Question 54·Hard·Command of Evidence
Agronomist Mei-Ling Chen contends that installing native flowering hedgerows around large-scale vegetable fields lowers the total amount of synthetic pesticides farmers must apply without reducing crop yields. According to Chen, the hedgerows bolster populations of predatory insects and birds that keep crop-damaging pests in check.
Which finding, if true, would most directly support Chen’s contention?
For SAT “Which finding would most directly support…” questions, first restate the claim in your own words and identify its essential parts (for example, “less pesticide and no drop in yield”). Then scan each answer for hard evidence—measurements or controlled comparisons—that match all parts of the claim, not just one. Quickly eliminate choices that only address the mechanism, omit one of the outcomes, or introduce a confounding explanation for the result.
Hints
Focus on the exact claim being tested
Underline the two main outcomes in Chen’s contention: what does she say happens to pesticide use and what does she say happens to crop yields when hedgerows are installed?
Look for concrete comparisons, not opinions
Ask yourself: which answer reports an actual measurement or study comparing farms with hedgerows to similar farms without them, especially in terms of pesticide use and harvest amounts?
Beware of side benefits or unrelated effects
Some choices may mention related ecological details. Check whether they directly show the two outcomes Chen cares about (less pesticide use and unchanged yields), not just something loosely connected to hedgerows.
Step-by-step Explanation
Restate Chen’s contention in simple terms
Chen is making a two-part claim about what happens when farms install native flowering hedgerows:
- Pesticide use goes down (they need less synthetic pesticide).
- Crop yields do not go down (they harvest about the same amount of vegetables as before).
Any choice that directly supports her should give evidence about both pesticide use and crop yields when hedgerows are present, ideally compared to similar farms without hedgerows.
Describe what ideal supporting evidence would look like
To support Chen’s contention most directly, we want a finding that:
- Compares farms with hedgerows to farms without hedgerows (or before vs. after hedgerows on the same farms).
- Shows a reduction in synthetic pesticide use on the hedgerow farms.
- Shows no reduction in yield (similar or higher harvest per acre) on those farms.
Now keep this “checklist” in mind as you read each answer choice.
Eliminate choices that don’t match both parts of the claim
Go through the options:
- Choice A shows more predators and fewer pests, but it explicitly says pesticide use was held constant, so it does not support the claim that hedgerows lower the amount of pesticide farmers must apply.
- Choice B gives information about yields but says pesticide application rates were not recorded, so it cannot support the “less pesticide” part of Chen’s contention.
- Choice D mentions lower pesticide use, but it attributes that difference primarily to pest-resistant crop varieties, not to the hedgerows, so it does not directly support Chen’s contention about hedgerows causing the reduction.
After eliminating these, one remaining option provides a controlled comparison that reports both reduced pesticide application and comparable yields.
Identify the answer that directly matches Chen’s claim
The finding that most directly supports Chen’s contention is the one that explicitly shows less pesticide use and similar crop yields on farms with hedgerows compared with similar farms without them. That is:
In a five-year controlled study, farms that added hedgerows applied 30 percent less pesticide yet harvested comparable quantities of vegetables per acre as similar farms without hedgerows.