Magnesium is a micronutrient required by plants, while nitrogen, phosphorus, and potassium are macronutrients.

Nitrogen fixation is the process by which nitrogen gas is converted into ammonia, which can then be used by plants.

Oxygen is not a greenhouse gas, while carbon dioxide, methane, and nitrous oxide are.

Decomposition is the process by which organic matter is broken down into simpler compounds by microorganisms.

Carbon fixation is the process by which plants take in carbon dioxide and release oxygen during photosynthesis.

The water cycle is a physical cycle, while the carbon cycle, nitrogen cycle, and phosphorus cycle are biogeochemical cycles.

Denitrification is the process by which nitrogen gas is released back into the atmosphere from soil.

Potassium is not a limiting nutrient in marine ecosystems, while nitrogen, phosphorus, and iron are.

Absorption is the process by which plants take in nutrients from the soil.

Nitrogen is a macronutrient required by plants, but not by animals.

Fossilisation is the process by which organic matter is converted into fossil fuels.

Water vapor is not a greenhouse gas, while carbon dioxide, methane, and nitrous oxide are.

Photorespiration is the process by which plants release oxygen into the atmosphere during photosynthesis.

The oxygen cycle is a physical cycle, while the carbon cycle, nitrogen cycle, and phosphorus cycle are biogeochemical cycles.

Denitrification is the process by which nitrogen gas is released back into the atmosphere from soil.