Research on Cover Crop Fields

Agricultural fields provide crucial overwintering habitat for many species of waterfowl in Delta.

In addition to soil benefits for farmers, planting cover crops over the winter provides foraging material for birds such as Snow Geese, Trumpeter Swans and American Wigeon.

Every week from October to March, we monitor waterfowl presence on farmland in Delta and Richmond to understand how waterfowl are utilizing agricultural fields.

Over the winter of 2024/2025, vegetation had a strong start, but on average, the Pollinator, Radish, and Spring Cereal cover crops experienced a 53% decrease in height from January to March.

This coincides with increased waterfowl grazing throughout the late winter. During the initial round of surveys in November, 60 fields (17%) showed some evidence of waterfowl grazing, although only 3 fields (0.8%) were grazed completely to the roots. By the final round in March, 28 fields (8%) were grazed to the roots, and 169 fields (51%) showed some visible signs of grazing at some point during the season.

Fewer fields were visibly grazed this year compared to the previous year’s survey, in which 36% of fields showed signs of grazing in November, increasing to 83% by March.

Region also played an interesting role in waterfowl grazing pressure. The Fraser Valley, overall, saw less grazing when compared to Metro Vancouver.

To learn more about our Winter Cover Crop surveys, download our yearly reports below.