Answer to Question 1
When excess amounts of soil enter a body of water, the water becomes muddy. Some species cannot tolerate this muddy water and die from a lack of oxygen or clean water. Also, new soil brings nutrients into the water, which increases the rate at which aquatic plants grow. Excessive plant growth clogs the waterways, causing some plants to die. When this happens, the organic matter decays and oxygen levels can be depleted.
Answer to Question 2
It is often difficult to grow new crops on land that has suffered from soil erosion because the soil that was removed is topsoil, which is the soil that contains the organic material that holds plant nutrients. Also, the remaining soil has a reduced water-holding capacity, which makes plants more susceptible to drought.
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