There's no way worrying about plant productivity in food crops should be at the top of the worry list. If you're already worrying about that, you should be worrying more about the impact of the microplastics in the food on the humans eating them.

Almost all of the comments here are talking about microplastics as something which is present everywhere at close to the same amounts, but they're specifically much higher on many vegetable croplands than everywhere else. The issue is mainly their use as what is in most references referred to as "greenhouses" which are actually nothing but plastic film which is then allowed to disintegrate into the cropland every year. They could instead have actual greenhouses, which even in the case of using plastic and not glass could be dismantled at their end of life at avoid most plastic contamination, but that would use more labor.