Passage Summary: Deeply plowing the soil is much worse for erosion than not plowing at all. Because of this, the author thinks farmers should stop deep plowing and use different ways to get air into the soil instead.

Conclusion: Farmers who currently use deep tillage should attempt to switch to no-till methods by adopting alternative aeration techniques.

Reasoning: Deep tillage results in ten times more topsoil erosion than no-till methods, making it significantly more harmful to the environment than previously thought.

Analysis: The author makes a leap from a problem (erosion) to a specific solution (alternative aeration techniques). For this recommendation to be sound, the author must assume that these alternative techniques are actually viable for the farmers in question. If those other techniques were impossible to implement or caused even worse problems, the advice to switch would fall apart. Look for an answer that confirms these alternative methods are a realistic option for these farmers.