Explanation:

Nutrient Cycling

Nutrient cycling is one of the most important processes that occur in an ecosystem. The nutrient cycle describes the use, movement, and recycling of nutrients in the environment. Valuable elements such as carbon, oxygen, hydrogen, phosphorus, and nitrogen are essential to life and must be recycled in order for organisms to exist. Nutrient cycles are inclusive of both living and non-living components and involve biological, geological, and chemical processes. For this reason, these nutrient circuits are known as biogeochemical cycles.

Statement 1 and 3 are correct: Ecosystem receives nutrients from external sources and stores them for further use through biological processes. For example, nutrients in dissolved state  are gained from rainfall (wet deposition) or in particulate state from dust fall (dry deposition).

Statement 2 and 4 are incorrect: Through runoff water and denitrification process in soil, nutrients are move out of the ecosystem.