Arable and grass fields

While the volume of biocidesA chemical substance or microorganism intended to destroy, deter, or control harmful organisms such as bacteria, fungi, viruses, insects, or other pests. They are commonly used in disinfectants, wood preservatives, and pest control products. (herbicides, insecticides, fungicides etc) applied to farmland has decreased and targeting has improved, the compounds used have become considerably more effective, both in intensity and spectrum of activity. 

On grassland, the main pesticides used are wormers (nematicides) applied direct to livestock either through ingestion or as pour-ons.  Some of these (e.g. ivermectins) are known to highly persistent in the environment, killing invertebrates inhabiting dung for example.  Treatments used to control blowflies and face flies may also be having widespread adverse impacts but research on this is currently lacking and a precautionary approach should be taken.

Rising costs, the continued loss of products that protect plants and animals and rising levels of resistance mean that the options for pesticides are shrinking. Integrated Pest Management is a coordinated farm strategy that includes the use of insects as a natural pest control. See Find out more below for more information.

The heavy application of fertilizers, whether artificial or manures, has severe environmental impacts.  These include raising the nutrient status of field margins and hedge bases so they become dominated by nettles and goosegrass and contamination of waterways, as well as damaging soil health and functioning.  They also result in air pollution, not only through increasing atmospheric nitrogen, known to be causing significant damage to many wildlife habitats, but also through ammonia release damaging communities of lichens (see the Air quality page).

Integrated Farm Management, organic farming and other ‘regenerative’ practices such as mob grazing and the use of herbal leys, aim to improve soil health and benefit biodiversity.  The popularity of such nature-friendly approaches is increasing among farmers.

Over much of the UK, minimum tillage ‘min-till’ or even no-till have been introduced, reducing soil disturbance. Depending on soil type and depth of cultivation, this decreases fossil fuel use and labour costs, increases carbon storage and nutrient and water retention, and generally improves soil health and biodiversity.  However, it can also increase the abundance of perennial and annual grass weeds at the expense of other arable plants. Where soils are already compacted minimum tillage will not on its own restore soil health and without other soil restoration measures can lead to further deterioration and therefore reduced carbon storage and increased soil run-off. See Rocks and soils.

There’s also growing appreciation of how flower-rich grasslands produce high-quality meat and dairy, improving human health and increasing farm income.

Maize is now widely grown on livestock farms for silage. However, the necessary cultivation of soil and high level of fertilizer and pesticide use often leads to loss of soil, severe water pollution and general environmental contamination.  It is also often accompanied by the loss of field margins, through ploughing and herbicide use right up to the edges.

There is increasing interest in planting trees within both arable and grass fields, both to increase overall productivity and the health of the environment, including wildlife.  Such planting is currently being promoted through agri-environment schemes. See Trees outside woodlands for useful links.

There is generally a lack of recognition of the importance of arable fields for rare plants and farmland birds. In some cases wildlife has declined due to intensification of arable (see About). However arable fields supporting rare plants and birds have also been lost due to inappropriate agri-environment options and/or converted to grassland due to a misconception that this is better for wildlife.

In comparison with other habitats, the wildlife value of arable land is poorly understood. This is partly because it covers so much land, making it difficult to survey. However, it’s also because crop types, agricultural inputs and the timing of operations vary between years, creating very different conditions. Rare arable plants can be dormant as seed in the soil for many years, only appearing when conditions such as weather and crop management are right. 

There are no currently accepted standard botanical survey or condition assessment methods for arable habitats, and no national register of biodiverse arable sites. These are significant obstacles to the conservation of arable biodiversity.

Arable field margins (as a UK priority habitat) are poorly defined – see more details and suggestions in Find out more.

Arable and grass fields are fundamental elements of the agricultural landscape and of great value for food production and economically. Any changes to their management must be evaluated within this context. Implementing actions for sustainable farming and nature (such as Integrated Pest Management) can lead to cost savings, especially in the long term. Nevertheless, many actions for nature and public goodsA commodity, product or service that’s available to all and that everyone can use repeatedly without reducing its availability to others, typically provided by a government and funded through taxes. such as natural flood management, need to be supported by public payments, usually through agri-environment schemes but sometimes private (green) finance. Others are done by farmers for the sheer enjoyment of helping and seeing wildlife.