The researchers used a method called USLE/GIS technology to figure out how to monitor soil erosion in farmland. They looked at factors like slope and land use in a specific area in Brazil. They found that slopes of 3-8% had more soil loss, but slopes under 3% had less. Different types of land use had different levels of soil loss, with only silviculture keeping soil loss below a safe limit. This shows that certain types of farming can help prevent too much soil erosion.