SARIC Translation: Grassland Management

Grassland is the dominant land use in the UK covering 12.4 million ha (71% of a total agricultural area). Grasslands and ruminants also have great importance to the UK economy. The value of the output (£8.2 billion) of the ruminant sector (dairy and beef cattle and sheep) is the largest in UK agriculture being substantially greater than the arable (£3.5 billion), the fruit and vegetable (£4.5 billion) and the combined pig and poultry sectors (£4.2 billion). UK grassland provides approximately 70% of the 42 million tonnes of forage dry matter consumed by UK ruminants. Hence improving UK grassland managers' systematic understanding of how daily grass growth responds to a changing climate and economic environment is critical in determining the future efficiency, resilience and profitability of the UK livestock sector.

This research translation project, undertaken with the Sustainable Agriculture Research and Innovation Club (SARIC) will translate a newly validated ESPRC UK process-based model of grass growth, termed here as the "Rothamsted grass model", (Qi et al., 2017) to create an adaptable decision-support and learning tool through co-design and innovative workshops with end-users.

The aim of the project is to translate, co-design and use a decision support and learning tool to improve the profitability and sustainability of how current and future UK farmers manage their grassland.
It has four objectives:
1. To develop the tool with the support of the Sustainable Agriculture Research and Innovation Club
2. To translate, and debug, the recently validated Rothamsted UK grass-growth model (Qi et al., 2017) into an open spreadsheet format to enable multi-functional and widespread use on farms.
3. To co-design the layout of a decision support and learning tool, using the model, with selected end-users to improve the grassland management of current and future land managers.
4. To develop current and future farmers' adaptive capacity to use the model using innovative social science methods.

The project will translate an open already-validated UK process-based model of grass growth (the Rothamsted grass model) in the format of a spreadsheet tool that can be linked to existing arable crop and financial modules. The planned impact of the project is to improve the use of grass on farms to increase profits and to minimise waste, to encourage systematic thinking to enthuse future grass managers, to provide a means of bench-marking grass productivity on farms, and to provide a tool which also potentially allows assessment of other ecosystem services provided by grassland.

Improved use of grass on-farm to increase profits: the use of the model will allow grassland farmers to systematically determine the impact of changes in temperature and rainfall, for specific soil types and cutting regimes, on the seasonal distribution of grass production and thereby more closely match supply with on-farm demand. Livestock systems are typically managed to provide a least-cost ration. Research at the University of Nottingham by Bell et al. (2011; 2015), using national production records and systems modelling, showed that improved efficiencies of production could profitably reduce greenhouse gas emissions from dairy herds. In dairy systems, if 10% of the 1.8 million dairy cows in Britain improved their feed utilisation by one kilogram per cow per day this would amount to about £9 million in increased annual profit (about £52 per cow per annum), and a potential reduction of 662 kg carbon dioxide equivalent emissions produced per cow (Bell et al. 2015). During the project we will undertake at least eight workshops with a range of grassland user groups. Assuming 10-20 farmers per group this implies at least 120 farmers. As resources allow we will seek to extend this number.

Minimising waste: optimising the use of grass will also help to minimise the proportion of nutrients consumed by the animal that are lost to the environment. For example, for ruminants, about 35% of energy consumed in the diet is lost in the form of enteric methane, faeces or urine and 77% of nitrogen consumed is excreted in faeces or urine (Bell et al. 2015). Information on supply of grass, and its associated variability, will allow better informed decisions on future needs.

Systematic thinking to enthuse future grass managers: the model will provide a systematic basis for grass-management by the next generation of farmers in the UK; demonstrating that excellent grass management can be informed by an understanding of crop ecology. Process-based models of, for example wheat growth, have enabled arable students over the past 20 years to understand how cool temperatures during grain-filling increase yields. It is an important part of the package that makes agricultural management an attractive and intellectually-stimulating career encouraging innovators to stay in the industry. We anticipate that there could also be potential spin-offs in the roadside maintenance, and grass management in urban-green space and the sports recreation sectors. From year 1 we will be working with AFTP who work with 1200 customers and potentially 200 students across five institutes (through at least two workshops).

Benchmarking: measurement is a critical step in improving grass productivity. However effective bench-marking will benefit from a systematic way of establishing if a recent high or low grass yield is the result of management or environmental effects such as higher temperatures. The model offers a way to address such confounding effects. At a time when the climate is changing, providing a systematic understanding of grass growth will enable mangers to adapt their management to changing conditions. In addition to new entrants, arable farmers are also increasingly using grass within arable rotation and they want to understand the options for improved grass management.

Cross-compatibility with multi-cropping and ecosystem models: models are not only informative in terms of yield, but they can describe how grass in different seasons, altitudes, and soil types create a range of ecosystem services. This includes supply of carbon to the soil, changes in evapotranspiration, and the capacity to retain nitrogen. Our vision is that the Rothamsted grass model will allow the UK to have a widely-used validated model that can describe how grassland creates wider societal benefits and thereby public cost-benefit analysis.