Biodiversity Fights Off Pestilences, Experts Encourage Multicropping in Farms

Infestation of pests are usually observed on monoculture or farm fields growing only one type of crop. Barely does this happen on fields with a variety of plants, but this has been left unconsidered through the years. Now, scientists have found another key factor on how diversity plays a crucial role in preventing pestilences.

Featured in Science Daily, a paper from the journal Nature showcased new findings regarding monoculture and insect infestation. A team of reserchers from the University of California-Davis explored existing studies regarding plant-herbivore interactions with performance and population dynamics of insects. A total of 1, 325 originally identified peer-reviewed papers were included in the first phase of data collection but was narrowed down to 190 researches that qualified on the team's set of standards. The experts calculated the Jensen's effect using a a bootstrapping approach to further understand the varying data from the different studies.

Based on the results of the study, they found out that a plant's nutrient level plays a crucial role in supressing the insect population. "Insects have a perfect nutrient level that they really like," William Wetzel, a PhD student and the lead author stated. "When it's too high or too low, they do poorly."

Read: Variability in plant nutrients reduces insect herbivore performance

Wetzel also discussed that monoculture plantations can be considered as a "buffet" for herbivore insects where they can eat as much as they want in a one-stop shop. The availability of the nutrients in one patch of land makes monocropped fields as an easy target for pests.

Meanwhile, a field with a vaiety of crops does the other way around. It is still a buffet, but since the insects do not necessarily eat everything planted on that farm, it is not necessary for them to stay or to call their colleagues.

With the current practices in agriculture, Wetzel and his group recommended mixing different genotypes of plants with varying nutrient levels to sustainably control pests. He cited some practices used on mixing wheat and a variety of rice in one farm as well as planting corn and broccoli which can help provide better produce.