Wildlife-friendly farming increases crop yield: evidence for ecological intensification

Abstract

Ecological intensification has been promoted as a means to achieve environmentally sustainable increases in crop yields by enhancing ecosystem functions that regulate and support production. There is, however, little direct evidence of yield benefits from ecological intensification on commercial farms growing globally important foodstuffs (grains, oilseeds and pulses). We replicated two treatments removing 3 or 8% of land at the field edge from production to create wildlife habitat in 50-60 ha patches over a 900 ha commercial arable farm in central England, and compared these to a business as usual control (no land removed). In the control fields, crop yields were reduced by as much as 38% at the field edge. Habitat creation in these lower yielding areas led to increased yield in the cropped areas of the fields, and this positive effect became more pronounced over 6 years. As a consequence, yields at the field scale were maintained--and, indeed, enhanced for some crops--despite the loss of cropland for habitat creation. These results suggested that over a 5-year crop rotation, there would be no adverse impact on overall yield in terms of monetary value or nutritional energy. This study provides a clear demonstration that wildlife-friendly management which supports ecosystem services is compatible with, and can even increase, crop yields.

Keywords: agri-environment schemes; ecosystem services; pest control; pollination; sustainable intensification of agriculture.

Figure 1.

A detailed crop yield map used to compare yield at the edge (0–9 m) with the rest of the field.

Figure 2.

Crop yield (mean ± s.e.) measured at the edge of the field (0–9 m) and the rest of the field for beans, oilseed rape and wheat between 2007 and 2011 for the 17 fields in the BAU control. N_fields = the number of fields a given crop occurred in the BAU treatment between 2007 and 2011; N_points = the total number of points used to calculate mean yields.

Figure 3.

Crop yield (mean ± s.e.) as a ratio of regional and national yields averaged for all crops (wheat, oilseed rape and field beans) and all years (2006–2011) for (a) cropped area and (b) whole field net of land removed for wildlife habitat creation. Treatments with a different letter are significantly different (p < 0.05).

Figure 4.

Yield of field beans (mean ± s.e.) as a ratio of national yields averaged over all years (2006–2011) for (a) cropped area and (b) whole field net of land removed for wildlife habitat creation. Treatments with a different letter are significantly different (p < 0.05).

Figure 5.

Trends in crop yield (mean ± s.e.) as a ratio of regional and national yields averaged for all crops (wheat, oilseed rape and field beans) for (a) cropped area and (b) whole field net of land removed for wildlife habitat creation. Treatments with a different letter are significantly different (p < 0.05).

Figure 6.

Mean (±s.e.) abundance of (a) oilseed rape and field bean pollinators (Apis mellifera and Bombus sp.) per hectare in each treatment between 2007 and 2010 and (b) predatory Carabid beetles recorded in each treatment in 2008.