Final answer:
Land use by humans affects nutrient cycles, particularly through farming and animal-based food production. The land used for animal nutrition, such as grassland, doesn't always result in human nutrient losses, as it may not be suitable for other crops or services.
However, agricultural pollution with chemicals can disrupt nutrient cycles and soil health, affecting the food chain and human health.
Step-by-step explanation:
One way that land use by humans affects nutrient cycles is through agricultural practices. When humans use land for animal-based food production, such as cattle raising, they often rely on grass, pasture, and silage for animal nutrition.
While some critics argue that this contributes to pollution and greenhouse gas emissions, it's essential to recognize that these lands may be unsuitable for growing crops directly consumable by humans.
Therefore, the conversion of these nutrients through animals doesn't necessarily translate into a loss of human-available nutrients, as some terrains are used precisely because they aren't suited for other agricultural or ecological services.
Human interventions in nutrient cycles often lead to pollution through the excessive use of nitrogen and pesticides in farming, which can end up in the water supply. This affects not just the water quality but also impacts the soil organisms that maintain nutrient cycles needed for crop growth.
Besides, these pollutants accumulate in the food chain, affecting both aquatic and terrestrial life, and ultimately, human health. It is important to acknowledge that the role of nutrient cycles is vast, ranging from aiding plant growth to affecting the overall quality of life for all organisms involved.
Thus, while farming and animal husbandry can affect nutrient cycles, they also rely on these cycles to ensure the soil is fertile and crops are successful. These activities form part of the ecosystem services that are integral to maintaining life-supporting systems on Earth.