Plant more than one crop per field (intercropping)
Overall effectiveness category Evidence not assessed
Number of studies: 1
Background information and definitions
Modern agricultural fields normally only contain a single crop, making sowing and harvest easier for the farmer. However, for sedentary butterfly and moth species, this may reduce the availability of resources. Planting more than one crop per field may increase the diversity of resources available for butterflies and moths, enabling less mobile species in particular to make better use of the landscape.
For studies on increasing diversity across a farm or farmed landscape, see “Increase crop diversity across a farm or farmed landscape”.
Supporting evidence from individual studies
A replicated, site comparison study in 2014 in 120 sites of agricultural land in Selangor, Malaysia (Asmah et al. 2017) found that smallholdings planted with oil palm and other crops (polyculture) did not differ in butterfly species richness, overall abundance or community composition from smallholdings planted with just oil palm (monoculture). There was no difference in the average number of butterfly species (polyculture: 4; monoculture: 3), overall number of individuals (polyculture: 29; monoculture: 36) or the composition of species between oil palm polycultures and monocultures (data presented as model results). Abundances of individual species in polycultures and monocultures were mixed and differences were not tested statistically (see paper for details). At 60 smallholdings oil palms were grown amongst other crops including bananas, coconuts, tapioca and sugar cane (polycultures), and at 60 oil palm was grown alone (monocultures). Smallholdings sampled were ≥300 m apart and mostly <5 ha in size. In January–August 2014, three fruit-baited traps were set ≥50 m apart from each other at each smallholding and operated for 12 h daily for three consecutive days, with regular checking. Butterflies caught were marked before release to avoid recounting. Each smallholding was sampled once.Study and other actions tested
Referenced paperAsmah S., Ghazali A., Syafiq M., Yahya M.S., Peng T.L., Norhisham A.R., Puan C.L., Azhar B. & Lindenmayer D.B. (2017) Effects of polyculture and monoculture farming in oil palm smallholdings on tropical fruit‐feeding butterfly diversity. Agricultural and Forest Entomology, 19, 70-80.