Question

an agricultural practice proposes significantly reducing the use of synthetic nitrogen fertilizers. which of the following best explains how this practice could positively and negatively impact the long - term sustainability of a terrestrial ecosystem? a. positive: it increases the amount of available nitrogen for plants. negative: it increases the need for farmers to use more pesticides. b. positive: it reduces the risk of eutrophication in nearby aquatic ecosystems. negative: it may lead to lower crop yields due to a limited nitrogen supply. c. positive: it increases the activity of denitrifying bacteria. negative: it could cause an increase in atmospheric nitrogen. d. positive: it decreases the amount of carbon in the atmosphere. negative: it leads to soil erosion and loss of topsoil.

Explanation:

Synthetic nitrogen - fertilizers can cause eutrophication in aquatic ecosystems when they runoff into water bodies. Reducing their use can lower this risk. However, nitrogen is essential for plant growth, and a limited supply may lead to lower crop yields. Option A has an incorrect negative - the use of synthetic nitrogen fertilizers is not directly related to pesticide use. Option C - increasing denitrifying bacteria activity is not a typical positive of reducing synthetic nitrogen fertilizers and increasing atmospheric nitrogen is not a common negative. Option D is incorrect as reducing synthetic nitrogen fertilizers has little to do with carbon in the atmosphere and soil erosion.

Answer:

B. Positive: It reduces the risk of eutrophication in nearby aquatic ecosystems. Negative: It may lead to lower crop yields due to a limited nitrogen supply