TOEFL Question

Shortage of Water Resources

The lack of clean, suitable water for agricultural purposes is a growing global problem. One of the best ways to counter this problem is to ensure that water is used more efficiently. Since agriculture is the greatest user of water, it is of great importance that farmers and agronomists alike seek out ways to increase the efficiency of irrigation. 

 A simple method of water conservation is already being used in many countries: sub-surface irrigation. When irrigation systems apply water above the surface of the ground, much of that water either evaporates of runs off. In warm climates, this waste has been estimated at nearly fifty percent. In other words, half of all the water applied is lost. In sub-surface irrigation, as the name implies, water is introduced below the surface of the ground. This action significantly reduces water loss. Not only is water saved, but the more uniform application of water to plants’ root systems leads to hardier plants with more abundant yields.

 Another novel way to use water more efficiently is to grow crops that are native to the region. Because species have adapted over time better than non-native species. Corn, native to parts of Mexico, is an example of how native species can reduce the need for significant irrigation. In the latter decades of the 20^th century, non-native species of corn from the United State were introduced to and sold in Mexico. While farmers enjoyed significant yields from these introduced species, their water usage skyrocketed. The resulted in water-table depletion throughout many agricultural regions in Mexico. In response, Mexican farmers have recently reintroduced native corn species that are better able to handle arid climates.

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Counter : to oppose; to express an opposite view

Agronomist : one who studies soil and crops

Evaprorate : to convert a liquid into a gas

Uniform : consistent

Hardier : stronger

Novel : new

Depletion : the act of reducing the supply of something

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Q. Based upon information in paragraph 2, all of the following are true EXCEPT:

1. An above-ground system is less efficient than a sub-surface system.

2. Underground irrigation reduces evaporation and runoff.

3. Crop yields improve when underground irrigation is used fifty percent of the time.

4. A sub-surface irrigation system gives water directly to the roots.

A > C. Crop yields improve when underground irrigation is used fifty percent of the time.