Cost-benefit analysis of an integrated cropping system for provision of environmental public goods at Balruddery, Scotland

Balruddery Farm is a 178-hectare arable farm situated 67–163 metres above sea level in a temperate Atlantic maritime environment, with average annual rainfall of 800 mm and a mean annual potential water deficit of 50–75 mm. Soils are imperfectly draining Balrownie Series with an average pH of 5.7, topsoil depths of 25–40 cm, textures ranging from sandy loam to sandy silt loam, and stone contents of 10–20% by volume. The climate has moderate exposure and moderate winters with 50–110 day degrees Celsius of accumulated frost, representing typical conditions for arable cropping in north-east Scotland.

To test, at a commercially realistic scale, whether an integrated arable cropping system can deliver improved environmental outcomes and higher levels of public goods compared with conventional practice, and to quantify the on-farm economic trade-offs during the transition from intensive to low-input management, informing the design of financial incentives for regenerative farming.

The platform is operated by the James Hutton Institute. Analysis of the first rotation found that the integrated system suffered an average financial loss of £509 per hectare per year across the full six-year rotation compared with conventional practice, ranging from £199 per hectare per year for beans to £722 per hectare per year for potatoes. This equates to a loss of 10% (potatoes) to 93% (oilseed rape) of gross margin, averaging 26% across the rotation. 

Increased costs were largely attributed to purchased municipal green waste compost; all crops had significantly lower fertiliser costs in the integrated system when compost was excluded. The authors note that any incentive scheme to promote integrated cropping would need to meet the annual financial loss identified, and that the Scottish Government's Sustainable Agriculture Grants Scheme (up to £20,000 for capital equipment) may partly cover transition costs.

Previous work at the site demonstrated improvements to soil properties and broadleaved weed diversity, and overall environmental sustainability. 

The integrated system reduces reliance on non-renewable inputs and minimises losses from the system, including nutrient leaching and greenhouse gas emissions. 

These environmental gains are predominantly public goods rather than private financial benefits to the farmer. 

Over the first six-year rotation, the integrated system achieved lower outputs and higher costs than the conventional system, with lower gross margins across all crops — a demonstration of the private cost of environmental public good provision rather than a long-term prediction, as the system aims to become more self-regulating over time.

Establishment of a split-field experimental design comparing conventional and integrated management across six fields over a six-year rotation. Integrated measures included conservation (non-inversion) tillage, tied-ridging in potatoes, compost amendment before sowing, straw chopping and incorporation, cover crops before potatoes and beans, mineral fertiliser rates based on soil nitrogen supply, clover co-cropping, blight forecasting, threshold-based pesticide applications with dose reductions, mineral biofortification, targeted weed control promoting diverse weed flora, and wildflower margins. Yield, input and economic data were collected annually and analysed using median commodity prices from 2011–2016 to avoid incorporating price fluctuations.

Michaela Roberts, The James Hutton Institute, michaela.roberts@hutton.ac.uk

Integrated arable cropping in Scotland

The Centre for Sustainable Cropping (CSC) at Balruddery Farm, near Dundee in north-east Scotland, is a long-term experimental platform established by the James Hutton Institute in 2009 to test whether arable farming can deliver improved environmental outcomes while maintaining commercial yields. It is, to the authors' knowledge, the only UK platform of its kind operating at a commercially realistic scale.

The platform uses a split-field design across a 42-hectare block of six arable fields, comparing two cropping systems side by side over a six-year rotation of potatoes, winter wheat, winter barley, winter oilseed rape, spring fava beans and spring barley. The conventional system follows standard commercial practice for the region, while the integrated system combines best-practice measures targeting soil health (conservation tillage, compost amendments, cover crops, straw incorporation), crop nutrition (legume undersowing for biological nitrogen fixation), crop protection (disease forecasting, threshold-based applications, bio-fortification) and biodiversity (wildflower margins, targeted weed control, integrated pest management). Previous work at the site demonstrated improvements in soil properties, broadleaved weed diversity and overall environmental sustainability.

Researchers used the first full six-year rotation of data to carry out a cost-benefit analysis comparing the two systems, considering fertiliser, pesticide and fuel costs alongside crop output. The analysis revealed that environmental gains from agroecological farming are largely public goods, such as biodiversity and soil maintenance, that have no direct market value. This evidence on the private costs of providing public goods informs the design of financial incentives to encourage uptake of regenerative farming practices.