The study looked at how agriculture affects water quality in a small watershed in the Qinling Mountains. Researchers monitored eight river segments for a year, measuring various water quality indicators and pollution levels. They found that nitrogen levels decreased over time, while phosphorus was highest in spring. The water quality mostly met standards, except for nitrogen levels. The main sources of pollution were sewage, farming, and livestock. Overall, the pollution in the area was a mix of agricultural and residential activities.