Arable crops were once home to a broad array of flowering annual plants, but unfortunately these have declined hugely with the advent of herbicides and harvesting machinery that removes weed seeds. As a consequence, these arable plants include some of the most endangered species in Britain. A rich understorey of annuals can provide food and cover for an immense diversity of insects, and these along with the annual weed seeds in turn are essential food sources for farmland birds and mammals.
This habitat will encourage the common annual arable plants and also the rare species that may still be present on some farms. Annual plants will most likely occur around the field edges and corners where herbicide and fertiliser inputs are typically lower and soils are poorer, thus this option is best located in these areas. Before deciding where to locate this habitat it is well worthwhile checking for the occurrence of rare arable plants; a local wildlife group may be willing to conduct a survey, therefore ensuring the most appropriate areas are included. However, also try to avoid locating them where aggressive grass weeds are present.
The margin can be cultivated annually in either spring or autumn to a depth of 15cm. Arable plants can be spring or autumn germinating, but the species that survive will be those that have adapted to traditional practices and therefore this is the timing that should be followed. For example, light chalky soils were traditionally cultivated in the spring and consequently spring germinating species are most likely to be found. If however, undesirable weeds start to build-up then the timing and depth of cultivation may be changed for a year or the margin rotated around different edges of the same field.
No fertilisers or manures should be applied. Noxious weeds can be controlled using spot treatments or with a weed wiper, however, if they build up to severe levels then a targeted, broad-spectrum herbicide may be applied once the annual have set seed which is usually by September.