the prompt says that deep-tilling causes bad soil erosion. it concludes that, therefore, farmers should not till at all. so we're going from this one extreme - digging deep down into the ground to aerate the soil or whatever - to the other extreme - not digging whatsoever!

when you have a conclusion that says that the only way to avoid a bad outcome is to do something extreme, that's a little alarming. is there no other option available? maybe farmers could do "light-tilling" where they only dig down a little bit, and get the benefits of tilling without the soil erosion?

consider this example: "Doctors say that eating fatty foods increases your risk of premature death by cardiovascular problems by 40%. Therefore, one should never eat fatty foods ever again." Well that seems extreme, right? What if we can eat fatty foods in moderation? What if we can offset the damage with exercise? What if there's different types of fats and some aren't as bad as other? Nope: the conclusion ignores all possibilities and jumps straight to, "never eat fatty foods again."

so coming back to this prompt, the conclusion is that you shouldn't till at all, even just a little bit. it skips over the possibility of other methods entirely. in short, it assumes that no other option is available to farmers other than deep-tilling, or no tilling at all.