Intensive and semi-intensive temperate grassland systems often revolve around landscapes which have poor ecosystem services delivery. This work demonstrates that the introduction of wide spaced trees in silvopastoral agroforestry systems can make these grassland landscapes more sustainable, deliver a wide range of ecosystem services and align with a sustainable grassland management strategy. The longer animals can remain on pasture in climates with high, unpredictable rainfall, the less ammonia will be emitted from the system. Silvopasture is shown to extend the grazing season to help higher grass utilisation and give resilience to grazing during extreme rainfall, while increasing short-term carbon storage and long term carbon sequestration.
Following recent changes in EU agricultural support policy, the impending imposition of controls on fertilizer use, concerns over eutrophication, pollution and loss of biodiversity and the introduction of the Single Farm Payment (SFP), grassland farmers in Ireland are seeking alternative, diversified options for land use. It is proposed that silvopastoral systems, where widely spaced, protected trees are grown in grazed pasture in a regular or varied pattern is a sustainable, economically viable land use option. Although there are few examples of silvopastoral practice on the island of Ireland, experiments and trial plantations established since 1989 have given encouraging results. In Northern Ireland, protected Ash (Fraxinus excelsior) planted at 5 m x 5 m (400/ha) spacing in intensive sheep grazed pasture have created landscape, environmental, production, economic, social, animal welfare and sustainability benefits. Trees have been successfully managed along with the stock (sheep until year 11 then cattle), no reduction in livestock output was found until year 10 and enhanced biodiversity and animal welfare was measured. At year 15, hurley quality ash butts (126/ha) were sold for €1048/ha plus firewood. Grass production increased following removal of the trees. There are several demonstration sites of on-farm practice. In Ireland, a silvopastoral experiment was established in 2002 in ryegrass-dominated pasture grazed by beef cattle using Quercus robur in an alley design at Teagasc Johnstown Research Centre in Co. Wexford. The system has been successfully established and a unique silvopastoral resource is now available for future research at a time of increasing interest in silvopastoral systems in the EU.
From a policy perspective, in N. Ireland silvopasture will be considered as forage area and eligible for SFP as long as agriculture remains the predominant land use. This, along with its suitability for alignment with the current generation of and proposed future agrienvironment schemes, make silvopasture a sustainable, viable land use option for a range of diversified scenarios incorporating trees onto stock farms in both Northern and Southern Ireland.
Hedgerows are an intrinsic part of the agricultural landscape in Europe. As an anthropogenic feature it is difficult to ascertain the carbon storage potential. We performed a systematic literature review on the potential of hedgerows to take in and store carbon. Results show two emerging trends to consider. Aboveground biomass storage estimates range from 5 t C ha-1 to 131 t C ha-1. Maintenance of hedges is ascribed as leading to differences in estimation as a result of continually trimming and shaping. .There has also been a decline in hedge length across Europe over the past decades leading to losses of biomass. Soil organic carbon stocks below hedgerows range from 5 t C ha-1 to 360 t C ha-1. Hedgerows can thicken soil horizons, prevent erosion and interact with soil water and nutrients. The hedgerow ecosystem is highly localised with differing levels of material input and decomposition. Therefore it is needed to ascertain carbon assimilation and storage to improve estimates for national GHG inventories.
The research programme at AFBI Loughgall, Northern Ireland showed that silvopastoralism (wide spaced trees planted Economic predictions and farmer surveys of agroforestry have been favourable but it is when agroforestry is accepted for state support that on-farm planting is likely to increase. In the current RDP (2014-2020) agroforestry was included as an option in forestry measures in Ireland and in 2017 as an option in the Environmental Farming Scheme (ie an Agricultural measure) in Northern Ireland. In both measures, the planting and management specification stipulated was largely based on the research findings from the AFBI research programme. Uptake has been encouraging and these farmers and land owners will form the nucleus of a group of examples in practice which hopefully will encourage other participants.
