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Providing evidence to improve practice

Individual study: Bird species richness and nesting density is higher in non-tilled compared to tilled cropland

Published source details

Basore N.S., Best L.B. & Wooley J.B. (1986) Bird Nesting in Iowa No-Tillage and Tilled Cropland. The Journal of Wildlife Management, 1, 19-28


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Reduce tillage Bird Conservation

A replicated, controlled study from May-July in 1982-1984 in nine experimental sites and three control sites in cropland in Iowa, USA (Basore et al. 1986), found that farmland bird species richness and nesting density and success were higher in fields without tillage. In total, 12 species were found nesting in the non-tillage fields with an average density of 36 nests/100 ha whereas only three species with an average of 4 nests/100 ha nested in tilled fields. Nest success was greatest in fields with corn residue (48% nestling survival rate). Three no-tillage treatments (corn planted in corn residue: 125 ha); corn planted in sod residue: 117 ha); and soybeans planted in corn residue: 113) and one control treatment (corn planted in tilled fields: 129 ha) were surveyed each year. Discovered nests were monitored every 2-3 days.