Final answer:
Nitrogen is the element most easily lost to the environment due to its participation in the nitrogen cycle, where it can be converted to various compounds that can be leached away by rain or lost as gases. Unlike nitrogen, phosphorus is primarily released by rock weathering and does not have a gaseous phase, while potassium tends to be less mobile.
Step-by-step explanation:
The element most easily lost to the environment is nitrogen. Nitrogen is abundant in the atmosphere in its gaseous form, and it is part of the nitrogen cycle, which includes the processes of nitrogen fixation, where gaseous nitrogen is fixed to yield ammonia, and other processes such as nitrification and denitrification. This cycle is essential as nitrogen is a macronutrient needed by prokaryotes. However, in agricultural and natural systems, nitrogen can be easily leached away by rain or lost through the gaseous emissions of nitrogen compounds. Compared to phosphorus and potassium, which are often bound within the soil, or sulfur, which can also be atmospherically cycled but is less mobile in many soils, nitrogen is the element most readily lost to the environment.
When it comes to phosphorus, it does not have a gaseous phase under normal environmental conditions, and it is typically released into the environment via rock weathering and the decomposition of organic molecules. Phosphorus can also enter the environment through volcanic activity. Elements like potassium are cycled through various biological and geological processes, and while they can be washed away from the soil, they do not readily enter the atmosphere like nitrogen does.