Introduction

A weed or not a weed?

A few weeds still cause major crop losses, and this might lead some arable farmers to wonder whether it is worth conserving any wild plants on arable land. Until very recently, only a few botanists were worried about the disappearance of these plants. But this has changed now that familiar plants such as Cornflower and Corn Marigold are now very rare, and the Corncockle is virtually extinct in the wild. Arable land also has a reputation for being a desert for wildlife, though well-managed arable farmland can be exceptionally rich in birds, mammals, insects and plants. This book will show how simple it is for arable flowers and modern arable agriculture to live happily, side by side.

Flanders Field

The poppy has entered the cultural landscape perhaps more than any other arable plant and is still readily recognised throughout northern Europe. It has as great a cultural resonance as any other European plant, and has been a symbol of rebirth and new life since ancient Egypt. This symbolism entered new dimensions in the aftermath of the appalling destruction of the battles of Ypres and the Somme between 1914 and 1917. The battlefields bloomed with sheets of blood-red poppies (and several other arable species) in the summers following these battles, and have entered the literature, mythology and the traditions of a whole continent. In France, the Cornflower occupies a similar symbolic position. Paper poppies are still worn in Remembrance in Britain. Poppies also feature in works by the artists Claude Monet and August Renoir, amongst others.

Going, going ...

The arable flora has undergone great changes throughout Europe since the end of the 19th century, and the losses accelerated towards the end of the 20th century. Most arable plants were overwhelmed by the massive revolution in arable farming methods, including:

• more efficient seed-cleaning techniques;
• the widespread adoption of herbicides;
• the development of highly nitrogen-responsive crops;
• the increase in nitrogen applications;
• the near-complete mechanisation of farming;
• changes in crop rotations; and
• efficient field drainage.

As a result, arable land in Britain has lost most of its arable plants: several species have become extinct and many more are now rare. These include some that were once extremely common and caused serious farming problems. Cornflower is now one of Britain's most endangered plants, but until the mid- 19th century it was abundant, "a pernicious weed injurious to the corn and blunting the reapers' sickles". Corncockle and Darnel are now virtually extinct in Britain, although both remained locally common until the early 20th century.

Technology that allowed better seed-cleaning caused an initial decline in arable plants in the late 19th century, but herbicide development in the 1940s was catastrophic for many more. Corn Buttercup and Shepherd's-needle were both abundant until the early 1950s; indeed, both are listed in early weedcontrol handbooks with recommendations for their control. Hefty increases in nitrogen application and the development of highly competitive crop varieties placed additional pressure on many arable plants and may have been the major factor in the extinction of Small Bur-parsley and Lamb's-succory.

The plants of irregularly cultivated field edges, and other places which are disturbed from time to time, have also suffered from increasingly efficient farming methods. Their plight may be even greater than that of more conventional arable plants, as their special requirements are less well understood. These plants cannot compete under the shade of an arable crop and have life-cycles that do not fit well with the timing of farming practices. Many have always been restricted to south-facing chalky slopes in the warmer parts of southern England, and include such rarities as Ground-pine and Cut-leaved Germander. The dry, sandy soils of the East Anglian Breckland are also good for these plants.

Uniform fields, uniform weeds

Arable land has become increasingly uniform, due to:

• the continual use of one type of crop;
• the use of herbicides; and
• massive increases in the applications of nitrogen.

Climatic, soil and management factors, which once led to diversity of arable habitats, are now much less important. The formerly common suite of arable plants has all but gone, replaced by a small but pernicious gang including Blackgrass, Cleavers and Barren Brome. These have thrived under intensive management and now occur over large areas of Britain. Arable flowers have declined across a range of scales: at the country level, the farm and even the field scale. On conventional farms, almost all uncommon arable plants are confined to the 4m strip along the field edge. This is due to the irregular application of herbicide and fertiliser, the less efficient drilling of the crop and the effects of soil compaction. So, even where arable plants have survived, they are confined to tiny areas. This restriction to field margin refuges renders them vulnerable to yet another threat. Hedgerows and other field boundaries have been removed on a massive scale in Britain and the rest of Europe to facilitate the use of large machinery. Only half the length of hedgerow present in Britain in 1945 was still present in 1990. Not only has this removed the physical boundaries, but also the strip of less-intensively farmed land alongside the boundary where the more diverse flora can survive.

Farmland birds Other farmland wildlife has also suffered in recent years. Birds have been particularly well-studied, and of the 26 species listed as priorities in the UK Biodiversity Action Plan (UKBAP), 13 are predominantly species of lowland farmland.These include the Grey Partridge,Turtle Dove,Tree Sparrow, Skylark and Corn Bunting, all of which have declined catastrophically. The major reasons that have been identified for these declines on arable land are: reduction in the area of spring-sown cereals, and the loss of crop stubbles in the winter and bare ground in the spring; loss of mixed farming due to simplification of crop rotations and regionalised specialisation; increased use of pesticides and fertilisers; and loss of field boundaries. These have removed nesting sites and reduced availability of food during the breeding season (e.g. food for chicks) and over the winter. Corn Bunting (above) and Skylark (below).

1 East Anglian Plain	2 Breckland
3 East Anglian Chalk	4 West Anglian Plain
5 Chilterns	6 London Basin
7 North Downs	8 Wealden Greensand
9 South Downs	10 Hampshire Downs
11 South Wessex Downs	12 Thames and Avon Vales
13 Mid Vale Ridge	14 Cotswolds
15 Severn and Avon Vales	16 Wessex Vales
17 Mid Somerset Hills	18 Cornish Killas and Granites

The best areas in England for arable plants.

Survival

Despite all the pressures under which the arable flora has suffered, there are some areas of Britain where uncommon arable plants still persist.

The majority have retreated from the north of the country, and few can now be found north of Yorkshire. A few, like Corn Marigold, are still relatively widespread particularly in western Scotland.

Hot spots

The richest areas are in the south-east of England, particularly where soils are light and chalky. Fields around the coasts of southwest England and Wales can, however, also be very rich in arable plants of both calcareous and acidic sandy soils: a National Trust property in north Cornwall is one of Britain's few arable plant reserves. The heavy calcareous soils of the mid- Somerset hills have several sites for uncommon arable plants like Spreading Hedgeparsley and Broad-leaved Spurge, and one of these is managed as a Somerset Wildlife Trust reserve. There are outstanding areas for arable plants on the chalk between Salisbury and Basingstoke, and in south Cambridgeshire. The Breckland of Suffolk and Norfolk is unique in Britain with its sandy soils and continental climate; it is home to an extraordinary variety of arable plants, several of which are found nowhere else in Britain.

National and international policy

The politics of agricultural production has had a direct effect on the fortunes of arable plants. In recent years, the emphasis on economic planning after the Second World War resulted in the 1947 Agriculture Act. This was superseded on Britain's accession to the Common Market by the Common Agricultural Policy (CAP). The overall effects of the Agriculture Act and the CAP have been to encourage the intensification of arable farming by subsidising production and guaranteeing markets for surpluses. This resulted in the rapid development of agrochemicals, artificial fertilisers and farm mechanisation, and led directly to the removal of hedgerows and field boundaries in the name of efficiency - all to the detriment of Europe's arable flora and other arable wildlife.

Attempts to redress the effects of intensification began in Britain in the late 1980s with the introduction of pilot agri-environment schemes. These measures were subsequently subsumed into the government-run Environmentally Sensitive Area and Countryside Stewardship Schemes. The prospects for arable plants now look even better following the recent introduction of Arable Stewardship. Under this option of the Countryside Stewardship Scheme, farmers can be paid to manage their land to encourage the development of arable plant communities.

Further attention has been directed towards the biodiversity of arable land as a result of the UK Biodiversity Action Plan (UKBAP). This was published in 1995 as the UK government's response to the Biodiversity Convention, which was signed at the Earth Summit in Rio de Janeiro in 1992. Twelve arable flowering plants and three mosses are included on the list of species of priority concern in the UKBAP (Appendix 3). In addition, cereal field margins are included as a habitat in need of urgent conservation action. A nationally-costed Action Plan is now in place for each of the species and for cereal field margins.

A typical weedy field margin.