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Providing evidence to improve practice

Action: Plant cereals for whole crop silage Farmland Conservation

Key messages

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  • Two studies (one review, one replicated trial) from the UK investigated the effects of cereal-based whole crop silage. One replicated study found that cereal-based whole crop silage fields were used more by farmland birds and supported a higher abundance of seed-eating songbirds, swallows and martins than other crop types. The same study also found that important bird food plants were more abundant in cereals than other crop types and more invertebrates were found in wheat, barley and grass silage fields compared to maize.
  • A review found one study in which cereal-based whole crop silage fields were avoided by seed-eating birds during winter, but used as much as a control during summer.

Supporting evidence from individual studies

1 

A replicated trial in 2004-2006 in northwest England (Mortimer et al. 2007) found that seed-eating songbirds and swallows and martins (Hirundinidae) were more abundant on cereal (wheat and barley) fields planted in livestock areas compared to grass silage and maize fields. For example, in winter 2005-2006, 1390-1564 seed-eating birds were recorded on barley stubbles compared to 48 on grass fields and 406 on maize. Large insect-eating birds (thrushes: Turdidae) were far more abundant on grass fields in winter (2,272 birds in total, compared to 28-789 on other field types). Important bird food plants - annual meadow grass Poa annua, field pansy Viola arvensis and chickweed Stellaria media, were more abundant in cereal crops than in maize, and in November and February were more abundant in barley stubbles than replanted wheat, maize or grass fields (only in November for chickweed). Beetles (Coleoptera), flies (Diptera) and bees, wasps, sawflies and ants (Hymenoptera) were more abundant in wheat, barley and grass fields than in maize. Winter wheat and spring barley were sown in 16 trial fields, each on a separate farm in Cheshire, Staffordshire and north Shropshire. Neighbouring maize or short-term grass silage fields were monitored for comparison. Plants, invertebrates and birds were monitored on each field, in summer 2005 and winter 2005-2006.

2 

A review of four experiments on the effects of agri-environment measures on livestock farms in the UK (Buckingham et al. 2010) found one study on cereal-based whole crop silage  (in which winter wheat planted for silage was avoided by seed-eating birds during winter, but used as much as a control spring barley crop during summer. Maize planted for silage was little used by birds in summer or winter. Fields on 16 livestock farms were studied for two growing seasons, from 2004 and 2006. Four crop-types were studied on each farm: grass, winter wheat, maize, spring barley. These results are reported in more detail by (Peach et al. 2011). This study formed part of a Defra-funded project BD1448 (Defra 2007).

Additional reference:

Defra (2007) Cereal-based whole crop silages: a potential conservation mechanism for farmland birds in pastoral landscapes. Defra report number BD1448.

3 

An update of (Mortimer et al. 2007) included data from winter 2004-2005 (Peach et al. 2011) and found that cereal-based whole crop silage fields were used significantly more by farmland birds than other crop types. Each farm contained two cereal-based whole crop silage fields (autumn-sown wheat, 5.3 ha, and spring-sown barley, 4.4 ha), one maize field (6.1 ha) and one grass field (2.1 ha). During summer, a total of 1,535 seed-eating birds and 1,901 swallows and martins (Hirundinidae) were found on barley cereal-based whole crop silage fields, compared with 847 and 197 for wheat cereal-based whole crop silage fields, 441 and 95 for maize fields, and 41 and 480 for grass fields. Northern lapwing Vanellus vanellus, insect-eating species, and crows (Corvidae) did not use cereal-based whole crop silage fields more than other types in summer. In winter, seed-eating species (seed-eating songbirds, Eurasian skylark Alauda arvensis, meadow pipit Anthus pratensis) used barley stubbles extensively, whilst insect-eating species used other crop stubbles more. The authors argue that cereal-based whole crop silage (with selectively applied herbicide, retention of over-winter stubbles and delayed harvesting) offer a practical conservation measure for seed-eating farmland birds. This study uses data from Defra report number BD1448 (Defra 2007).

Additional reference:

Defra (2007) Cereal-based whole crop silages: a potential conservation mechanism for farmland birds in pastoral landscapes. Defra report number BD1448.

Referenced papers

Please cite as:

Dicks, L.V., Ashpole, J.E., Dänhardt, J., James, K., Jönsson, A., Randall, N., Showler, D.A., Smith, R.K., Turpie, S., Williams D.R. & Sutherland, W.J. (2019) Farmland Conservation Pages 291-330 in: W.J. Sutherland, L.V. Dicks, N. Ockendon, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2019. Open Book Publishers, Cambridge, UK.