A Lithuanian study published in Water found that relative to intensive conventional production, organic practices significantly reduce water pollution in ecosystems adjacent to farms. By limiting nitrogen and phosphorus pollution specifically, organic farms can help prevent eutrophication and freshwater ecosystem degradation from agricultural runoff, ultimately lessening the environmental impact of food production. 

Scientists collected 324 surface water samples and 828 groundwater samples from agricultural land along five rivers in the Nemunas River Basin District between 2012 and 2016. Four organic and four conventional farms were included in the study based on their similar soil profiles, slopes, and crops. Each sample collected was measured for total nitrogen and phosphorus concentrations, in addition to nitrates, nitrites, ammonium, and orthophosphates, all key indicators of water quality and potential agricultural contamination. Analyses showed that nutrient concentrations were lowest in groundwater near organic farms, moderate in surface waters, and highest in groundwater near intensive conventional farms, supporting the assumption that runoff and leaching from chemically managed operations are significant contributors to nutrient pollution in surrounding environments.

These findings demonstrate the protective nature of organic farming for the environment beyond soil health and biodiversity. The study also highlights the importance of monitoring groundwater in addition to surface water in order to more accurately estimate pollution levels linked to farming practices. By restricting synthetic fertilizer use and incorporating practices like planting perennial cover crops, organic systems limit nutrient losses that can ultimately harm freshwater ecosystems and contaminate groundwater. The authors go as far as recommending an expansion of organic farmland to the EU’s recommendation of 25% of total agricultural land, as part of the solution to improving agriculture’s ecological impact while envisioning a sustainable, holistic approach to producing food.