Project Team: David Patterson and Gillian Young

Project code: DBS-99-19

Background:

Finding a suitable balance between maintaining profitable and sustainable livestock performance from grassland and improving farm ecosystem services is a critical challenge for the livestock industry. The species included in MSS need to be appropriately matched to deliver productivity and environmental benefits. Multispecies swards have the potential to increase dry matter production from lower fertiliser nitrogen (N) inputs while increasing livestock performance. The ever increasing environmental concerns about production systems across Europe, along with concerns about food quality and safety, favour a greater role for grassland-based livestock systems in the future.  

This project will investigate ways of combining the provision of regulating and supporting ecosystem services from grassland, with high production efficiency at farm and regional level. Apart from meat and milk production (provisioning services), multi species swards can enhance regulating ecosystems services such as carbon sequestration which might partly counteract methane emissions from ruminants, and supporting services such as soil formation and protection, nitrogen fixation and nutrient cycling. In general, the provision of ecosystems services is enhanced by species diversity. Fertile, mixed swards containing legumes can reduce energy consumption by replacing highly energy demanding nitrogen (N) fertilizer, by natural nitrogen fixation, whilst maintaining biomass production. Multi species swards may also facilitate the extension of the growing season as some species will be more productive at the beginning and end of the traditional grass growing season.  The EU Multisward project (2014) demonstrated that multi species swards combining legumes, grasses as well as shallow and deep rooting species were as productive as fertilized grasses - they produced high quality forage which gave high animal performance and high animal output per ha. Importantly these results did not appear to conflict with the enhanced delivery of a range of ecosystem services. 

Nitrogen is one of the most important factors affecting soil organic-matter formation and thus soil C accumulation. MSS which include N-fixing species can ensure the N supply necessary to support soil organic matter formation and accumulation. Previous studies show how the presence of grasses, legumes, and herbs in MSS maximize seasonal N supply (e.g. nitrate levels in soils) and N uptake by plants. There is evidence of a positive relationship between MSS and plant yields partly due to the beneficial effects that MSS may have on soil N supply, N uptake, N-use efficiency, and the overall plant-N pool of the sward. Our hypothesis is that within 3 years of seeding a MSS there should be detectable changes in the biogeochemical properties of soil organic matter, which would suggest an increase in soil C (and N) accumulation. Efficiencies in carbon and nitrogen cycling can help in mitigating GHG emissions from livestock farming systems. 

 

Project Outline:

In this project the challenge is to evaluate how multi species swards can enhance such ecosystem services whilst also investigating features of more sustainable livestock systems such as the reported advantages of reduced parasitic burden and the enhanced major and trace element supply to the grazing ruminant.  

This project will investigate aspects of: agronomy; soil health (C and N economy & species diversity); root dynamics; animal health, welfare & emissions; along with production economics. Collectively these will assess the agronomic, environmental and economic value of MSS under NI climatic conditions and how they can be best used to achieve a balance between the sustainable animal production and enhanced farm ecosystem services. This balance of provisioning service and ecosystem service, through the use of multi species swards in meat and milk production systems, will provide a much better appreciation of the interaction between land based industries and the natural environment. In turn this will help to promote enhanced policy making and regulatory capabilities for a more sustainable environment in NI.

 

Project Objectives:

The overall objective is to investigate the potential for multi species swards to enhance ecosystem services within sustainable livestock production systems. The literature review element will focus on: agronomy; soil health (Carbon economy & species diversity); root dynamics; animal health, welfare & emissions; and economics.

A consultation/steering group will be formed to provide a decision support function to ensure that project outcomes, such as farmer involvement, project outputs, linkages with the industry, are thoroughly vetted throughout the project life. 

The specific objectives of this project are: 

  1. Production of a comprehensive literature review for each topic plus a detailed experimental plan designed to address priority research questions. This will form the scientific foundations for a transformative phase 2 project.
  2. Establish a platform of MSS field plot areas to address key baseline agronomic knowledge gaps, under local conditions, in years 1-3. This will include investigation of:
  • Herbage yield: above ground biomass assessed up to six times annually and annual yield.
  • Herbage quality: N content, C content, ADF, NDF, dNDF, IVTD and CNCPS Protein fractions. NIRS calibrations for analysis of MSS will be formulated.
  • Species composition and weed invasion: assess species composition including weed biomass.
  • Soil health: decomposition rate and litter stabilisation

 

Additional Benefits:

This project will also address knowledge gaps in the following areas:

  • Agronomy
  • Soil Health
  • Root dynamics
  • Animal health and welfare
  • GHG emissions
  • Economics