UK: Encouraging biodiversity at Colworth Estate

Colworth Estate

Deep in the English countryside near Bedford, Unilever scientists are exploring how advanced molecular and cellular biology can be used to create better foods and improve everyday products, such as washing powders and toothpastes.

When the scientists look out of their laboratory windows they can see their colleagues working to make agriculture more sustainable. The focus is largely on the impact farming has on biodiversity. Learning how to protect biodiversity can help improve farming practices worldwide.

Colworth is home to 700 scientists, technologists, legal professionals and support staff with a diverse range of skills in various areas – including agriculture. The estate covers 489 hectares, of which 83 hectares are the Colworth Science Park, including parkland, sports facilities, and a nine-hole golf course.

The remaining 406 hectares are run as a commercial farm with 328 hectares of arable land, a small amount of grassland, and 78 hectares of woodland. The farm grows oilseed rape, winter and spring wheat, field beans and also operates crop trials. The farm also runs a small pig fattening unit with 240 locally sourced pigs. A team of eight staff manage and maintain the farm and the estate.

Biodiversity action plan

Colworth faces the same challenges as other European farms where biodiversity is under threat from modern farming practices and land use.

For many years it has been managed in an environmentally sensitive manner. In 2001, working with members of Unilever's Sustainable Agriculture Programme, Colworth agronomists developed a biodiversity action plan to improve land management techniques around the farm. Key elements include:

• Woodland is periodically pruned to clear space for new plant species and, over time, encourage re-growth. Clippings are either used to maintain hedgerows or left as cover for wildlife. Open areas of land between woodland act as wildlife corridors and are only mown once wild flowers have finished flowering.

• Since the mid 1990s field margins have been established across the farm, many planted with wild flowers. They offer a habitat for birds, insects, spiders and small mammals. Research shows that natural field margins can increase overall biodiversity levels by 500% compared with cropped margins.

• Under a new plan starting in 2007, crop stubble will be left in fields between the August harvest and spring crops in February/March. The stubble helps control weeds and encourages landing birds. Skylark numbers have increased mainly as a result of rotating open crops such as peas, whilst Buzzards and Red Kites are now a regular sight around the estate.

• Existing hedgerows are maintained while new hedges are planted. Species of hedge plants are carefully chosen to match those already found on the estate, and create a diverse habitat for wildlife. Mature hedges are not trimmed between March and July to allow for bird nesting and chick rearing.

• A field that suffers from soil and drainage problems is being converted into a wetland area, complete with shallow ponds, to encourage wading birds such as Snipe.

• Only fields used for hay or silage are mown. The remaining fields are naturally grazed by livestock to maintain cover for small mammals and flowering plants.

• The estate includes a nine-hole golf course. Rough areas with flowering plants are marked as 'out of bounds'. No mowing or cutting takes place during the flowering season.

Colworth farm project

On the farm, 60 hectares are set aside for research purposes. With the help of wildlife organisations (such as The British Trust for Ornithology), consultants, academics and government bodies, agriculturists explore the effect different farming techniques have on crop yields and biodiversity.

In 2005, results from a six year study into experimental crop rotation practices, pesticide and fertiliser use, weeding and field margin management, showed a positive impact on biodiversity. Plant species and invertebrate numbers increased. Wild birds – an important biodiversity indicator – were monitored by the British Trust for Ornithology. Trial areas saw an increase in numbers, followed by a decrease once the study was over.

The land is now used for the Controlled Traffic Farming project. This looks at ways to reduce machinery costs while increasing crop yields and improving soil health. Techniques include better soil preparation and seed planting practices, along with satellite guided self-steering tractors.

The findings will be used to improve farming practices at Unilever supplier farms worldwide. Read more below.