Question

year after year, xavier raises a vegetable garden in the same plot of soil. he observes that the plants grow less abundantly from one year to the next, and they produce fewer vegetables. which of these processes could help explain xaviers observations? the rate at which soil bacteria perform photosynthesis the rate at which soil bacteria perform denitrification the rate at which soil bacteria perform nitrogen fixation the rate at which soil bacteria perform chemosynthesis laney is asked to research an organism that performs denitrification. which strategy is the most likely to be successful? look for phytoplankton that perform photosynthesis. look for ocean - dwelling organisms that perform chemosynthesis. look for soil bacteria that convert atmospheric nitrogen to nitrates. look for soil bacteria that convert nitrates to nitrogen gas.

Explanation:

1. For Xavier's problem, denitrification by soil - bacteria reduces soil nitrogen. Nitrogen is an essential nutrient for plant growth. A decrease in soil nitrogen due to high - rate denitrification can lead to less abundant plant growth and lower vegetable production. Soil bacteria do not perform photosynthesis or chemosynthesis, and nitrogen fixation increases soil nitrogen.
2. For Laney's problem, denitrification is the process by which soil bacteria convert nitrates ($NO_3^-$) into nitrogen gas ($N_2$), returning it to the atmosphere. Phytoplankton performing photosynthesis, ocean - dwelling organisms performing chemosynthesis, and soil bacteria converting atmospheric nitrogen to nitrates are not related to denitrification.

Answer:

1. the rate at which soil bacteria perform denitrification
2. Look for soil bacteria that convert nitrates to nitrogen gas.