gas measurements carried out by Saoirse Cummins showed that the annual greenhouse gas emissions per unit output (DM yield or biomass N) from the multi-species mixture were lower than those from perennial ryegrass receiving either 150 or 300 kg ha-1 yr-1 of inorganic nitrogen (N).

Webinar: piloting a biodiversity indicator in the Teagasc National Farm Survey

As part of the EU SmartAgriHubs project, Teagasc is investigating how to incorporate biodiversity into the Teagasc National Farm Survey. In a recent webinar, I presented the first results from the application of a habitat index to a sample of 300 farms in the NFS. 

Friday, 20 August 2021

Multi-species swards: more forage with less fertiliser, and more resilient to drought

Based on a Teagasc press release from August 2021

Six-species swards outperformed perennial ryegrass monocultures and were considerably more resistant to drought. New research from Teagasc, Johnstown Castle and Trinity College Dublin shows that multi-species mixtures receiving 150 kg/ha/year of nitrogen fertiliser, out-yielded perennial ryegrass monocultures receiving double that amount of fertiliser (300 kg/ha/year). Increases in plant diversity up to six species in intensively managed grasslands reduced the impact of drought, and produced more yield with less fertiliser.

6-species swards from dairy grazing system at Teagasc, Johnstown Castle.