Globally, agriculture intensification is a dominant driver of biodiversity loss. The concepts of land sparing and land sharing are alternatives to seek a balance between maintaining and restoring biodiversity while producing adequate food. To date, land sparing has been suggested as the best strategy to maintain biodiversity, but very few intact lands remain on Earth for sparing. Recently, international policies for nature conservation have proposed removing land from agricultural management to meet the need for more land sparing. However, the idea of land sparing has not considered the risk of biological invasions in abandoned land. Many abandoned agricultural lands are colonized by invasive species, creating monospecific patches with low biodiversity. Such invasions have cascading effects on other trophic levels and decrease ecosystem services in nearby agricultural fields, which negatively impacts yield. Moreover, invaded abandoned fields have lower biodiversity than extensively managed agricultural land. Thus, the risk of inducing plant invasions and triggering detrimental impacts on biodiversity, ecosystem services, and agricultural yields limits land sparing from abandonment as a conservation strategy. Our simulations also suggest that land sharing may be the best solution for sustaining biodiversity when the risk of invasion is high.