'Cover crop' definitions:

Definition of 'cover crop'

(from WordNet)
noun
Crop planted to prevent soil erosion and provide green manure

Definition of 'Cover crop'

From: GCIDE
  • Cover crop \Cov"er crop\ A catch crop planted, esp. in orchards. as a protection to the soil in winter, as well as for the benefit of the soil when plowed under in spring. [Webster 1913 Suppl.]