Logical Reasoning

PT113 · S4 · Q5 After 1950, in response to record

A free, expert breakdown of this official LSAT Logical Reasoning question.

Save & drill this skill — build targeted practice sets from questions like this one
Video walkthroughs — watch every question solved step by step
81 official LSATs — as questions, timed sections & full-length tests

Start practicing free

After 1950, in response to record growth in worldwide food demand, farmers worldwide sharply increased fertilizer use.

Background

After 1950, farmers greatly increased fertilizer use, which led to a doubling of farmland productivity by 1985.

Since 1985, they've been trying to increase productivity even more.

Surprising Claim

And yet, since 1985, they've started using less fertilizer.

Evaluate / Goal

Given that ... fertilizer was so effective at increasing productivity from 1950-1985 Why is it that ... since 1985, the effort to increase productivity has involved using slightly less fertilizer than before?

It seems like the answer will have to say something like, "Fertilizer stopped working to increase productivity" or .

Which one of the following, if true, most helps to resolve the apparent discrepancy in the information above?

Since 1985 the rate at
Doesn't Explain
This seems to just underscore why we would be seeking to increase farmland's productivity even further, but it does nothing to resolve the mystery of why we're now using less fertilizer.
8% picked this
Several varieties of crop plants
Deepens Paradox
We're looking for answer to give us a reason why they aren't using fertilizer as much, and this gives us a reason why they would continue to use fertilizer at least as much: a new popular crop responds just as well as the crops that responded well in the 1950-1985 period.
2% picked this
Between 1950 and 1985 farmers
Reiterates Background Doesn't Help Explain
This just talks about the background. We already know that fertilizer was successful. That's why we're confused by the fact that farmers aren't using as much of it anymore. We're looking for an answer to tell us why they aren't using it as much anymore.
2% picked this
Correct
After fertilizer has been added
Why this is right
This supplies a reason why they would be using less fertilizer in the post-1985 era. Since they used it for 35 years, according to this answer choice, adding more fertilizer wouldn't actually do much to improve productivity. In reality, since it only takes "several years" for this phenomenon to kick in, it's possible that by the late 50s they were already seeing less gains from fertilizer, and that as the 60s and 70s went on, they kept seeing fewer and fewer boosts in productivity from adding fertilizer, so by 1985, they had pretty much learned the lesson that adding more fertilizer was not actually doing anything good for productivity anymore.
Skill tested: Paradox · how this choice captures the argument's function is the move to repeat next time.
82% picked this
Between 1975 and 1980 fertilizer
Wrong Timeframe
A hike in the price of fertilizer certainly could have worked as a reason why farmers are using less fertilizer in the post-1985 era. However, this answer is saying that the price temporarily went up (and then back down) between 1975-1980. So it's not giving us any reason why there's less fertilizer use in the 1985-present timeframe.
5% picked this

Continue the review in LSAT Lab

Save this question, watch the video walkthrough, and drill similar questions in your LSAT Lab account.

Save and practice this skill

LSAT Lab

Turn this review into a targeted study plan.

Save this question, drill more like it, watch the video walkthrough, and track your progress in your LSAT Lab account.

Start practicing free