E.g. US corn subsidies are an anomaly. The world does not need so much corn and biofuels are a particularly lousy excuse to grow that much corn. Corn syrup is not an ingredient that is either common or high in demand outside the US. It's a market that only exists because of corn subsidies. In the same way, we're subsidizing soy, which gets exported from Brazil and from freshly burned down rain forest. The US is a close second for this stuff. Again subsidies combined with mostly very unsustainable styles of farming. Both industries depend on large scale use of pesticides and a few other unsustainable practices and exports to countries that look the other way.
If you are a vegetarian and want to save the planet, stop eating unsustainably grown soy. If you are a meat eater, stop eating unsustainably grown meat where the animals grew up eating unsustainably grown corn and soy. At a macro level it's multiple layers of unsustainable practices that we subsidize so we can have some artificially cheap food that probably isn't that good for you. It's not cheap at all. You just pay for it via your taxes. And we're leaving the damage cleanup for future generations. We're just really good at allowing people to dodge the real cost of things.
The Netherlands has a nice ongoing debate about reducing nitrogen emissions from mostly cattle and traffic. The reasoning goes as follows: high nox concentrations are bad for health (fact), therefore building close to where the concentrations are high is no longer allowed (because it kills people). This simple ruling basically shut down construction next to highways, which is where a lot of prime real estate is in the Netherlands. That is causing a lot of farmers to adapt their behavior because the communities they operate in are not cool with the high nox concentrations any more. They even reduced maximum speeds on the highways from 130 km/h to 100 km/h to cut down on the emissions and thus allow construction projects to resume.
That basically happens when you put numbers on the damage, change the incentives, and put some simple rulings in place. This btw. happened under a mostly conservative right leaning government too. Headed by the party that not so long ago championed the raising of the speed limit to 130 km/h (VVD). The current government is more or less the polar opposite of tree hugging hippies. Highway loving VVD and farmer friendly CDA are two of the coalition parties. And they got this done.
We should do the same with pesticides. There's plenty of good reasons to stop killing our environment like that. The least we can do is stop subsidizing that.