The aim of the research was to determine the significance of cattle farming (especially dairy cows) in the use of forage area, mainly permanent grassland, and its relationship with the natural environment in terms of greenhouse gas emissions (methane), water consumption, and biodiversity. The analysis concerned 1,823 dairy farms under observation of the Polish FADN between 2018 and 2020 and managed by natural persons. The following aspects were taken into account: production potential of farms, production and economic results, organization of plant and animal production depending on the structure of forage area determined by the share of permanent grassland in the area. It was found that the production potential of the dairy farms under consideration and their production and economic results were negatively correlated with increased share of permanent grassland in the forage area. It was also found that a higher share of permanent grassland in the forage area: meant a higher share of valuable nature area in the farm; was specifically correlated with the balance of organic matter in the soil; the balance was positive in all of the considered cases, i.e., they kept an increasing amount of water in the soil and increasing amounts of carbon dioxide each year; resulted in a significant increase in water consumption per 1 liter of milk produced, but the situation was related to increased share of permanent grassland in the forage area and lower milk yield of cows.