Increased eutrophication and nutrient imbalances in the agricultural soils of NE Catalonia (Spain) during the last four decades.

Peñuelas J, Sardans J, Alcañiz JM, Poch JM (2009) Increased eutrophication and nutrient imbalances in the agricultural soils of NE Catalonia (Spain) during the last four decades. Journal of Environmental Biology 30: 841-846.