Guest Blog from Dr Rob Field, Senior Conservation Scientist, RSPB Centre for Conservation Science

A while ago, a and I colleague wrote a short piece about some work we’d done examining the relative societal benefits of land in the east Anglian fens under a nature reserve compared to its being farmed. This dealt with the trade-offs that society might want to make between various obvious (food) and less obvious (nature, flood prevention, carbon storage) benefits of any piece of land. Another piece of recently published research looks at how a land owner might balance these competing interests. It uses as its basis Hope Farm, the RSPBs arable farm in Cambridgeshire.

Entrance to RSPB Hope Farm    copyright RSPB/Andy Hay

Producing food whilst allowing wildlife to thrive

First, a bit of history: the RSPB bought Hope Farm in 1999/2000, with the aim of demonstrating that it was (and still is) possible to produce commercial quantities of food and have thriving wildlife on a ‘standard’ arable farm.

The farm essentially remained as it was before we bought it – farming conventional wheat and oilseed rape crops as any other local farmer would do, with an increasingly diverse rotation, still majoring on wheat, but with beans and peas as additional break crops. However, alongside this, very small areas of some fields (usually the least productive edge areas) started to be given over to ‘non-crops’ – vegetation that would provide seed or invertebrate food for farmland birds.

Hope Farm bird population has tripled since 2009

With the advent of Environmental Stewardship in 2007, these areas became part of an Entry Level agreement (open to any farmer in England). Over the 15 years since then, the farmland bird population of Hope Farm has tripled, in stark contrast to the national picture, of a continued decline.

Skylark chicks at Hope Farm     copyright RSPB

New research – modelling scenarios of food production

Our new paper ‘Making explicit agricultural ecosystem service trade-offs: a case study of an English lowland arable farm’ published in the International Journal of Agricultural Sustainability uses Hope Farm as it has been, with the dual aim of food production and farmland bird recovery as the starting point. We calculated the amount of food produced (using the yield figures from the combined harvesters), as well as the greenhouse gas emissions as a result of our farm management. We then contrasted this with some ‘imaginary’, modelled scenarios, in which the ‘imaginary farmer’ had different priorities. These were, farming for maximum production (no land given up to environmental stewardship, and a strict wheat dominated rotation) and farming for profit, but with a simple Entry-level stewardship agreement, using the minimum amount of land whilst ensuring effective wild bird provision).

Harvest at Hope Farm    copyright RSPB/Andy Hay

Prioritising land for farmland birds can reduce greenhouse gas emissions

The results showed that prioritising farmland bird recovery, and an increasingly diverse rotation, including leguminous, crops led to a reduction of greenhouse gas emissions of around 10%, and a reduction in total food production of around the same amount, when compared to focussing purely on food production.

However, if food yield is measured not just in quantity of food energy, but in terms of protein, the yield loss is less than 4%. This difference is due to the differing protein and energy content of different crops, and shows the potential benefits of a more diverse rotation, both for a multifunctional countryside, and for peoples’ diets. We need to grow things other than wheat!

Interestingly, we also showed that if we had stuck to a simpler rotation, but had still entered into environmental stewardship, we could have still increased bird numbers by 50% (as opposed to 200%) whist loosing only a tiny proportion of our yield.

However, emissions would have increased in line with the amount of land farmed. In reality, we managed to reduce our emissions because some land wasn’t farmed, or was farmed with beans or peas, so-called leguminous crops. This means we used less manufactured nitrogen fertiliser. Leguminous crops fix their own nitrogen from the atmosphere by using an ingenious symbiotic relationship with nitrogen fixing bacteria in their root, whereas humans have to do this via very energy intensive industrial processes.

Field beans growing at Hope Farm    copyright RSPB/Andy Hay

Finding a balance with what we want from our land

The relevance of all this is that we need, as a society, to decide how to optimise the outputs from our land. We all want various things, food, scenery, wildlife, a sense of place, a clean atmosphere.

However, farmers have to choose which of these are the priority for their land, which has knock-on consequences for other things. If you prioritise financial performance (or maximum food production – the two are not always the same), this has implications for other things, as does prioritising other things.

This work has shown just what these relationships are at a typical arable farm, and what you the impact on production to get some of the less quantifiable things we also value. Its surprisingly little to get to a less extreme system, especially if we also consider long term sustainability and the changeable nature of world markets, which currently favour wheat much less than a few years ago.

Understanding how we optimise the outputs from our land will only become more important as the global population increase and climate change presents more challenges to people and wildlife. Our results demonstrate that it is relatively easy to deliver for wildlife, which coupled with progress on food wastage and inefficient food chains will help deliver a better food system for people and wildlife.