Many homeowners regularly add commercial fertilizers to their lawns and gardens to maintain a healthy balance of nutr...

Mehran on October 17, 2018

Hi @Jaimee-Salgado, thanks for your post. You can diagram this stimulus, but it may not be necessary. Let's take a careful look at it first.

This stimulus presents a set of facts - there is no conclusion. You are given the following factual information:
1. Many homeowners regularly add commercial fertilizers to their lawns and gardens to maintain a healthy balance of nutrients in soil.
2. The widely available commercial fertilizers contain only macronutrients - namely, nitrogen, phosphorus, and potassium.
3. To remain healthy in the long term, soil for lawns requires the presence of these macronutrients, and
4. also trace amounts of micronutrients such as zinc, iron, and copper,
5. which are depleted when grass clippings are raked up rather than allowed to decay and return to the soil.

The question stem asks you what can be properly inferred from these factual statements. This means that the correct answer must be true according to these facts. The correct answer is (C): widely available commercial fertilizers are not alone sufficient to maintain a healthy balance of nutrients in soil for lawns where grass clippings are not allowed to decay and return to the soil. This must be true. Fact #2 tells you that widely available commercial fertilizers contain only macronutrients; fact #3 says long-term soil health requires micronutrients, too; and fact #5 says that when grass clippings are raked up and not allowed to decay, micronutrients are depleted. For these reasons, (C) must be true - widely available commercial fertilizers are not, alone, sufficient.

Hope this helps! Please let us know if you have any additional questions.

amf on April 6, 2020

Hi can you please explain why d and e are incorrect? Thanks

ryanconnor1234 on April 13, 2020

@amf I'm not an instructor but I believe answer choice D is incorrect because it states that commercial fertilizers are required, but the passage indicates that the macronutrients from the fertilizers are what's required. Technically these macronutrients could come from other sources! I got this wrong because I selected D without noticing the distinction

on August 26, 2020

I believe E (Homeowners who rake up their grass clippings are unable to maintain the long-term health of the soil in their lawns and gardens.) is incorrect because you can rake the grass clippings and add the required micronutrients (Zinc, Iron, and Copper) through other means.