Annual cultivated margins

Annual cultivated margins

Many cornfield flowers are now confined to the edges of arable fields.

Some of the once familiar plants such as cornflower, corncockle and corn marigold are now very rare and on the list of endangered species. Annual cultivated margins can help to provide space for these traditional plants in a modern farm landscape.

What

Uncropped cultivated margins and corners undergo annual management. The soil is disturbed, often by ploughing each year in the spring or autumn depending on the cornfield flowers present and the best time for germination. This is the most effective measure to conserve these rare and charismatic plants.

Cultivated uncropped field corner, West Hook Farm Pembrokeshire, July 2011 Cath Shellswell (Plantlife)

Why

Cornfield flowers provide food and shelter for a huge variety of wildlife, many of which have also declined across the landscape. During the spring and summer, flowers provide an essential nectar and pollen source for insects, and winter seeds are eaten by farmland birds and small mammals.

Managing margins through annual cultivation provides disturbed bare ground for annual plants to germinate and prevents more competitive grasses from dominating. Without this management, many arable plants can find it difficult to survive in the modern landscape.

There are different associations of cornfield flowers depending on the type of soil:

  • Free-draining and sandy soils tend to have a community of plants that feature corn marigold, corn spurrey and field woundwort. Regional rarities include small-flowered catchfly and lesser quaking-grass in south-west England, Wales and the Isles of Scilly, whilst Breckland sands support spring, Breckland and fingered speedwells.
  • Low-permeable and clay soils have hemp-nettles, dead-nettles and corn mint. Rare arable plants associated with these areas include corn buttercup, spreading hedge-parsley and shepherd’s-needle, and in the Cambridgeshire gateways grass-poly may grow.
  • Calcareous limestone and chalk derived soils are the most flower-rich with flowers such as night-flowering catchfly, prickly and rough poppies and Venus’-looking-glass. Rare ground-pine is found on the North Down chalk ridge running from Kent into Surrey.

Although there are some very rare plants that are tied to particular soil types and locations, there are no strict rules as often species will be present on different types of soils.

First year arable reversion, including: Smooth sowthistle (Sonchus oleraceus), Groundsel (Senecio vulgaris), White clover (Trifolium repens), Red clover (Trifolium pratense), Yellow rattle (Rhinanthus minor), Ox-eye daisy (Leucanthemum vulgare), Cornflower (Centaurea cyanus), Poppy (Papaver rhoeas), Field pansy (Viola arvensis), Ribwort plantain (Plantago lanceolata). Winterbourne Downs RSPB reserve (Manor Farm). Wiltshire, England. September 2008.

How

It is important to choose sites for annually cultivated margins carefully. Arable land is the most under-surveyed habitat in the UK, and there are still many undiscovered locations of rare arable plants. A survey in June or July may help to identify where rare and threatened arable plants could be present, and help target management to encourage their survival. It is vital for the conservation of cornfield flowers that perennial grass margins, flower-rich margins and corners and nectar-rich margins are not established where they occur. Management for these habitats does not disturb the ground sufficiently to encourage cornfield flowers and they are unlikely to bloom after the first year.

Management for cornfield flowers is part of an annual regime starting with creating bare ground.  Management for rare and threatened arable plants is only suitable if you know where they are growing, but there are wider benefits for all wildlife by managing other areas as cultivated margins in addition to targeting rare and threatened species.

The ground should be cultivated once a year in March or October/November, turning over the soil to create bare ground. The timing of cultivation depends on whether the plants present are autumn or spring germinating.

Ploughing is often better at bringing buried seed to the soil surface and minimum tillage may not disturb the ground sufficiently to trigger germination. Also, it may not remove the previous year’s vegetation growth, particularly grasses, which will reduce the light reaching the soil surface and inhibit germination. A fine seed bed should be created which allows seedlings to push their roots into the soil. This is all the management you should need to do for cornfield flowers to germinate, grow and bloom.

Consider rotating management of margins and corners around a farm or within a field to stop the build-up of problem weeds. Alternating between spring and autumn cultivation may also help reduce weed burden. Locations with rare and threatened arable plants with short seed longevity in the soil seed bank should be cultivated regularly to maintain populations.

Herbicides should be avoided during the growing season, but targeted graminicide use may be possible where grass weeds are present. Broad-spectrum herbicides could be used later in the year once the rare and threatened arable plants have set seed. However, specialist advice should always be sought about how to manage weed problems without harming the rare and threatened cornfield flowers.

Cultivated margin Chris Tomson

More information

For more specialist information and advice on arable plants, visit the Plantlife website

In practice

Here are some useful case studies and articles about how farmers are putting Farm Wildlife into practice on their farms

Case Study: Using unharvested cereal headlands combined with cultivated margins on heavy land

By Kathryn Smith | 26th September 2014

Author: Martin Lines Farm: Papley Grove Farm, Cambridgeshire Aims: Using options that need spring establishment can be difficult on heavy land. We wanted to find a way of providing conservation management without needing a great deal of work in the spring and without causing undue problems to the crop following it. I grow winter wheat, winter […]

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Case Study: Cultivated margins

By Kathryn Smith | 12th June 2013

  Author: Nicholas Watts Farm: Vine House Farm, Lincolnshire Aims: The aim was to create an insect-rich foraging habitat for farmland birds. I farm on fertile peat soils, so effective control of pernicious weeds is essential. Management: I started using this option 5 years ago. For the first four years, I cultivated annually in the spring. […]

Read More