How does farming affect the phosphorus cycle?

Because farmers often use excessive amounts of phosphorus, runoff from agricultural fields contributes to phosphorus problems in lakes, reservoirs, streams, and ponds. It has been estimated that non-point type sources in the USA account for about 90% of impaired lakes' failure to meet water quality standards, even in the absence of no-point source inputs (Carpenter et al., 1998).

The addition of phosphorus to agricultural fields through industrial fertilizers and manure resulted in an accumulation of phosphorus in farm and pasture lands that is approximately 25 percent higher than background levels in the United States (Carpenter et al., 1998).

Citation:

Nonpoint pollution of surface waters with phosphorus and nitrogen by Carpenter, S., Caraco, N. F., Correll, D. L., Howarth, R. W., Sharpley, A. N., and Smith, V. H. (1998). Issues in Ecology, 3: 1–12.

Farming can impact the phosphorus cycle through the extensive use of phosphorus-containing fertilizers. Excessive application of these fertilizers can lead to phosphorus runoff into water bodies, contributing to water pollution. This can result in eutrophication, negatively affecting aquatic ecosystems. Additionally, soil erosion from agricultural practices can transport phosphorus from fields to waterways, further influencing the phosphorus cycle. Overall, farming activities can disrupt the natural balance of the phosphorus cycle, with potential environmental consequences.