effect of crop, cultivation and seed addition for birds on surface weed seed densities in arable crops during winter

• Published in: Weed research Vol. 48; no. 6; pp. 503 - 511
• Main Authors: HOLLAND, J.M, SMITH, B.M, SOUTHWAY, S.E, BIRKETT, T.C, AEBISCHER, N.J
• Format: Journal Article
• Language: English
• Published: Oxford, UK Oxford, UK : Blackwell Publishing Ltd 01.12.2008; Blackwell Publishing Ltd; Wiley-Blackwell
• Subjects: agroecology; Agronomy. Soil science and plant productions; arable crops; Biological and medical sciences; birds; Cropping systems. Cultivation. Soil tillage; cultivation; Fundamental and applied biological sciences. Psychology; General agroecology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; Generalities. Agricultural and farming systems. Agricultural development; Generalities. Cropping systems and patterns; Parasitic plants. Weeds; Phytopathology. Animal pests. Plant and forest protection; predation; seed return; seedbank; weed control; Weeds; Cultural practice; Weed control; Vegetals; Seeds; Weed; Cropping system; seedbank; Ecology; arable crops; birds; Density; Agroecology; cultivation; Vertebrata; Weed science; Arable cropping system; Seed bank; Cultivated plant; Predation; Aves; seed return
• ISSN: 0043-1737; 1365-3180
• DOI: 10.1111/j.1365-3180.2008.00663.x

Weed seeds present an agronomic threat, but are also an important food resource for wildlife in winter. Weed seed densities on the soil surface in winter were examined from 1999 to 2002 in 105 fields on three different farms in UK. The effect of the preceding crop, cultivation, position within the field and the application of seed for birds (bird seed) on surface seed abundance and species composition was tested. Six or fewer species comprised c. 80% of the weed seeds. By January of each study year, the densities of seeds important for farmland birds (key seeds) were 73% or 87% lower compared with early winter on two of the farms, but were stable on the third where seeds were incorporated through cultivation. At the edge and mid-field, seed densities only exceeded 400 m⁻² in 17%, 10% and 12% of fields for total, key and dicotyledonous seeds respectively. The preceding crop only affected seed densities at one site; stubbles of winter barley had fewer seeds compared with winter wheat or spring barley. Seed densities varied between the edge and mid-field, but trends were inconsistent between sites. The density of the larger seeds (Atriplex patula, Viola arvensis, Polygonum aviculare and Chenopodium album) were reduced in fields receiving bird seed. The objectives of weed control and conservation may not be mutually exclusive because seed return was most reduced where the ground remained uncultivated through the winter, yet this also provided the best foraging opportunities for surface feeding seed predators.