Never a clear answer and "the" answer varies from one place to another. Homeowners are poorly trained in the use and application plus the cost to anyone individual is minimal so there are over applications, off-label uses, etc. Farmers do get a bad wrap but the truth is that they have very few options because the large seed/pesticide companies don't offer them many choices plus there is a strong social side to it all with farmers in one area all using about the same methods, etc. Farmers are generally better trained (here they have to be certified to use certain chemicals) and the price hits their bottom line so they are less likely to overapply, etc. The issue is how much of a given landscape is in the various cover types--be it backyards, farmed fields, or whatever. I never worry about my bees foraging on corn or even soybeans because my locations have better choices for them. In less desirable spots where good bee forage is limiting, the bees do forage on corn and other low quality or even contaminated flowers because that's about all they have during dearth periods. In my neck of the woods, farmed fields are the dominant cover type and backyards (and sadly conservation lands) are only a minute portion of what is available. The ratios will obviously change depending on geographic location. Bottonline is that there are many positive things that homeowners can do but education is needed to facilitate that change. Change in the ag community is difficult and far more complicated but for different reasons, mostly economic ones that rarely have positive conservation outcomes.