That's what the industry has been saying here for decades and they tried a lot of things, but the problem has only gotten worse. At some point you have to say - apparently you can't fix it, so we have to buy out farmers near nature reserves.
But the farmers have been intimidating politicians by blocking highways and inner cities with tractors and other equipment. Funnily, if anyone else does this they get arrested, but farmers get a carte blanche to disrupt society.
Nobody wants to shut down all the farming, just reduce it. For example, the Netherlands produces 250% of its own meat consumption. Since it's subsidized, the net financial gain is very low. You could say reducing the production to 125/150% of consumption would leave enough for local consumption plus a little export in good times or a buffer in bad times.
Unfortunately, big agricultural companies hired a marketing company to start a political party which claims to be pro local/small farmers, but is actually just pro big agriculture.
The questions are mainly targeted at the consumption of animal products: meat, dairy products and eggs. Their research shows that reducing the consumption of animal products, and therefore switching from a meat-eating to a vegetarian or vegan diet, reduces land requirements by two-thirds.
So in other words you want to reduce everyones quality of life. Let me guess, when people object and then go vote the parties you don't like you are going to blame everyone except these kind of policies.
Make no mistake, these hypocritical do-gooder authoritarians will still be flying first class and eating steak while they force us proletariats to eat bugs and soy sloop.
Farm animal excrement is far from the whole picture. Fertilization is the main contributor (and animal excrement is used for that, but far from exclusively).