Q23 - Deep tillage is even more

[mrudula_2005]

hi,

I'm having trouble wrapping my head around why A does not need to be assumed.

I can definitely see how answer choice C is the correct answer, however, where does A go wrong?

If A were false and topsoil erosion DID make farmers want to till more deeply, that would indicate that the argument's evidence has the causality reversed - that when it states "For example, farmers who till deeply are ten times more likely to lose topsoil to erosion than are farmers who use no-till methods", this association exists because having lost topsoil to erosion MAKES farmers want to till more deeply (rather than the other way around as concluded by the argument in the first line in establishing its final recommendation in the last line) and that therefore deep tillage is not the culprit here - that deep tillage is not being harmful to the world's topsoil supply (some other factor is being harmful to it) and the evidence does not prove or indicate anything about deep tillage causing topsoil erosion (since the causality goes the other way if A is negated and thereby shatters the evidence in support of the conclusion).

I hope what I'm saying is clear - let me know if you need me to clarify. Anyways, what am I missing here? What makes A wrong?

Thanks a lot!

[bbirdwell]

The evidence is not up for debate. You must accept a given premise as fact.

That farmers who till deeply are 10 times more likely to lose topsoil is a fact.

From this, the author draws the conclusion that those farmers who till deeply now should use no-till methods instead.

The burning question on my mind at this point, is why go from tilling deeply to not tilling at all? The "no-till" part of the conclusion is not really supported.... unless something is assumed.

(A) is irrelevant. It doesn't matter what the farmers want.
(B) isn't necessary. Perhaps anything past 1 ft affects topsoil the same way. There need not be a "sliding scale' effect for the conclusion to be drawn.
(C) Absolutely. This explains why the conclusion says "no-till" must replace "deep till."
(D) expense is irrelevant.
(E) aeration is irrelevant.

Does that help?

[mrudula_2005]

I'm not trying to undermine the evidence here, I'm just saying that if A were not true and if topsoil erosion DID make farmers want to till more deeply, it would provide a different interpretation to the evidence - as it is right now the "for example, farmers..." statement is meant to imply a causality (that deep tilling causes topsoil erosion) when in fact it is just a correlation (all it is reporting is an association - that one group is "more likely" to have one trait over another) that, if A were false, would not logically lead to the argument's current conclusion. I mean there would be no need to ditch the deep tilling methods and opt for no-till methods if it was topsoil erosion that caused farmers to till more deeply as opposed to deep tillage causing topsoil erosion as the argument assumes (or so I think).

That being said, I absolutely see how C is clearly an assumption, but I am really sold on A as well still.

[bbirdwell]

Here's a fact from the argument: farmers who till deeply are more likely have topsoil erosion.

Here's the conclusion: Farmers should use no-till methods.

Here's your negation of A: Erosion makes farmers want to till deeply.

Logically, this does nothing to the argument. Stretching the imagination, if anything at all, this negation ENHANCES the conclusion. Deep tillage is more likely to erode, and the erosion makes farmers want to till deeply. This would be a self-fulfilling cycle of destruction that would continue to make the erosion worse and worse, and therefore support the argument against tillage even more.

It simply doesn't matter what the farmers "want" or "don't want" -- it is immaterial to this argument, which is about what farmers should or should not "do."

[mrudula_2005]

Here's a fact from the argument: farmers who till deeply are more likely have topsoil erosion.

Here's the conclusion: Farmers should use no-till methods.

Here's your negation of A: Erosion makes farmers want to till deeply.

Logically, this does nothing to the argument. Stretching the imagination, if anything at all, this negation ENHANCES the conclusion. Deep tillage is more likely to erode, and the erosion makes farmers want to till deeply. This would be a self-fulfilling cycle of destruction that would continue to make the erosion worse and worse, and therefore support the argument against tillage even more.

It simply doesn't matter what the farmers "want" or "don't want" -- it is immaterial to this argument, which is about what farmers should or should not "do."

oh my gosh, I totally get it now. wow, that went right over my head the first time around. thank you SO much!!!!!

[bbirdwell]

whew! that's great news -- i was running out of ways to talk about this one via forum-style writings. cheers!

[cdjmarmon]

I need to get this straight in my head. C is correct because the author says farmers who till deeply are losing 10 times more topsoil so there need to not till at all.

His assumption is deep tilling is the only viable tilling option?

Is that because if there were other viable tilling methods besides deep tilling farmers could use those methods instead of not tilling at all?

[timmydoeslsat]

I need to get this straight in my head. C is correct because the author says farmers who till deeply are losing 10 times more topsoil so there need to not till at all.

His assumption is deep tilling is the only viable tilling option?

Is that because if there were other viable tilling methods besides deep tilling farmers could use those methods instead of not tilling at all?

I think that is an accurate assessment.

We learn about how deep tilling leads to this bad thing. Then we are told that farmers should do other techniques to do no tilling.

As the negation of (C) shows, if those non-deep till methods were a viable option, it makes our argument irrelevant in arriving at avoiding all tilling methods.