Selection Considerations for Polyculture Development.

Perennial grain and oilseed production, in conjunction with polyculture, possesses the potential to move agriculture towards sustainability and provide an adaptive capacity to changing environmental conditions. Important alterations may include the broadening of the genetic make-up of perennial grain and oilseeds in cultivar development and the inclusion of food materials that may be harvested infrequently or only once at the termination of a perennial polyculture planting. Selection for community coexistence versus individual plant production has been suggested to enhance overall productivity.  Additionally, selection methodologies may need to include multi-species, competitive nurseries where both antagonistic and synergistic interactions, as seen in grasslands, may be identified. Included within a polyculture will be numerous ancillary species providing ecological and cultural benefits to the perennial crop species. Examples include legumes for N₂ fixation, numerous flowering species for pollinator attraction and retention and species selected to reduce weed encroachment with the potential of many of the included species providing multiple benefits. Polyculture design will need to be tailored to the landscape. Overall food production capacity per unit area may decrease and some end-use variability is foreseen, however long-term benefits to diversity, soils, the environment and agricultural sustainability should outweigh these concerns.