Which of the following is NOT a major biogeochemical cycle?

The hydrogen cycle is not considered a major biogeochemical cycle in the same way that the carbon, nitrogen, and phosphorus cycles are. Major biogeochemical cycles refer to the comprehensive pathways through which essential elements like carbon, nitrogen, and phosphorus circulate through the environment, including their movement through biological, geological, and chemical processes.

The carbon cycle is crucial for regulating the climate and supporting life, as it involves the movement of carbon through the atmosphere, biosphere, hydrosphere, and geosphere. The nitrogen cycle is equally vital, as nitrogen is an essential nutrient for all living organisms, impacting ecosystems through processes like nitrogen fixation, nitrification, and denitrification. The phosphorus cycle is significant as well, focusing on how phosphorus moves through soil, water, and living organisms, which is critical for biological energy transfer and genetic material.

In contrast, while hydrogen is an essential element for life and participates in many biochemical reactions, it does not have a distinct biogeochemical cycle akin to the others mentioned. Instead, hydrogen's movements are often considered part of the cycles of other elements rather than as a standalone cycle.