5.1.2. Field-scale transects

Colonies can be placed at one end of a crop field, a linear sampling transect established across the field, and the number of bees visiting flowers counted (visits per min) and seed-set assessed at points along the transect to determine whether these bee visitation and yield decline with distance from the colonies (e.g. Manning and Boland, 2000). This may only be useful in large areas of crops. It is good practice to repeat the trial with the colonies at the other end of the crop. For transects,

  • Use very long fields (>400 m)
  • Establish a bee density gradient by locating colonies at one end of the field only
  • Use multiple sampling sites at intervals of 100-200 m away from the colonies