Field margin botanical diversity, composition and quality on intensively managed farming systems

peer-reviewedRemaining semi-natural habitats are important refuges for farmland biodiversity, and field margins are one such habitat. Field margins consist of strips of herbaceous vegetation that are located between field boundary features such as hedgerows and the main grassland or arable field. However, little is known about their extent or ecological quality on intensively managed farmlands in Ireland. This lack of knowledge can only be addressed through the application of a standardised assessment methodology, which we developed and implemented in this study. A survey of field margins was conducted on 92 intensively managed farms, across three enterprise types (arable, beef and dairy farms) in Ireland. We describe the botanical composition and assess the ecological quality of field margins based on threshold levels of the percentage cover of positive, neutral and negative botanical indicator species that are predominantly informed by existing European Union (EU)-accepted methods for vegetation classification. Positive indicator species occurred in 77% of margins and had a mean cover of 10%. There was a high incidence of negative indicator species, occurring in 93% of margins with a mean cover of 55%. Using our quality appraisal system, 16% of field margins were of high or very high quality, and the majority (55%) were of low or very low quality. Compared to either arable or dairy farms, beef farms had a greater percentage of higher-quality margins, higher species richness and greater percentage of positive indicator species. Retaining areas of high-quality farmland habitat and enhancing those areas that have become ecologically degraded will be key to achieving the Common Agricultural Policy (CAP) objective of protecting landscapes and biodiversity. However, the implementation of appropriate management decisions requires effective evaluation of the current ecological condition of these habitats. Field margins are ubiquitous habitats in Irish farmlands and comprise a significant proportion of overall farmland habitat area. However, our results show that the majority in more intensively managed systems are in a botanically impoverished condition. Our standardised field margin quality assessment technique may offer an appropriate method of tracking change in habitat quality in response to conservation actions to improve habitat quality

A novel hybrid coagulation-constructed wetland system for the treatment of dairy wastewater

peer-reviewedConstructed wetlands (CWs) are a cost-effective and sustainable treatment technology that may be used on farms to treat dairy wastewater (DWW). However, CWs require a large area for optimal treatment and have poor long-term phosphorus removal. To overcome these limitations, this study uses a novel, pilot-scale coagulation-sedimentation process prior to loading CWs with DWW. This hybrid system, which was operated on an Irish farm over an entire milking season, performed well at higher hydraulic loading rates than conventional CWs, and obtained removal efficiencies ≥99 % for all measured water quality parameters (chemical oxygen demand, total nitrogen and phosphorus, total suspended solids and turbidity), which complied with EU directives concerning urban wastewater treatment. Overall, the hybrid coagulation-CW is a promising technology that requires a smaller area than conventional CWs and minimal operator input, and produces high effluent quality

Selecting appropriate plant indicator species for Result-Based Agri-Environment Payments schemes

peer-reviewedAgri-Environment Schemes (AES) have long been implemented across Europe to incentivise farmers to alter their management practices to improve biodiversity and water, air and soil quality. However, the cost-effectiveness of traditional action-based schemes has been questioned, and Result-Based Payment (RBP) schemes have been recommended as an alternative. To evaluate the effectiveness of management actions, RBP approaches often rely on indicator species to monitor changes in environmental conditions. The selection of appropriate indicator species for RBP follows several steps and criteria. One of the mentioned criteria is that the species should react to the farmer’s management choices. Thus, the main objective of this study is to understand how existing lists of indicator plant species (aimed at assessing ecological integrity of grasslands and hedgerows in Ireland) are suitable for RBP schemes, by assessing how different environmental and management variables are related to the presence of the plant species selected. Extensive field surveys were conducted to assess the presence and cover of indicator species in grasslands and hedgerows in two study regions in Ireland. The indicator plant species occurrence and diversity (species richness and Simpson’s Diversity Index) were correlated with variables within farmers’ control and variables outside farmers’ control. Results showed that grassland indicator species occurrence and diversity was mainly related to grassland semi-naturalness and to the diversity of habitats existing on the farm – both variables within farmers’ control – and thus were appropriate indicators for assessing the effectiveness of management and suitable for use in RBP schemes. Conversely, the occurrence and diversity of hedgerow indicator species was not strongly related to any of the explanatory variables, making them unsuitable for use in a RBP scheme. For a RBP scheme targeted at hedgerows, clear objectives will need to be established and the farmers’ management choices need to be better linked to the selected indicator species. The selection of indicator species needs to undergo scientific scrutiny to develop fair results assessments as shown by the results of this study. The analyses conducted highlight the importance of testing if the species react to the farmers’ management choices and should be a key methodological step before final indicator species lists are implemented in RBP schemes. Recommendations for results assessments in RBP approaches are discussed based on the results of this study

Does Landscape Structure Affect the Presence of Woodland Specialist Pollinators in Farmland? Implications for Agri-Environment Scheme Design

Publication history: Accepted - 19 October 2021; Published - 16 March 2022.natural or semi-natural habitats to nest and/or forage. Landscape structure has been shown to influence pollinator communities and understanding how landscape structure affects farmland pollinators can improve Agri-Environment Schemes (AES). This study explored how landscape metrics affect the presence of pollinators associated with woody vegetation in farmland in the Republic of Ireland. Two study regions were selected, and pollinators were collected using pan traps placed in farm linear features. Hoverfly and bee species were selected based on their body size and association with woody vegetation. Relevant landscape structure metrics were extracted from around each trap and used to develop explanatory models for the abundance of pollinators. The total abundance of target species was relatively low but correlated with three explanatory variables: the connectivity of the linear feature to woodlands; the distance from the trap to the closest woodland; and edge density. Hoverfly and bee abundance data, when analysed separately, showed significant differences within regions. Results seem to indicate that incentivising the connectivity of farm linear features to surrounding woodland patches and increasing optimal habitat availability in agricultural landscapes could benefit woodland specialists. This information is helpful to improving AES design.This work was supported by the Irish Department of Agriculture, Food and the Marine (DAFM) (RSF15_S_619). Open Access funding provided by IReL

Pollinator responses to farmland habitat features: one-size does not fit all

• Globally, pollinating insects face significant pressure, largely due to intensively managed agricultural systems. There has been considerable focus on the provision of resources for pollinators in agricultural landscapes, but without understanding how existing farmland habitats affect pollinators there is a risk these conservation actions could fail. • The aim of this study was to explore the relationships between the quantity, diversity, and quality of on-farm habitats with pollinator communities. To meet this aim, pollinator, floral and habitat features were assessed at twenty-nine sites, encompassing both livestock and crop systems, at a range of farming intensities, in two regions of Ireland. • Results showed that the three main taxonomic pollinator groups (hoverflies, social bees, and solitary bees) were inconsistent in their responses to habitat and environmental variables. Hoverflies were negatively associated with farms with increasing amounts of linear feature and fewer drainage ditches, whereas bumblebees were positively associated with crop farms and the number of grassy margins, drainage ditches and hedgerows at a site. Solitary bees were negatively associated with crop farms and positively associated with high floral species richness. At a species level, community analysis showed that within taxonomic groups, individual species responded differently to environmental variables. • This study demonstrates that different farm types and habitat features impact pollinator groups differently. One-size does not fit all, thus on-farm conservation actions should be designed with knowledge of taxon-specific responses to maximise benefits. The quantity and diversity of essential habitats are important along with the quality of those features in terms of their capacity to provide sufficient resources for pollinators

Opportunities within the Revised EU Common Agricultural Policy to Address the Decline of Farmland Birds: An Irish Perspective

The loss of global biological diversity continues despite on-going conservation efforts. Agriculture is the major terrestrial land use in Europe and any conservation efforts to protect biological diversity must address sustainable use of these food production systems. Using Ireland, within the European Union policy framework, as an example, the declines in farmland birds are discussed. The opportunities afforded to farmland bird conservation as a result of the recent reform to the Common Agricultural Policy (CAP) are outlined. The potential for revised and refined CAP, specifically agri-environment schemes, to deliver benefits for biodiversity and for farmland bird species within Irish agricultural ecosystems is explored. Despite all the efforts to date and the significant resources invested in implementing agri-environment measures and schemes, few attempts have been made to collect monitoring and surveillance data with which to quantitatively assess the effectiveness of schemes, and measures that are designed to assist in the recovery of farmland biodiversity, including bird species, in Ireland

The effectiveness and feasibility of using ochre as a soil amendment to sequester dissolved reactive phosphorus in runoff

Incidental losses of dissolved reactive phosphorus (DRP) to a surface waterbody originate from direct losses during land application of fertilizer, or where a rainfall event occurs immediately thereafter. Another source is the soil. One way of immobilising DRP in runoff before discharge to a surface waterbody, is to amend soil within the edge of field area with a high phosphorus (P) sequestration material. One such amendment is iron ochre, a by-product of acid mine drainage. Batch experiments utilising two grassland soils at two depths (topsoil and sub-soil), six ochre amendment rates (0, 0.15, 1.5, 7.5, 15 and 30 g kg(-1) mass per dry weight of soil) and five P concentrations (0, 5, 10, 20 and 40 mg L-1) were carried out. A proportional equation, which incorporated P sources and losses, was developed and used to form a statistical model. Back calculation identified optimal rates of ochre amendment to soil to ameliorate a specific DRP concentration in runoff. Ochre amendment of soils (with no further P inputs) was effective at decreasing DRP concentrations to acceptable levels. A rate of 30 g ochre kg(-1) soil was needed to decrease DRP concentrations to acceptable levels for P inputs of <= 10 mg L-1, which represents the vast majority of cases in grassland runoff experiments. However, although very quick and sustained metal release above environmental limits occurred, which makes it unfeasible for use as a soil amendment to control P release to a waterbody, the methodology developed within this paper may be used to test the effectiveness and feasibility of other amendments