In nearly all healthy ecosystems, there is an intricate network of living organisms that coexist and provide balance to the environment. Modern approaches to agriculture counter this balance and embrace monoculture production. Within monoculture systems, there is only one type of crop which opens the crop to a number of problems, like pest infestations or disease, that result in crop damage or failure.
To counteract problems stemming from monoculture, sustainable agriculture aims to establish a more biologically diverse production environment. One common approach to achieving this is intercropping. Intercropped systems are those in which two or more crops are grown together for a specific amount of time. There are four common patterns for intercropping:
- Strip: crops are grown simultaneously in independent rows within the same field
- Row: crops are grown together simultaneously and a minimum of one crop is planted in a row
- Mixed: there is no specific order to the crops
- Relay: the growing system is dependent on the lifecycle stage of the intercropped plants. Typically, the second crop in the intercropping schedule is planted after the first crop reaches the reproductive stage and before it reaches peak maturity
In larger production environments, strip and row patterns are the most common because the crops can be harvested mechanically. When intercropping, the crops selected are chosen for profitability rather than another quality. In smaller production environments, space must be maximized and manual labor is better suited to harvesting heterogeneous plantings so mixed and relay crops might also be used.
Companion planting, conversely, is rooted in symbiotic relationships between different plants [rather than specific spacing patterns]. These relationships are designed to, for example, encourage improved resistance to pests, improved growth rigor, or for flavor enhancement.
At present, companion planting is not a common activity in industrial production environments. However, as consumer demand and environmental factors evolve, practices may change. Contrastingly, in resource poor and marginal growing environments, companion planting is already becoming more mainstream. Gardeners are also traditional practitioners of companion planting.
When companion planting practices are incorporated into agricultural production systems, companion planting can be implemented using intercropping practices. Accordingly, companion planting can be considered a sub-genre of intercropping.
In these instances, the style of intercropping, while maintaining the qualities of the four standard patterns [row, strip, mixed, and relay], is often given a unique name.
For instance, repellent intercropping is an approach where plant varieties that are offensive to a specific type of pest are incorporated into a growing space to deter the pest. Similarly, the trap crop method describes an approach where either a cultivar more attractive to a given pest is planted alongside the main crop or the same crop is planted in two intervals so that a subsection of that crop is at the pest’s preferred maturity before the main crop reaches full maturity.
- Bickerton, M. W. & Hamilton, C. G. (2012). Effects of Intercropping With Flowering Plants on Predation of Ostrinia nubilalis (Lepidoptera: Crambidae) Eggs by Generalist Predators in Bell Peppers. In Environmental Entomology, 41(3), pp. 612-620.
- Bomford, M. K. (2004). Yield, pest density, and tomato flavor effects of companion planting in garden-scale studies incorporating tomato, basil, and brussels sprout (Doctoral dissertation, West Virginia University).
- Brion, G. (2014). Controlling Pests with Plants: The power of intercropping.
- Parker, J. E., Snyder, W. E., Hamilton, G. C., & Rodriguez‐Saona, C. (2013). Companion planting and insect pest control. In Weed and Pest Control-Conventional and New Challenges. IntechOpen.