Plant cereals for whole crop silage

Overall effectiveness category Unknown effectiveness (limited evidence)
Number of studies: 3
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How is the evidence assessed?

Effectiveness

80%
Certainty

28%
Harms

not assessed

Calculating overall effectiveness category

Background information and definitions

Cereal-based wholecrop silage is an intervention that involves growing crops, not grass, to turn into silage. This may provide seed resources for grain-eating farmland birds throughout the year and provide habitat for invertebrates.

Study locations

Key messages

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.

About key messages

Key messages provide a descriptive index to studies we have found that test this intervention.

Studies are not directly comparable or of equal value. When making decisions based on this evidence, you should consider factors such as study size, study design, reported metrics and relevance of the study to your situation, rather than simply counting the number of studies that support a particular interpretation.

Supporting evidence from individual studies

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.
Study and other actions tested
Referenced paper
Mortimer S.R. (2007) Cereal-based whole crop silages: potential biodiversity benefits of cereal production in pastoral landscapes. Aspects of Applied Biology, 81, 77-86.
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.
Study and other actions tested
Referenced paper
Buckingham D.L, Atkinson P.W., Peel S. & Peach W. (2010) New conservation measures for birds on grassland and livestock farms. Proceedings of the Lowland Farmland Birds III: delivering solutions in an uncertain world, 60.
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.
Study and other actions tested
Referenced paper
Peach W.J., Dodd S., Westbury D.B., Mortimer S.R., Lewis P., Brook A.J., Harris S.J., Kessock-Philip R., Buckingham D.L. & Chaney K. (2011) Cereal-based wholecrop silages: a potential conservation measure for farmland birds in pastoral landscapes. Biological Conservation, 836-850.

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. (2020) Farmland Conservation. Pages 283-321 in: W.J. Sutherland, L.V. Dicks, S.O. Petrovan & R.K. Smith (eds) What Works in Conservation 2020. Open Book Publishers, Cambridge, UK.

Where has this evidence come from?

List of journals searched by synopsis

All the journals searched for all synopses

This Action forms part of the Action Synopsis:

Farmland Conservation

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